#!/usr/bin/env bash
# License: GPLv3
# Credits: Felipe Facundes

SCRIPT="${0##*/}"
TMPDIR="${TMPDIR:-/tmp}"
FONTPREVIEWTEMPDIR="${TMPDIR}/${SCRIPT%.*}"
TEMP_FILE="$FONTPREVIEWTEMPDIR/temp_prev.jpg"

[[ -d "${FONTPREVIEWTEMPDIR}" ]] && rm -rf "${FONTPREVIEWTEMPDIR}"
[[ ! -d "${FONTPREVIEWTEMPDIR}" ]] && mkdir -p "${FONTPREVIEWTEMPDIR}"


VERSION=1.0
FONT_SIZE="${FONT_SIZE:-24}"
SIZE="${SIZE:-1000x700}"

BG_COLOR=${BG_COLOR:-"#ffffff"}
FG_COLOR=${FG_COLOR:-"#000000"}
PREVIEW_TEXT="${PREVIEW_TEXT:-$(
	cat <<-EOF
	{}

	ABCDEFGHIJKLMNOPQRSTUVWXYZ

	abcdefghijklmnopqrstuvwxyz

	1234567890

	'$\!/\%|&*@+=#?()[]'

	A white sheep peacefully 
	grazes on the green pasture.
	EOF
)}"

# Check if fzf and ImageMagick are installed
if ! command -v fzf magick &> /dev/null; then
    echo "Error: This script requires 'fzf' and 'ImageMagick' to be installed."
    exit 1
fi

imv -s none -i imv-preview 1>&2 2>/dev/null &
IMV_PID=$!

cleanup() { [[ -d "${FONTPREVIEWTEMPDIR}" ]] && rm -rf "${FONTPREVIEWTEMPDIR}" && kill -9 "$IMV_PID"; }
trap cleanup INT EXIT

MODE="$TEMP_FILE && (imv-msg $IMV_PID close all && imv-msg $IMV_PID open $TEMP_FILE)"

read -ra cmd <<< "$MODE"

clipboard_copy() {
    echo "$1" | wl-copy
    echo "Font copied to clipboard!"
}

show_requirements() {
printf "%s" "\
usage: $SCRIPT [--requirements]

Essential dependencies and their purposes:

Core requirements:
   fzf                    Fuzzy finder for interactive font selection
   ImageMagick            Font preview generation and display (magick command)

Optional dependencies:
   wl-copy                (Wayland) Copy fonts to clipboard
   xclip                  (X11) Copy fonts to clipboard  
   termux-clipboard-set   (Termux) Copy fonts to clipboard
   feh                    Fallback image viewer for terminals without Sixel support
   xdg-open               Fallback image viewer for Desktops without feh
"
}

show_help() {
printf "%s" "\
usage: $SCRIPT [-h] [--size \"px\"] [--font-size \"FONT_SIZE\"] [--bg-color \"BG_COLOR\"] 
                      [--fg-color \"FG_COLOR\"] [--preview-text \"PREVIEW_TEXT\"] [-i font.otf] 
                      [-o fontpreview.png] [--dark] [--version]
 
┌─┐┌─┐┌┐┌┌┬┐┌─┐┬─┐┌─┐┬  ┬┬┌─┐┬ ┬
├┤ │ ││││ │ ├─┘├┬┘├┤ └┐┌┘│├┤ │││
└  └─┘┘└┘ ┴ ┴  ┴└─└─┘ └┘ ┴└─┘└┴┘
Very customizable and minimal font previewer written in bash
 
optional arguments:
   -h,  --help            show this help message and exit
   -r,  --requirements    show dependencies and their purposes
   -i,  --input           filename of the input font (.otf, .ttf, .woff are supported)
   -o,  --output          filename of the output preview image (input.png if not set)
   -s,  --size            size of the font preview window (default: $SIZE)
   -fs, --font-size       font size (default: $FONT_SIZE)
   -bg, --bg-color        background color of the font preview window (default: $BG_COLOR)
   -fg, --fg-color        foreground color of the font preview window (default: $FG_COLOR)
   -t,  --text            preview text that should be displayed in the font preview window
   -v,  --version         show the version of fontpreview you are using
   -d,  --dark            switch to dark mode

Environment Variables:
   FONT_SIZE              Set default font size (currently: $FONT_SIZE)
   SIZE                   Set default preview size (currently: $SIZE)
   BG_COLOR               Set default background color (currently: $BG_COLOR)
   FG_COLOR               Set default foreground color (currently: $FG_COLOR)
   PREVIEW_TEXT           Set default preview text
"
echo
show_requirements
}

while [[ $# -gt 0 ]]; do
    case "$1" in
        -s|--size)
            shift
            SIZE="$1"
            ;;
        -mr|--margin-right)
            shift
            FZF_MARGIN_R="$1"
            ;;
        -mh|--margin-height)
            shift
            FZF_MARGIN_H="$1"
            ;;
        -h|--help)
            show_help
            exit
            ;;
        -r|--requirements)
            show_requirements
            exit
            ;;
        -v|--version)
            echo "$VERSION"
            exit
            ;;
        -i|--input)
            shift
            input_font="$1"
            ;;
        -in|--install)
            shift
            install_font
            ;;
        -o|--output)
            shift
            output_file="$1"
            ;;
        -fs|--font-size)
            shift
            FONT_SIZE="$1"
            ;;
        -bg|--bg-color)
            shift
            BG_COLOR="$1"
            ;;
        -fg|--fg-color)
            shift
            FG_COLOR="$1"
            ;;
        -t|--text)
            shift
            PREVIEW_TEXT="$1"
            ;;
        -d|--dark)
            shift
            DARK=1
            ;;
        --)
            shift
            break
            ;;
        *)
            shift
            break
            ;;
    esac
    shift
done

if [[ -n "$DARK" ]]; then
    _tmpcolor="$BG_COLOR"
    BG_COLOR="$FG_COLOR"
    FG_COLOR="$_TMPCOL"
    unset _tmpcolor
fi

# If an input file was specified, use only that
if [[ -f "$input_font" ]]; then
    font_list="$input_font"
else
    # Generate font list only if no input file was specified
    font_list=$(magick -list font | grep "Font:" | awk '{print $2}' | sort -u)
fi

if [[ -n "$output_file" ]]; then
	[[ ! -f "$font_list" ]] && echo "Use -i to specify the font file and -o to extract the image" && exit 1
	magick -size "$SIZE" -background "$BG_COLOR" -fill "$FG_COLOR" -font "$font_list" \
		-pointsize "$FONT_SIZE" label:"$PREVIEW_TEXT" -geometry "$SIZE" "$output_file"
	exit 0
elif [[ -z "$output_file" ]]; then
	# Use fzf for interactive selection with Sixel preview
	selected_font=$(echo "$font_list" | fzf \
		--prompt="Select a font: " \
		--preview="magick -size \"$SIZE\" -background \"$BG_COLOR\" -fill \"$FG_COLOR\" -font '{}' \
		-pointsize \"$FONT_SIZE\" label:\"$PREVIEW_TEXT\" -geometry \"$SIZE\" ${cmd[*]}")
	# If a font was selected, show confirmation
	if [[ -n "$selected_font" ]]; then
		echo "Selected font: $selected_font"
		clipboard_copy "$selected_font"
	else
		echo "No font selected."
	fi
fi