Update participant and study API routes

.env

@@ -5,8 +5,8 @@
 DATABASE_URL="postgresql://postgres:jusxah-jufrew-niwjY5@db:5432/hristudio"
 
 # Clerk
-NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY=pk_test_cmVmaW5lZC1kcnVtLTIzLmNsZXJrLmFjY291bnRzLmRldiQ
-CLERK_SECRET_KEY=sk_test_3qESERGxZqHpROHzFe7nYxjfqfVhpHWS1UVDQt86v8
+NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY=pk_test_YWxsb3dlZC1zYWxtb24tNjMuY2xlcmsuYWNjb3VudHMuZGV2JA
+CLERK_SECRET_KEY=sk_test_nUKl0GTM5ibgUH12WbTH6pNVHAyRshlSFi64IrEeWD
 NEXT_PUBLIC_CLERK_SIGN_IN_URL=/sign-in
 NEXT_PUBLIC_CLERK_SIGN_UP_URL=/sign-up
 

.gitignore

@@ -4,6 +4,7 @@
 ### NextJS ###
 # dependencies
 /node_modules
+.pnpm-store/
 /.pnp
 .pnp.js
 

docker-compose.yml

@@ -1,6 +1,3 @@
-# Use Docker Compose file format version 3.9
-# version: '3.9'
-
 services:
   app:
     build:
@@ -8,13 +5,15 @@ services:
       dockerfile: Dockerfile
     ports:
       - '3000:3000' # Node.js
-      - '4983:4983' # Drizzle Studio
+      # - '4983:4983' # Drizzle Studio
     volumes:
       - .:/app
       - /app/node_modules
     environment:
       NODE_ENV: development
-    command: ["pnpm", "run", "dev"]
+    command: ["sh", "-c", "pnpm db:push && pnpm run dev"]
+    depends_on:
+      - db
 
   db:
     image: postgres

package.json

@@ -18,8 +18,12 @@
     "@radix-ui/react-avatar": "^1.1.0",
     "@radix-ui/react-dialog": "^1.1.1",
     "@radix-ui/react-icons": "^1.3.0",
+    "@radix-ui/react-label": "^2.1.0",
+    "@radix-ui/react-select": "^2.1.1",
     "@radix-ui/react-separator": "^1.1.0",
     "@radix-ui/react-slot": "^1.1.0",
+    "@radix-ui/react-toast": "^1.2.1",
+    "@radix-ui/react-tooltip": "^1.1.2",
     "@t3-oss/env-nextjs": "^0.10.1",
     "class-variance-authority": "^0.7.0",
     "clsx": "^2.1.1",
@@ -30,6 +34,7 @@
     "next": "^14.2.12",
     "next-themes": "^0.3.0",
     "postgres": "^3.4.4",
+    "radix-ui": "^1.0.1",
     "react": "^18.3.1",
     "react-dom": "^18.3.1",
     "react-icons": "^5.3.0",

src/app/api/participants/[id]/route.ts

@@ -0,0 +1,37 @@
+import { db } from "~/server/db";
+import { participants } from "~/server/db/schema";
+import { NextResponse } from "next/server";
+import { eq } from "drizzle-orm";
+
+export async function DELETE(
+  request: Request,
+  { params }: { params: { id: string } }
+) {
+  console.log('DELETE route hit, params:', params);
+  const id = parseInt(params.id);
+  
+  if (isNaN(id)) {
+    console.log('Invalid ID:', id);
+    return NextResponse.json({ error: 'Invalid ID' }, { status: 400 });
+  }
+
+  try {
+    console.log('Attempting to delete participant with ID:', id);
+    const deletedParticipant = await db.delete(participants)
+      .where(eq(participants.id, id))
+      .returning();
+
+    console.log('Deleted participant:', deletedParticipant);
+
+    if (deletedParticipant.length === 0) {
+      console.log('Participant not found');
+      return NextResponse.json({ error: 'Participant not found' }, { status: 404 });
+    }
+
+    console.log('Participant deleted successfully');
+    return NextResponse.json({ message: "Participant deleted successfully" });
+  } catch (error) {
+    console.error('Error deleting participant:', error);
+    return NextResponse.json({ error: 'Failed to delete participant', details: String(error) }, { status: 500 });
+  }
+}

src/app/api/participants/route.ts

@@ -0,0 +1,25 @@
+import { db } from "~/server/db";
+import { participants } from "~/server/db/schema";
+import { NextResponse } from "next/server";
+import { eq } from "drizzle-orm";
+
+export async function GET(request: Request) {
+  const { searchParams } = new URL(request.url);
+  const studyId = searchParams.get('studyId');
+  
+  if (!studyId) {
+    return NextResponse.json({ error: 'Study ID is required' }, { status: 400 });
+  }
+
+  const allParticipants = await db.select().from(participants).where(eq(participants.studyId, parseInt(studyId)));
+  return NextResponse.json(allParticipants);
+}
+
+export async function POST(request: Request) {
+  const { name, studyId } = await request.json();
+  if (!name || !studyId) {
+    return NextResponse.json({ error: 'Name and Study ID are required' }, { status: 400 });
+  }
+  const newParticipant = await db.insert(participants).values({ name, studyId }).returning();
+  return NextResponse.json(newParticipant[0]);
+}

src/app/api/studies/[id]/route.ts

@@ -0,0 +1,86 @@
+import { db } from "~/server/db";
+import { studies } from "~/server/db/schema";
+import { NextResponse } from "next/server";
+import { eq, and } from "drizzle-orm";
+import { auth } from "@clerk/nextjs/server";
+
+export async function GET(
+  request: Request,
+  { params }: { params: { id: string } }
+) {
+  const { userId } = auth();
+  if (!userId) {
+    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
+  }
+
+  const id = parseInt(params.id);
+  if (isNaN(id)) {
+    return NextResponse.json({ error: 'Invalid ID' }, { status: 400 });
+  }
+
+  const study = await db.select().from(studies).where(and(eq(studies.id, id), eq(studies.userId, userId))).limit(1);
+
+  if (study.length === 0) {
+    return NextResponse.json({ error: 'Study not found' }, { status: 404 });
+  }
+
+  return NextResponse.json(study[0]);
+}
+
+export async function PUT(
+  request: Request,
+  { params }: { params: { id: string } }
+) {
+  const { userId } = auth();
+  if (!userId) {
+    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
+  }
+
+  const id = parseInt(params.id);
+  if (isNaN(id)) {
+    return NextResponse.json({ error: 'Invalid ID' }, { status: 400 });
+  }
+
+  const { title, description } = await request.json();
+  if (!title) {
+    return NextResponse.json({ error: 'Title is required' }, { status: 400 });
+  }
+
+  const updatedStudy = await db
+    .update(studies)
+    .set({ title, description })
+    .where(and(eq(studies.id, id), eq(studies.userId, userId)))
+    .returning();
+
+  if (updatedStudy.length === 0) {
+    return NextResponse.json({ error: 'Study not found or unauthorized' }, { status: 404 });
+  }
+
+  return NextResponse.json(updatedStudy[0]);
+}
+
+export async function DELETE(
+  request: Request,
+  { params }: { params: { id: string } }
+) {
+  const { userId } = auth();
+  if (!userId) {
+    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
+  }
+
+  const id = parseInt(params.id);
+  if (isNaN(id)) {
+    return NextResponse.json({ error: 'Invalid ID' }, { status: 400 });
+  }
+
+  const deletedStudy = await db
+    .delete(studies)
+    .where(and(eq(studies.id, id), eq(studies.userId, userId)))
+    .returning();
+
+  if (deletedStudy.length === 0) {
+    return NextResponse.json({ error: 'Study not found or unauthorized' }, { status: 404 });
+  }
+
+  return NextResponse.json({ message: "Study deleted successfully" });
+}

src/app/api/studies/route.ts

@@ -2,30 +2,29 @@ import { db } from "~/server/db";
 import { studies } from "~/server/db/schema";
 import { NextResponse } from "next/server";
 import { eq } from "drizzle-orm";
+import { auth } from "@clerk/nextjs/server";
 
-export async function GET() {
-  const allStudies = await db.select().from(studies);
+export async function GET(request: Request) {
+  const { userId } = auth();
+  if (!userId) {
+    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
+  }
+
+  const allStudies = await db.select().from(studies).where(eq(studies.userId, userId));
   return NextResponse.json(allStudies);
 }
 
 export async function POST(request: Request) {
+  const { userId } = auth();
+  if (!userId) {
+    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
+  }
+
   const { title, description } = await request.json();
-  const newStudy = await db.insert(studies).values({ title, description }).returning();
+  if (!title) {
+    return NextResponse.json({ error: 'Title is required' }, { status: 400 });
+  }
+
+  const newStudy = await db.insert(studies).values({ title, description, userId }).returning();
   return NextResponse.json(newStudy[0]);
 }
-
-export async function PUT(request: Request) {
-  const { id, title, description } = await request.json();
-  const updatedStudy = await db
-    .update(studies)
-    .set({ title, description })
-    .where(eq(studies.id, id))
-    .returning();
-  return NextResponse.json(updatedStudy[0]);
-}
-
-export async function DELETE(request: Request) {
-  const { id } = await request.json();
-  await db.delete(studies).where(eq(studies.id, id));
-  return NextResponse.json({ message: "Study deleted" });
-}

src/app/api/users/route.ts

@@ -0,0 +1,21 @@
+import { db } from "~/server/db";
+import { users } from "~/server/db/schema";
+import { NextResponse } from "next/server";
+
+export async function POST(request: Request) {
+  try {
+    const { email } = await request.json();
+    
+    // Check if email is provided
+    if (!email) {
+      return NextResponse.json({ error: "Email is required" }, { status: 400 });
+    }
+
+    // Insert the new user into the database
+    const newUser = await db.insert(users).values({ email }).returning();
+    return NextResponse.json(newUser[0]);
+  } catch (error) {
+    console.error("Error creating user:", error);
+    return NextResponse.json({ error: "Failed to create user" }, { status: 500 });
+  }
+}

src/app/dash/layout.tsx

@@ -1,26 +0,0 @@
-import { type PropsWithChildren } from "react"
-import { Sidebar } from "~/components/sidebar"
-import { Inter } from "next/font/google"
-
-import "~/styles/globals.css"
-
-const inter = Inter({
-  subsets: ["latin"],
-  display: "swap",
-  variable: "--font-sans",
-})
-
-export default function RootLayout({ children }: PropsWithChildren) {
-  return (
-    <html lang="en">
-      <body className={`font-sans ${inter.variable}`}>
-        <div className="flex h-screen">
-          <Sidebar />
-          <main className="flex-1 overflow-y-auto">
-            {children}
-          </main>
-        </div>
-      </body>
-    </html>
-  )
-}

src/app/dash/page.tsx

@@ -1,21 +1,45 @@
-import { Card, CardContent, CardHeader, CardTitle, CardDescription } from '~/components/ui/card';
-import { Button } from '~/components/ui/button';
-import { Studies } from "~/components/Studies";
+import Layout from "~/components/layout";
+import { Card, CardHeader, CardTitle, CardContent } from "~/components/ui/card";
 
-const HomePage: React.FC = () => {
-    return (
-        <div className="min-h-screen bg-gradient-to-b from-blue-100 to-white pt-14 lg:pt-0">
-            <div className="container mx-auto px-4 py-16">
-                <header className="text-center mb-16">
-                    <h1 className="text-5xl font-bold mb-4 text-blue-800">Welcome to the HRIStudio Dashboard!</h1>
-                    <p className="text-xl text-gray-600 max-w-3xl mx-auto">
-                        Manage your Human-Robot Interaction projects and experiments
-                    </p>
-                </header>
-                <Studies />
-            </div>
-        </div>
-    );
+const DashboardPage: React.FC = () => {
+  return (
+    <Layout>
+      <div className="grid grid-cols-1 md:grid-cols-2 gap-4">
+        <Card>
+          <CardHeader>
+            <CardTitle>Platform Information</CardTitle>
+          </CardHeader>
+          <CardContent>
+            {/* Add content for Platform Information */}
+          </CardContent>
+        </Card>
+        <Card>
+          <CardHeader>
+            <CardTitle>Participants</CardTitle>
+          </CardHeader>
+          <CardContent>
+            {/* Add content for Participants */}
+          </CardContent>
+        </Card>
+        <Card>
+          <CardHeader>
+            <CardTitle>Project Members</CardTitle>
+          </CardHeader>
+          <CardContent>
+            {/* Add content for Project Members */}
+          </CardContent>
+        </Card>
+        <Card>
+          <CardHeader>
+            <CardTitle>Completed Trials</CardTitle>
+          </CardHeader>
+          <CardContent>
+            {/* Add content for Completed Trials */}
+          </CardContent>
+        </Card>
+      </div>
+    </Layout>
+  );
 };
 
-export default HomePage;
+export default DashboardPage;

src/app/layout.tsx

@@ -1,5 +1,6 @@
 import { ClerkProvider } from '@clerk/nextjs'
 import { Inter } from "next/font/google"
+import { StudyProvider } from '~/context/StudyContext'
 
 import "~/styles/globals.css"
 
@@ -10,7 +11,7 @@ const inter = Inter({
 })
 
 export const metadata = {
-  title: "T3 App",
+  title: "HRIStudio",
   description: "Created with create-t3-app",
   icons: [{ rel: "icon", url: "/favicon.ico" }],
 }
@@ -18,13 +19,13 @@ export const metadata = {
 export default function RootLayout({ children }: React.PropsWithChildren) {
   return (
     <ClerkProvider>
-      {/* <ThemeProvider attribute="class" defaultTheme="system" enableSystem> */}
+      <StudyProvider>
         <html lang="en" className={inter.variable}>
           <body className="font-sans">
             {children}
           </body>
         </html>
-      {/* </ThemeProvider> */}
+      </StudyProvider>
     </ClerkProvider>
   )
 }

src/app/participants/page.tsx

@@ -0,0 +1,12 @@
+import Layout from "~/components/layout";
+import { Participants } from "~/components/participant/Participants";
+
+const ParticipantsPage = () => {
+  return (
+    <Layout>
+      <Participants />
+    </Layout>
+  );
+};
+
+export default ParticipantsPage;

src/app/sign-up/[[...sign-up]]/page.tsx

@@ -29,6 +29,20 @@ export default function SignUpPage() {
 
       if (result.status === "complete") {
         await setActive({ session: result.createdSessionId })
+
+        // Create a user entry in the database
+        const response = await fetch('/api/users', {
+          method: 'POST',
+          headers: { 'Content-Type': 'application/json' },
+          body: JSON.stringify({ email: emailAddress }),
+        })
+
+        if (!response.ok) {
+          const errorData = await response.json()
+          console.error("Error creating user in database:", errorData.error)
+          return // Optionally handle the error (e.g., show a message to the user)
+        }
+
         router.push("/dash")
       }
     } catch (err) {

src/app/studies/page.tsx

@@ -0,0 +1,10 @@
+import Layout from "~/components/layout";
+import { Studies } from "~/components/study/Studies";
+
+export default function StudiesPage() {
+  return (
+    <Layout>
+      <Studies />
+    </Layout>
+  );
+}

src/components/Studies.tsx

@@ -1,122 +0,0 @@
-"use client";
-
-import React, { useState, useEffect } from 'react';
-import { Card, CardContent, CardHeader, CardTitle } from "~/components/ui/card";
-import { Button } from "~/components/ui/button";
-import { Input } from "~/components/ui/input";
-import { Dialog, DialogContent, DialogHeader, DialogTitle, DialogTrigger } from "~/components/ui/dialog";
-
-interface Study {
-  id: number;
-  title: string;
-  description: string;
-}
-
-export function Studies() {
-  const [studies, setStudies] = useState<Study[]>([]);
-  const [newStudy, setNewStudy] = useState({ title: '', description: '' });
-  const [editingStudy, setEditingStudy] = useState<Study | null>(null);
-
-  useEffect(() => {
-    fetchStudies();
-  }, []);
-
-  const fetchStudies = async () => {
-    const response = await fetch('/api/studies');
-    const data = await response.json();
-    setStudies(data);
-  };
-
-  const createStudy = async () => {
-    const response = await fetch('/api/studies', {
-      method: 'POST',
-      headers: { 'Content-Type': 'application/json' },
-      body: JSON.stringify(newStudy),
-    });
-    const createdStudy = await response.json();
-    setStudies([...studies, createdStudy]);
-    setNewStudy({ title: '', description: '' });
-  };
-
-  const updateStudy = async () => {
-    if (!editingStudy) return;
-    const response = await fetch('/api/studies', {
-      method: 'PUT',
-      headers: { 'Content-Type': 'application/json' },
-      body: JSON.stringify(editingStudy),
-    });
-    const updatedStudy = await response.json();
-    setStudies(studies.map(s => s.id === updatedStudy.id ? updatedStudy : s));
-    setEditingStudy(null);
-  };
-
-  const deleteStudy = async (id: number) => {
-    await fetch('/api/studies', {
-      method: 'DELETE',
-      headers: { 'Content-Type': 'application/json' },
-      body: JSON.stringify({ id }),
-    });
-    setStudies(studies.filter(s => s.id !== id));
-  };
-
-  return (
-    <div className="space-y-4">
-      <h2 className="text-2xl font-bold">Studies</h2>
-      <Dialog>
-        <DialogTrigger asChild>
-          <Button>Create New Study</Button>
-        </DialogTrigger>
-        <DialogContent>
-          <DialogHeader>
-            <DialogTitle>Create New Study</DialogTitle>
-          </DialogHeader>
-          <Input
-            placeholder="Title"
-            value={newStudy.title}
-            onChange={(e) => setNewStudy({ ...newStudy, title: e.target.value })}
-          />
-          <Input
-            placeholder="Description"
-            value={newStudy.description}
-            onChange={(e) => setNewStudy({ ...newStudy, description: e.target.value })}
-          />
-          <Button onClick={createStudy}>Create</Button>
-        </DialogContent>
-      </Dialog>
-      {studies.map((study) => (
-        <Card key={study.id}>
-          <CardHeader>
-            <CardTitle>{study.title}</CardTitle>
-          </CardHeader>
-          <CardContent>
-            <p>{study.description}</p>
-            <div className="flex space-x-2 mt-2">
-              <Dialog>
-                <DialogTrigger asChild>
-                  <Button variant="outline" onClick={() => setEditingStudy(study)}>Edit</Button>
-                </DialogTrigger>
-                <DialogContent>
-                  <DialogHeader>
-                    <DialogTitle>Edit Study</DialogTitle>
-                  </DialogHeader>
-                  <Input
-                    placeholder="Title"
-                    value={editingStudy?.title || ''}
-                    onChange={(e) => setEditingStudy({ ...editingStudy!, title: e.target.value })}
-                  />
-                  <Input
-                    placeholder="Description"
-                    value={editingStudy?.description || ''}
-                    onChange={(e) => setEditingStudy({ ...editingStudy!, description: e.target.value })}
-                  />
-                  <Button onClick={updateStudy}>Update</Button>
-                </DialogContent>
-              </Dialog>
-              <Button variant="destructive" onClick={() => deleteStudy(study.id)}>Delete</Button>
-            </div>
-          </CardContent>
-        </Card>
-      ))}
-    </div>
-  );
-}

src/components/layout.tsx

@@ -0,0 +1,19 @@
+import { PropsWithChildren } from "react";
+import { Sidebar } from "~/components/sidebar";
+import { StudyHeader } from "~/components/study/StudyHeader";
+
+const Layout = ({ children }: PropsWithChildren) => {
+  return (
+    <div className="flex h-screen bg-gradient-to-b from-blue-100 to-white">
+      <Sidebar />
+      <main className="flex-1 overflow-y-auto p-4 pt-16 lg:pt-4">
+        <div className="container mx-auto space-y-4">
+          <StudyHeader />
+          {children}
+        </div>
+      </main>
+    </div>
+  );
+};
+
+export default Layout;

src/components/participant/CreateParticipantDialog.tsx

@@ -0,0 +1,52 @@
+import React, { useState } from 'react';
+import { Button } from "~/components/ui/button";
+import { Input } from "~/components/ui/input";
+import { Dialog, DialogContent, DialogHeader, DialogTitle, DialogTrigger } from "~/components/ui/dialog";
+import { Label } from "~/components/ui/label";
+import { PlusCircle } from 'lucide-react';
+
+interface CreateParticipantDialogProps {
+  onCreateParticipant: (name: string) => void;
+}
+
+export function CreateParticipantDialog({ onCreateParticipant }: CreateParticipantDialogProps) {
+  const [newParticipant, setNewParticipant] = useState({ name: '' });
+  const [isOpen, setIsOpen] = useState(false);
+
+  const handleCreate = () => {
+    if (newParticipant.name) {
+      onCreateParticipant(newParticipant.name);
+      setNewParticipant({ name: '' });
+      setIsOpen(false);
+    }
+  };
+
+  return (
+    <Dialog open={isOpen} onOpenChange={setIsOpen}>
+      <DialogTrigger asChild>
+        <Button variant="outline" size="icon">
+          <PlusCircle className="h-4 w-4" />
+        </Button>
+      </DialogTrigger>
+      <DialogContent>
+        <DialogHeader>
+          <DialogTitle>Add New Participant</DialogTitle>
+        </DialogHeader>
+        <div className="grid gap-4 py-4">
+          <div className="grid grid-cols-4 items-center gap-4">
+            <Label htmlFor="name" className="text-right">
+              Name
+            </Label>
+            <Input
+              id="name"
+              value={newParticipant.name}
+              onChange={(e) => setNewParticipant({ name: e.target.value })}
+              className="col-span-3"
+            />
+          </div>
+        </div>
+        <Button onClick={handleCreate}>Add Participant</Button>
+      </DialogContent>
+    </Dialog>
+  );
+}

src/components/participant/Participants.tsx

@@ -0,0 +1,112 @@
+"use client";
+
+import React, { useState, useEffect } from 'react';
+import { Card, CardContent, CardHeader, CardTitle } from "~/components/ui/card";
+import { Button } from "~/components/ui/button";
+import { useStudyContext } from '../../context/StudyContext';
+import { Participant } from '../../types/Participant';
+import { CreateParticipantDialog } from './CreateParticipantDialog';
+import { Trash2 } from 'lucide-react';
+import { useToast } from '~/hooks/use-toast';
+
+export function Participants() {
+  const [participants, setParticipants] = useState<Participant[]>([]);
+  const { selectedStudy } = useStudyContext();
+  const { toast } = useToast();
+
+  useEffect(() => {
+    if (selectedStudy) {
+      fetchParticipants();
+    }
+  }, [selectedStudy]);
+
+  const fetchParticipants = async () => {
+    if (!selectedStudy) return;
+    const response = await fetch(`/api/participants?studyId=${selectedStudy.id}`);
+    const data = await response.json();
+    setParticipants(data);
+  };
+
+  const createParticipant = async (name: string) => {
+    if (!selectedStudy) return;
+    const response = await fetch('/api/participants', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ name, studyId: selectedStudy.id }),
+    });
+    const createdParticipant = await response.json();
+    setParticipants([...participants, createdParticipant]);
+  };
+
+  const deleteParticipant = async (id: number) => {
+    if (!selectedStudy) return;
+    try {
+      console.log(`Attempting to delete participant with ID: ${id}`);
+      const response = await fetch(`/api/participants/${id}`, {
+        method: 'DELETE',
+      });
+      console.log('Delete response:', response);
+
+      const contentType = response.headers.get("content-type");
+      if (contentType && contentType.indexOf("application/json") !== -1) {
+        const result = await response.json();
+        console.log('Delete result:', result);
+
+        if (!response.ok) {
+          throw new Error(result.error || `Failed to delete participant. Status: ${response.status}`);
+        }
+
+        setParticipants(participants.filter(p => p.id !== id));
+        toast({
+          title: "Success",
+          description: "Participant deleted successfully",
+        });
+      } else {
+        const text = await response.text();
+        console.error('Unexpected response:', text);
+        throw new Error(`Unexpected response from server. Status: ${response.status}`);
+      }
+    } catch (error) {
+      console.error('Error deleting participant:', error);
+      toast({
+        title: "Error",
+        description: error instanceof Error ? error.message : 'Failed to delete participant',
+        variant: "destructive",
+      });
+    }
+  };
+
+  if (!selectedStudy) {
+    return <div>Please select a study to manage participants.</div>;
+  }
+
+  return (
+    <Card>
+      <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
+        <CardTitle className="text-2xl font-bold">Participants for {selectedStudy.title}</CardTitle>
+        <CreateParticipantDialog onCreateParticipant={createParticipant} />
+      </CardHeader>
+      <CardContent>
+        {participants.length > 0 ? (
+          <ul className="space-y-2">
+            {participants.map(participant => (
+              <li key={participant.id} className="bg-gray-100 p-2 rounded flex justify-between items-center">
+                <span>{participant.name}</span>
+                <Button 
+                  variant="ghost" 
+                  size="sm" 
+                  onClick={() => deleteParticipant(participant.id)}
+                  className="text-red-500 hover:text-red-700"
+                >
+                  <Trash2 className="h-4 w-4" />
+                </Button>
+              </li>
+            ))}
+          </ul>
+        ) : (
+          <p>No participants added yet.</p>
+        )}
+      </CardContent>
+    </Card>
+  );
+}

src/components/sidebar.tsx

@@ -19,8 +19,8 @@ import { cn } from "~/lib/utils"
 
 const navItems = [
   { name: "Dashboard", href: "/dash", icon: LayoutDashboard },
-  { name: "Projects", href: "/projects", icon: FolderIcon },
-  { name: "Experiments", href: "/experiments", icon: BeakerIcon },
+  { name: "Studies", href: "/studies", icon: FolderIcon },
+  { name: "Participants", href: "/participants", icon: BeakerIcon },
   { name: "Data Analysis", href: "/analysis", icon: BarChartIcon },
   { name: "Settings", href: "/settings", icon: Settings },
 ];

src/components/study/CreateStudyDialog.tsx

@@ -0,0 +1,90 @@
+import { useState } from 'react';
+import { Dialog, DialogContent, DialogHeader, DialogTitle, DialogTrigger } from "~/components/ui/dialog";
+import { Button } from "~/components/ui/button";
+import { Input } from "~/components/ui/input";
+import { Textarea } from "~/components/ui/textarea";
+import { Label } from "~/components/ui/label";
+import { PlusCircle } from 'lucide-react';
+import { Study } from '../../types/Study';
+
+interface CreateStudyDialogProps {
+  onCreateStudy: (study: Omit<Study, 'id'>) => void;
+}
+
+export function CreateStudyDialog({ onCreateStudy }: CreateStudyDialogProps) {
+  const [isOpen, setIsOpen] = useState(false);
+  const [newStudy, setNewStudy] = useState({ title: '', description: '' });
+  const [touched, setTouched] = useState({ title: false, description: false });
+
+  const handleInputChange = (e: React.ChangeEvent<HTMLInputElement | HTMLTextAreaElement>) => {
+    const { name, value } = e.target;
+    setNewStudy({ ...newStudy, [name]: value });
+    setTouched({ ...touched, [name]: true });
+  };
+
+  const isFieldInvalid = (field: 'title' | 'description') => {
+    return field === 'title' ? (touched.title && !newStudy.title) : false;
+  };
+
+  const handleCreateStudy = () => {
+    setTouched({ title: true, description: true });
+
+    if (!newStudy.title) {
+      return;
+    }
+
+    onCreateStudy({
+      title: newStudy.title,
+      description: newStudy.description || undefined
+    });
+
+    setNewStudy({ title: '', description: '' });
+    setTouched({ title: false, description: false });
+    setIsOpen(false);
+  };
+
+  return (
+    <Dialog open={isOpen} onOpenChange={setIsOpen}>
+      <DialogTrigger asChild>
+        <Button variant="outline" size="icon">
+          <PlusCircle className="h-4 w-4" />
+        </Button>
+      </DialogTrigger>
+      <DialogContent>
+        <DialogHeader>
+          <DialogTitle>Create New Study</DialogTitle>
+        </DialogHeader>
+        <div className="grid gap-4 py-4">
+          <div className="grid grid-cols-4 items-center gap-4">
+            <Label htmlFor="title" className="text-right">
+              Title
+            </Label>
+            <Input
+              id="title"
+              name="title"
+              className={`col-span-3 ${isFieldInvalid('title') ? 'border-red-500' : ''}`}
+              value={newStudy.title}
+              onChange={handleInputChange}
+            />
+          </div>
+          {isFieldInvalid('title') && (
+            <p className="text-red-500 text-sm col-span-4">Title is required</p>
+          )}
+          <div className="grid grid-cols-4 items-center gap-4">
+            <Label htmlFor="description" className="text-right">
+              Description
+            </Label>
+            <Textarea
+              id="description"
+              name="description"
+              className="col-span-3"
+              value={newStudy.description}
+              onChange={handleInputChange}
+            />
+          </div>
+        </div>
+        <Button onClick={handleCreateStudy}>Create Study</Button>
+      </DialogContent>
+    </Dialog>
+  );
+}

src/components/study/Studies.tsx

@@ -0,0 +1,28 @@
+"use client";
+
+import React from 'react';
+import { Card, CardContent, CardHeader, CardTitle } from "~/components/ui/card";
+import { useStudies } from '~/hooks/useStudies';
+import { Button } from "~/components/ui/button";
+
+export function Studies() {
+  const { studies, deleteStudy } = useStudies();
+
+  return (
+    <div className="space-y-4">
+      {studies.map((study) => (
+        <Card key={study.id}>
+          <CardHeader>
+            <CardTitle>{study.title}</CardTitle>
+          </CardHeader>
+          <CardContent>
+            <p>{study.description}</p>
+            <div className="flex space-x-2 mt-2">
+              <Button variant="destructive" onClick={() => deleteStudy(study.id)}>Delete</Button>
+            </div>
+          </CardContent>
+        </Card>
+      ))}
+    </div>
+  );
+}

src/components/study/StudyHeader.tsx

@@ -0,0 +1,75 @@
+"use client";
+
+import React, { useEffect } from 'react';
+import { Card, CardContent } from "~/components/ui/card";
+import { Tooltip, TooltipContent, TooltipProvider, TooltipTrigger } from "~/components/ui/tooltip";
+import { useStudyContext } from '~/context/StudyContext';
+import { StudySelector } from './StudySelector';
+import { CreateStudyDialog } from '~/components/study/CreateStudyDialog';
+import { Study } from '~/types/Study';
+
+export function StudyHeader() {
+  const { studies, selectedStudy, setSelectedStudy, validateAndSetSelectedStudy, fetchAndSetStudies } = useStudyContext();
+
+  useEffect(() => {
+    const savedStudyId = localStorage.getItem('selectedStudyId');
+    if (savedStudyId) {
+      validateAndSetSelectedStudy(parseInt(savedStudyId, 10));
+    }
+  }, [validateAndSetSelectedStudy]);
+
+  const handleStudyChange = (studyId: string) => {
+    const study = studies.find(s => s.id.toString() === studyId);
+    if (study) {
+      setSelectedStudy(study);
+      localStorage.setItem('selectedStudyId', studyId);
+    }
+  };
+
+  const createStudy = async (newStudy: Omit<Study, "id">) => {
+    const response = await fetch('/api/studies', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify(newStudy),
+    });
+    if (!response.ok) {
+      throw new Error('Failed to create study');
+    }
+    const createdStudy = await response.json();
+    await fetchAndSetStudies();
+    return createdStudy;
+  };
+
+  const handleCreateStudy = async (newStudy: Omit<Study, "id">) => {
+    const createdStudy = await createStudy(newStudy);
+    setSelectedStudy(createdStudy);
+    localStorage.setItem('selectedStudyId', createdStudy.id.toString());
+  };
+
+  return (
+    <Card className="mt-2 lg:mt-0">
+      <CardContent className="flex justify-between items-center p-4">
+        <TooltipProvider>
+          <Tooltip>
+            <TooltipTrigger asChild>
+              <h2 className="text-2xl font-bold truncate max-w-[200px]">
+                {selectedStudy ? selectedStudy.title : 'Select a Study'}
+              </h2>
+            </TooltipTrigger>
+            <TooltipContent>
+              <p>{selectedStudy ? selectedStudy.title : 'No study selected'}</p>
+            </TooltipContent>
+          </Tooltip>
+        </TooltipProvider>
+        <div className="flex items-center space-x-2">
+          <StudySelector
+            studies={studies}
+            selectedStudy={selectedStudy}
+            onStudyChange={handleStudyChange}
+          />
+          <CreateStudyDialog onCreateStudy={(study: Omit<Study, "id">) => handleCreateStudy(study as Study)} />
+        </div>
+      </CardContent>
+    </Card>
+  );
+}

src/components/study/StudySelector.tsx

@@ -0,0 +1,31 @@
+import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "~/components/ui/select";
+import { Study } from '../../types/Study';
+
+interface StudySelectorProps {
+  studies: Study[];
+  selectedStudy: Study | null;
+  onStudyChange: (studyId: string) => void;
+}
+
+export function StudySelector({ studies, selectedStudy, onStudyChange }: StudySelectorProps) {
+  return (
+    <Select onValueChange={onStudyChange} value={selectedStudy?.id?.toString() || ""}>
+      <SelectTrigger className="w-[200px]">
+        <SelectValue placeholder="Select a study" />
+      </SelectTrigger>
+      <SelectContent>
+        {studies.length > 0 ? (
+          studies.map((study) => (
+            <SelectItem key={study.id} value={study.id.toString()}>
+              {study.title}
+            </SelectItem>
+          ))
+        ) : (
+          <SelectItem value="no-studies" disabled className="text-gray-400 italic">
+            No studies available
+          </SelectItem>
+        )}
+      </SelectContent>
+    </Select>
+  );
+}

src/components/ui/label.tsx

@@ -0,0 +1,26 @@
+"use client"
+
+import * as React from "react"
+import * as LabelPrimitive from "@radix-ui/react-label"
+import { cva, type VariantProps } from "class-variance-authority"
+
+import { cn } from "~/lib/utils"
+
+const labelVariants = cva(
+  "text-sm font-medium leading-none peer-disabled:cursor-not-allowed peer-disabled:opacity-70"
+)
+
+const Label = React.forwardRef<
+  React.ElementRef<typeof LabelPrimitive.Root>,
+  React.ComponentPropsWithoutRef<typeof LabelPrimitive.Root> &
+    VariantProps<typeof labelVariants>
+>(({ className, ...props }, ref) => (
+  <LabelPrimitive.Root
+    ref={ref}
+    className={cn(labelVariants(), className)}
+    {...props}
+  />
+))
+Label.displayName = LabelPrimitive.Root.displayName
+
+export { Label }

src/components/ui/select.tsx

@@ -0,0 +1,164 @@
+"use client"
+
+import * as React from "react"
+import {
+  CaretSortIcon,
+  CheckIcon,
+  ChevronDownIcon,
+  ChevronUpIcon,
+} from "@radix-ui/react-icons"
+import * as SelectPrimitive from "@radix-ui/react-select"
+
+import { cn } from "~/lib/utils"
+
+const Select = SelectPrimitive.Root
+
+const SelectGroup = SelectPrimitive.Group
+
+const SelectValue = SelectPrimitive.Value
+
+const SelectTrigger = React.forwardRef<
+  React.ElementRef<typeof SelectPrimitive.Trigger>,
+  React.ComponentPropsWithoutRef<typeof SelectPrimitive.Trigger>
+>(({ className, children, ...props }, ref) => (
+  <SelectPrimitive.Trigger
+    ref={ref}
+    className={cn(
+      "flex h-9 w-full items-center justify-between whitespace-nowrap rounded-md border border-input bg-transparent px-3 py-2 text-sm shadow-sm ring-offset-background placeholder:text-muted-foreground focus:outline-none focus:ring-1 focus:ring-ring disabled:cursor-not-allowed disabled:opacity-50 [&>span]:line-clamp-1",
+      className
+    )}
+    {...props}
+  >
+    {children}
+    <SelectPrimitive.Icon asChild>
+      <CaretSortIcon className="h-4 w-4 opacity-50" />
+    </SelectPrimitive.Icon>
+  </SelectPrimitive.Trigger>
+))
+SelectTrigger.displayName = SelectPrimitive.Trigger.displayName
+
+const SelectScrollUpButton = React.forwardRef<
+  React.ElementRef<typeof SelectPrimitive.ScrollUpButton>,
+  React.ComponentPropsWithoutRef<typeof SelectPrimitive.ScrollUpButton>
+>(({ className, ...props }, ref) => (
+  <SelectPrimitive.ScrollUpButton
+    ref={ref}
+    className={cn(
+      "flex cursor-default items-center justify-center py-1",
+      className
+    )}
+    {...props}
+  >
+    <ChevronUpIcon />
+  </SelectPrimitive.ScrollUpButton>
+))
+SelectScrollUpButton.displayName = SelectPrimitive.ScrollUpButton.displayName
+
+const SelectScrollDownButton = React.forwardRef<
+  React.ElementRef<typeof SelectPrimitive.ScrollDownButton>,
+  React.ComponentPropsWithoutRef<typeof SelectPrimitive.ScrollDownButton>
+>(({ className, ...props }, ref) => (
+  <SelectPrimitive.ScrollDownButton
+    ref={ref}
+    className={cn(
+      "flex cursor-default items-center justify-center py-1",
+      className
+    )}
+    {...props}
+  >
+    <ChevronDownIcon />
+  </SelectPrimitive.ScrollDownButton>
+))
+SelectScrollDownButton.displayName =
+  SelectPrimitive.ScrollDownButton.displayName
+
+const SelectContent = React.forwardRef<
+  React.ElementRef<typeof SelectPrimitive.Content>,
+  React.ComponentPropsWithoutRef<typeof SelectPrimitive.Content>
+>(({ className, children, position = "popper", ...props }, ref) => (
+  <SelectPrimitive.Portal>
+    <SelectPrimitive.Content
+      ref={ref}
+      className={cn(
+        "relative z-50 max-h-96 min-w-[8rem] overflow-hidden rounded-md border bg-popover text-popover-foreground shadow-md data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0 data-[state=closed]:zoom-out-95 data-[state=open]:zoom-in-95 data-[side=bottom]:slide-in-from-top-2 data-[side=left]:slide-in-from-right-2 data-[side=right]:slide-in-from-left-2 data-[side=top]:slide-in-from-bottom-2",
+        position === "popper" &&
+          "data-[side=bottom]:translate-y-1 data-[side=left]:-translate-x-1 data-[side=right]:translate-x-1 data-[side=top]:-translate-y-1",
+        className
+      )}
+      position={position}
+      {...props}
+    >
+      <SelectScrollUpButton />
+      <SelectPrimitive.Viewport
+        className={cn(
+          "p-1",
+          position === "popper" &&
+            "h-[var(--radix-select-trigger-height)] w-full min-w-[var(--radix-select-trigger-width)]"
+        )}
+      >
+        {children}
+      </SelectPrimitive.Viewport>
+      <SelectScrollDownButton />
+    </SelectPrimitive.Content>
+  </SelectPrimitive.Portal>
+))
+SelectContent.displayName = SelectPrimitive.Content.displayName
+
+const SelectLabel = React.forwardRef<
+  React.ElementRef<typeof SelectPrimitive.Label>,
+  React.ComponentPropsWithoutRef<typeof SelectPrimitive.Label>
+>(({ className, ...props }, ref) => (
+  <SelectPrimitive.Label
+    ref={ref}
+    className={cn("px-2 py-1.5 text-sm font-semibold", className)}
+    {...props}
+  />
+))
+SelectLabel.displayName = SelectPrimitive.Label.displayName
+
+const SelectItem = React.forwardRef<
+  React.ElementRef<typeof SelectPrimitive.Item>,
+  React.ComponentPropsWithoutRef<typeof SelectPrimitive.Item>
+>(({ className, children, ...props }, ref) => (
+  <SelectPrimitive.Item
+    ref={ref}
+    className={cn(
+      "relative flex w-full cursor-default select-none items-center rounded-sm py-1.5 pl-2 pr-8 text-sm outline-none focus:bg-accent focus:text-accent-foreground data-[disabled]:pointer-events-none data-[disabled]:opacity-50",
+      className
+    )}
+    {...props}
+  >
+    <span className="absolute right-2 flex h-3.5 w-3.5 items-center justify-center">
+      <SelectPrimitive.ItemIndicator>
+        <CheckIcon className="h-4 w-4" />
+      </SelectPrimitive.ItemIndicator>
+    </span>
+    <SelectPrimitive.ItemText>{children}</SelectPrimitive.ItemText>
+  </SelectPrimitive.Item>
+))
+SelectItem.displayName = SelectPrimitive.Item.displayName
+
+const SelectSeparator = React.forwardRef<
+  React.ElementRef<typeof SelectPrimitive.Separator>,
+  React.ComponentPropsWithoutRef<typeof SelectPrimitive.Separator>
+>(({ className, ...props }, ref) => (
+  <SelectPrimitive.Separator
+    ref={ref}
+    className={cn("-mx-1 my-1 h-px bg-muted", className)}
+    {...props}
+  />
+))
+SelectSeparator.displayName = SelectPrimitive.Separator.displayName
+
+export {
+  Select,
+  SelectGroup,
+  SelectValue,
+  SelectTrigger,
+  SelectContent,
+  SelectLabel,
+  SelectItem,
+  SelectSeparator,
+  SelectScrollUpButton,
+  SelectScrollDownButton,
+}

src/components/ui/textarea.tsx

@@ -0,0 +1,24 @@
+import * as React from "react"
+
+import { cn } from "~/lib/utils"
+
+export interface TextareaProps
+  extends React.TextareaHTMLAttributes<HTMLTextAreaElement> {}
+
+const Textarea = React.forwardRef<HTMLTextAreaElement, TextareaProps>(
+  ({ className, ...props }, ref) => {
+    return (
+      <textarea
+        className={cn(
+          "flex min-h-[60px] w-full rounded-md border border-input bg-transparent px-3 py-2 text-sm shadow-sm placeholder:text-muted-foreground focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring disabled:cursor-not-allowed disabled:opacity-50",
+          className
+        )}
+        ref={ref}
+        {...props}
+      />
+    )
+  }
+)
+Textarea.displayName = "Textarea"
+
+export { Textarea }

src/components/ui/toast.tsx

@@ -0,0 +1,129 @@
+"use client"
+
+import * as React from "react"
+import { Cross2Icon } from "@radix-ui/react-icons"
+import * as ToastPrimitives from "@radix-ui/react-toast"
+import { cva, type VariantProps } from "class-variance-authority"
+
+import { cn } from "~/lib/utils"
+
+const ToastProvider = ToastPrimitives.Provider
+
+const ToastViewport = React.forwardRef<
+  React.ElementRef<typeof ToastPrimitives.Viewport>,
+  React.ComponentPropsWithoutRef<typeof ToastPrimitives.Viewport>
+>(({ className, ...props }, ref) => (
+  <ToastPrimitives.Viewport
+    ref={ref}
+    className={cn(
+      "fixed top-0 z-[100] flex max-h-screen w-full flex-col-reverse p-4 sm:bottom-0 sm:right-0 sm:top-auto sm:flex-col md:max-w-[420px]",
+      className
+    )}
+    {...props}
+  />
+))
+ToastViewport.displayName = ToastPrimitives.Viewport.displayName
+
+const toastVariants = cva(
+  "group pointer-events-auto relative flex w-full items-center justify-between space-x-2 overflow-hidden rounded-md border p-4 pr-6 shadow-lg transition-all data-[swipe=cancel]:translate-x-0 data-[swipe=end]:translate-x-[var(--radix-toast-swipe-end-x)] data-[swipe=move]:translate-x-[var(--radix-toast-swipe-move-x)] data-[swipe=move]:transition-none data-[state=open]:animate-in data-[state=closed]:animate-out data-[swipe=end]:animate-out data-[state=closed]:fade-out-80 data-[state=closed]:slide-out-to-right-full data-[state=open]:slide-in-from-top-full data-[state=open]:sm:slide-in-from-bottom-full",
+  {
+    variants: {
+      variant: {
+        default: "border bg-background text-foreground",
+        destructive:
+          "destructive group border-destructive bg-destructive text-destructive-foreground",
+      },
+    },
+    defaultVariants: {
+      variant: "default",
+    },
+  }
+)
+
+const Toast = React.forwardRef<
+  React.ElementRef<typeof ToastPrimitives.Root>,
+  React.ComponentPropsWithoutRef<typeof ToastPrimitives.Root> &
+    VariantProps<typeof toastVariants>
+>(({ className, variant, ...props }, ref) => {
+  return (
+    <ToastPrimitives.Root
+      ref={ref}
+      className={cn(toastVariants({ variant }), className)}
+      {...props}
+    />
+  )
+})
+Toast.displayName = ToastPrimitives.Root.displayName
+
+const ToastAction = React.forwardRef<
+  React.ElementRef<typeof ToastPrimitives.Action>,
+  React.ComponentPropsWithoutRef<typeof ToastPrimitives.Action>
+>(({ className, ...props }, ref) => (
+  <ToastPrimitives.Action
+    ref={ref}
+    className={cn(
+      "inline-flex h-8 shrink-0 items-center justify-center rounded-md border bg-transparent px-3 text-sm font-medium transition-colors hover:bg-secondary focus:outline-none focus:ring-1 focus:ring-ring disabled:pointer-events-none disabled:opacity-50 group-[.destructive]:border-muted/40 group-[.destructive]:hover:border-destructive/30 group-[.destructive]:hover:bg-destructive group-[.destructive]:hover:text-destructive-foreground group-[.destructive]:focus:ring-destructive",
+      className
+    )}
+    {...props}
+  />
+))
+ToastAction.displayName = ToastPrimitives.Action.displayName
+
+const ToastClose = React.forwardRef<
+  React.ElementRef<typeof ToastPrimitives.Close>,
+  React.ComponentPropsWithoutRef<typeof ToastPrimitives.Close>
+>(({ className, ...props }, ref) => (
+  <ToastPrimitives.Close
+    ref={ref}
+    className={cn(
+      "absolute right-1 top-1 rounded-md p-1 text-foreground/50 opacity-0 transition-opacity hover:text-foreground focus:opacity-100 focus:outline-none focus:ring-1 group-hover:opacity-100 group-[.destructive]:text-red-300 group-[.destructive]:hover:text-red-50 group-[.destructive]:focus:ring-red-400 group-[.destructive]:focus:ring-offset-red-600",
+      className
+    )}
+    toast-close=""
+    {...props}
+  >
+    <Cross2Icon className="h-4 w-4" />
+  </ToastPrimitives.Close>
+))
+ToastClose.displayName = ToastPrimitives.Close.displayName
+
+const ToastTitle = React.forwardRef<
+  React.ElementRef<typeof ToastPrimitives.Title>,
+  React.ComponentPropsWithoutRef<typeof ToastPrimitives.Title>
+>(({ className, ...props }, ref) => (
+  <ToastPrimitives.Title
+    ref={ref}
+    className={cn("text-sm font-semibold [&+div]:text-xs", className)}
+    {...props}
+  />
+))
+ToastTitle.displayName = ToastPrimitives.Title.displayName
+
+const ToastDescription = React.forwardRef<
+  React.ElementRef<typeof ToastPrimitives.Description>,
+  React.ComponentPropsWithoutRef<typeof ToastPrimitives.Description>
+>(({ className, ...props }, ref) => (
+  <ToastPrimitives.Description
+    ref={ref}
+    className={cn("text-sm opacity-90", className)}
+    {...props}
+  />
+))
+ToastDescription.displayName = ToastPrimitives.Description.displayName
+
+type ToastProps = React.ComponentPropsWithoutRef<typeof Toast>
+
+type ToastActionElement = React.ReactElement<typeof ToastAction>
+
+export {
+  type ToastProps,
+  type ToastActionElement,
+  ToastProvider,
+  ToastViewport,
+  Toast,
+  ToastTitle,
+  ToastDescription,
+  ToastClose,
+  ToastAction,
+}

src/components/ui/toaster.tsx

@@ -0,0 +1,35 @@
+"use client"
+
+import { useToast } from "~/hooks/use-toast"
+import {
+  Toast,
+  ToastClose,
+  ToastDescription,
+  ToastProvider,
+  ToastTitle,
+  ToastViewport,
+} from "~/components/ui/toast"
+
+export function Toaster() {
+  const { toasts } = useToast()
+
+  return (
+    <ToastProvider>
+      {toasts.map(function ({ id, title, description, action, ...props }) {
+        return (
+          <Toast key={id} {...props}>
+            <div className="grid gap-1">
+              {title && <ToastTitle>{title}</ToastTitle>}
+              {description && (
+                <ToastDescription>{description}</ToastDescription>
+              )}
+            </div>
+            {action}
+            <ToastClose />
+          </Toast>
+        )
+      })}
+      <ToastViewport />
+    </ToastProvider>
+  )
+}

src/components/ui/tooltip.tsx

@@ -0,0 +1,30 @@
+"use client"
+
+import * as React from "react"
+import * as TooltipPrimitive from "@radix-ui/react-tooltip"
+
+import { cn } from "~/lib/utils"
+
+const TooltipProvider = TooltipPrimitive.Provider
+
+const Tooltip = TooltipPrimitive.Root
+
+const TooltipTrigger = TooltipPrimitive.Trigger
+
+const TooltipContent = React.forwardRef<
+  React.ElementRef<typeof TooltipPrimitive.Content>,
+  React.ComponentPropsWithoutRef<typeof TooltipPrimitive.Content>
+>(({ className, sideOffset = 4, ...props }, ref) => (
+  <TooltipPrimitive.Content
+    ref={ref}
+    sideOffset={sideOffset}
+    className={cn(
+      "z-50 overflow-hidden rounded-md bg-primary px-3 py-1.5 text-xs text-primary-foreground animate-in fade-in-0 zoom-in-95 data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=closed]:zoom-out-95 data-[side=bottom]:slide-in-from-top-2 data-[side=left]:slide-in-from-right-2 data-[side=right]:slide-in-from-left-2 data-[side=top]:slide-in-from-bottom-2",
+      className
+    )}
+    {...props}
+  />
+))
+TooltipContent.displayName = TooltipPrimitive.Content.displayName
+
+export { Tooltip, TooltipTrigger, TooltipContent, TooltipProvider }

src/context/StudyContext.tsx

@@ -0,0 +1,69 @@
+"use client";
+
+import React, { createContext, useContext, useState, useEffect } from 'react';
+import { Study } from '~/types/Study';
+
+interface StudyContextType {
+  selectedStudy: Study | null;
+  setSelectedStudy: (study: Study | null) => void;
+  validateAndSetSelectedStudy: (studyId: number) => Promise<void>;
+  studies: Study[];
+  fetchAndSetStudies: () => Promise<void>;
+}
+
+const StudyContext = createContext<StudyContextType | undefined>(undefined);
+
+export const StudyProvider: React.FC<React.PropsWithChildren> = ({ children }) => {
+  const [selectedStudy, setSelectedStudy] = useState<Study | null>(null);
+  const [studies, setStudies] = useState<Study[]>([]);
+
+  const fetchAndSetStudies = async () => {
+    const response = await fetch('/api/studies');
+    const fetchedStudies = await response.json();
+    setStudies(fetchedStudies);
+  };
+
+  const validateAndSetSelectedStudy = async (studyId: number) => {
+    const existingStudy = studies.find(s => s.id === studyId);
+    if (existingStudy) {
+      setSelectedStudy(existingStudy);
+      return;
+    }
+
+    try {
+      const response = await fetch(`/api/studies/${studyId}`);
+      if (!response.ok) {
+        throw new Error('Study not found');
+      }
+      const study = await response.json();
+      setSelectedStudy(study);
+    } catch (error) {
+      console.warn(`Study with id ${studyId} not found`);
+      setSelectedStudy(null);
+    }
+  };
+
+  useEffect(() => {
+    fetchAndSetStudies();
+  }, []);
+
+  return (
+    <StudyContext.Provider value={{ 
+      selectedStudy, 
+      setSelectedStudy, 
+      validateAndSetSelectedStudy,
+      studies, 
+      fetchAndSetStudies 
+    }}>
+      {children}
+    </StudyContext.Provider>
+  );
+};
+
+export const useStudyContext = () => {
+  const context = useContext(StudyContext);
+  if (context === undefined) {
+    throw new Error('useStudyContext must be used within a StudyProvider');
+  }
+  return context;
+};

src/hooks/use-toast.ts

@@ -0,0 +1,194 @@
+"use client"
+
+// Inspired by react-hot-toast library
+import * as React from "react"
+
+import type {
+  ToastActionElement,
+  ToastProps,
+} from "~/components/ui/toast"
+
+const TOAST_LIMIT = 1
+const TOAST_REMOVE_DELAY = 1000000
+
+type ToasterToast = ToastProps & {
+  id: string
+  title?: React.ReactNode
+  description?: React.ReactNode
+  action?: ToastActionElement
+}
+
+const actionTypes = {
+  ADD_TOAST: "ADD_TOAST",
+  UPDATE_TOAST: "UPDATE_TOAST",
+  DISMISS_TOAST: "DISMISS_TOAST",
+  REMOVE_TOAST: "REMOVE_TOAST",
+} as const
+
+let count = 0
+
+function genId() {
+  count = (count + 1) % Number.MAX_SAFE_INTEGER
+  return count.toString()
+}
+
+type ActionType = typeof actionTypes
+
+type Action =
+  | {
+      type: ActionType["ADD_TOAST"]
+      toast: ToasterToast
+    }
+  | {
+      type: ActionType["UPDATE_TOAST"]
+      toast: Partial<ToasterToast>
+    }
+  | {
+      type: ActionType["DISMISS_TOAST"]
+      toastId?: ToasterToast["id"]
+    }
+  | {
+      type: ActionType["REMOVE_TOAST"]
+      toastId?: ToasterToast["id"]
+    }
+
+interface State {
+  toasts: ToasterToast[]
+}
+
+const toastTimeouts = new Map<string, ReturnType<typeof setTimeout>>()
+
+const addToRemoveQueue = (toastId: string) => {
+  if (toastTimeouts.has(toastId)) {
+    return
+  }
+
+  const timeout = setTimeout(() => {
+    toastTimeouts.delete(toastId)
+    dispatch({
+      type: "REMOVE_TOAST",
+      toastId: toastId,
+    })
+  }, TOAST_REMOVE_DELAY)
+
+  toastTimeouts.set(toastId, timeout)
+}
+
+export const reducer = (state: State, action: Action): State => {
+  switch (action.type) {
+    case "ADD_TOAST":
+      return {
+        ...state,
+        toasts: [action.toast, ...state.toasts].slice(0, TOAST_LIMIT),
+      }
+
+    case "UPDATE_TOAST":
+      return {
+        ...state,
+        toasts: state.toasts.map((t) =>
+          t.id === action.toast.id ? { ...t, ...action.toast } : t
+        ),
+      }
+
+    case "DISMISS_TOAST": {
+      const { toastId } = action
+
+      // ! Side effects ! - This could be extracted into a dismissToast() action,
+      // but I'll keep it here for simplicity
+      if (toastId) {
+        addToRemoveQueue(toastId)
+      } else {
+        state.toasts.forEach((toast) => {
+          addToRemoveQueue(toast.id)
+        })
+      }
+
+      return {
+        ...state,
+        toasts: state.toasts.map((t) =>
+          t.id === toastId || toastId === undefined
+            ? {
+                ...t,
+                open: false,
+              }
+            : t
+        ),
+      }
+    }
+    case "REMOVE_TOAST":
+      if (action.toastId === undefined) {
+        return {
+          ...state,
+          toasts: [],
+        }
+      }
+      return {
+        ...state,
+        toasts: state.toasts.filter((t) => t.id !== action.toastId),
+      }
+  }
+}
+
+const listeners: Array<(state: State) => void> = []
+
+let memoryState: State = { toasts: [] }
+
+function dispatch(action: Action) {
+  memoryState = reducer(memoryState, action)
+  listeners.forEach((listener) => {
+    listener(memoryState)
+  })
+}
+
+type Toast = Omit<ToasterToast, "id">
+
+function toast({ ...props }: Toast) {
+  const id = genId()
+
+  const update = (props: ToasterToast) =>
+    dispatch({
+      type: "UPDATE_TOAST",
+      toast: { ...props, id },
+    })
+  const dismiss = () => dispatch({ type: "DISMISS_TOAST", toastId: id })
+
+  dispatch({
+    type: "ADD_TOAST",
+    toast: {
+      ...props,
+      id,
+      open: true,
+      onOpenChange: (open) => {
+        if (!open) dismiss()
+      },
+    },
+  })
+
+  return {
+    id: id,
+    dismiss,
+    update,
+  }
+}
+
+function useToast() {
+  const [state, setState] = React.useState<State>(memoryState)
+
+  React.useEffect(() => {
+    listeners.push(setState)
+    return () => {
+      const index = listeners.indexOf(setState)
+      if (index > -1) {
+        listeners.splice(index, 1)
+      }
+    }
+  }, [state])
+
+  return {
+    ...state,
+    toast,
+    dismiss: (toastId?: string) => dispatch({ type: "DISMISS_TOAST", toastId }),
+  }
+}
+
+export { useToast, toast }

src/hooks/useStudies.ts

@@ -0,0 +1,55 @@
+import { useState, useEffect } from 'react';
+import { Study } from '../types/Study';
+import { useStudyContext } from '../context/StudyContext';
+
+export function useStudies() {
+  const [studies, setStudies] = useState<Study[]>([]);
+  const { selectedStudy, setSelectedStudy } = useStudyContext();
+
+  useEffect(() => {
+    fetchStudies();
+  }, []);
+
+  const fetchStudies = async () => {
+    const response = await fetch('/api/studies');
+    if (!response.ok) {
+      throw new Error('Failed to fetch studies');
+    }
+    const data = await response.json();
+    setStudies(data);
+  };
+
+  const handleStudyChange = (studyId: string) => {
+    const study = studies.find(s => s.id.toString() === studyId);
+    setSelectedStudy(study || null);
+  };
+
+  const addStudy = async (newStudy: Omit<Study, 'id'>) => {
+    const response = await fetch('/api/studies', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify(newStudy),
+    });
+    if (!response.ok) {
+      throw new Error('Failed to create study');
+    }
+    const createdStudy = await response.json();
+    setStudies(prevStudies => [...prevStudies, createdStudy]);
+    setSelectedStudy(createdStudy);
+  };
+
+  const deleteStudy = async (id: number) => {
+    const response = await fetch(`/api/studies/${id}`, {
+      method: 'DELETE',
+    });
+    if (!response.ok) {
+      throw new Error('Failed to delete study');
+    }
+    setStudies(studies.filter(s => s.id !== id));
+    if (selectedStudy?.id === id) {
+      setSelectedStudy(null);
+    }
+  };
+
+  return { studies, selectedStudy, handleStudyChange, addStudy, deleteStudy };
+}

src/server/db/schema.ts

@@ -2,16 +2,14 @@
 // https://orm.drizzle.team/docs/sql-schema-declaration
 
 import { pgTableCreator } from "drizzle-orm/pg-core";
-import { ColumnBaseConfig, ColumnDataType, SQL, sql } from "drizzle-orm";
 import { 
-  index,
-  pgTable,
   serial, 
-  integer,
-  timestamp,
   varchar, 
-  ExtraConfigColumn,
+  timestamp, 
+  integer, 
+  pgTable 
 } from "drizzle-orm/pg-core";
+import { sql } from "drizzle-orm";
 
 /**
  * This is an example of how to use the multi-project schema feature of Drizzle ORM. Use the same
@@ -21,37 +19,30 @@ import {
  */
 export const createTable = pgTableCreator((name) => `hristudio_${name}`);
 
-export const posts = createTable(
-  "post",
-  {
-    id: serial("id").primaryKey(),
-    name: varchar("name", { length: 256 }),
-    createdAt: timestamp("created_at", { withTimezone: true })
-      .default(sql`CURRENT_TIMESTAMP`)
-      .notNull(),
-    updatedAt: timestamp("updated_at", { withTimezone: true }).$onUpdate(
-      () => new Date()
-    ),
-  },
-  (example: { name: SQL<unknown> | Partial<ExtraConfigColumn<ColumnBaseConfig<ColumnDataType, string>>>; }) => ({
-    nameIndex: index("name_idx").on(example.name),
-  })
-);
-
 export const studies = createTable(
   "study",
   {
     id: serial("id").primaryKey(),
     title: varchar("title", { length: 256 }).notNull(),
     description: varchar("description", { length: 1000 }),
+    userId: varchar("user_id", { length: 256 }).notNull(),
     createdAt: timestamp("created_at", { withTimezone: true })
       .default(sql`CURRENT_TIMESTAMP`)
       .notNull(),
     updatedAt: timestamp("updated_at", { withTimezone: true }).$onUpdate(
       () => new Date()
     ),
-  },
-  (study: { title: SQL<unknown> | Partial<ExtraConfigColumn<ColumnBaseConfig<ColumnDataType, string>>>; }) => ({
-    titleIndex: index("title_idx").on(study.title),
-  })
+  }
+);
+
+export const participants = createTable(
+  "participant",
+  {
+    id: serial("id").primaryKey(),
+    name: varchar("name", { length: 256 }).notNull(),
+    studyId: integer("study_id").references(() => studies.id).notNull(),
+    createdAt: timestamp("created_at", { withTimezone: true })
+      .default(sql`CURRENT_TIMESTAMP`)
+      .notNull(),
+  }
 );

src/types/Participant.ts

@@ -0,0 +1,5 @@
+export interface Participant {
+    id: number;
+    name: string;
+    studyId: number;
+  }

src/types/Study.ts

@@ -0,0 +1,5 @@
+export interface Study {
+    id: number;
+    title: string;
+    description?: string;
+  }