#!/bin/bash

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

# Ensure correct number of arguments
if [ "$#" -ne 2 ]; then
    echo "Usage: $0 <mkv-file> <track-number>"
    exit 1
fi

mkv_file="$1"
default_track="$2"

# Ensure the file exists
if [[ ! -f "$mkv_file" ]]; then
    echo "Error: File '$mkv_file' not found."
    exit 1
fi

# Get subtitle track IDs
subtitle_tracks=$(mkvmerge -i "$mkv_file" | grep 'subtitles' | awk -F ': ' '{print $1}' | awk '{print $3}')

if [[ -z "$subtitle_tracks" ]]; then
    echo "No subtitle tracks found in '$mkv_file'."
    exit 1
fi

# Remove default and forced flags from all subtitle tracks
for track_id in $subtitle_tracks; do
    echo "Running: mkvpropedit \"$mkv_file\" --edit track:$track_id --set flag-default=0 --set flag-forced=0"
    mkvpropedit "$mkv_file" --edit track:$track_id --set flag-default=0 --set flag-forced=0
done

# Set the specified track as default
echo "Running: mkvpropedit \"$mkv_file\" --edit track:$default_track --set flag-default=1"
mkvpropedit "$mkv_file" --edit track:$default_track --set flag-default=1

echo "Subtitle track $default_track set as default in '$mkv_file'."