import SwiftUI
import SwiftData

@main
struct KangkangApp: App {
    @State private var lang = LanguageManager.shared

    var sharedModelContainer: ModelContainer = {
        let schema = Schema([
            Indicator.self,
            Report.self,
            DiaryEntry.self,
            Asset.self,
            ChatTurn.self,
            Symptom.self,
            UserProfile.self,
            MetricReminder.self,
            CustomMonitorMetric.self,
            HealthExport.self,
            CustomReminder.self,
        ])
        let config = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false)
        do {
            return try ModelContainer(for: schema, configurations: [config])
        } catch {
            // Demo 阶段 schema 仍在演进:某次改动若超出 SwiftData 自动轻量迁移能力
            // (最常见:给已存在的 @Model 新增「非可选且无内联默认值」的属性),自动迁移会抛错。
            // 这里不再静默删库,而是把旧 store 连同 -wal/-shm 整体挪到带时间戳的备份目录后重建——
            // 既保证 App 能启动,又让旧数据可手动恢复(挪不动才降级为删除)。
            // ⚠️ 正式发布前仍应改为 VersionedSchema + SchemaMigrationPlan 的正式迁移。
            // 注:新增 @Model 属性请一律给「可选」或「内联默认值」,即可走轻量迁移、不触发本兜底。
            print("⚠️ ModelContainer 创建失败,备份旧 store 后重建: \(error)")
            KangkangApp.backupIncompatibleStore(at: config.url)
            do {
                return try ModelContainer(for: schema, configurations: [config])
            } catch {
                fatalError("Could not create ModelContainer even after store reset: \(error)")
            }
        }
    }()

    /// 把与新 schema 不兼容的旧 store(含 `-wal` / `-shm`)挪到
    /// `Application Support/StoreBackups/<时间戳>/`,而不是直接删除。
    /// 既清出路径让新库能建起来,又把旧数据留作可手动恢复的备份;挪不动时才降级为删除。
    private static func backupIncompatibleStore(at storeURL: URL) {
        let fm = FileManager.default
        let fmt = DateFormatter()
        fmt.locale = Locale(identifier: "en_US_POSIX")
        fmt.dateFormat = "yyyyMMdd-HHmmss"
        let stamp = fmt.string(from: Date())
        let backupDir = storeURL.deletingLastPathComponent()
            .appendingPathComponent("StoreBackups/\(stamp)", isDirectory: true)
        try? fm.createDirectory(at: backupDir, withIntermediateDirectories: true)
        for suffix in ["", "-wal", "-shm"] {
            let src = URL(fileURLWithPath: storeURL.path + suffix)
            guard fm.fileExists(atPath: src.path) else { continue }
            let dst = backupDir.appendingPathComponent(src.lastPathComponent)
            do {
                try fm.moveItem(at: src, to: dst)
            } catch {
                try? fm.removeItem(at: src)   // 挪不动就删,至少保证能启动
            }
        }
    }

    var body: some Scene {
        WindowGroup {
            AppLockContainer {
                RootView()
                    .environment(\.locale, lang.locale)
                    .id(lang.current)   // 语言切换 → 整树重建,即时生效
            }
        }
        .modelContainer(sharedModelContainer)
    }
}