import os
import pysrt
from pydub import AudioSegment

def get_last_timestamp(srt_file):
    """Gets the end time of the last subtitle in an SRT file."""
    try:
        subs = pysrt.open(srt_file)
        if subs:
            return subs[-1].end.ordinal
    except Exception as e:
        print(f"Error reading SRT file: {srt_file}")
        print(f"Error message: {e}")
    return None

def trim_audio_files(srt_dir, audio_dir, output_dir):
    """Trims audio files based on the last timestamp in corresponding SRT files."""
    os.makedirs(output_dir, exist_ok=True)
    
    srt_files = sorted([f for f in os.listdir(srt_dir) if f.endswith('.srt')])
    
    for srt_filename in srt_files:
        srt_path = os.path.join(srt_dir, srt_filename)
        last_timestamp = get_last_timestamp(srt_path)
        
        if last_timestamp is None:
            print(f"Could not get timestamp for {srt_filename}, skipping.")
            continue

        audio_filename = os.path.splitext(srt_filename)[0] + '.opus'
        audio_path = os.path.join(audio_dir, audio_filename)
        
        if not os.path.exists(audio_path):
            print(f"Audio file not found: {audio_path}, skipping.")
            continue

        try:
            print(f"Processing {audio_filename}...")
            audio = AudioSegment.from_file(audio_path, format="opus")
            trimmed_audio = audio[:last_timestamp]
            
            output_path = os.path.join(output_dir, audio_filename)
            trimmed_audio.export(output_path, format="opus")
            print(f"  -> Trimmed and saved to {output_path}")
        except Exception as e:
            print(f"Error processing {audio_path}: {e}")

if __name__ == "__main__":
    SRT_DIRECTORY = "./srt/lukdinggei"
    AUDIO_DIRECTORY = "./source/lukdinggei"
    OUTPUT_DIRECTORY = "./source/lukdinggei_trimmed"
    
    trim_audio_files(SRT_DIRECTORY, AUDIO_DIRECTORY, OUTPUT_DIRECTORY)
    
    print(f"\nTrimming complete. Trimmed files are saved in '{OUTPUT_DIRECTORY}'.")