#!/bin/bash

# Check if two arguments are provided
if [ $# -lt 2 ]; then
  echo "Usage: $0 <input_file.webp> <output_prefix>"
  exit 1
fi

# Assign arguments to variables
input_file="$1"
output_prefix="$2"

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

input_dimensions=$(magick identify -format "%wx%h" "$input_file")
echo "Input file is ${input_dimensions}"

# Determine the file extension
extension="${input_file##*.}"

# Skip conversion if the file is already a .jpg
if [[ "$extension" != "jpg" ]]; then

    # Set the output file name based on the input file extension
    if [[ "$extension" == "webp" ]]; then
      output_file="${input_file%.webp}.jpg"
    elif [[ "$extension" == "png" ]]; then
      output_file="${input_file%.png}.jpg"
    else
      echo "Error: Unsupported file type. Only webp, jpg and pgn files are supported."
      exit 1
    fi

    # Check if the output file already exists
    if [ -f "$output_file" ]; then
      echo "Error: Output file '$output_file' already exists."
      exit 1
    fi

    # Perform the conversion
    echo "Converting '$input_file' to '$output_file'..."
    if magick "$input_file" "$output_file"; then
      echo "Conversion successful. '$output_file' created."
    else
      echo "Error: Conversion failed."
      exit 1
    fi
fi


# Define the output widths
widths=(1600 1400 1200 800)

# Loop through the widths and resize the image
for width in "${widths[@]}"; do
  # Create the output file name with the .jpg extension
  output_file="${output_prefix}-${width}x.jpg"

  # Resize the image and convert to JPG
  magick "$input_file" -resize "${width}x" "$output_file"

  # Check if the operation was successful
  if [ $? -eq 0 ]; then
    echo "Created $output_file"
  else
    echo "Error resizing to ${width}px"
  fi
done