import Darwin
import Dispatch
import Foundation

@main
private struct MeetingAssistantLauncher {
    private static let serviceDirectoryName = "MeetingAssistant"

    static func main() {
        let runtimeDirectory = Bundle.main.bundleURL
            .appendingPathComponent("Contents/Resources/app", isDirectory: true)
        let assemblyPath = runtimeDirectory.appendingPathComponent("MeetingAssistant.dll").path
        let environmentFile = FileManager.default.homeDirectoryForCurrentUser
            .appendingPathComponent("Library/Application Support")
            .appendingPathComponent(serviceDirectoryName)
            .appendingPathComponent("config/meeting-assistant.env")

        guard FileManager.default.fileExists(atPath: assemblyPath) else {
            fail("Meeting Assistant runtime not found at \(assemblyPath)")
        }

        guard FileManager.default.fileExists(atPath: environmentFile.path) else {
            fail("Meeting Assistant environment file not found at \(environmentFile.path)")
        }

        let process = Process()
        process.executableURL = URL(fileURLWithPath: "/bin/zsh")
        process.arguments = [
            "-c",
            "set -a; source \"$1\"; set +a; exec /usr/local/share/dotnet/dotnet \"$2\" --contentRoot \"$3\"",
            "meeting-assistant-launcher",
            environmentFile.path,
            assemblyPath,
            runtimeDirectory.path
        ]
        process.currentDirectoryURL = runtimeDirectory

        signal(SIGTERM, SIG_IGN)
        signal(SIGINT, SIG_IGN)

        let terminationSignal = DispatchSource.makeSignalSource(signal: SIGTERM, queue: .global())
        terminationSignal.setEventHandler {
            if process.isRunning {
                process.terminate()
            }
        }
        terminationSignal.resume()

        let interruptSignal = DispatchSource.makeSignalSource(signal: SIGINT, queue: .global())
        interruptSignal.setEventHandler {
            if process.isRunning {
                kill(process.processIdentifier, SIGINT)
            }
        }
        interruptSignal.resume()

        do {
            try process.run()
            process.waitUntilExit()
            Darwin.exit(process.terminationStatus)
        } catch {
            fail("Meeting Assistant launcher failed: \(error)")
        }
    }

    private static func fail(_ message: String) -> Never {
        FileHandle.standardError.write(Data("\(message)\n".utf8))
        Darwin.exit(1)
    }
}