import { z } from "zod";
import { eq, and } from "drizzle-orm";
import { createTRPCRouter, protectedProcedure } from "~/server/api/trpc";
import {
  users,
  clients,
  businesses,
  invoices,
  invoiceItems
} from "~/server/db/schema";

// Validation schemas for backup data
const ClientBackupSchema = z.object({
  name: z.string(),
  email: z.string().optional(),
  phone: z.string().optional(),
  addressLine1: z.string().optional(),
  addressLine2: z.string().optional(),
  city: z.string().optional(),
  state: z.string().optional(),
  postalCode: z.string().optional(),
  country: z.string().optional(),
});

const BusinessBackupSchema = z.object({
  name: z.string(),
  email: z.string().optional(),
  phone: z.string().optional(),
  addressLine1: z.string().optional(),
  addressLine2: z.string().optional(),
  city: z.string().optional(),
  state: z.string().optional(),
  postalCode: z.string().optional(),
  country: z.string().optional(),
  website: z.string().optional(),
  taxId: z.string().optional(),
  logoUrl: z.string().optional(),
  isDefault: z.boolean().default(false),
});

const InvoiceItemBackupSchema = z.object({
  date: z.date(),
  description: z.string(),
  hours: z.number(),
  rate: z.number(),
  amount: z.number(),
  position: z.number().default(0),
});

const InvoiceBackupSchema = z.object({
  invoiceNumber: z.string(),
  businessName: z.string().optional(),
  clientName: z.string(),
  issueDate: z.date(),
  dueDate: z.date(),
  status: z.string().default("draft"),
  totalAmount: z.number().default(0),
  taxRate: z.number().default(0),
  notes: z.string().optional(),
  items: z.array(InvoiceItemBackupSchema),
});

const BackupDataSchema = z.object({
  exportDate: z.string(),
  version: z.string().default("1.0"),
  user: z.object({
    name: z.string().optional(),
    email: z.string(),
  }),
  clients: z.array(ClientBackupSchema),
  businesses: z.array(BusinessBackupSchema),
  invoices: z.array(InvoiceBackupSchema),
});

export const settingsRouter = createTRPCRouter({
  // Get user profile information
  getProfile: protectedProcedure.query(async ({ ctx }) => {
    const user = await ctx.db.query.users.findFirst({
      where: eq(users.id, ctx.session.user.id),
      columns: {
        id: true,
        name: true,
        email: true,
        image: true,
      },
    });

    return user;
  }),

  // Update user profile
  updateProfile: protectedProcedure
    .input(
      z.object({
        name: z.string().min(1, "Name is required"),
      })
    )
    .mutation(async ({ ctx, input }) => {
      await ctx.db
        .update(users)
        .set({
          name: input.name,
        })
        .where(eq(users.id, ctx.session.user.id));

      return { success: true };
    }),

  // Export user data (backup)
  exportData: protectedProcedure.query(async ({ ctx }) => {
    const userId = ctx.session.user.id;

    // Get user info
    const user = await ctx.db.query.users.findFirst({
      where: eq(users.id, userId),
      columns: {
        name: true,
        email: true,
      },
    });

    // Get all clients
    const userClients = await ctx.db.query.clients.findMany({
      where: eq(clients.createdById, userId),
      columns: {
        id: true,
        name: true,
        email: true,
        phone: true,
        addressLine1: true,
        addressLine2: true,
        city: true,
        state: true,
        postalCode: true,
        country: true,
      },
    });

    // Get all businesses
    const userBusinesses = await ctx.db.query.businesses.findMany({
      where: eq(businesses.createdById, userId),
      columns: {
        id: true,
        name: true,
        email: true,
        phone: true,
        addressLine1: true,
        addressLine2: true,
        city: true,
        state: true,
        postalCode: true,
        country: true,
        website: true,
        taxId: true,
        logoUrl: true,
        isDefault: true,
      },
    });

    // Get all invoices with their items
    const userInvoices = await ctx.db.query.invoices.findMany({
      where: eq(invoices.createdById, userId),
      with: {
        client: {
          columns: {
            name: true,
          },
        },
        business: {
          columns: {
            name: true,
          },
        },
        items: {
          columns: {
            date: true,
            description: true,
            hours: true,
            rate: true,
            amount: true,
            position: true,
          },
          orderBy: (items, { asc }) => [asc(items.position)],
        },
      },
    });

    // Format the data for export
    const backupData = {
      exportDate: new Date().toISOString(),
      version: "1.0",
      user: {
        name: user?.name ?? "",
        email: user?.email ?? "",
      },
      clients: userClients.map(client => ({
        name: client.name,
        email: client.email ?? undefined,
        phone: client.phone ?? undefined,
        addressLine1: client.addressLine1 ?? undefined,
        addressLine2: client.addressLine2 ?? undefined,
        city: client.city ?? undefined,
        state: client.state ?? undefined,
        postalCode: client.postalCode ?? undefined,
        country: client.country ?? undefined,
      })),
      businesses: userBusinesses.map(business => ({
        name: business.name,
        email: business.email ?? undefined,
        phone: business.phone ?? undefined,
        addressLine1: business.addressLine1 ?? undefined,
        addressLine2: business.addressLine2 ?? undefined,
        city: business.city ?? undefined,
        state: business.state ?? undefined,
        postalCode: business.postalCode ?? undefined,
        country: business.country ?? undefined,
        website: business.website ?? undefined,
        taxId: business.taxId ?? undefined,
        logoUrl: business.logoUrl ?? undefined,
        isDefault: business.isDefault ?? false,
      })),
      invoices: userInvoices.map(invoice => ({
        invoiceNumber: invoice.invoiceNumber,
        businessName: invoice.business?.name,
        clientName: invoice.client.name,
        issueDate: invoice.issueDate,
        dueDate: invoice.dueDate,
        status: invoice.status,
        totalAmount: invoice.totalAmount,
        taxRate: invoice.taxRate,
        notes: invoice.notes ?? undefined,
        items: invoice.items,
      })),
    };

    return backupData;
  }),

  // Import user data (restore)
  importData: protectedProcedure
    .input(BackupDataSchema)
    .mutation(async ({ ctx, input }) => {
      const userId = ctx.session.user.id;

      return await ctx.db.transaction(async (tx) => {
        // Create a map to track old to new client IDs
        const clientIdMap = new Map<string, string>();
        const businessIdMap = new Map<string, string>();

        // Import clients
        for (const clientData of input.clients) {
          const [newClient] = await tx
            .insert(clients)
            .values({
              ...clientData,
              createdById: userId,
            })
            .returning({ id: clients.id });

          if (newClient) {
            clientIdMap.set(clientData.name, newClient.id);
          }
        }

        // Import businesses
        for (const businessData of input.businesses) {
          const [newBusiness] = await tx
            .insert(businesses)
            .values({
              ...businessData,
              createdById: userId,
            })
            .returning({ id: businesses.id });

          if (newBusiness) {
            businessIdMap.set(businessData.name, newBusiness.id);
          }
        }

        // Import invoices
        for (const invoiceData of input.invoices) {
          const clientId = clientIdMap.get(invoiceData.clientName);
          if (!clientId) {
            throw new Error(`Client ${invoiceData.clientName} not found`);
          }

          const businessId = invoiceData.businessName
            ? businessIdMap.get(invoiceData.businessName)
            : null;

          const [newInvoice] = await tx
            .insert(invoices)
            .values({
              invoiceNumber: invoiceData.invoiceNumber,
              businessId,
              clientId,
              issueDate: invoiceData.issueDate,
              dueDate: invoiceData.dueDate,
              status: invoiceData.status,
              totalAmount: invoiceData.totalAmount,
              taxRate: invoiceData.taxRate,
              notes: invoiceData.notes,
              createdById: userId,
            })
            .returning({ id: invoices.id });

          if (newInvoice && invoiceData.items.length > 0) {
            // Import invoice items
            await tx.insert(invoiceItems).values(
              invoiceData.items.map(item => ({
                ...item,
                invoiceId: newInvoice.id,
              }))
            );
          }
        }

        return {
          success: true,
          imported: {
            clients: input.clients.length,
            businesses: input.businesses.length,
            invoices: input.invoices.length,
            items: input.invoices.reduce((sum, inv) => sum + inv.items.length, 0),
          }
        };
      });
    }),

  // Get data statistics
  getDataStats: protectedProcedure.query(async ({ ctx }) => {
    const userId = ctx.session.user.id;

    const [clientCount, businessCount, invoiceCount] = await Promise.all([
      ctx.db
        .select({ count: clients.id })
        .from(clients)
        .where(eq(clients.createdById, userId))
        .then(result => result.length),
      ctx.db
        .select({ count: businesses.id })
        .from(businesses)
        .where(eq(businesses.createdById, userId))
        .then(result => result.length),
      ctx.db
        .select({ count: invoices.id })
        .from(invoices)
        .where(eq(invoices.createdById, userId))
        .then(result => result.length),
    ]);

    return {
      clients: clientCount,
      businesses: businessCount,
      invoices: invoiceCount,
    };
  }),

  // Delete all user data (for account deletion)
  deleteAllData: protectedProcedure
    .input(z.object({
      confirmText: z.string().refine(val => val === "DELETE ALL DATA", {
        message: "You must type 'DELETE ALL DATA' to confirm",
      }),
    }))
    .mutation(async ({ ctx }) => {
      const userId = ctx.session.user.id;

      return await ctx.db.transaction(async (tx) => {
        // Delete in order due to foreign key constraints
        // 1. Invoice items (cascade should handle this, but being explicit)
        const userInvoiceIds = await tx
          .select({ id: invoices.id })
          .from(invoices)
          .where(eq(invoices.createdById, userId));

        if (userInvoiceIds.length > 0) {
          for (const invoice of userInvoiceIds) {
            await tx.delete(invoiceItems).where(eq(invoiceItems.invoiceId, invoice.id));
          }
        }

        // 2. Invoices
        await tx.delete(invoices).where(eq(invoices.createdById, userId));

        // 3. Clients
        await tx.delete(clients).where(eq(clients.createdById, userId));

        // 4. Businesses
        await tx.delete(businesses).where(eq(businesses.createdById, userId));

        return { success: true };
      });
    }),
});