from pathlib import Path
from typing import Optional, List, Dict

from moviepy import (
    VideoFileClip, AudioFileClip, CompositeAudioClip,
    CompositeVideoClip
)

from scripts.generate_subtitles import create_animated_subtitle_clip


def edit_video(
    video_path: str,
    audio_path: str,
    music_path: Optional[str],
    output_path: str,
    *,
    music_volume: float = 0.10,
    subtitles: Optional[List[Dict]] = None,   # ← nouveau
):
    """
    Encodage final : ajoute voix, (optionnel) musique et sous-titres
    en UNE seule passe.
    """
    vid_clip   = VideoFileClip(video_path)
    voice_clip = AudioFileClip(audio_path)

    # ── piste audio composite ─────────────────────────────────
    tracks = [voice_clip]
    if music_path and Path(music_path).is_file():
        try:
            music_clip = (
                AudioFileClip(music_path)
                .with_volume_scaled(music_volume)
                .with_duration(vid_clip.duration)
            )
            tracks.insert(0, music_clip)
        except Exception as err:
            print(f"⚠️ Music ignored: {err}")

    final_audio = CompositeAudioClip(tracks).with_duration(vid_clip.duration)

    # ── couche(s) vidéo / sous-titres ─────────────────────────
    layers = [vid_clip]
    if subtitles:
        w, h = vid_clip.size
        for sub in subtitles:
            layers.append(
                create_animated_subtitle_clip(
                    sub["text"], sub["start"], sub["end"], w, h
                )
            )

    final_clip = (
        CompositeVideoClip(layers, size=vid_clip.size)
        .with_duration(vid_clip.duration)
        .with_audio(final_audio)
    )

    # ── export ────────────────────────────────────────────────
    Path(output_path).parent.mkdir(parents=True, exist_ok=True)
    final_clip.write_videofile(
        output_path,
        codec="libx264",
        audio_codec="aac",
        fps=30,
        threads=os.cpu_count(),
        preset="medium",
        ffmpeg_params=["-pix_fmt", "yuv420p"]
    )
    print(f"✅ Video written → {output_path}")

    # ── nettoyage ─────────────────────────────────────────────
    voice_clip.close()
    if "music_clip" in locals():
        music_clip.close()
    final_audio.close()
    final_clip.close()
    vid_clip.close()