//
//  DataExportView.swift
//  Haru_Danim
//
//  원시 데이터 내보내기 (설정 → 데이터).
//  모든 기록을 CSV 파일로 만들어 공유한다 — 백업·이동·스프레드시트 분석용.
//  리포트 이미지(ExportImageView)와 달리 가공 없는 원본 값을 담는다.
//  무료 사용자도 사용 가능 (자기 데이터에 대한 접근권).
//

import SwiftUI
import SwiftData

struct DataExportView: View {
    @Query(sort: \Action.createdAt) private var actions: [Action]
    @Query(sort: \TimeSession.startAt) private var sessions: [TimeSession]
    @Query(sort: \CountEntry.timestamp) private var entries: [CountEntry]
    @Query(sort: [SortDescriptor(\Goal.sortOrder), SortDescriptor(\Goal.createdAt)]) private var goals: [Goal]

    @State private var isRendering = false
    @State private var resultURLs: [URL] = []

    var body: some View {
        List {
            Section {
                row("figure.walk", String(localized: "행동"), String(localized: "\(actions.count)개"))
                row("timer", String(localized: "시간 기록"), String(localized: "\(sessions.count)건"))
                row("number", String(localized: "횟수 기록"), String(localized: "\(entries.count)건"))
                row("flag.checkered", String(localized: "목표·다짐"), String(localized: "\(goals.count)개"))
            } header: {
                Text("내보낼 데이터")
            } footer: {
                Text("행동·시간 기록·횟수 기록·목표·다짐을 각각 CSV 파일로 만들어요. 스프레드시트에서 열거나 백업으로 보관할 수 있어요. 시각은 ISO 8601 형식이에요.")
            }
            Section {
                if isRendering {
                    HStack {
                        ProgressView()
                        Text("만드는 중…")
                            .foregroundStyle(.secondary)
                    }
                } else if resultURLs.isEmpty {
                    Button {
                        export()
                    } label: {
                        Label("CSV 만들기", systemImage: "tablecells")
                            .frame(maxWidth: .infinity)
                    }
                } else {
                    ShareLink(items: resultURLs) {
                        Label("파일 \(resultURLs.count)개 공유", systemImage: "square.and.arrow.up")
                            .frame(maxWidth: .infinity)
                    }
                    Button("다시 만들기") {
                        resultURLs = []
                    }
                    .frame(maxWidth: .infinity)
                }
            }
        }
        .tint(AppTheme.green)
        .scrollContentBackground(.hidden)
        .background(AppTheme.background)
        .navigationTitle("데이터 내보내기")
        .navigationBarTitleDisplayMode(.inline)
        .toolbar(.hidden, for: .tabBar)
        #if DEBUG
        .onAppear {
            // 검증용: -dataExportRun YES → 자동 생성 후 Documents에 결과 복사
            if UserDefaults.standard.bool(forKey: "dataExportRun") {
                export()
            }
        }
        #endif
    }

    private func row(_ symbol: String, _ title: String, _ count: String) -> some View {
        HStack {
            Label {
                Text(title)
            } icon: {
                Image(systemName: symbol)
                    .foregroundStyle(AppTheme.green)
            }
            Spacer()
            Text(count).foregroundStyle(.secondary)
        }
    }

    // MARK: CSV 생성

    private func export() {
        isRendering = true
        Task { @MainActor in
            var urls: [URL?] = []
            // 파일명·헤더(열 이름)는 언어별 현지화 — 수신 환경이 한글을 지원하지 않을 수 있고,
            // 스프레드시트에서 열 이름은 곧 UI다. 값 중 rawValue(time/count 등)는 데이터라 그대로.
            urls.append(write(String(localized: "행동"), header: [
                "id", String(localized: "이름"), String(localized: "추적 방식"),
                String(localized: "꼬리표"), String(localized: "즐겨찾기"), String(localized: "만든날"),
            ],
                              rows: actions.map { action in
                [action.uuid.uuidString, action.name,
                 action.trackingType == .time ? "time" : "count",
                 action.sortedTags.map(\.name).joined(separator: "; "),
                 action.isFavorite ? "true" : "false",
                 iso(action.createdAt)]
            }))
            urls.append(write(String(localized: "시간기록", comment: "CSV 파일명용 (공백 없이)"), header: [
                String(localized: "행동id"), String(localized: "행동"), String(localized: "시작"),
                String(localized: "종료"), String(localized: "초"), String(localized: "메모"),
            ],
                              rows: sessions.compactMap { session in
                guard let action = session.action else { return nil }
                return [action.uuid.uuidString, action.name,
                        iso(session.startAt),
                        session.endAt.map(iso) ?? "",
                        String(Int(session.duration())),
                        session.note]
            }))
            urls.append(write(String(localized: "횟수기록", comment: "CSV 파일명용 (공백 없이)"), header: [
                String(localized: "행동id"), String(localized: "행동"), String(localized: "시각"),
                String(localized: "수량"), String(localized: "메모"),
            ],
                              rows: entries.compactMap { entry in
                guard let action = entry.action else { return nil }
                return [action.uuid.uuidString, action.name,
                        iso(entry.timestamp), String(entry.amount), entry.note]
            }))
            urls.append(write(String(localized: "목표"), header: [
                "id", String(localized: "내용"), String(localized: "시작일"),
                String(localized: "종료일"), String(localized: "상태"), String(localized: "달성기준%"),
            ],
                              rows: goals.map { goal in
                [goal.uuid.uuidString, goal.title, iso(goal.startDate),
                 goal.endDate.map(iso) ?? "", goal.statusRaw,
                 String(goal.achieveThresholdPercent)]
            }))
            urls.append(write(String(localized: "다짐"), header: [
                "id", String(localized: "목표"), String(localized: "대상"),
                String(localized: "주기"), String(localized: "목표량"), String(localized: "방향"),
            ],
                              rows: goals.flatMap(\.sortedQuests).map { quest in
                [quest.uuid.uuidString, quest.goal?.title ?? "",
                 quest.targetName, quest.scheduleLabel,
                 quest.measure == .time ? String(Int(quest.targetSeconds)) + "s" : String(quest.targetCount),
                 quest.direction == .atLeast ? "atLeast" : "atMost"]
            }))
            resultURLs = urls.compactMap(\.self)
            isRendering = false
            #if DEBUG
            if UserDefaults.standard.bool(forKey: "dataExportRun"),
               let docs = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first {
                for url in resultURLs {
                    let dest = docs.appendingPathComponent(url.lastPathComponent)
                    try? FileManager.default.removeItem(at: dest)
                    try? FileManager.default.copyItem(at: url, to: dest)
                }
            }
            #endif
        }
    }

    private func iso(_ date: Date) -> String {
        date.formatted(.iso8601)
    }

    /// CSV 필드 이스케이프 (쉼표·따옴표·줄바꿈 포함 시 따옴표로 감쌈)
    private func escape(_ field: String) -> String {
        if field.contains(",") || field.contains("\"") || field.contains("\n") {
            return "\"" + field.replacingOccurrences(of: "\"", with: "\"\"") + "\""
        }
        return field
    }

    private func write(_ name: String, header: [String], rows: [[String]]) -> URL? {
        let lines = [header.map(escape).joined(separator: ",")]
            + rows.map { $0.map(escape).joined(separator: ",") }
        // 엑셀이 UTF-8 한글을 바로 인식하도록 BOM을 붙인다
        let content = "\u{FEFF}" + lines.joined(separator: "\n")
        let url = FileManager.default.temporaryDirectory
            .appendingPathComponent(String(localized: "하루다님-\(name).csv"))
        do {
            try content.write(to: url, atomically: true, encoding: .utf8)
            return url
        } catch {
            return nil
        }
    }
}