import Cocoa

/// LLM 设置窗口
final class SettingsWindow: NSWindow {

    private let baseURLField: NSTextField
    private let apiKeyField: NSSecureTextField
    private let modelField: NSTextField
    private let testButton: NSButton
    private let saveButton: NSButton
    private let statusLabel: NSTextField

    init() {
        // 表单字段
        baseURLField = NSTextField(frame: .zero)
        apiKeyField = NSSecureTextField(frame: .zero)
        modelField = NSTextField(frame: .zero)
        testButton = NSButton(title: "Test", target: nil, action: nil)
        saveButton = NSButton(title: "Save", target: nil, action: nil)
        statusLabel = NSTextField(labelWithString: "")

        let windowRect = NSRect(x: 0, y: 0, width: 420, height: 280)
        super.init(
            contentRect: windowRect,
            styleMask: [.titled, .closable, .miniaturizable],
            backing: .buffered,
            defer: false
        )

        configureWindow()
        buildUI()
        loadCurrentConfig()
    }

    private func configureWindow() {
        title = "LLM Settings"
        isReleasedWhenClosed = false
        center()
    }

    private func buildUI() {
        guard let content = contentView else { return }

        // 标签
        func makeLabel(_ text: String) -> NSTextField {
            let label = NSTextField(labelWithString: text)
            label.font = .systemFont(ofSize: 11, weight: .semibold)
            label.textColor = .secondaryLabelColor
            label.alignment = .right
            label.translatesAutoresizingMaskIntoConstraints = false
            return label
        }

        func makeField(_ placeholder: String, isSecure: Bool = false) -> NSTextField {
            let field = isSecure ? NSSecureTextField(frame: .zero) : NSTextField(frame: .zero)
            field.placeholderString = placeholder
            field.font = .systemFont(ofSize: 13)
            field.bezelStyle = .roundedBezel
            field.translatesAutoresizingMaskIntoConstraints = false
            return field
        }

        let baseURLLabel = makeLabel("API Base URL:")
        let apiKeyLabel = makeLabel("API Key:")
        let modelLabel = makeLabel("Model:")

        // 使用实例字段
        baseURLField.placeholderString = "https://api.openai.com"
        baseURLField.font = .systemFont(ofSize: 13)
        baseURLField.bezelStyle = .roundedBezel
        baseURLField.translatesAutoresizingMaskIntoConstraints = false

        apiKeyField.placeholderString = "sk-..."
        apiKeyField.font = .systemFont(ofSize: 13)
        apiKeyField.bezelStyle = .roundedBezel
        apiKeyField.translatesAutoresizingMaskIntoConstraints = false

        modelField.placeholderString = "gpt-3.5-turbo"
        modelField.font = .systemFont(ofSize: 13)
        modelField.bezelStyle = .roundedBezel
        modelField.translatesAutoresizingMaskIntoConstraints = false

        testButton.bezelStyle = .rounded
        testButton.translatesAutoresizingMaskIntoConstraints = false
        testButton.target = self
        testButton.action = #selector(testConnection)

        saveButton.bezelStyle = .rounded
        saveButton.translatesAutoresizingMaskIntoConstraints = false
        saveButton.keyEquivalent = "\r"
        saveButton.target = self
        saveButton.action = #selector(saveConfig)

        statusLabel.font = .systemFont(ofSize: 11)
        statusLabel.textColor = .secondaryLabelColor
        statusLabel.alignment = .center
        statusLabel.maximumNumberOfLines = 2
        statusLabel.translatesAutoresizingMaskIntoConstraints = false

        // 布局
        let grid = NSGridView(views: [
            [baseURLLabel, baseURLField],
            [apiKeyLabel,  apiKeyField],
            [modelLabel,   modelField]
        ])
        grid.translatesAutoresizingMaskIntoConstraints = false
        grid.column(at: 0).xPlacement = .trailing
        grid.column(at: 1).width = 260
        grid.rowSpacing = 12
        grid.columnSpacing = 8

        let buttonStack = NSStackView(views: [testButton, saveButton])
        buttonStack.translatesAutoresizingMaskIntoConstraints = false
        buttonStack.orientation = .horizontal
        buttonStack.spacing = 12
        buttonStack.distribution = .fillEqually

        content.addSubview(grid)
        content.addSubview(buttonStack)
        content.addSubview(statusLabel)

        NSLayoutConstraint.activate([
            grid.topAnchor.constraint(equalTo: content.topAnchor, constant: 24),
            grid.leadingAnchor.constraint(equalTo: content.leadingAnchor, constant: 20),
            grid.trailingAnchor.constraint(equalTo: content.trailingAnchor, constant: -20),

            buttonStack.topAnchor.constraint(equalTo: grid.bottomAnchor, constant: 20),
            buttonStack.centerXAnchor.constraint(equalTo: content.centerXAnchor),
            buttonStack.widthAnchor.constraint(equalToConstant: 220),

            statusLabel.topAnchor.constraint(equalTo: buttonStack.bottomAnchor, constant: 12),
            statusLabel.centerXAnchor.constraint(equalTo: content.centerXAnchor),
            statusLabel.widthAnchor.constraint(equalToConstant: 380)
        ])
    }

    private func loadCurrentConfig() {
        baseURLField.stringValue = Config.shared.llmBaseURL
        apiKeyField.stringValue = Config.shared.llmAPIKey
        modelField.stringValue = Config.shared.llmModel
    }

    @objc private func testConnection() {
        // 使用输入框当前值进行测试

        statusLabel.stringValue = "Testing..."
        statusLabel.textColor = .systemBlue

        testButton.isEnabled = false
        saveButton.isEnabled = false

        let url = baseURLField.stringValue.trimmingCharacters(in: CharacterSet(charactersIn: "/"))
        let key = apiKeyField.stringValue
        let model = modelField.stringValue

        guard !url.isEmpty, !key.isEmpty, !model.isEmpty else {
            statusLabel.stringValue = "Please fill all fields"
            statusLabel.textColor = .systemRed
            testButton.isEnabled = true
            saveButton.isEnabled = true
            return
        }

        Task { @MainActor in
            let refiner = LLMRefiner()
            // 临时写入配置
            let original = (Config.shared.llmBaseURL, Config.shared.llmAPIKey, Config.shared.llmModel)
            Config.shared.llmBaseURL = url
            Config.shared.llmAPIKey = key
            Config.shared.llmModel = model

            do {
                let result = try await refiner.testConnection(config: Config.shared)
                statusLabel.stringValue = "✅ Connected! Response: \(result)"
                statusLabel.textColor = .systemGreen
            } catch {
                statusLabel.stringValue = "❌ Error: \(error.localizedDescription)"
                statusLabel.textColor = .systemRed
            }

            // 恢复
            Config.shared.llmBaseURL = original.0
            Config.shared.llmAPIKey = original.1
            Config.shared.llmModel = original.2

            testButton.isEnabled = true
            saveButton.isEnabled = true
        }
    }

    @objc private func saveConfig() {
        let url = baseURLField.stringValue.trimmingCharacters(in: CharacterSet(charactersIn: "/"))
        let key = apiKeyField.stringValue
        let model = modelField.stringValue

        Config.shared.llmBaseURL = url
        Config.shared.llmAPIKey = key
        Config.shared.llmModel = model

        statusLabel.stringValue = "✅ Saved"
        statusLabel.textColor = .systemGreen

        DispatchQueue.main.asyncAfter(deadline: .now() + 0.8) { [weak self] in
            self?.statusLabel.stringValue = ""
        }
    }
}