import SwiftUI
import SwiftData

/// 이미 저장된 기록의 유통기한(날짜·시간)을 수정하는 시트.
/// 촬영 플로우와 같은 규칙: 기본은 날짜만, 필요할 때만 '시간 추가'.
struct RecordEditView: View {
    let record: ProductRecord

    @Environment(\.dismiss) private var dismiss
    @Environment(\.modelContext) private var context

    @State private var selectedDate: Date
    @State private var includeTime: Bool
    @State private var timeSelection: Date

    init(record: ProductRecord) {
        self.record = record
        _selectedDate = State(initialValue: record.expiryDate)
        _includeTime = State(initialValue: record.hasTime)
        _timeSelection = State(initialValue: record.hasTime
            ? record.expiryDate
            : (KoreanCalendar.calendar.date(bySettingHour: 18, minute: 0, second: 0, of: .now) ?? .now))
    }

    var body: some View {
        NavigationStack {
            ZStack {
                Theme.bg.ignoresSafeArea()
                ScrollView {
                    VStack(spacing: 16) {
                        currentHeader
                        datePickerCard
                        timeRow
                        saveButton
                    }
                    .padding(20)
                }
                .scrollIndicators(.hidden)
            }
            .navigationTitle("유통기한 수정")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .cancellationAction) {
                    Button("취소") { dismiss() }
                }
            }
        }
        .presentationDragIndicator(.visible)
    }

    // MARK: - 현재 값 요약

    private var currentHeader: some View {
        HStack(spacing: 12) {
            Group {
                if let image = UIImage(data: record.thumbnailData) {
                    Image(uiImage: image)
                        .resizable()
                        .scaledToFill()
                } else {
                    Theme.surfaceHi
                }
            }
            .frame(width: 56, height: 56)
            .clipShape(RoundedRectangle(cornerRadius: 12, style: .continuous))
            .overlay(
                RoundedRectangle(cornerRadius: 12, style: .continuous)
                    .strokeBorder(Theme.stroke, lineWidth: 1)
            )

            VStack(alignment: .leading, spacing: 3) {
                Text("현재 유통기한")
                    .font(.caption)
                    .foregroundStyle(Theme.textSecondary)
                Text(currentText)
                    .font(.system(.headline, design: .rounded))
                    .foregroundStyle(Theme.textPrimary)
            }
            Spacer()
        }
        .padding(14)
        .cardStyle()
    }

    private var currentText: String {
        let formatter = DateFormatter()
        formatter.locale = Locale(identifier: "ko_KR")
        formatter.dateFormat = record.hasTime ? "M월 d일 (E) a h:mm" : "M월 d일 (E)"
        return formatter.string(from: record.expiryDate)
    }

    // MARK: - 날짜 선택

    private var datePickerCard: some View {
        DatePicker(
            "유통기한 날짜",
            selection: $selectedDate,
            displayedComponents: .date
        )
        .datePickerStyle(.graphical)
        .tint(Theme.accent)
        .environment(\.locale, Locale(identifier: "ko_KR"))
        .environment(\.calendar, KoreanCalendar.calendar)
        .padding(10)
        .cardStyle()
    }

    // MARK: - 시간 추가 (선택)

    @ViewBuilder
    private var timeRow: some View {
        if includeTime {
            HStack(spacing: 10) {
                Image(systemName: "clock.fill")
                    .font(.footnote)
                    .foregroundStyle(Theme.accent)
                Text("유통 시각")
                    .font(.system(.subheadline, design: .rounded).weight(.semibold))
                    .foregroundStyle(Theme.textPrimary)
                Spacer()
                DatePicker(
                    "",
                    selection: $timeSelection,
                    displayedComponents: .hourAndMinute
                )
                .labelsHidden()
                .tint(Theme.accent)
                Button {
                    withAnimation(.snappy) { includeTime = false }
                    Haptics.tap()
                } label: {
                    Image(systemName: "xmark.circle.fill")
                        .font(.title3)
                        .foregroundStyle(Theme.textSecondary)
                }
                .buttonStyle(.plain)
            }
            .padding(.horizontal, 14)
            .padding(.vertical, 10)
            .cardStyle()
        } else {
            Button {
                withAnimation(.snappy) { includeTime = true }
                Haptics.tap()
            } label: {
                Label("시간 추가", systemImage: "clock")
                    .font(.system(.footnote, design: .rounded).weight(.semibold))
                    .foregroundStyle(Theme.textSecondary)
                    .padding(.horizontal, 14)
                    .padding(.vertical, 8)
                    .background(Capsule().fill(Theme.surfaceHi))
            }
            .buttonStyle(.plain)
        }
    }

    // MARK: - 저장

    private var saveButton: some View {
        Button {
            save()
        } label: {
            Label("저장하기", systemImage: "checkmark.circle.fill")
                .font(.system(.body, design: .rounded).weight(.bold))
                .foregroundStyle(Theme.onAccent)
                .frame(maxWidth: .infinity)
                .frame(height: 54)
                .background(Capsule().fill(Theme.accentGradient))
        }
        .padding(.top, 4)
    }

    private func save() {
        let calendar = KoreanCalendar.calendar
        let base = calendar.startOfDay(for: selectedDate)
        if includeTime {
            let t = calendar.dateComponents([.hour, .minute], from: timeSelection)
            record.expiryDate = calendar.date(
                bySettingHour: t.hour ?? 0,
                minute: t.minute ?? 0,
                second: 0,
                of: base
            ) ?? base
        } else {
            record.expiryDate = base
        }
        record.hasTime = includeTime
        try? context.save()
        Haptics.success()
        dismiss()
    }
}