import Foundation

/// 崩溃捕获器
final class CrashCapture {

    typealias CrashHandler = (NSException, String) -> Void

    private let handler: CrashHandler
    private var previousHandler: (@convention(c) (NSException) -> Void)?

    init(handler: @escaping CrashHandler) {
        self.handler = handler
    }

    /// 安装崩溃捕获
    func install() {
        // 捕获 Objective-C 异常
        previousHandler = NSGetUncaughtExceptionHandler()
        NSSetUncaughtExceptionHandler { exception in
            let stacktrace = exception.callStackSymbols.joined(separator: "\n")

            // 保存到磁盘
            CrashCapture.handleCrash(exception: exception, stacktrace: stacktrace)

            // 调用之前的 handler
            CrashCapture.shared?.previousHandler?(exception)
        }

        // 捕获 POSIX 信号
        installSignalHandlers()
    }

    private static var shared: CrashCapture?

    private static func handleCrash(exception: NSException, stacktrace: String) {
        shared?.handler(exception, stacktrace)
    }

    /// 安装信号处理器
    private func installSignalHandlers() {
        let signals = [SIGABRT, SIGSEGV, SIGBUS, SIGFPE, SIGILL, SIGTRAP]

        for sig in signals {
            let prev = signal(sig) { sig in
                let exception = NSException(
                    name: NSExceptionName("Signal \(sig)"),
                    reason: "Received signal \(sig)",
                    userInfo: nil
                )
                let stacktrace = Thread.callStackSymbols.joined(separator: "\n")

                CrashCapture.handleCrash(exception: exception, stacktrace: stacktrace)

                // 恢复默认处理
                signal(sig, SIG_DFL)
                raise(sig)
            }
            _ = prev
        }
    }
}