#!/bin/bash

# Ensure mkvmerge is installed
if ! command -v mkvmerge &> /dev/null; then
    echo "Error: mkvmerge is not installed. Please install mkvtoolnix."
    exit 1
fi

# Default directories
VIDEO_DIR=""
SUBTITLE_DIR=""
MUXED_DIR=""

# Parse arguments
while [[ "$#" -gt 0 ]]; do
    case "$1" in
        --vidsrc)
            VIDEO_DIR="$2"
            shift 2
            ;;
        --subsrc)
            SUBTITLE_DIR="$2"
            shift 2
            ;;
        -o)
            MUXED_DIR="$2"
            shift 2
            ;;
        *)
            echo "Unknown option: $1"
            exit 1
            ;;
    esac
done

# Ensure required arguments are provided
if [[ -z "$VIDEO_DIR" || -z "$SUBTITLE_DIR" || -z "$MUXED_DIR" ]]; then
    echo "Usage: $0 --vidsrc <video_directory> --subsrc <subtitle_directory> -o <output_directory>"
    exit 1
fi

# Create output directory
mkdir -p "$MUXED_DIR"

# Process each video file
for video_file in "$VIDEO_DIR"/*.mkv; do
    [[ -e "$video_file" ]] || continue
    
    # Extract SxxExx pattern
    episode_id=$(basename "$video_file" | grep -oE 'S[0-9]{2}E[0-9]{2}')
    
    if [[ -z "$episode_id" ]]; then
        echo "Skipping $video_file (no episode pattern found)"
        continue
    fi
    
    # Find matching subtitle file
    subtitle_file=$(find "$SUBTITLE_DIR" -type f -name "*${episode_id}*.mkv" | head -n 1)
    
    if [[ -z "$subtitle_file" ]]; then
        echo "Warning: No subtitle file found for $video_file"
        continue
    fi
    
    # Define output file
    output_file="$MUXED_DIR/${episode_id}.mkv"
    
    echo "Muxing: $video_file + $subtitle_file -> $output_file"
    
    # Mux using mkvmerge (video+audio from video file, subtitles+attachments from subtitle file)
    mkvmerge -o "$output_file" \
        --no-subtitles "$video_file" \
        --no-video --no-audio "$subtitle_file"

done

echo "Muxing complete."