// ── Reschedule Sheet ──────────────────────────────────────────
// NL-style reschedule options: "I slept in", "Push everything", "Skip next"

import SwiftUI

struct RescheduleSheet: View {
    @EnvironmentObject var store: TimerStore
    @Environment(\.dismiss) private var dismiss
    @State private var customMinutes: Double = 30

    var body: some View {
        NavigationStack {
            ZStack {
                CMColors.bg.ignoresSafeArea()

                ScrollView {
                    VStack(spacing: CMSpacing.xl) {
                        // Smart suggestions (if any)
                        if !store.rescheduleSuggestions.isEmpty {
                            smartSuggestionsSection
                        }

                        // Quick actions
                        quickActionsSection

                        // Custom shift
                        customShiftSection

                        // Skip next
                        skipSection
                    }
                    .padding(.horizontal, CMSpacing.lg)
                    .padding(.bottom, CMSpacing.xxl)
                }
            }
            .navigationTitle("Reschedule")
            .navigationBarTitleDisplayMode(.inline)
            .toolbarBackground(CMColors.surface, for: .navigationBar)
            .toolbarColorScheme(.dark, for: .navigationBar)
            .toolbar {
                ToolbarItem(placement: .cancellationAction) {
                    Button("Cancel") { dismiss() }
                        .foregroundStyle(CMColors.textSecondary)
                }
            }
        }
    }

    // MARK: - Smart Suggestions

    private var smartSuggestionsSection: some View {
        VStack(alignment: .leading, spacing: CMSpacing.md) {
            HStack(spacing: CMSpacing.sm) {
                Image(systemName: "sparkles")
                    .foregroundStyle(CMColors.accent)
                Text("SUGGESTED")
                    .font(CMFonts.body(size: 11, weight: .bold))
                    .foregroundStyle(CMColors.textMuted)
                    .tracking(1.5)
            }

            ForEach(store.rescheduleSuggestions) { suggestion in
                RescheduleOptionButton(
                    title: suggestion.title,
                    subtitle: suggestion.subtitle,
                    icon: suggestion.icon,
                    color: CMColors.accent
                ) {
                    applyAndDismiss(suggestion.action)
                }
            }
        }
    }

    // MARK: - Quick Actions

    private var quickActionsSection: some View {
        VStack(alignment: .leading, spacing: CMSpacing.md) {
            Text("QUICK ACTIONS")
                .font(CMFonts.body(size: 11, weight: .bold))
                .foregroundStyle(CMColors.textMuted)
                .tracking(1.5)

            ForEach(RescheduleSuggestion.quickActions) { action in
                RescheduleOptionButton(
                    title: action.title,
                    subtitle: action.subtitle,
                    icon: action.icon,
                    color: CMColors.text
                ) {
                    applyAndDismiss(action.action)
                }
            }
        }
    }

    // MARK: - Custom Shift

    private var customShiftSection: some View {
        VStack(alignment: .leading, spacing: CMSpacing.md) {
            Text("CUSTOM")
                .font(CMFonts.body(size: 11, weight: .bold))
                .foregroundStyle(CMColors.textMuted)
                .tracking(1.5)

            VStack(spacing: CMSpacing.md) {
                HStack {
                    Text("Shift by")
                        .font(CMFonts.body(size: 14))
                        .foregroundStyle(CMColors.textSecondary)
                    Spacer()
                    Text("\(Int(customMinutes)) min")
                        .font(CMFonts.mono(size: 18, weight: .bold))
                        .foregroundStyle(CMColors.accent)
                }

                Slider(value: $customMinutes, in: 5...120, step: 5)
                    .tint(CMColors.accent)

                HStack(spacing: CMSpacing.md) {
                    Button {
                        applyAndDismiss(.pushAll(interval: TimeInterval(customMinutes * 60)))
                    } label: {
                        HStack {
                            Image(systemName: "arrow.right")
                            Text("Push Later")
                        }
                        .font(CMFonts.body(size: 14, weight: .semibold))
                        .foregroundStyle(.white)
                        .frame(maxWidth: .infinity)
                        .padding(.vertical, CMSpacing.md)
                        .background(CMColors.accent)
                        .clipShape(RoundedRectangle(cornerRadius: CMRadius.sm))
                    }

                    Button {
                        applyAndDismiss(.pushAll(interval: TimeInterval(-customMinutes * 60)))
                    } label: {
                        HStack {
                            Image(systemName: "arrow.left")
                            Text("Pull Earlier")
                        }
                        .font(CMFonts.body(size: 14, weight: .semibold))
                        .foregroundStyle(CMColors.text)
                        .frame(maxWidth: .infinity)
                        .padding(.vertical, CMSpacing.md)
                        .background(CMColors.surface)
                        .clipShape(RoundedRectangle(cornerRadius: CMRadius.sm))
                        .overlay(
                            RoundedRectangle(cornerRadius: CMRadius.sm)
                                .stroke(CMColors.border, lineWidth: 1)
                        )
                    }
                }
            }
            .padding(CMSpacing.lg)
            .background(CMColors.surface)
            .clipShape(RoundedRectangle(cornerRadius: CMRadius.md))
        }
    }

    // MARK: - Skip

    private var skipSection: some View {
        VStack(alignment: .leading, spacing: CMSpacing.md) {
            if let next = store.nextFiringTimer {
                RescheduleOptionButton(
                    title: "Skip \"\(next.label)\"",
                    subtitle: "Dismiss your next timer and adjust remaining",
                    icon: "forward.fill",
                    color: CMColors.important
                ) {
                    applyAndDismiss(.skip(timerId: next.id))
                }
            }
        }
    }

    // MARK: - Helpers

    private func applyAndDismiss(_ action: RescheduleAction) {
        HapticEngine.tap()
        store.applyReschedule(action)
        dismiss()
    }
}

// MARK: - Option Button

struct RescheduleOptionButton: View {
    let title: String
    let subtitle: String
    let icon: String
    let color: Color
    let action: () -> Void

    var body: some View {
        Button(action: action) {
            HStack(spacing: CMSpacing.md) {
                Image(systemName: icon)
                    .font(.title3)
                    .foregroundStyle(color)
                    .frame(width: 32, height: 32)

                VStack(alignment: .leading, spacing: CMSpacing.xxs) {
                    Text(title)
                        .font(CMFonts.body(size: 15, weight: .semibold))
                        .foregroundStyle(CMColors.text)
                    Text(subtitle)
                        .font(CMFonts.body(size: 12))
                        .foregroundStyle(CMColors.textMuted)
                }

                Spacer()

                Image(systemName: "chevron.right")
                    .font(.caption)
                    .foregroundStyle(CMColors.textMuted)
            }
            .padding(CMSpacing.md)
            .background(CMColors.surface)
            .clipShape(RoundedRectangle(cornerRadius: CMRadius.sm))
            .overlay(
                RoundedRectangle(cornerRadius: CMRadius.sm)
                    .stroke(CMColors.border, lineWidth: 1)
            )
        }
        .buttonStyle(.plain)
    }
}