//
//  CameraHistoryImportViewModelTests.swift
//  suixinkanTests
//

import XCTest
@testable import suixinkan

@MainActor
/// 相机历史导入 ViewModel 测试。
final class CameraHistoryImportViewModelTests: XCTestCase {
    /// 测试按日分组与今天/昨天标题。
    func testLoadPhotosGroupsByDay() async throws {
        let calendar = Calendar.current
        let today = calendar.startOfDay(for: Date())
        let yesterday = calendar.date(byAdding: .day, value: -1, to: today)!

        let driver = MockHistoryImportCameraDriver()
        driver.objects = [
            makeObject(id: "today-1", filename: "today1.JPG", day: today, hour: 10),
            makeObject(id: "today-2", filename: "today2.JPG", day: today, hour: 9),
            makeObject(id: "yesterday-1", filename: "yesterday1.JPG", day: yesterday, hour: 15),
        ]

        let sink = MockHistoryImportPhotoSink()
        let viewModel = CameraHistoryImportViewModel(
            albumId: 1,
            accountKey: "test",
            driver: driver,
            photoSink: sink,
            onImported: {}
        )

        viewModel.loadPhotos()
        try await waitUntilLoaded(viewModel)

        guard case .loaded = viewModel.state else {
            return XCTFail("expected loaded state, got \(viewModel.state)")
        }
        XCTAssertEqual(viewModel.sections.count, 2)
        XCTAssertEqual(viewModel.sections[0].title, "今天")
        XCTAssertEqual(viewModel.sections[0].photos.map(\.id), ["today-1", "today-2"])
        XCTAssertEqual(viewModel.sections[1].title, "昨天")
    }

    /// 测试已导入照片不可选。
    func testAlreadyImportedPhotoIsNotSelectable() async throws {
        let driver = MockHistoryImportCameraDriver()
        driver.objects = [makeObject(id: "dup|1024", filename: "dup.JPG", day: Date(), hour: 12)]

        let sink = MockHistoryImportPhotoSink()
        sink.existingIDs = ["dup|1024"]

        let viewModel = CameraHistoryImportViewModel(
            albumId: 1,
            accountKey: "test",
            driver: driver,
            photoSink: sink,
            onImported: {}
        )

        viewModel.loadPhotos()
        try await waitUntilLoaded(viewModel)

        XCTAssertTrue(viewModel.isPhotoAlreadyInAlbum(id: "dup|1024"))
        viewModel.togglePhoto(id: "dup|1024")
        XCTAssertTrue(viewModel.selectedPhotoIDs.isEmpty)
    }

    /// 测试分组全选与取消全选。
    func testToggleSectionSelectsImportablePhotosOnly() async throws {
        let day = Calendar.current.startOfDay(for: Date())
        let driver = MockHistoryImportCameraDriver()
        driver.objects = [
            makeObject(id: "a|100", filename: "a.JPG", day: day, hour: 10),
            makeObject(id: "b|200", filename: "b.JPG", day: day, hour: 9),
        ]

        let sink = MockHistoryImportPhotoSink()
        sink.existingIDs = ["b|200"]

        let viewModel = CameraHistoryImportViewModel(
            albumId: 1,
            accountKey: "test",
            driver: driver,
            photoSink: sink,
            onImported: {}
        )

        viewModel.loadPhotos()
        try await waitUntilLoaded(viewModel)

        let section = try XCTUnwrap(viewModel.sections.first)
        viewModel.toggleSection(section)
        XCTAssertEqual(viewModel.selectedPhotoIDs, ["a|100"])

        viewModel.toggleSection(section)
        XCTAssertTrue(viewModel.selectedPhotoIDs.isEmpty)
    }

    /// 测试 Sony catalog 为空时显示 MTP 帮助入口。
    func testSonyEmptyCatalogShowsMTPHelp() async throws {
        let driver = MockHistoryImportCameraDriver()
        driver.platform = .sony
        driver.objects = []

        let viewModel = CameraHistoryImportViewModel(
            albumId: 1,
            accountKey: "test",
            driver: driver,
            photoSink: MockHistoryImportPhotoSink(),
            onImported: {}
        )

        viewModel.loadPhotos()
        try await waitForFailedState(viewModel)

        XCTAssertTrue(viewModel.shouldShowSonyMTPHelp)
    }

    private func makeObject(id: String, filename: String, day: Date, hour: Int) -> CameraObject {
        let capturedAt = Calendar.current.date(bySettingHour: hour, minute: 0, second: 0, of: day) ?? day
        return CameraObject(id: id, filename: filename, fileSize: 1024, capturedAt: capturedAt)
    }

    private func waitUntilLoaded(
        _ viewModel: CameraHistoryImportViewModel,
        timeout: TimeInterval = 2
    ) async throws {
        let deadline = Date().addingTimeInterval(timeout)
        while Date() < deadline {
            if case .loaded = viewModel.state { return }
            if case .failed = viewModel.state {
                XCTFail("unexpected failed: \(viewModel.state)")
                return
            }
            try await Task.sleep(nanoseconds: 50_000_000)
        }
        XCTFail("timed out waiting for loaded state")
    }

    private func waitForFailedState(
        _ viewModel: CameraHistoryImportViewModel,
        timeout: TimeInterval = 2
    ) async throws {
        let deadline = Date().addingTimeInterval(timeout)
        while Date() < deadline {
            if case .failed = viewModel.state { return }
            try await Task.sleep(nanoseconds: 50_000_000)
        }
        XCTFail("timed out waiting for failed state")
    }
}

@MainActor
private final class MockHistoryImportCameraDriver: NSObject, CameraDriver {
    var platform: CameraPlatform = .canon
    var deviceInfo = CameraDeviceInfo(
        name: "Mock Camera",
        manufacturer: nil,
        model: nil,
        serialNumber: nil,
        usbVendorID: nil,
        usbProductID: nil
    )
    var objects: [CameraObject] = []

    func connect() async throws {}
    func disconnect() {}

    func listObjects() async throws -> [CameraObject] {
        objects
    }

    func requestThumbnailData(for object: CameraObject, maxPixelSize: Int) async -> Data? {
        nil
    }

    func downloadObject(_ object: CameraObject, to directory: URL) async throws -> URL {
        let url = directory.appendingPathComponent(object.filename)
        try Data(repeating: 0x01, count: 16).write(to: url)
        return url
    }
}

@MainActor
private final class MockHistoryImportPhotoSink: OTGPhotoSink {
    var existingIDs: Set<String> = []
    private(set) var savedCount = 0

    func saveLiveShot(
        data: Data,
        filename: String,
        capturedAt: Date,
        cameraObjectID: String
    ) async throws -> SavedOTGPhoto {
        savedCount += 1
        return SavedOTGPhoto(
            assetID: cameraObjectID,
            relativeLocalPath: "mock/\(filename)",
            filename: filename,
            capturedAt: capturedAt
        )
    }

    func saveDownloadedFile(
        at url: URL,
        filename: String,
        capturedAt: Date,
        cameraObjectID: String
    ) async throws -> SavedOTGPhoto {
        savedCount += 1
        return SavedOTGPhoto(
            assetID: cameraObjectID,
            relativeLocalPath: "mock/\(filename)",
            filename: filename,
            capturedAt: capturedAt
        )
    }

    func existingCameraObjectIDs() async -> Set<String> {
        existingIDs
    }
}