import SwiftUI

struct EditTaskView: View {
    @Binding var isPresented: Bool
    @EnvironmentObject var authManager: AuthManager
    let task: PulseTask
    let onSaved: () async -> Void

    @State private var title: String
    @State private var description: String
    @State private var priority: Int
    @State private var selectedIcon: String
    @State private var selectedColor: String
    @State private var hasDueDate: Bool
    @State private var dueDate: Date
    @State private var isRecurring: Bool
    @State private var recurrenceType: String
    @State private var recurrenceInterval: String
    @State private var hasRecurrenceEnd: Bool
    @State private var recurrenceEndDate: Date
    @State private var isLoading = false

    let recurrenceTypes: [(String, String)] = [
        ("daily", "Ежедневно"),
        ("weekly", "Еженедельно"),
        ("monthly", "Ежемесячно"),
        ("custom", "Каждые N дней")
    ]

    let priorities: [(Int, String, String)] = [
        (1, "Низкий", "8888aa"),
        (2, "Средний", "ffa502"),
        (3, "Высокий", "ff4757")
    ]
    let icons = ["✅","📌","🎯","💼","🏠","🛒","📞","🎓","💊","🚗",
                 "📅","⚡","🔧","📬","💡","🏋️","🌿","🎵","✍️","🌏"]
    let colors = ["#0D9488","#7c3aed","#ff4757","#ffa502","#6366f1",
                  "#ec4899","#14b8a6","#f59e0b","#10b981","#3b82f6"]

    init(isPresented: Binding<Bool>, task: PulseTask, onSaved: @escaping () async -> Void) {
        self._isPresented = isPresented
        self.task = task
        self.onSaved = onSaved
        self._title = State(initialValue: task.title)
        self._description = State(initialValue: task.description ?? "")
        self._priority = State(initialValue: task.priority ?? 2)
        self._selectedIcon = State(initialValue: task.icon ?? "✅")
        self._selectedColor = State(initialValue: task.color ?? "#0D9488")
        if let dueDateStr = task.dueDate, let parsed = Self.parseDate(dueDateStr) {
            self._hasDueDate = State(initialValue: true)
            self._dueDate = State(initialValue: parsed)
        } else {
            self._hasDueDate = State(initialValue: false)
            self._dueDate = State(initialValue: Date())
        }
        self._isRecurring = State(initialValue: task.isRecurring ?? false)
        self._recurrenceType = State(initialValue: task.recurrenceType ?? "daily")
        self._recurrenceInterval = State(initialValue: String(task.recurrenceInterval ?? 1))
        if let endStr = task.recurrenceEndDate, let parsed = Self.parseDate(endStr) {
            self._hasRecurrenceEnd = State(initialValue: true)
            self._recurrenceEndDate = State(initialValue: parsed)
        } else {
            self._hasRecurrenceEnd = State(initialValue: false)
            self._recurrenceEndDate = State(initialValue: Date().addingTimeInterval(86400 * 30))
        }
    }

    static func parseDate(_ str: String) -> Date? {
        let df = DateFormatter()
        df.dateFormat = "yyyy-MM-dd"
        return df.date(from: String(str.prefix(10)))
    }

    var body: some View {
        ZStack {
            Color(hex: "06060f").ignoresSafeArea()
            VStack(spacing: 0) {
                RoundedRectangle(cornerRadius: 3)
                    .fill(Color.white.opacity(0.2)).frame(width: 40, height: 4).padding(.top, 12)
                HStack {
                    Button("Отмена") { isPresented = false }
                        .font(.callout).foregroundColor(Color(hex: "8888aa"))
                    Spacer()
                    Text("Редактировать").font(.headline).foregroundColor(.white)
                    Spacer()
                    Button(action: save) {
                        if isLoading { ProgressView().tint(Theme.teal).scaleEffect(0.8) }
                        else { Text("Готово").font(.callout.bold()).foregroundColor(title.isEmpty ? Color(hex: "8888aa") : Theme.teal) }
                    }.disabled(title.isEmpty || isLoading)
                }
                .padding(.horizontal, 16).padding(.vertical, 14)
                Divider().background(Color.white.opacity(0.1))
                ScrollView {
                    VStack(spacing: 16) {
                        VStack(alignment: .leading, spacing: 8) {
                            Label("Название", systemImage: "pencil").font(.caption).foregroundColor(Color(hex: "8888aa"))
                            TextField("Что нужно сделать?", text: $title, axis: .vertical)
                                .lineLimit(1...3).foregroundColor(.white).padding(14)
                                .background(RoundedRectangle(cornerRadius: 12).fill(Color.white.opacity(0.07)))
                        }
                        VStack(alignment: .leading, spacing: 8) {
                            Label("Описание", systemImage: "text.alignleft").font(.caption).foregroundColor(Color(hex: "8888aa"))
                            TextField("Детали...", text: $description, axis: .vertical)
                                .lineLimit(2...4).foregroundColor(.white).padding(14)
                                .background(RoundedRectangle(cornerRadius: 12).fill(Color.white.opacity(0.07)))
                        }
                        VStack(alignment: .leading, spacing: 8) {
                            Label("Приоритет", systemImage: "flag.fill").font(.caption).foregroundColor(Color(hex: "8888aa"))
                            HStack(spacing: 8) {
                                ForEach(priorities, id: \.0) { p in
                                    Button(action: { priority = p.0 }) {
                                        Text(p.1).font(.caption.bold())
                                            .foregroundColor(priority == p.0 ? .black : Color(hex: p.2))
                                            .padding(.horizontal, 12).padding(.vertical, 8)
                                            .background(RoundedRectangle(cornerRadius: 20).fill(priority == p.0 ? Color(hex: p.2) : Color(hex: p.2).opacity(0.15)))
                                    }
                                }
                            }
                        }
                        VStack(alignment: .leading, spacing: 8) {
                            HStack {
                                Label("Срок выполнения", systemImage: "calendar").font(.caption).foregroundColor(Color(hex: "8888aa"))
                                Spacer()
                                Toggle("", isOn: $hasDueDate).tint(Color(hex: "0D9488")).labelsHidden()
                            }
                            if hasDueDate {
                                DatePicker("", selection: $dueDate, in: Date()..., displayedComponents: .date)
                                    .datePickerStyle(.compact)
                                    .colorInvert()
                                    .colorMultiply(Color(hex: "0D9488"))
                            }
                        }
                        VStack(alignment: .leading, spacing: 8) {
                            Label("Иконка", systemImage: "face.smiling").font(.caption).foregroundColor(Color(hex: "8888aa"))
                            LazyVGrid(columns: Array(repeating: GridItem(.flexible()), count: 5), spacing: 8) {
                                ForEach(icons, id: \.self) { icon in
                                    Button(action: { selectedIcon = icon }) {
                                        Text(icon).font(.title3)
                                            .frame(width: 44, height: 44)
                                            .background(Circle().fill(selectedIcon == icon ? Color(hex: "0D9488").opacity(0.25) : Color.white.opacity(0.05)))
                                            .overlay(Circle().stroke(selectedIcon == icon ? Color(hex: "0D9488") : Color.clear, lineWidth: 2))
                                    }
                                }
                            }
                        }
                        VStack(alignment: .leading, spacing: 8) {
                            Label("Цвет", systemImage: "paintpalette").font(.caption).foregroundColor(Color(hex: "8888aa"))
                            LazyVGrid(columns: Array(repeating: GridItem(.flexible()), count: 5), spacing: 10) {
                                ForEach(colors, id: \.self) { c in
                                    Button(action: { selectedColor = c }) {
                                        Circle().fill(Color(hex: String(c.dropFirst()))).frame(width: 32, height: 32)
                                            .overlay(Circle().stroke(.white, lineWidth: selectedColor == c ? 2 : 0))
                                            .scaleEffect(selectedColor == c ? 1.15 : 1.0)
                                    }
                                }
                            }
                        }
                        // Recurrence
                        VStack(alignment: .leading, spacing: 10) {
                            HStack {
                                Label("Повторение", systemImage: "repeat").font(.caption).foregroundColor(Color(hex: "8888aa"))
                                Spacer()
                                Toggle("", isOn: $isRecurring).tint(Color(hex: "0D9488")).labelsHidden()
                            }
                            if isRecurring {
                                VStack(spacing: 8) {
                                    ForEach(recurrenceTypes, id: \.0) { rt in
                                        Button(action: { recurrenceType = rt.0 }) {
                                            HStack {
                                                Text(rt.1).foregroundColor(recurrenceType == rt.0 ? .white : Color(hex: "8888aa"))
                                                Spacer()
                                                if recurrenceType == rt.0 { Image(systemName: "checkmark").foregroundColor(Color(hex: "0D9488")) }
                                            }
                                            .padding(12)
                                            .background(RoundedRectangle(cornerRadius: 10).fill(recurrenceType == rt.0 ? Color(hex: "0D9488").opacity(0.15) : Color.white.opacity(0.05)))
                                        }
                                    }
                                    if recurrenceType == "custom" {
                                        HStack {
                                            Text("Каждые").foregroundColor(Color(hex: "8888aa")).font(.callout)
                                            TextField("1", text: $recurrenceInterval).keyboardType(.numberPad)
                                                .foregroundColor(.white).frame(width: 50).padding(8)
                                                .background(RoundedRectangle(cornerRadius: 8).fill(Color.white.opacity(0.07)))
                                            Text("дней").foregroundColor(Color(hex: "8888aa")).font(.callout)
                                        }
                                    }
                                    HStack {
                                        Label("Дата окончания", systemImage: "calendar.badge.minus").font(.caption).foregroundColor(Color(hex: "8888aa"))
                                        Spacer()
                                        Toggle("", isOn: $hasRecurrenceEnd).tint(Color(hex: "0D9488")).labelsHidden()
                                    }
                                    if hasRecurrenceEnd {
                                        DatePicker("", selection: $recurrenceEndDate, in: Date()..., displayedComponents: .date)
                                            .labelsHidden()
                                            .colorInvert()
                                            .colorMultiply(Color(hex: "0D9488"))
                                    }
                                }
                            }
                        }
                    }.padding(20)
                }
            }
        }
    }

    func save() {
        isLoading = true
        let df = DateFormatter(); df.dateFormat = "yyyy-MM-dd"
        let dueDateStr = hasDueDate ? df.string(from: dueDate) : nil
        let recEndStr = (isRecurring && hasRecurrenceEnd) ? df.string(from: recurrenceEndDate) : nil
        let interval = recurrenceType == "custom" ? (Int(recurrenceInterval) ?? 1) : nil
        Task {
            let req = UpdateTaskRequest(
                title: title,
                description: description.isEmpty ? nil : description,
                priority: priority,
                dueDate: dueDateStr,
                completed: nil,
                icon: selectedIcon,
                color: selectedColor,
                isRecurring: isRecurring ? true : nil,
                recurrenceType: isRecurring ? recurrenceType : nil,
                recurrenceInterval: interval,
                recurrenceEndDate: recEndStr
            )
            try? await APIService.shared.updateTask(token: authManager.token, id: task.id, request: req)
            await onSaved()
            await MainActor.run { isPresented = false }
        }
    }
}