#!/usr/bin/env bash
set -euo pipefail

extract_spanish_subs() {
  local input_file="$1"
  local output_file="${input_file%.*}.srt"

  # Check if input file exists
  if [[ ! -f "$input_file" ]]; then
    echo "Error: Input file '$input_file' does not exist."
    return 1
  fi

  echo "Analyzing subtitle tracks in $input_file..."

  # Get subtitle track information
  local sub_info
  sub_info=$(ffprobe -v error -select_streams s -show_entries stream=index:stream_tags=language -of csv=p=0 "$input_file")

  # Find Spanish subtitle track index
  local spa_track=""
  while IFS="," read -r index lang; do
    if [[ "$lang" == "spa" || "$lang" == "es" || "$lang" == "spanish" ]]; then
      spa_track="$index"
      break
    fi
  done <<< "$sub_info"

  # Extract subtitle if Spanish track found
  if [[ -n "$spa_track" ]]; then
    echo "Found Spanish subtitle track at index $spa_track. Extracting to $output_file..."
    ffmpeg -v error -i "$input_file" -map "0:${spa_track}" -c:s srt "$output_file"
    echo "✅ Spanish subtitles extracted to $output_file"
    return 0
  else
    echo "❌ No Spanish subtitle track found in $input_file."
    return 1
  fi
}

# Run the function if script is executed directly
if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
  if [[ $# -eq 0 ]]; then
    echo "Usage: $(basename "$0") <media_file>"
    exit 1
  fi

  extract_spanish_subs "$1"
fi