import Foundation
import Testing
@testable import LocalData

private func makeLegacyStringKey(name: String, domain: StorageDomain) -> StorageKey<String> {
    StorageKey(
        name: name,
        domain: domain,
        security: .none,
        owner: "Legacy",
        description: "Legacy string key"
    )
}

private func makeModernStringKey(
    name: String,
    domain: StorageDomain,
    legacyKey: AnyStorageKey?
) -> StorageKey<String> {
    StorageKey(
        name: name,
        domain: domain,
        security: .none,
        owner: "Modern",
        description: "Modern string key",
        migration: { destinationKey in
            guard let legacyKey else { return nil }
            return AnyStorageMigration(
                SimpleLegacyMigration(destinationKey: destinationKey, sourceKey: legacyKey)
            )
        }
    )
}

private func makePhoneOnlyKey(name: String, domain: StorageDomain) -> StorageKey<String> {
    StorageKey(
        name: name,
        domain: domain,
        security: .none,
        owner: "PhoneOnly",
        description: "Phone-only key",
        availability: .phoneOnly
    )
}

private func makeSourceStringKey(name: String, domain: StorageDomain) -> StorageKey<String> {
    StorageKey(
        name: name,
        domain: domain,
        security: .none,
        owner: "Source",
        description: "Source key"
    )
}

private func makeDestinationIntKey(name: String, domain: StorageDomain) -> StorageKey<Int> {
    StorageKey(
        name: name,
        domain: domain,
        security: .none,
        owner: "Destination",
        description: "Destination int key"
    )
}

@Suite(.serialized)
struct MigrationAdditionalTests {
    private let router: StorageRouter

    init() {
        let testBaseURL = FileManager.default.temporaryDirectory.appending(path: "MigrationAdditionalTests-\(UUID().uuidString)")
        router = StorageRouter(
            keychain: MockKeychainHelper(),
            encryption: EncryptionHelper(keychain: MockKeychainHelper()),
            file: FileStorageHelper(configuration: FileStorageConfiguration(baseURL: testBaseURL)),
            defaults: UserDefaultsHelper(defaults: UserDefaults(suiteName: "MigrationAdditionalTests.\(UUID().uuidString)")!)
        )
    }

    @Test func migrationHistoryTrackingTest() async throws {
        let legacyKey = makeLegacyStringKey(name: "legacy.history", domain: .userDefaults(suite: nil))
        let modernKey = makeModernStringKey(
            name: "modern.history",
            domain: .userDefaults(suite: nil),
            legacyKey: .key(legacyKey)
        )

        try await router.set("history", for: legacyKey)
        _ = try await router.forceMigration(for: modernKey)

        let history = await router.migrationHistory(for: modernKey)
        #expect(history != nil)
    }

    @Test func migrationFailureKeepsSourceTest() async throws {
        let sourceKey = makeSourceStringKey(name: "legacy.rollback", domain: .userDefaults(suite: nil))
        let destinationKey = makeDestinationIntKey(name: "modern.rollback", domain: .userDefaults(suite: nil))

        try await router.set("not-a-number", for: sourceKey)

        let migration = DefaultTransformingMigration(
            destinationKey: destinationKey,
            sourceKey: sourceKey
        ) { _ in
            throw MigrationError.transformationFailed("Invalid integer")
        }

        let result = try await migration.migrate(using: router, context: MigrationContext())
        #expect(result.success == false)
        #expect(try await router.exists(sourceKey) == true)
        #expect(try await router.exists(destinationKey) == false)
    }

    @Test func watchAvailabilityBlocksMigrationTest() async throws {
        let legacyKey = makeLegacyStringKey(name: "legacy.watch", domain: .userDefaults(suite: nil))
        let destinationKey = makePhoneOnlyKey(name: "modern.watch", domain: .userDefaults(suite: nil))

        let migration = SimpleLegacyMigration(destinationKey: destinationKey, sourceKey: .key(legacyKey))
        let deviceInfo = DeviceInfo(
            platform: .watchOS,
            systemVersion: "10.0",
            model: "Watch",
            isSimulator: true
        )
        let context = MigrationContext(deviceInfo: deviceInfo)

        let shouldMigrate = try await migration.shouldMigrate(using: router, context: context)
        #expect(shouldMigrate == false)
    }

    @Test func largeDataMigrationTest() async throws {
        let legacyKey = makeLegacyStringKey(name: "legacy.large", domain: .userDefaults(suite: nil))
        let modernKey = makeModernStringKey(
            name: "modern.large",
            domain: .userDefaults(suite: nil),
            legacyKey: .key(legacyKey)
        )

        let largeValue = String(repeating: "a", count: 1_200_000)
        try await router.set(largeValue, for: legacyKey)

        let migration = SimpleLegacyMigration(destinationKey: modernKey, sourceKey: .key(legacyKey))
        let result = try await migration.migrate(using: router, context: MigrationContext())
        #expect(result.success == true)

        let migratedValue = try await router.get(modernKey)
        #expect(migratedValue == largeValue)
    }

    @Test func typeErasureMigrationTest() async throws {
        let legacyKey = makeLegacyStringKey(name: "legacy.erased", domain: .userDefaults(suite: nil))
        let modernKey = makeModernStringKey(
            name: "modern.erased",
            domain: .userDefaults(suite: nil),
            legacyKey: .key(legacyKey)
        )

        try await router.set("erased", for: legacyKey)
        let migration = AnyStorageMigration(
            SimpleLegacyMigration(destinationKey: modernKey, sourceKey: .key(legacyKey))
        )

        let shouldMigrate = try await migration.shouldMigrate(using: router, context: MigrationContext())
        #expect(shouldMigrate == true)

        let result = try await migration.migrate(using: router, context: MigrationContext())
        #expect(result.success == true)
    }
}