import os
import subprocess
import sys
from utils import verify_file_not_empty

def run_ffmpeg(args):
    """
    Runs ffmpeg, automatically escaping Flatpak sandbox if necessary.
    """
    in_flatpak = os.path.exists("/.flatpak-info")
    cmd = ["flatpak-spawn", "--host", "ffmpeg"] + args if in_flatpak else ["ffmpeg"] + args
    
    try:
        subprocess.run(cmd, check=True)
        return True
    except subprocess.CalledProcessError as e:
        print(f"FFmpeg Error: {e}")
        return False
    except FileNotFoundError:
        print("Error: 'ffmpeg' command not found. Please ensure it is installed on your host system.")
        return False

def extract_audio(video_path, output_path=None):
    """
    Extracts audio from a video file using ffmpeg.
    """
    if not os.path.exists(video_path):
        raise FileNotFoundError(f"Video file not found: {video_path}")

    if output_path is None:
        base_name = os.path.splitext(video_path)[0]
        output_path = f"{base_name}.wav"

    if verify_file_not_empty(output_path):
        print(f"Audio file already exists: {output_path}")
        return output_path

    print(f"Extracting audio from {video_path}...")
    
    args = [
        "-i", video_path,
        "-ar", "16000",
        "-ac", "1",
        "-c:a", "pcm_s16le",
        "-y",
        "-v", "error",
        output_path
    ]

    if run_ffmpeg(args):
        if not verify_file_not_empty(output_path):
            raise Exception("FFmpeg succeeded but output is empty.")
        print(f"Audio extracted to: {output_path}")
        return output_path
    else:
        sys.exit(1)

def embed_subtitles(video_path, srt_path, output_path=None):
    """
    Embeds subtitles into the video file (Soft Subs) and sets them as primary.
    """
    if not os.path.exists(video_path) or not os.path.exists(srt_path):
        print("Error: Video or SRT file not found for embedding.")
        return

    if output_path is None:
        base, ext = os.path.splitext(video_path)
        output_path = f"{base}.subbed{ext}"

    print(f"Embedding subtitles into: {output_path}...")
    
    sub_codec = "mov_text" if video_path.lower().endswith(".mp4") else "srt"

    args = [
        "-ignore_editlist", "1",
        "-i", video_path,
        "-i", srt_path,
        "-map", "0:v",
        "-map", "0:a",
        "-map", "1:0",
        "-c", "copy",
        "-c:s", sub_codec,
        "-disposition:s:0", "default",
        "-metadata:s:s:0", "language=eng",
        "-metadata:s:s:0", "title=English (AI Translated)",
        "-max_interleave_delta", "0",
        "-avoid_negative_ts", "make_zero",
        "-y",
        "-v", "error",
        output_path
    ]

    if run_ffmpeg(args):
        if not verify_file_not_empty(output_path):
             raise Exception("FFmpeg succeeded but output video is empty.")
        print(f"Subtitles embedded successfully: {output_path}")
    else:
        print("Error: Embedding failed.")