import ArgumentParser
import Foundation
import RunnerCore
import RunnerHost

/// `gitea-macos-runner service …` — manage the `launchd` LaunchAgent.
///
/// - Important: This installs a **LaunchAgent** in the logged-in user's session,
///   never a LaunchDaemon. Virtualization needs a GUI session, and macOS 15+
///   additionally needs an unlocked `login.keychain` to start a VM — neither of
///   which exists in the system context. The host should be set to log in
///   automatically.
struct ServiceCommand: AsyncParsableCommand {
    static let configuration = CommandConfiguration(
        commandName: "service",
        abstract: "Install, remove, or inspect the launchd LaunchAgent.",
        subcommands: [Install.self, Uninstall.self, Status.self]
    )

    /// `service install` — write the plist and load the job.
    struct Install: AsyncParsableCommand {
        static let configuration = CommandConfiguration(
            commandName: "install",
            abstract: "Write ~/Library/LaunchAgents/\(LaunchdService.label).plist and load it.",
            discussion: """
                Points the agent at the installed, signed .app bundle — not at a bare \
                binary. The com.apple.security.virtualization entitlement only survives \
                on the signed bundle, so a daemon started from .build/ cannot start VMs.
                """
        )

        @OptionGroup var options: GlobalOptions

        /// Path to the installed executable inside the signed `.app`.
        @Option(name: .long, help: "Path to the installed executable (default: ~/Applications/GiteaMacosRunner.app/Contents/MacOS/gitea-macos-runner).")
        var executable: String?

        func run() async throws {
            let executablePath = executable ?? LaunchdService.defaultExecutablePath

            // Only pass --config when it is not the default; a plist that
            // hard-codes the default path is one more thing to keep in sync.
            let configPath = options.configPath == RunnerConfig.defaultPath ? nil : options.configPath

            if (try? options.loadConfig()) == nil {
                CLI.note("warning: \(RunnerConfig.expandTilde(options.configPath)) is missing or invalid; the agent will fail to start until it is fixed")
            }

            // Done before install (which also does it) purely so the operator
            // is told: an agent silently vanishing from launchctl is alarming
            // if you do not know a rename happened.
            for legacy in LaunchdService.removeLegacyAgents() {
                CLI.note("removed legacy agent \(legacy) (renamed to \(LaunchdService.label))")
            }

            try LaunchdService.install(executablePath: executablePath, configPath: configPath)

            print("installed \(LaunchdService.agentPlistURL.path)")
            print("program:  \(RunnerConfig.expandTilde(executablePath)) daemon")
            print("logs:     \(LaunchdService.logDirectoryURL.path)")
            print("")
            print("check it with: gitea-macos-runner service status")
        }
    }

    /// `service uninstall` — unload and remove the plist.
    struct Uninstall: AsyncParsableCommand {
        static let configuration = CommandConfiguration(
            commandName: "uninstall",
            abstract: "Unload the LaunchAgent and remove its plist."
        )

        @OptionGroup var options: GlobalOptions

        func run() async throws {
            let path = LaunchdService.agentPlistURL.path
            let existed = FileManager.default.fileExists(atPath: path)
            let legacy = LaunchdService.removeLegacyAgents()
            try LaunchdService.uninstall()
            for label in legacy {
                print("removed legacy agent \(label)")
            }
            print(existed ? "removed \(path)" : "not installed (\(path))")
        }
    }

    /// `service status` — report whether the agent is installed and running.
    struct Status: AsyncParsableCommand {
        static let configuration = CommandConfiguration(
            commandName: "status",
            abstract: "Report LaunchAgent installation and run state."
        )

        @OptionGroup var options: GlobalOptions

        func run() async throws {
            let status = try LaunchdService.status()

            print("label:     \(LaunchdService.label)")
            print("plist:     \(status.plistPath)")
            print("installed: \(status.installed ? "yes" : "no")")
            print("loaded:    \(status.loaded ? "yes" : "no")")
            if let pid = status.pid {
                print("pid:       \(pid)")
            }
            if let lastExitStatus = status.lastExitStatus {
                print("last exit: \(lastExitStatus)")
            }
            print("logs:      \(LaunchdService.logDirectoryURL.path)")

            if status.installed, !status.loaded {
                print("")
                CLI.note("installed but not loaded — reinstall with `service install`, or check the logs above")
                throw ExitCode(1)
            }
        }
    }
}