#!/bin/bash
# Usage: ./convert.sh -c <chapter_number> -n <name> -i <index> [-d]
# Example: ./convert.sh -c 3 -n building_systems -i 3 -d
#
# This will create a base filename: c03-building_systems-03
# Input file:  orig/c03-building_systems-03.mov
# Output file: video/c03-building_systems-03.mp4
# If -d is provided, it will prompt to delete the original file after conversion.

usage() {
    echo "Usage: $0 -c <chapter_number> -n <name> -i <index> [-d]"
    exit 1
}

# Initialize variables
chapter=""
name=""
index=""
delete_flag=false

# Parse command-line options
while getopts "c:n:i:d" opt; do
  case "$opt" in
    c) chapter="$OPTARG" ;;
    n) name="$OPTARG" ;;
    i) index="$OPTARG" ;;
    d) delete_flag=true ;;
    *) usage ;;
  esac
done

# Make sure all required options are provided
if [ -z "$chapter" ] || [ -z "$name" ] || [ -z "$index" ]; then
    usage
fi

# Format chapter and index as two-digit numbers
formatted_chapter=$(printf "%02d" "$chapter")
formatted_index=$(printf "%02d" "$index")

# Construct the base filename: cXX-name_XX
BASENAME="c${formatted_chapter}-${name}-${formatted_index}"

# Construct the input and output filenames
INPUT="orig/${BASENAME}.mov"
OUTPUT="video/${BASENAME}.mp4"


echo "Converting..."
echo "Input file: $INPUT"
echo "Output file: $OUTPUT"

# Run ffmpeg with your chosen parameters
ffmpeg -i "$INPUT" -vf "scale=-2:720" -preset slow -crf 30 -b:v 500k -c:v libx264 -c:a aac -b:a 96k "$OUTPUT"

# Check if -d flag was used and prompt for deletion
if [ "$delete_flag" = true ]; then
    while true; do
        read -p "Do you want to delete the original file $INPUT? Y/n " confirm
        if [[ -z "$confirm" || "$confirm" =~ ^[Yy]$ ]]; then
            rm "$INPUT"
            echo "Original file deleted."
            break
        elif [[ "$confirm" =~ ^[Nn]$ ]]; then
            echo "Original file kept."
            break
        else
            echo "Invalid input. Please enter Y/n."
        fi
    done
fi