import Foundation

// Lightweight helper to manage the user LaunchAgent that runs kubectl port-forwards.
// This replaces the in-app PortForwardManager supervision.
final class LaunchAgentManager {
    // Filenames/paths
    private let label = "org.prole.prole-db.kpf-dev"
    private var plistURL: URL {
        let home = FileManager.default.homeDirectoryForCurrentUser
        return home.appendingPathComponent("Library/LaunchAgents/\(label).plist")
    }
    private var helperScriptURL: URL {
        let home = FileManager.default.homeDirectoryForCurrentUser
        return home.appendingPathComponent("Library/Application Support/Prole/bin/prole-kpf.sh")
    }

    // Key that stores the list of commands inside the plist (array of strings)
    private let commandsKey = "ProleCommands"

    // Read commands from the LaunchAgent plist. Returns empty if missing.
    func readCommands() -> [String] {
        guard let data = try? Data(contentsOf: plistURL) else { return [] }
        var format = PropertyListSerialization.PropertyListFormat.xml
        guard let obj = try? PropertyListSerialization.propertyList(from: data, options: [], format: &format),
              let dict = obj as? [String: Any],
              let cmds = dict[commandsKey] as? [String] else {
            return []
        }
        return cmds
    }

    // Write commands back to the plist, preserving other keys if present.
    func writeCommands(_ commands: [String]) {
        var dict: [String: Any] = [:]
        if let data = try? Data(contentsOf: plistURL),
           let obj = try? PropertyListSerialization.propertyList(from: data, options: [], format: nil),
           let existing = obj as? [String: Any] {
            dict = existing
        }
        dict[commandsKey] = commands
        if let out = try? PropertyListSerialization.data(fromPropertyList: dict, format: .xml, options: 0) {
            // Ensure parent directory exists
            try? FileManager.default.createDirectory(at: plistURL.deletingLastPathComponent(), withIntermediateDirectories: true)
            try? out.write(to: plistURL)
        }
    }

    // Reload the LaunchAgent: try kickstart; if not present, bootstrap then kickstart.
    func resetAgent() {
        let uid = getuid()
        let domainTarget = "gui/\(uid)/\(label)"

        // Try kickstart first (reload)
        let ks = run("/bin/launchctl", ["kickstart", "-k", domainTarget])
        if ks.exitCode == 0 { return }

        // If kickstart failed, try bootout then bootstrap, then kickstart again
        _ = run("/bin/launchctl", ["bootout", "gui/\(uid)", domainTarget])
        // bootstrap requires path to plist
        _ = run("/bin/launchctl", ["bootstrap", "gui/\(uid)", plistURL.path])
        _ = run("/bin/launchctl", ["kickstart", "-k", domainTarget])
    }

    // Ensure the helper shell script exists by copying the external bundled script; no inline content.
    func ensureHelperScript() {
        let fm = FileManager.default
        let dir = helperScriptURL.deletingLastPathComponent()
        try? fm.createDirectory(at: dir, withIntermediateDirectories: true)
        // Locate external script in app bundle Resources
        let bundle = Bundle.main
        let scriptInBundleURL = bundle.url(forResource: "init-port-fowards", withExtension: "sh")
        guard let srcURL = scriptInBundleURL else { return }
        var needsCopy = true
        if fm.fileExists(atPath: helperScriptURL.path) {
            if let srcAttr = try? fm.attributesOfItem(atPath: srcURL.path),
               let dstAttr = try? fm.attributesOfItem(atPath: helperScriptURL.path),
               let srcMod = srcAttr[.modificationDate] as? Date,
               let dstMod = dstAttr[.modificationDate] as? Date,
               dstMod >= srcMod {
                needsCopy = false
            }
        }
        if needsCopy {
            _ = try? fm.removeItem(at: helperScriptURL)
            do {
                try fm.copyItem(at: srcURL, to: helperScriptURL)
            } catch {
                if let data = try? Data(contentsOf: srcURL) {
                    try? data.write(to: helperScriptURL)
                }
            }
            try? fm.setAttributes([.posixPermissions: NSNumber(value: Int16(0o755))], ofItemAtPath: helperScriptURL.path)
        }
    }

    static let defaultHelperScript = ""

    // MARK: - Helpers
    @discardableResult
    private func run(_ path: String, _ args: [String]) -> (exitCode: Int32, out: String, err: String) {
        let p = Process()
        p.executableURL = URL(fileURLWithPath: path)
        p.arguments = args
        let outPipe = Pipe(); let errPipe = Pipe()
        p.standardOutput = outPipe
        p.standardError = errPipe
        do { try p.run() } catch {
            return (exitCode: -1, out: "", err: String(describing: error))
        }
        p.waitUntilExit()
        let outData = outPipe.fileHandleForReading.readDataToEndOfFile()
        let errData = errPipe.fileHandleForReading.readDataToEndOfFile()
        let outStr = String(data: outData, encoding: .utf8) ?? ""
        let errStr = String(data: errData, encoding: .utf8) ?? ""
        return (p.terminationStatus, outStr, errStr)
    }
}