package daemon

import (
	"context"
	"errors"
	"log"
	"os"
	"os/exec"
	"path/filepath"
	"sync"
	"syscall"
	"time"

	"lel/internal/aiprocess"
	"lel/internal/audio"
	"lel/internal/clip"
	"lel/internal/config"
	"lel/internal/inject"
	"lel/internal/whisper"
	"lel/internal/x11"
)

type State string

const (
	StateIdle         State = "idle"
	StateRecording    State = "recording"
	StateTranscribing State = "transcribing"
	StateProcessing   State = "processing"
)

type Daemon struct {
	cfg config.Config
	x11 *x11.Conn
	log *log.Logger
	inj inject.Backend
	ai  aiprocess.Processor

	mu      sync.Mutex
	state   State
	ffmpeg  *audio.Recorder
	cmd     *exec.Cmd
	record  *audio.RecordResult
	timer   *time.Timer
	stateCh chan State
}

func New(cfg config.Config, x *x11.Conn, logger *log.Logger, inj inject.Backend, ai aiprocess.Processor) *Daemon {
	r := &audio.Recorder{Input: cfg.FfmpegInput}
	return &Daemon{cfg: cfg, x11: x, log: logger, inj: inj, ai: ai, state: StateIdle, ffmpeg: r, stateCh: make(chan State, 4)}
}

func (d *Daemon) UpdateConfig(cfg config.Config) {
	d.mu.Lock()
	d.cfg = cfg
	if d.ffmpeg != nil {
		d.ffmpeg.Input = cfg.FfmpegInput
	}
	d.mu.Unlock()
}

func (d *Daemon) UpdateBackend(inj inject.Backend) {
	d.mu.Lock()
	d.inj = inj
	d.mu.Unlock()
}

func (d *Daemon) UpdateAI(proc aiprocess.Processor) {
	d.mu.Lock()
	d.ai = proc
	d.mu.Unlock()
}

func (d *Daemon) setState(state State) {
	d.mu.Lock()
	d.state = state
	d.notify(state)
	d.mu.Unlock()
}

func (d *Daemon) setStateLocked(state State) {
	d.state = state
	d.notify(state)
}

func (d *Daemon) State() State {
	d.mu.Lock()
	defer d.mu.Unlock()
	return d.state
}

func (d *Daemon) StateChanges() <-chan State {
	return d.stateCh
}

func (d *Daemon) Toggle() {
	d.mu.Lock()
	switch d.state {
	case StateIdle:
		if err := d.startRecordingLocked(); err != nil {
			d.log.Printf("record start failed: %v", err)
		}
	case StateRecording:
		d.setStateLocked(StateTranscribing)
		d.mu.Unlock()
		go d.stopAndProcess("user")
		return
	default:
		d.log.Printf("busy (%s), trigger ignored", d.state)
	}
	d.mu.Unlock()
}

func (d *Daemon) StopRecording(reason string) {
	d.mu.Lock()
	if d.state != StateRecording {
		d.mu.Unlock()
		return
	}
	d.setStateLocked(StateTranscribing)
	d.mu.Unlock()
	go d.stopAndProcess(reason)
}

func (d *Daemon) WaitForIdle(ctx context.Context) bool {
	ticker := time.NewTicker(100 * time.Millisecond)
	defer ticker.Stop()
	for {
		if d.State() == StateIdle {
			return true
		}
		select {
		case <-ctx.Done():
			return false
		case <-ticker.C:
		}
	}
}

func (d *Daemon) startRecordingLocked() error {
	if d.state != StateIdle {
		return errors.New("not idle")
	}

	cmd, result, err := d.ffmpeg.Start(context.Background())
	if err != nil {
		return err
	}

	d.cmd = cmd
	d.record = result
	d.state = StateRecording
	d.notify(StateRecording)

	if d.timer != nil {
		d.timer.Stop()
	}
	d.timer = time.AfterFunc(time.Duration(d.cfg.RecordTimeoutSec)*time.Second, func() {
		d.mu.Lock()
		if d.state != StateRecording {
			d.mu.Unlock()
			return
		}
		d.setStateLocked(StateTranscribing)
		d.mu.Unlock()
		go d.stopAndProcess("timeout")
	})

	d.log.Printf("recording started (%s)", d.record.WavPath)
	return nil
}

func (d *Daemon) stopAndProcess(reason string) {
	d.mu.Lock()
	cmd := d.cmd
	rec := d.record
	d.cmd = nil
	d.record = nil
	if d.timer != nil {
		d.timer.Stop()
		d.timer = nil
	}
	d.mu.Unlock()

	if cmd == nil || rec == nil {
		d.setIdle("missing recording state")
		return
	}

	status := "done"
	defer func() {
		d.cleanup(rec.TempDir)
		d.setIdle(status)
	}()

	d.log.Printf("stopping recording (%s)", reason)
	if cmd.Process != nil {
		_ = syscall.Kill(-cmd.Process.Pid, syscall.SIGINT)
	}
	_ = audio.WaitWithTimeout(cmd, 5*time.Second)

	info, err := os.Stat(rec.WavPath)
	if err != nil || info.Size() == 0 {
		status = "no audio captured"
		return
	}

	outDir := filepath.Join(rec.TempDir, "out")
	text, err := whisper.Transcribe(context.Background(), rec.WavPath, outDir, whisper.Config{
		Model:     d.cfg.WhisperModel,
		Language:  d.cfg.WhisperLang,
		Device:    d.cfg.WhisperDevice,
		ExtraArgs: d.cfg.WhisperExtraArgs,
		Timeout:   time.Duration(d.cfg.WhisperTimeoutSec) * time.Second,
	})
	if err != nil {
		status = "whisper failed: " + err.Error()
		return
	}
	d.log.Printf("transcript: %s", text)

	if d.cfg.AIEnabled && d.ai != nil {
		d.log.Printf("ai enabled")
		d.setState(StateProcessing)
		aiCtx, cancel := context.WithTimeout(context.Background(), time.Duration(d.cfg.AITimeoutSec)*time.Second)
		cleaned, err := d.ai.Process(aiCtx, text)
		cancel()
		if err != nil {
			d.log.Printf("ai process failed: %v", err)
		} else if cleaned != "" {
			text = cleaned
		}
	}

	d.log.Printf("output: %s", text)
	clipCtx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
	defer cancel()
	if err := clip.WriteClipboard(clipCtx, text); err != nil {
		status = "clipboard failed: " + err.Error()
		return
	}

	injCtx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
	defer cancel()
	if d.inj != nil {
		if err := d.inj.Inject(injCtx, text); err != nil {
			d.log.Printf("inject failed: %v", err)
		}
	}
}

func (d *Daemon) setIdle(msg string) {
	d.setState(StateIdle)
	d.log.Printf("idle (%s)", msg)
}

func (d *Daemon) cleanup(dir string) {
	if dir == "" {
		return
	}
	_ = os.RemoveAll(dir)
}

func (d *Daemon) notify(state State) {
	select {
	case d.stateCh <- state:
	default:
	}
}