//go:build darwin

package service

import (
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
)

func newPlatformManager(configDir string) (platformManager, error) {
	return &macosServiceManager{configDir: configDir}, nil
}

// macosServiceManager manages services via launchd. Direct port of
// MacOSServiceManager in service_manager.py. Unlike the Python version
// (which shells out to a separate macos_service_wrapper.py for DNS
// handling), the generated plist invokes this same ss binary in
// "service run-macos" mode (see wrapper_darwin.go) — no second script file
// is needed.
type macosServiceManager struct {
	configDir string
}

func (d *macosServiceManager) launchdPath(name string) string {
	return filepath.Join("/Library/LaunchDaemons", "com."+name+".plist")
}

func (d *macosServiceManager) createLaunchdPlist(cfg Config) error {
	selfPath, err := os.Executable()
	if err != nil {
		return fmt.Errorf("failed to determine ss executable path: %w", err)
	}

	workingDir := filepath.Dir(cfg.ExecutablePath)

	programArgs := []string{
		selfPath,
		"service", "run-macos",
		cfg.ExecutablePath,
		workingDir,
	}

	if cfg.Args != "" {
		extra, err := shlexSplit(cfg.Args)
		if err != nil {
			return fmt.Errorf("failed to parse service args: %w", err)
		}
		programArgs = append(programArgs, extra...)
	}

	programArgsXML := ""
	for _, arg := range programArgs {
		programArgsXML += fmt.Sprintf("        <string>%s</string>\n", xmlEscape(arg))
	}

	plistContent := fmt.Sprintf(`<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>com.%s</string>
    <key>ProgramArguments</key>
    <array>
%s    </array>
    <key>RunAtLoad</key>
    <true/>
    <key>KeepAlive</key>
    <true/>
    <key>StandardOutPath</key>
    <string>/var/log/%s.log</string>
    <key>StandardErrorPath</key>
    <string>/var/log/%s.error.log</string>
</dict>
</plist>
`, cfg.Name, programArgsXML, cfg.Name, cfg.Name)

	plistPath := d.launchdPath(cfg.Name)
	if err := os.WriteFile(plistPath, []byte(plistContent), 0o644); err != nil {
		return fmt.Errorf("failed to create launchd plist: %w", err)
	}
	return nil
}

var xmlReplacer = strings.NewReplacer(
	"&", "&amp;",
	"<", "&lt;",
	">", "&gt;",
	`"`, "&quot;",
	"'", "&apos;",
)

func xmlEscape(s string) string {
	return xmlReplacer.Replace(s)
}

func (d *macosServiceManager) Install(cfg Config) error {
	if err := d.createLaunchdPlist(cfg); err != nil {
		return err
	}

	plistPath := d.launchdPath(cfg.Name)
	if out, err := exec.Command("launchctl", "load", plistPath).CombinedOutput(); err != nil {
		return fmt.Errorf("failed to install service: %s", out)
	}
	if out, err := exec.Command("launchctl", "start", "com."+cfg.Name).CombinedOutput(); err != nil {
		return fmt.Errorf("failed to install service: %s", out)
	}
	return nil
}

func (d *macosServiceManager) Uninstall(name string) error {
	exec.Command("launchctl", "stop", "com."+name).Run()

	plistPath := d.launchdPath(name)
	if _, err := os.Stat(plistPath); err == nil {
		if out, err := exec.Command("launchctl", "unload", plistPath).CombinedOutput(); err != nil {
			return fmt.Errorf("failed to uninstall service: %s", out)
		}
		os.Remove(plistPath)
	}
	return nil
}

func (d *macosServiceManager) Start(name string) error {
	if out, err := exec.Command("launchctl", "start", "com."+name).CombinedOutput(); err != nil {
		return fmt.Errorf("failed to start service: %s", out)
	}
	return nil
}

func (d *macosServiceManager) Stop(name string) error {
	if out, err := exec.Command("launchctl", "stop", "com."+name).CombinedOutput(); err != nil {
		return fmt.Errorf("failed to stop service: %s", out)
	}
	return nil
}

func (d *macosServiceManager) Restart(name string) error {
	exec.Command("launchctl", "stop", "com."+name).Run()
	if out, err := exec.Command("launchctl", "start", "com."+name).CombinedOutput(); err != nil {
		return fmt.Errorf("failed to restart service: %s", out)
	}
	return nil
}