import os
import subprocess
from moviepy.video.io.VideoFileClip import VideoFileClip
from moviepy.audio.io.AudioFileClip import AudioFileClip
from moviepy.audio.AudioClip import CompositeAudioClip
from moviepy.config import change_settings

# --- Robust FFmpeg Configuration ---
BASE_DIR = os.path.dirname(os.path.abspath(__file__))
ff_local = os.path.join(BASE_DIR, "ffmpeg.exe")
if os.path.exists(ff_local):
    change_settings({"FFMPEG_BINARY": ff_local})

from moviepy.audio.fx.volumex import volumex

def finalize_video_pro(video_path, output_path, segments_info):
    """
    Surgical Audio Replacement Engine:
    Keeps original interviewer voice, replaces candidate segments with Elite AI.
    """
    video = VideoFileClip(video_path)
    original_audio = video.audio
    
    # 1. Create SRT & AI Audio Clips
    srt_content = ""
    ai_clips = []
    
    # We will "duck" the original audio during AI segments
    # For simplicity in this demo, we'll use a CompositeAudioClip with the original as base
    for idx, (audio_path, start_time, text) in enumerate(segments_info):
        if os.path.exists(audio_path) and text.strip():
            a_clip = AudioFileClip(audio_path).set_start(start_time)
            ai_clips.append(a_clip)
            
            # Format SRT
            def to_srt_time(seconds):
                hrs = int(seconds // 3600); mins = int((seconds % 3600) // 60); secs = int(seconds % 60)
                ms = int((seconds - int(seconds)) * 1000)
                return f"{hrs:02}:{mins:02}:{secs:02},{ms:03}"
            
            srt_content += f"{idx+1}\n{to_srt_time(start_time)} --> {to_srt_time(start_time + a_clip.duration)}\n{text}\n\n"

    with open("temp.srt", "w", encoding="utf-8") as f: f.write(srt_content)

    # 2. Master Audio Mix (Original + AI Overlays)
    # We lower original volume slightly using the direct FX function
    final_audio = CompositeAudioClip([volumex(original_audio, 0.3)] + ai_clips)
    
    temp_video = "temp_render.mp4"
    video.set_audio(final_audio).write_videofile(temp_video, codec="libx264", audio_codec="aac")
    
    # 3. Burn-in Subtitles
    ff_cmd = ff_local if os.path.exists(ff_local) else "ffmpeg"
    # Double-escaping for Windows FFmpeg path requirements
    srt_path = os.path.abspath("temp.srt").replace("\\", "/").replace(":", "\\:")
    
    subprocess.run([
        ff_cmd, "-i", temp_video,
        "-vf", f"subtitles='{srt_path}':force_style='FontSize=26,PrimaryColour=&H00FFFFFF,OutlineColour=&H00000000,BorderStyle=1,Outline=2,Shadow=1,MarginV=35,Alignment=2'",
        "-c:a", "copy",
        output_path, "-y"
    ])

    # Cleanup
    video.close()
    for c in ai_clips: c.close()
    if os.path.exists(temp_video): os.remove(temp_video)
    if os.path.exists("temp.srt"): os.remove("temp.srt")