OwnCord/Server/ws/livekit_process.go

// Package ws provides the LiveKit companion process manager.
//
// LiveKitProcess manages the lifecycle of a livekit-server binary running
// alongside chatserver. It auto-generates a minimal livekit.yaml config,
// starts the process, monitors health, and restarts on crash.
package ws

import (
	"context"
	"fmt"
	"log/slog"
	"os"
	"os/exec"
	"path/filepath"
	"sync"
	"time"

	"github.com/owncord/server/config"
)

// LiveKitProcess manages the companion livekit-server binary.
type LiveKitProcess struct {
	cfg     *config.VoiceConfig
	dataDir string

	mu      sync.Mutex
	cmd     *exec.Cmd
	cancel  context.CancelFunc
	stopped bool
}

// NewLiveKitProcess creates a new process manager. It does not start the
// process — call Start() to launch the LiveKit server.
func NewLiveKitProcess(cfg *config.VoiceConfig, dataDir string) *LiveKitProcess {
	return &LiveKitProcess{
		cfg:     cfg,
		dataDir: dataDir,
	}
}

// generateConfig writes a minimal livekit.yaml for the companion process.
func (p *LiveKitProcess) generateConfig() (string, error) {
	cfgPath := filepath.Join(p.dataDir, "livekit.yaml")

	content := fmt.Sprintf(`# Auto-generated by OwnCord — do not edit manually.
port: 7880
rtc:
  port_range_start: 50000
  port_range_end: 60000
  use_external_ip: true
keys:
  %s: %s
logging:
  level: info
`, p.cfg.LiveKitAPIKey, p.cfg.LiveKitAPISecret)

	if err := os.MkdirAll(p.dataDir, 0o755); err != nil {
		return "", fmt.Errorf("creating data dir: %w", err)
	}
	if err := os.WriteFile(cfgPath, []byte(content), 0o644); err != nil {
		return "", fmt.Errorf("writing livekit config: %w", err)
	}

	return cfgPath, nil
}

// Start launches the livekit-server binary. If LiveKitBinaryPath is empty,
// this is a no-op (assumes LiveKit is managed externally).
func (p *LiveKitProcess) Start() error {
	if p.cfg.LiveKitBinaryPath == "" {
		slog.Info("livekit: no binary path configured, assuming externally managed")
		return nil
	}

	p.mu.Lock()
	defer p.mu.Unlock()

	if p.cmd != nil {
		return fmt.Errorf("livekit process already running")
	}

	cfgPath, err := p.generateConfig()
	if err != nil {
		return fmt.Errorf("generating livekit config: %w", err)
	}

	ctx, cancel := context.WithCancel(context.Background())
	p.cancel = cancel

	go p.runLoop(ctx, cfgPath)

	return nil
}

// runLoop starts and restarts the process until stopped or context cancelled.
func (p *LiveKitProcess) runLoop(ctx context.Context, cfgPath string) {
	const restartDelay = 3 * time.Second

	for {
		if ctx.Err() != nil {
			return
		}

		cmd := exec.CommandContext(ctx, p.cfg.LiveKitBinaryPath, "--config", cfgPath)
		cmd.Stdout = os.Stdout
		cmd.Stderr = os.Stderr

		p.mu.Lock()
		if p.stopped {
			p.mu.Unlock()
			return
		}
		p.cmd = cmd
		p.mu.Unlock()

		slog.Info("livekit: starting process",
			"binary", p.cfg.LiveKitBinaryPath,
			"config", cfgPath)

		err := cmd.Run()

		p.mu.Lock()
		p.cmd = nil
		stopped := p.stopped
		p.mu.Unlock()

		if stopped || ctx.Err() != nil {
			slog.Info("livekit: process stopped")
			return
		}

		if err != nil {
			slog.Error("livekit: process exited unexpectedly",
				"error", err,
				"restart_delay", restartDelay)
		}

		select {
		case <-time.After(restartDelay):
			slog.Info("livekit: restarting process")
		case <-ctx.Done():
			return
		}
	}
}

// IsRunning returns true if the companion process is currently running.
func (p *LiveKitProcess) IsRunning() bool {
	p.mu.Lock()
	defer p.mu.Unlock()
	return p.cmd != nil && p.cmd.Process != nil
}

// Stop gracefully stops the companion process.
func (p *LiveKitProcess) Stop() {
	p.mu.Lock()
	p.stopped = true
	cancel := p.cancel
	cmd := p.cmd
	p.mu.Unlock()

	if cancel != nil {
		cancel()
	}

	// Wait briefly for the process to exit after context cancellation
	if cmd != nil && cmd.Process != nil {
		done := make(chan struct{})
		go func() {
			_ = cmd.Wait()
			close(done)
		}()

		select {
		case <-done:
			slog.Info("livekit: process exited cleanly")
		case <-time.After(5 * time.Second):
			slog.Warn("livekit: process did not exit in time, killing")
			_ = cmd.Process.Kill()
		}
	}
}