import AppKit
import SwiftUI

struct NewTaskView: View {
    @Binding var isPresented: Bool
    @State private var path = ""
    @State private var errorMessage: String?

    var body: some View {
        VStack(alignment: .leading, spacing: 18) {
            HStack(spacing: 14) {
                Image(systemName: "plus.square.dashed")
                    .font(.system(size: 32))
                    .foregroundStyle(.tint)
                VStack(alignment: .leading, spacing: 3) {
                    Text("Run new task").font(.title2.weight(.semibold))
                    Text("Open an application, document, or executable.").foregroundStyle(.secondary)
                }
            }

            HStack {
                TextField("Application or executable path", text: $path)
                    .textFieldStyle(.roundedBorder)
                    .onSubmit { launch() }
                Button("Browse…") { browse() }
            }

            if let errorMessage {
                Label(errorMessage, systemImage: "exclamationmark.triangle.fill")
                    .font(.callout)
                    .foregroundStyle(.red)
            }

            HStack {
                Text("Tip: drag an app or file from Finder into the path field.")
                    .font(.caption)
                    .foregroundStyle(.secondary)
                Spacer()
                Button("Cancel") { isPresented = false }
                    .keyboardShortcut(.cancelAction)
                Button("Run") { launch() }
                    .keyboardShortcut(.defaultAction)
                    .buttonStyle(.borderedProminent)
                    .disabled(path.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty)
            }
        }
        .padding(24)
        .frame(width: 560)
    }

    private func browse() {
        let panel = NSOpenPanel()
        panel.title = "Choose an application, executable, or document"
        panel.canChooseDirectories = false
        panel.canChooseFiles = true
        panel.allowsMultipleSelection = false
        if panel.runModal() == .OK, let url = panel.url { path = url.path }
    }

    private func launch() {
        let cleaned = (path as NSString).expandingTildeInPath.trimmingCharacters(in: .whitespacesAndNewlines)
        let url = URL(fileURLWithPath: cleaned)
        guard FileManager.default.fileExists(atPath: cleaned) else {
            errorMessage = "That file could not be found."
            return
        }
        if NSWorkspace.shared.open(url) {
            isPresented = false
        } else {
            errorMessage = "macOS could not open this item."
        }
    }
}

struct SettingsView: View {
    @Environment(SystemMonitor.self) private var monitor
    @AppStorage("alwaysOnTop") private var alwaysOnTop = false
    @AppStorage("defaultStartPage") private var defaultStartPage: TaskSection = .processes
    @AppStorage("diagnosticReportDuration") private var diagnosticDuration = 5
    @AppStorage("diagnosticAskEveryTime") private var diagnosticAskEveryTime = true
    @AppStorage("diagnosticReportDirectory") private var diagnosticDirectory = ""

    var body: some View {
        @Bindable var monitor = monitor
        VStack(spacing: 0) {
            PageHeader(title: "Settings", subtitle: "Customize Puter")
            Form {
                Section("General") {
                    Picker("Default start page", selection: $defaultStartPage) {
                        ForEach(TaskSection.allCases.filter { $0 != .settings }) { section in
                            Text(section.rawValue).tag(section)
                        }
                    }
                    Picker("Real-time update speed", selection: $monitor.updateSpeed) {
                        ForEach(UpdateSpeed.allCases) { speed in
                            Text(speed.rawValue).tag(speed)
                        }
                    }
                    Toggle("Always on top", isOn: $alwaysOnTop)
                        .onChange(of: alwaysOnTop) { _, enabled in
                            NSApp.keyWindow?.level = enabled ? .floating : .normal
                        }
                }

                Section("Process data") {
                    LabeledContent("Refresh interval", value: intervalLabel)
                    LabeledContent("Process source", value: "macOS process table")
                    LabeledContent("Memory units", value: "Automatic")
                }

                Section("Diagnostic reports") {
                    Picker("Sample duration", selection: $diagnosticDuration) {
                        Text("1 second").tag(1)
                        Text("5 seconds").tag(5)
                        Text("10 seconds").tag(10)
                    }
                    Toggle("Ask where to save each report", isOn: $diagnosticAskEveryTime)
                    LabeledContent("Output folder") {
                        HStack(spacing: 10) {
                            Text(diagnosticDirectory.isEmpty ? "Not selected" : URL(fileURLWithPath: diagnosticDirectory).lastPathComponent)
                                .foregroundStyle(.secondary)
                            Button("Choose…") { chooseDiagnosticDirectory() }
                        }
                    }
                }

                Section("About") {
                    LabeledContent("Application", value: "Puter")
                    LabeledContent("Version", value: appVersion)
                    LabeledContent("Framework", value: "Native SwiftUI")
                }
            }
            .formStyle(.grouped)
            .scrollContentBackground(.hidden)
            .frame(maxWidth: 720)
            .frame(maxWidth: .infinity, alignment: .leading)
        }
        .task {
            NSApp.keyWindow?.level = alwaysOnTop ? .floating : .normal
        }
    }

    private var intervalLabel: String {
        switch monitor.updateSpeed {
        case .high: "Every second"
        case .normal: "Every 2 seconds"
        case .low: "Every 5 seconds"
        case .paused: "Paused"
        }
    }

    private var appVersion: String {
        Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString") as? String ?? "Development"
    }

    private func chooseDiagnosticDirectory() {
        let panel = NSOpenPanel()
        panel.title = "Choose diagnostic report folder"
        panel.prompt = "Choose"
        panel.canChooseFiles = false
        panel.canChooseDirectories = true
        panel.allowsMultipleSelection = false
        if !diagnosticDirectory.isEmpty {
            panel.directoryURL = URL(fileURLWithPath: diagnosticDirectory, isDirectory: true)
        }
        if panel.runModal() == .OK, let url = panel.url {
            diagnosticDirectory = url.path
        }
    }
}