mycode/myApp/HaruDanim/IOS/Views/GoalDetailView.swift

//
//  GoalDetailView.swift
//  HaruDanim
//
//  Shows a `Goal`'s details and its `Quest`s, and hosts a sheet for
//  creating new quests. Progress calculation is intentionally omitted.
//

import SwiftUI
import SwiftData

struct GoalDetailView: View {
    @Environment(\.modelContext) private var modelContext
    @Bindable var goal: Goal

    @State private var isAddQuestPresented = false

    private var dateFormatter: Date.FormatStyle {
        .dateTime.year().month().day()
    }

    /// Quests sorted newest first for stable display order.
    private var sortedQuests: [Quest] {
        goal.quests.sorted { $0.createdAt > $1.createdAt }
    }

    var body: some View {
        List {
            Section("목표") {
                HStack(spacing: 12) {
                    Circle()
                        .fill(Color(hex: goal.colorHex))
                        .frame(width: 20, height: 20)
                    Text(goal.title)
                    Spacer()
                }
                LabeledContent("시작일", value: goal.startDate.formatted(dateFormatter))
                LabeledContent("종료일", value: goal.endDate.formatted(dateFormatter))
            }

            Section("다짐") {
                if sortedQuests.isEmpty {
                    Text("아직 다짐이 없어요.")
                        .foregroundStyle(.secondary)
                } else {
                    ForEach(sortedQuests) { quest in
                        QuestRow(quest: quest)
                    }
                    .onDelete(perform: deleteQuests)
                }
            }
        }
        .navigationTitle(goal.title)
        .navigationBarTitleDisplayMode(.inline)
        .toolbar {
            ToolbarItem(placement: .topBarTrailing) {
                Button {
                    isAddQuestPresented = true
                } label: {
                    Label("다짐 추가", systemImage: "plus")
                }
            }
        }
        .sheet(isPresented: $isAddQuestPresented) {
            AddQuestSheet(goal: goal)
        }
    }

    private func deleteQuests(at offsets: IndexSet) {
        let toDelete = offsets.map { sortedQuests[$0] }
        for quest in toDelete {
            modelContext.delete(quest)
        }
    }
}

// MARK: - Quest Row

private struct QuestRow: View {
    let quest: Quest

    private var targetName: String {
        quest.targetAction?.name ?? quest.targetTag?.name ?? "대상 없음"
    }

    private var targetIcon: String {
        if quest.targetAction != nil { return "bolt" }
        if quest.targetTag != nil { return "tag" }
        return "questionmark"
    }

    var body: some View {
        HStack(spacing: 12) {
            Image(systemName: targetIcon)
                .frame(width: 24)
                .foregroundStyle(Color.brandPrimary)

            VStack(alignment: .leading, spacing: 4) {
                Text(quest.title.isEmpty ? targetName : quest.title)
                Text("\(quest.period.displayName) · \(targetName) \(QuestFormatting.value(quest.targetValue, usesTime: quest.usesTime)) \(quest.direction.displayName)")
                    .font(.caption)
                    .foregroundStyle(.secondary)
            }

            Spacer()
        }
    }
}

// MARK: - Add Quest Sheet

private struct AddQuestSheet: View {
    @Environment(\.modelContext) private var modelContext
    @Environment(\.dismiss) private var dismiss

    let goal: Goal

    @Query(sort: \Action.createdAt, order: .reverse) private var actions: [Action]
    @Query(sort: \Tag.createdAt, order: .reverse) private var tags: [Tag]

    /// Which kind of entity the quest targets.
    private enum TargetKind: String, CaseIterable, Identifiable {
        case action
        case tag
        var id: String { rawValue }
        var displayName: String { self == .action ? "행동" : "꼬리표" }
    }

    @State private var title = ""
    @State private var targetKind: TargetKind = .action
    @State private var selectedActionID: UUID?
    @State private var selectedTagID: UUID?
    @State private var period: QuestPeriod = .daily
    @State private var direction: QuestDirection = .above
    /// Measurement type used when targeting a tag (actions derive it from the action).
    @State private var tagMeasureType: ActionType = .time
    /// Amount entered by the user: minutes when time-based, units when count-based.
    @State private var amount: Double = 0

    private var selectedAction: Action? {
        actions.first { $0.id == selectedActionID }
    }

    private var selectedTag: Tag? {
        tags.first { $0.id == selectedTagID }
    }

    /// Whether the target is measured in time (vs. counts).
    private var usesTime: Bool {
        switch targetKind {
        case .action: return selectedAction?.type == .time
        case .tag: return tagMeasureType == .time
        }
    }

    private var hasTarget: Bool {
        switch targetKind {
        case .action: return selectedAction != nil
        case .tag: return selectedTag != nil
        }
    }

    private var isValid: Bool {
        hasTarget && amount > 0
    }

    var body: some View {
        NavigationStack {
            Form {
                Section("이름 (선택)") {
                    TextField("다짐 이름", text: $title)
                }

                Section("대상") {
                    Picker("종류", selection: $targetKind) {
                        ForEach(TargetKind.allCases) { kind in
                            Text(kind.displayName).tag(kind)
                        }
                    }
                    .pickerStyle(.segmented)

                    switch targetKind {
                    case .action:
                        if actions.isEmpty {
                            Text("먼저 행동을 추가하세요.")
                                .foregroundStyle(.secondary)
                        } else {
                            Picker("행동", selection: $selectedActionID) {
                                Text("선택 안 함").tag(UUID?.none)
                                ForEach(actions) { action in
                                    Text(action.name).tag(UUID?.some(action.id))
                                }
                            }
                        }
                    case .tag:
                        if tags.isEmpty {
                            Text("먼저 꼬리표를 추가하세요.")
                                .foregroundStyle(.secondary)
                        } else {
                            Picker("꼬리표", selection: $selectedTagID) {
                                Text("선택 안 함").tag(UUID?.none)
                                ForEach(tags) { tag in
                                    Text(tag.name).tag(UUID?.some(tag.id))
                                }
                            }
                            Picker("측정", selection: $tagMeasureType) {
                                Text("시간").tag(ActionType.time)
                                Text("횟수").tag(ActionType.count)
                            }
                            .pickerStyle(.segmented)
                        }
                    }
                }

                Section("주기") {
                    Picker("주기", selection: $period) {
                        Text("매일").tag(QuestPeriod.daily)
                        Text("매주").tag(QuestPeriod.weekly)
                        Text("매월").tag(QuestPeriod.monthly)
                    }
                    .pickerStyle(.segmented)
                }

                Section(usesTime ? "목표 시간 (분)" : "목표 횟수") {
                    TextField(usesTime ? "분" : "횟수", value: $amount, format: .number)
                        .keyboardType(.numberPad)
                }

                Section("방향") {
                    Picker("방향", selection: $direction) {
                        Text("이상").tag(QuestDirection.above)
                        Text("이하").tag(QuestDirection.below)
                    }
                    .pickerStyle(.segmented)
                }
            }
            .navigationTitle("새 다짐")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .cancellationAction) {
                    Button("취소") { dismiss() }
                }
                ToolbarItem(placement: .confirmationAction) {
                    Button("저장") { save() }
                        .disabled(!isValid)
                }
            }
        }
    }

    private func save() {
        // Time targets are entered in minutes but stored in seconds.
        let targetValue = usesTime ? amount * 60 : amount
        let trimmedTitle = title.trimmingCharacters(in: .whitespacesAndNewlines)
        let quest = Quest(
            title: trimmedTitle,
            period: period,
            direction: direction,
            targetValue: targetValue,
            usesTime: usesTime,
            goal: goal,
            targetAction: targetKind == .action ? selectedAction : nil,
            targetTag: targetKind == .tag ? selectedTag : nil
        )
        modelContext.insert(quest)
        dismiss()
    }
}

// MARK: - Display Helpers

private enum QuestFormatting {
    /// Formats a stored `targetValue` for display: minutes for time, units for count.
    static func value(_ value: Double, usesTime: Bool) -> String {
        if usesTime {
            let minutes = Int((value / 60).rounded())
            return "\(minutes)분"
        }
        return "\(Int(value.rounded()))회"
    }
}

private extension QuestPeriod {
    var displayName: String {
        switch self {
        case .daily: return "매일"
        case .weekly: return "매주"
        case .monthly: return "매월"
        case .custom: return "사용자"
        }
    }
}

private extension QuestDirection {
    var displayName: String {
        switch self {
        case .above: return "이상"
        case .below: return "이하"
        }
    }
}

#Preview {
    NavigationStack {
        GoalDetailView(goal: Goal(title: "미리보기 목표"))
    }
    .modelContainer(for: [Goal.self, Quest.self, Action.self, Tag.self], inMemory: true)
}