//
//  ActionViews.swift
//  Haru_Danim
//
//  행동 탭: 꼬리표별 그룹 리스트 + 상세 + 추가/수정 (CLAUDE.md §6.2)
//

import SwiftUI
import SwiftData

// MARK: - 행동 리스트 (꼬리표별 그룹)

struct ActionListView: View {
    @Environment(\.modelContext) private var context
    @Query(sort: [SortDescriptor(\Tag.sortOrder), SortDescriptor(\Tag.createdAt)]) private var tags: [Tag]
    @Query(sort: \Action.createdAt) private var allActions: [Action]
    private let premium = PremiumManager.shared

    @State private var showingAdd = false
    @State private var showLimitAlert = false
    @State private var showingTagOrder = false

    // 행동 표시 순서는 모음 탭 배치와 같은 기기별 로컬 설정을 따른다 (LocalPrefs 참고)
    @AppStorage(LocalPrefsKeys.actionOrder, store: AppGroup.defaults) private var actionOrderRaw = ""

    private var actions: [Action] {
        LocalPrefs.orderedActions(allActions, raw: actionOrderRaw)
    }

    private var favoriteActions: [Action] {
        actions.filter(\.isFavorite)
    }

    private var untaggedActions: [Action] {
        actions.filter { $0.tags.isEmpty && !$0.isFavorite }
    }

    var body: some View {
        List {
            if !favoriteActions.isEmpty {
                Section {
                    ForEach(favoriteActions) { action in
                        actionLink(action)
                    }
                } header: {
                    Label("즐겨찾기", systemImage: "star.fill")
                        .foregroundStyle(AppTheme.yellow)
                }
            }
            ForEach(tags) { tag in
                let group = actions.filter { $0.tags.contains(tag) && !$0.isFavorite }
                if !group.isEmpty {
                    Section {
                        ForEach(group) { action in
                            actionLink(action)
                        }
                    } header: {
                        HStack(spacing: 6) {
                            Circle().fill(tag.color).frame(width: 10, height: 10)
                            Text(tag.name)
                        }
                    }
                }
            }
            if !untaggedActions.isEmpty {
                Section("꼬리표 없음") {
                    ForEach(untaggedActions) { action in
                        actionLink(action)
                    }
                }
            }
            if actions.isEmpty {
                ContentUnavailableView(
                    "등록된 행동이 없어요",
                    systemImage: "figure.walk",
                    description: Text("오른쪽 위 + 버튼으로 행동을 추가하세요.")
                )
            }
        }
        .scrollContentBackground(.hidden)
        .background(AppTheme.background)
        .navigationTitle("행동")
        .toolbar {
            ToolbarItem(placement: .topBarTrailing) {
                Menu {
                    Button {
                        showingTagOrder = true
                    } label: {
                        Label("꼬리표 순서 변경", systemImage: "arrow.up.arrow.down")
                    }
                } label: {
                    Image(systemName: "ellipsis.circle")
                }
            }
            ToolbarItem(placement: .topBarTrailing) {
                Button {
                    if !premium.canAddAction(currentCount: actions.count) {
                        showLimitAlert = true
                    } else {
                        showingAdd = true
                    }
                } label: {
                    Image(systemName: "plus")
                }
            }
        }
        .sheet(isPresented: $showingAdd) {
            ActionEditorView(action: nil)
        }
        .sheet(isPresented: $showingTagOrder) {
            TagOrderSheet()
        }
        .alert("무료 사용 한도", isPresented: $showLimitAlert) {
            Button("확인", role: .cancel) {}
        } message: {
            Text("무료 버전에서는 행동을 최대 \(FreeLimits.actions)개까지 만들 수 있어요. 프리미엄으로 업그레이드하면 무제한으로 사용할 수 있습니다.")
        }
    }

    private func actionLink(_ action: Action) -> some View {
        NavigationLink {
            ActionDetailView(action: action)
        } label: {
            ActionRow(action: action)
        }
        .swipeActions(edge: .leading, allowsFullSwipe: true) {
            Button {
                action.isFavorite.toggle()
            } label: {
                Label(
                    action.isFavorite ? String(localized: "즐겨찾기 해제") : String(localized: "즐겨찾기"),
                    systemImage: action.isFavorite ? "star.slash" : "star.fill"
                )
            }
            .tint(AppTheme.yellow)
        }
    }
}

struct ActionRow: View {
    let action: Action

    var body: some View {
        HStack(spacing: 12) {
            Image(systemName: action.symbolName)
                .font(.system(size: 16, weight: .semibold))
                .foregroundStyle(.white)
                .frame(width: 34, height: 34)
                .background(action.color, in: RoundedRectangle(cornerRadius: 9, style: .continuous))
            VStack(alignment: .leading, spacing: 2) {
                HStack(spacing: 4) {
                    Text(action.name)
                        .font(.body.weight(.medium))
                    if action.isFavorite {
                        Image(systemName: "star.fill")
                            .font(.caption2)
                            .foregroundStyle(AppTheme.yellow)
                    }
                }
                Text(action.trackingType.label)
                    .font(.caption)
                    .foregroundStyle(.secondary)
            }
        }
    }
}

// MARK: - 꼬리표 순서 변경 시트 (행동 탭 그룹 순서에 반영)

struct TagOrderSheet: View {
    @Environment(\.dismiss) private var dismiss
    @Query(sort: [SortDescriptor(\Tag.sortOrder), SortDescriptor(\Tag.createdAt)]) private var tags: [Tag]

    var body: some View {
        NavigationStack {
            List {
                ForEach(tags) { tag in
                    HStack(spacing: 10) {
                        Circle().fill(tag.color).frame(width: 14, height: 14)
                        Text(tag.name)
                    }
                }
                .onMove { source, destination in
                    var ordered = tags
                    ordered.move(fromOffsets: source, toOffset: destination)
                    for (index, tag) in ordered.enumerated() {
                        tag.sortOrder = index
                    }
                }
            }
            .environment(\.editMode, .constant(.active))
            .navigationTitle("꼬리표 순서")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .confirmationAction) {
                    Button("완료") { dismiss() }
                }
            }
        }
        .presentationDetents([.medium, .large])
    }
}

// MARK: - 행동 상세

struct ActionDetailView: View {
    @Environment(\.modelContext) private var context
    @Environment(\.dismiss) private var dismiss
    let action: Action

    @State private var showingEdit = false
    @State private var showingDelete = false

    var body: some View {
        List {
            Section("기본 정보") {
                HStack {
                    Text("이름")
                    Spacer()
                    Text(action.name).foregroundStyle(.secondary)
                }
                Toggle(isOn: Bindable(action).isFavorite) {
                    Label {
                        Text("즐겨찾기")
                    } icon: {
                        Image(systemName: "star.fill")
                            .foregroundStyle(AppTheme.yellow)
                    }
                }
                // 메모 창 표시 여부는 기기별 로컬 설정 (CloudKit 동기화 제외, LocalPrefs 참고)
                Toggle(isOn: Binding(
                    get: { LocalPrefs.promptsForNote(action.uuid) },
                    set: { LocalPrefs.setPromptsForNote(action.uuid, enabled: $0) }
                )) {
                    Label {
                        Text("기록 시 메모 창 표시")
                    } icon: {
                        Image(systemName: "note.text")
                            .foregroundStyle(AppTheme.green)
                    }
                }
                HStack {
                    Text("아이콘")
                    Spacer()
                    Image(systemName: action.symbolName)
                        .foregroundStyle(.white)
                        .frame(width: 30, height: 30)
                        .background(action.color, in: RoundedRectangle(cornerRadius: 8))
                }
                HStack {
                    Text("추적 방식")
                    Spacer()
                    Label(action.trackingType.label, systemImage: action.trackingType.symbol)
                        .foregroundStyle(.secondary)
                }
            }
            Section("꼬리표") {
                if action.tags.isEmpty {
                    Text("지정된 꼬리표 없음").foregroundStyle(.secondary)
                } else {
                    ForEach(action.sortedTags) { tag in
                        HStack(spacing: 8) {
                            Circle().fill(tag.color).frame(width: 10, height: 10)
                            Text(tag.name)
                        }
                    }
                }
            }
            Section("누적 기록") {
                statsRows
            }
            Section {
                Button("행동 삭제", role: .destructive) {
                    showingDelete = true
                }
            }
        }
        .scrollContentBackground(.hidden)
        .background(AppTheme.background)
        .navigationTitle(action.name)
        .navigationBarTitleDisplayMode(.inline)
        .toolbar(.hidden, for: .tabBar)
        .toolbar {
            ToolbarItem(placement: .topBarTrailing) {
                Button("수정") { showingEdit = true }
            }
        }
        .sheet(isPresented: $showingEdit) {
            ActionEditorView(action: action)
        }
        .alert("행동 삭제", isPresented: $showingDelete) {
            Button("삭제", role: .destructive) {
                context.delete(action)
                DataChange.commit(context: context)
                dismiss()
            }
            Button("취소", role: .cancel) {}
        } message: {
            Text("‘\(action.name)’ 행동을 삭제할까요? 기록도 함께 삭제됩니다.")
        }
    }

    @ViewBuilder
    private var statsRows: some View {
        let agg = Aggregator()
        let math = agg.math
        let now = Date.now
        switch action.trackingType {
        case .time:
            statRow(String(localized: "오늘"), Format.durationShort(agg.seconds(for: action, in: math.dayRange(containing: now))))
            statRow(String(localized: "이번 주"), Format.durationShort(agg.seconds(for: action, in: math.weekRange(containing: now))))
            statRow(String(localized: "이번 달"), Format.durationShort(agg.seconds(for: action, in: math.monthRange(containing: now))))
        case .count:
            statRow(String(localized: "오늘"), String(localized: "\(agg.count(for: action, in: math.dayRange(containing: now)))회"))
            statRow(String(localized: "이번 주"), String(localized: "\(agg.count(for: action, in: math.weekRange(containing: now)))회"))
            statRow(String(localized: "이번 달"), String(localized: "\(agg.count(for: action, in: math.monthRange(containing: now)))회"))
        }
    }

    private func statRow(_ title: String, _ value: String) -> some View {
        HStack {
            Text(title)
            Spacer()
            Text(value).foregroundStyle(.secondary)
        }
    }
}

// MARK: - 행동 추가/수정

struct ActionEditorView: View {
    @Environment(\.modelContext) private var context
    @Environment(\.dismiss) private var dismiss
    @Query(sort: \Tag.createdAt) private var allTags: [Tag]
    @Query private var allActions: [Action]

    /// nil이면 새 행동 추가
    let action: Action?

    @State private var name = ""
    @State private var symbolName = "star.fill"
    @State private var trackingType: TrackingType = .time
    @State private var promptsForNote = false
    @State private var selectedTags: Set<PersistentIdentifier> = []
    @State private var showingSymbolPicker = false
    @State private var showingNewTag = false

    var body: some View {
        NavigationStack {
            Form {
                Section("이름") {
                    TextField("행동 이름 (예: 독서)", text: $name)
                }
                Section("아이콘") {
                    Button {
                        showingSymbolPicker = true
                    } label: {
                        HStack {
                            Image(systemName: symbolName)
                                .font(.system(size: 20))
                                .foregroundStyle(AppTheme.green)
                                .frame(width: 36, height: 36)
                            Text("아이콘 선택")
                            Spacer()
                            Image(systemName: "chevron.right")
                                .font(.caption)
                                .foregroundStyle(.tertiary)
                        }
                        .contentShape(Rectangle())
                    }
                    .buttonStyle(.plain)
                }
                Section {
                    ForEach(allTags) { tag in
                        Button {
                            toggleTag(tag)
                        } label: {
                            HStack(spacing: 8) {
                                Circle().fill(tag.color).frame(width: 12, height: 12)
                                Text(tag.name)
                                    .foregroundStyle(.primary)
                                Spacer()
                                if selectedTags.contains(tag.persistentModelID) {
                                    Image(systemName: "checkmark")
                                        .foregroundStyle(AppTheme.green)
                                        .fontWeight(.semibold)
                                }
                            }
                            .contentShape(Rectangle())
                        }
                    }
                    Button {
                        showingNewTag = true
                    } label: {
                        Label("새 꼬리표 만들기", systemImage: "plus.circle")
                            .foregroundStyle(AppTheme.green)
                    }
                } header: {
                    Text("꼬리표 (복수 선택 가능)")
                } footer: {
                    Text("행동 버튼의 색은 지정한 꼬리표의 색을 따라요.")
                }
                Section("추적 방식") {
                    Picker("추적 방식", selection: $trackingType) {
                        ForEach(TrackingType.allCases) { type in
                            Label(type.label, systemImage: type.symbol).tag(type)
                        }
                    }
                    .pickerStyle(.inline)
                    .labelsHidden()
                }
                Section {
                    Toggle(isOn: $promptsForNote) {
                        Label {
                            Text("기록 시 메모 창 표시")
                        } icon: {
                            Image(systemName: "note.text")
                                .foregroundStyle(AppTheme.green)
                        }
                    }
                } footer: {
                    Text(trackingType == .time
                        ? String(localized: "켜면 시간 측정을 종료할 때 메모 창이 떠요. 건너뛸 수 있어요.")
                        : String(localized: "켜면 횟수를 추가할 때마다 메모 창이 떠요. 건너뛸 수 있어요."))
                }
            }
            .navigationTitle(action == nil ? String(localized: "행동 추가") : String(localized: "행동 수정"))
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .cancellationAction) {
                    Button("취소") { dismiss() }
                }
                ToolbarItem(placement: .confirmationAction) {
                    Button("저장") { save() }
                        .disabled(name.trimmingCharacters(in: .whitespaces).isEmpty)
                }
            }
            .sheet(isPresented: $showingSymbolPicker) {
                SymbolPickerView(selection: $symbolName)
            }
            .sheet(isPresented: $showingNewTag) {
                TagEditorView(tag: nil)
            }
            .onAppear(perform: load)
        }
    }

    private func load() {
        guard let action else { return }
        name = action.name
        symbolName = action.symbolName
        trackingType = action.trackingType
        promptsForNote = LocalPrefs.promptsForNote(action.uuid)
        selectedTags = Set(action.tags.map(\.persistentModelID))
    }

    private func toggleTag(_ tag: Tag) {
        if selectedTags.contains(tag.persistentModelID) {
            selectedTags.remove(tag.persistentModelID)
        } else {
            selectedTags.insert(tag.persistentModelID)
        }
    }

    private func save() {
        let tags = allTags.filter { selectedTags.contains($0.persistentModelID) }
        let trimmed = name.trimmingCharacters(in: .whitespaces)
        if let action {
            action.name = trimmed
            action.symbolName = symbolName
            action.trackingType = trackingType
            action.tags = tags
            LocalPrefs.setPromptsForNote(action.uuid, enabled: promptsForNote)
        } else {
            // sortOrder는 로컬 배치 순서가 없는 기기(첫 실행·다른 기기)에서의 폴백 정렬용으로만 기록
            let maxOrder = allActions.map(\.sortOrder).max() ?? -1
            let newAction = Action(
                name: trimmed,
                symbolName: symbolName,
                trackingType: trackingType,
                sortOrder: maxOrder + 1
            )
            newAction.tags = tags
            context.insert(newAction)
            // 이 기기의 로컬 배치 맨 끝에 추가 + 메모 창 설정 저장
            LocalPrefs.appendActionToOrder(newAction.uuid)
            LocalPrefs.setPromptsForNote(newAction.uuid, enabled: promptsForNote)
        }
        DataChange.commit(context: context)
        dismiss()
    }
}