import Foundation
import UIKit
import XuqmCoreSDK

/// BugCollect 崩溃收集 SDK
@MainActor
public final class BugCollectSDK {

    public static let shared = BugCollectSDK()

    private var logLevel: LogLevel = .warn
    private var environment: String = "production"
    private var queue: LogQueue?
    private var crashCapture: CrashCapture?

    private var breadcrumbBuffer: [Breadcrumb] = []
    private let breadcrumbLock = NSLock()
    private let maxBreadcrumbs = 50

    private var pendingErrors: [IssueEvent] = []
    private let pendingErrorsLock = NSLock()

    private let sdkName = "bugcollect.ios"
    private let sdkVersion = "1.0.0"

    private init() {}

    // MARK: - Public API

    /// 设置日志级别
    public func setLogLevel(_ level: LogLevel) {
        self.logLevel = level
    }

    /// 设置环境
    public func setEnvironment(_ env: String) {
        self.environment = env
    }

    /// 添加面包屑
    public func addBreadcrumb(
        category: String,
        message: String,
        level: String = "info",
        data: [String: Any?] = [:]
    ) {
        breadcrumbLock.lock()
        defer { breadcrumbLock.unlock() }

        if breadcrumbBuffer.count >= maxBreadcrumbs {
            breadcrumbBuffer.removeFirst()
        }
        breadcrumbBuffer.append(Breadcrumb(
            timestamp: Int(Date().timeIntervalSince1970 * 1000),
            category: category,
            message: message,
            level: level,
            data: data
        ))
    }

    /// 记录事件
    public func event(name: String, properties: [String: Any?] = [:]) {
        guard isReady() else { return }

        let logEvent = LogEvent(
            name: name,
            properties: properties,
            appKey: XuqmSDK.shared.requireConfig().appKey,
            userId: XuqmSDK.shared.userId ?? XuqmSDK.shared.deviceId,
            platform: "ios",
            release: appVersion(),
            environment: environment,
            sdk: IssueEvent.SdkInfo(name: sdkName, version: sdkVersion)
        )
        queue?.push(logEvent)
        FunnelTracker.shared.track(name: name, properties: properties)
    }

    /// 捕获错误
    public func captureError(_ error: Error, tags: [String: Any?] = [:], fingerprint: String? = nil) {
        let crumbs = breadcrumbLock.lockAndRun { breadcrumbBuffer }

        let fp = fingerprint ?? Fingerprint.compute(
            type: String(describing: type(of: error)),
            message: error.localizedDescription,
            stacktrace: Thread.callStackSymbols.joined(separator: "\n")
        )

        let issueEvent = IssueEvent(
            level: "error",
            platform: "ios",
            fingerprint: fp,
            appKey: XuqmSDK.shared.requireConfig().appKey,
            exception: IssueEvent.ExceptionInfo(
                type: String(describing: type(of: error)),
                value: error.localizedDescription,
                stacktrace: Thread.callStackSymbols.joined(separator: "\n")
            ),
            breadcrumbs: crumbs,
            release: appVersion(),
            environment: environment,
            userId: XuqmSDK.shared.userId ?? XuqmSDK.shared.deviceId,
            user: IssueEvent.UserInfo(id: XuqmSDK.shared.userId ?? XuqmSDK.shared.deviceId),
            device: buildDeviceInfo(),
            tags: tags
        )

        if !isReady() {
            pendingErrorsLock.lock()
            pendingErrors.append(issueEvent)
            pendingErrorsLock.unlock()
            return
        }

        flushPendingErrors()
        queue?.push(issueEvent)
    }

    /// 捕获致命错误
    public func captureCrash(_ error: Error, tags: [String: Any?] = [:]) {
        guard isReady() else { return }

        let crumbs = breadcrumbLock.lockAndRun { breadcrumbBuffer }

        let issueEvent = IssueEvent(
            level: "fatal",
            platform: "ios",
            fingerprint: Fingerprint.compute(
                type: String(describing: type(of: error)),
                message: error.localizedDescription,
                stacktrace: Thread.callStackSymbols.joined(separator: "\n")
            ),
            appKey: XuqmSDK.shared.requireConfig().appKey,
            exception: IssueEvent.ExceptionInfo(
                type: String(describing: type(of: error)),
                value: error.localizedDescription,
                stacktrace: Thread.callStackSymbols.joined(separator: "\n")
            ),
            breadcrumbs: crumbs,
            release: appVersion(),
            environment: environment,
            userId: XuqmSDK.shared.userId ?? XuqmSDK.shared.deviceId,
            user: IssueEvent.UserInfo(id: XuqmSDK.shared.userId ?? XuqmSDK.shared.deviceId),
            device: buildDeviceInfo(),
            tags: tags
        )
        queue?.push(issueEvent)
    }

    /// 记录警告
    public func warn(_ message: String, tags: [String: Any?] = [:]) {
        guard logLevel.rawValue <= LogLevel.warn.rawValue else { return }
        guard isReady() else { return }

        let crumbs = breadcrumbLock.lockAndRun { breadcrumbBuffer }
        let issueEvent = IssueEvent(
            level: "warning",
            platform: "ios",
            fingerprint: Fingerprint.compute(type: "Warning", message: message, stacktrace: ""),
            appKey: XuqmSDK.shared.requireConfig().appKey,
            exception: IssueEvent.ExceptionInfo(type: "Warning", value: message),
            breadcrumbs: crumbs,
            release: appVersion(),
            environment: environment,
            userId: XuqmSDK.shared.userId ?? XuqmSDK.shared.deviceId,
            user: IssueEvent.UserInfo(id: XuqmSDK.shared.userId ?? XuqmSDK.shared.deviceId),
            device: buildDeviceInfo(),
            tags: tags
        )
        queue?.push(issueEvent)
    }

    /// 记录信息
    public func info(_ message: String, tags: [String: Any?] = [:]) {
        guard logLevel.rawValue <= LogLevel.info.rawValue else { return }
        event(name: "__log_info", properties: tags.merging(["message": message]) { _, new in new })
    }

    // MARK: - Lifecycle

    /// 启动崩溃捕获
    public func startCrashCapture() {
        guard crashCapture == nil else { return }
        crashCapture = CrashCapture { [weak self] exception, stacktrace in
            self?.handleCrash(exception: exception, stacktrace: stacktrace)
        }
        crashCapture?.install()
    }

    /// 初始化队列
    public func startQueue() {
        guard queue == nil else { return }
        let config = XuqmSDK.shared.requireConfig()
        queue = LogQueue(appKey: config.appKey, sdkName: sdkName, sdkVersion: sdkVersion)
        queue?.start()
    }

    // MARK: - Private

    private var isReady: Bool {
        XuqmSDK.shared.isInitialized && queue != nil
    }

    private func flushPendingErrors() {
        pendingErrorsLock.lock()
        let errors = pendingErrors
        pendingErrors = []
        pendingErrorsLock.unlock()

        for error in errors {
            queue?.push(error)
        }
    }

    private func handleCrash(exception: NSException, stacktrace: String) {
        let crumbs = breadcrumbLock.lockAndRun { breadcrumbBuffer }

        let issueEvent = IssueEvent(
            level: "fatal",
            platform: "ios",
            fingerprint: Fingerprint.compute(
                type: exception.name.rawValue,
                message: exception.reason ?? "",
                stacktrace: stacktrace
            ),
            appKey: XuqmSDK.shared.requireConfig().appKey,
            exception: IssueEvent.ExceptionInfo(
                type: exception.name.rawValue,
                value: exception.reason ?? "",
                stacktrace: stacktrace
            ),
            breadcrumbs: crumbs,
            release: appVersion(),
            environment: environment,
            userId: XuqmSDK.shared.userId ?? XuqmSDK.shared.deviceId,
            user: IssueEvent.UserInfo(id: XuqmSDK.shared.userId ?? XuqmSDK.shared.deviceId),
            device: buildDeviceInfo(),
            tags: [:]
        )

        // 崩溃时同步写入磁盘
        LogStorage.saveCrash(issueEvent)
    }

    private func appVersion() -> String {
        Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String ?? "unknown"
    }

    private func buildDeviceInfo() -> IssueEvent.DeviceInfo {
        let device = UIDevice.current
        let processInfo = ProcessInfo.processInfo

        // 使用 os_proc_available_memory() 获取可用内存（如果可用）
        let freeMemoryMb: Int
        if #available(iOS 13.0, *) {
            let availableMemory = os_proc_available_memory()
            freeMemoryMb = Int(availableMemory / 1024 / 1024)
        } else {
            // Fallback: 使用物理内存（不准确但有值）
            freeMemoryMb = Int(processInfo.physicalMemory / 1024 / 1024)
        }

        return IssueEvent.DeviceInfo(
            model: device.model,
            manufacturer: "Apple",
            osName: device.systemName,
            osVersion: device.systemVersion,
            locale: Locale.current.identifier,
            timezone: TimeZone.current.identifier,
            isEmulator: isSimulator(),
            freeMemoryMb: freeMemoryMb,
            buildType: isDebug() ? "debug" : "release"
        )
    }

    private func isSimulator() -> Bool {
        #if targetEnvironment(simulator)
        return true
        #else
        return false
        #endif
    }

    private func isDebug() -> Bool {
        #if DEBUG
        return true
        #else
        return false
        #endif
    }
}

// MARK: - NSLock Extension

private extension NSLock {
    func lockAndRun<T>(_ block: () -> T) -> T {
        lock()
        defer { unlock() }
        return block()
    }
}