#!/usr/bin/env sh

# Create a theme with wal and copy the theme JSON in the appropriate location. 

# Dependencies:
# * GNU coreutils 8.31
# * wal 3.3.0

function extract_path_without_ext() {
    local path=$1

    local filename=$(basename -- "$path")

    # Return the filename without the file extension. 
    # For more information, you can look up the parameter expansion in 
    # https://www.gnu.org/software/bash/manual/html_node/Shell-Parameter-Expansion.html. 
    # Even if the filename has no extension, it will print the whole filename. 
    printf "${filename%.*}"
}

# Constant settings 
LIGHT_MODE_SUFFIX='__light'
XDG_CACHE_HOME=${XDG_CACHE_HOME:-"$HOME/.cache"}
CACHE_DIR=${PYWAL_CACHE_DIR:-"$XDG_CACHE_HOME/wal"}

help_section="Create a theme with wal and copy the theme JSON in the appropriate location. 

Usage: $0 IMAGE_PATH [-o/--output OUTPUT_DIR] [--light-mode]

Options:
* -o, --output OUTPUT_DIR   -   The location where the JSON file will be copied. 
                                The given argument should be a directory that already exists. 
                                The default value is given from the 'OUTPUT' variable. 
* --light-mode              -   Create a light mode theme. 
                                Appends the resulting file name with '$LIGHT_MODE_SUFFIX'. 
* -b, --background BG_COLOR -   Creates the theme with the following background color.
                                This is passed to the 'wal' command. 
"

# Setting the variables for the program. 
# Feel free to change `OUTPUT_DIR`. 
OUTPUT_DIR="~/.local/share/wal"
LIGHT_MODE=0
IMAGE_PATH="$1"

while [[ $# -gt 0 ]]
do
    case $1 in 
        -h|--help)
            printf "$help_section"
            exit 0;;
        -o|--output)
            OUTPUT_DIR="$2"
            shift
            shift;;
        --light-mode)
            LIGHT_MODE=1
            shift;;
        -b|--background)
            BG_COLOR="$2"
            shift
            shift;;
        *)
            shift;;
    esac
done

image_basename=$(extract_path_without_ext "$IMAGE_PATH")
wal_command_string="wal -i $IMAGE_PATH"
output_file=$([ $LIGHT_MODE -eq 1 ] && echo "$OUTPUT_DIR/$image_basename$LIGHT_MODE_SUFFIX.json" || echo "$OUTPUT_DIR/$image_basename.json")

if [[ $LIGHT_MODE -eq 1 ]]; then
    wal_command_string+=" -l"
fi

if [[ -n "$BG_COLOR" ]]; then
    wal_command_string+=" -b $BG_COLOR"
fi

command -p $wal_command_string && cp "$CACHE_DIR/colors.json" "$output_file"