#!/bin/bash

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

# Process each .mkv file in the current directory
for mkv in *.mkv; do
    # Skip if no .mkv files exist
    [[ -e "$mkv" ]] || continue

    base_name="${mkv%.mkv}"

    # Unset all subtitle tracks in the MKV file before adding new ones
    echo "Executing command: mkvmerge -o temp.mkv --no-subtitles \"$mkv\""
    if mkvmerge -o temp.mkv --no-subtitles "$mkv"; then
        echo "Subtitle tracks unset successfully."

        # Mux the new subtitle files with the language "eng"
        echo "Executing command: mkvmerge -o out.mkv \"temp.mkv\" --language 0:eng \"${base_name}\"*.srt"
        if mkvmerge -o out.mkv "temp.mkv" --language 0:eng "${base_name}"*.srt; then
            echo "Muxing successful, replacing original file and deleting subtitles."
            mv out.mkv "$mkv"
            rm -f "${base_name}"*.srt
        else
            echo "Muxing failed, keeping original files."
        fi

        # Clean up temporary file
        rm -f temp.mkv
    else
        echo "Failed to unset subtitles, keeping original files."
    fi
done