import SwiftUI

struct ContentView: View {
    @EnvironmentObject private var store: TimerStore

    var body: some View {
        VStack(spacing: 16) {
            header

            ScrollView {
                LazyVStack(spacing: 12) {
                    ForEach($store.timers) { $timer in
                        TimerRow(timer: $timer)
                            .environmentObject(store)
                    }
                }
                .padding(.horizontal)
                .padding(.bottom)
            }
        }
        .padding(.top)
    }

    private var header: some View {
        HStack {
            VStack(alignment: .leading, spacing: 4) {
                Text("MultiTimer")
                    .font(.largeTitle)
                    .bold()

                Text("Bis zu 15 parallele Timer mit Alarm und Wiederholung")
                    .foregroundStyle(.secondary)
            }

            Spacer()

            Button {
                store.addTimer()
            } label: {
                Label("Timer hinzufügen", systemImage: "plus")
            }
            .disabled(store.timers.count >= 15)
        }
        .padding(.horizontal)
    }
}

struct TimerRow: View {
    @EnvironmentObject private var store: TimerStore
    @Binding var timer: TimerItem

    @State private var durationText: String = ""
    @State private var durationInputIsInvalid = false

    var body: some View {
        VStack(spacing: 12) {
            HStack(spacing: 12) {
                TextField("Name", text: $timer.name)
                    .textFieldStyle(.roundedBorder)
                    .font(.headline)

                Spacer()

                Text(timer.formattedRemaining)
                    .font(.system(size: 34, weight: .semibold, design: .monospaced))
                    .frame(width: 150, alignment: .trailing)
            }

            ProgressView(value: timer.progress)
                .progressViewStyle(.linear)

            HStack(spacing: 12) {
                HStack(spacing: 6) {
                    Text("Dauer")

                    TextField("hh:mm", text: $durationText)
                        .textFieldStyle(.roundedBorder)
                        .font(.system(.body, design: .monospaced))
                        .frame(width: 70)
                        .disabled(timer.isRunning)
                        .onSubmit {
                            commitDuration()
                        }
                        .onChange(of: durationText) { _ in
                            durationInputIsInvalid = false
                        }

                    Text("hh:mm")
                        .foregroundStyle(.secondary)
                }

                if durationInputIsInvalid {
                    Text("Ungültig")
                        .foregroundStyle(.red)
                        .font(.caption)
                }

                Stepper(
                    value: Binding(
                        get: { timer.durationSeconds / 60 },
                        set: { newMinutes in
                            let seconds = max(1, newMinutes) * 60
                            store.durationChanged(for: timer.id, newDurationSeconds: seconds)
                            durationText = TimerItem.formatHHMM(seconds: seconds)
                        }
                    ),
                    in: 1...(24 * 60)
                ) {
                    Text("")
                }
                .labelsHidden()
                .disabled(timer.isRunning)

                Toggle("Auto-Wiederholung", isOn: $timer.autoRepeat)
                    .toggleStyle(.checkbox)

                Spacer()

                if timer.isRunning {
                    Button {
                        commitDuration()
                        store.pause(timer)
                    } label: {
                        Label("Pause", systemImage: "pause.fill")
                    }
                } else {
                    Button {
                        commitDuration()
                        store.start(timer)
                    } label: {
                        Label("Start", systemImage: "play.fill")
                    }
                }

                Button {
                    store.reset(timer)
                    durationText = TimerItem.formatHHMM(seconds: timer.durationSeconds)
                } label: {
                    Label("Reset", systemImage: "arrow.counterclockwise")
                }

                Button(role: .destructive) {
                    store.removeTimer(timer)
                } label: {
                    Label("Löschen", systemImage: "trash")
                }

                Text("Fertig: \(timer.completedCount)x")
                    .foregroundStyle(.secondary)
                    .frame(width: 80, alignment: .trailing)
            }
        }
        .padding()
        .background(.regularMaterial)
        .clipShape(RoundedRectangle(cornerRadius: 14))
        .onAppear {
            durationText = TimerItem.formatHHMM(seconds: timer.durationSeconds)
        }
        .onChange(of: timer.durationSeconds) { newValue in
            if !timer.isRunning {
                durationText = TimerItem.formatHHMM(seconds: newValue)
            }
        }
    }

    private func commitDuration() {
        guard !timer.isRunning else { return }

        if let seconds = TimerItem.parseHHMM(durationText) {
            durationInputIsInvalid = false
            store.durationChanged(for: timer.id, newDurationSeconds: seconds)
            durationText = TimerItem.formatHHMM(seconds: seconds)
        } else {
            durationInputIsInvalid = true
            durationText = TimerItem.formatHHMM(seconds: timer.durationSeconds)
        }
    }
}