#!/usr/bin/env bash
readonly ID_PREVIEW="preview"

#PLAY_GIF="yes"
# By enabling this option the GIF will be animated, by leaving it commented like it
# is now will make the gif previews behave the same way as video previews.

#AUTO_REMOVE="yes"
# By enabling this option the script will remove the preview file after it is drawn
# and by doing so the preview will always be up-to-date with the file.
# This however, requires more CPU and therefore affects the overall performance.

# The messy code below is for moving pages in pdf files in the vifm file preview by
# utilizing the < and > keys which will be bound to `vifmimg inc` or `vifmimg dec`.
PDF_PAGE_CONFIG="$HOME/.config/vifm/vifmimgpdfpage"
PDF_FILE_CONFIG="$HOME/.config/vifm/vifmimgpdffile"
PDF_PAGE=1
PDF_FILE=""
# Initialize the variables and required files
[[ -f "$PDF_PAGE_CONFIG" ]] && PDF_PAGE=$(cat $PDF_PAGE_CONFIG) || touch $PDF_PAGE_CONFIG
[[ -f "$PDF_FILE_CONFIG" ]] && PDF_FILE=$(cat $PDF_FILE_CONFIG) || touch $PDF_FILE_CONFIG


# Create temporary working directory if the directory structure doesn't exist
if [[ ! -d "/tmp$PWD/" ]]; then
    mkdir -p "/tmp$PWD/"
fi

function inc() {
	VAL="$(cat $PDF_PAGE_CONFIG)"
	echo "$(expr $VAL + 1)" > $PDF_PAGE_CONFIG
}

function dec() {
	VAL="$(cat $PDF_PAGE_CONFIG)"
	echo "$(expr $VAL - 1)" > $PDF_PAGE_CONFIG
	if [[ $VAL -le 0 ]]; then
		echo 0 > $PDF_PAGE_CONFIG
	fi
}

function previewclear() {
    declare -p -A cmd=([action]=remove [identifier]="$ID_PREVIEW") \
        > "$FIFO_UEBERZUG"
}

function fileclean() {
    if [[ -f "/tmp$PWD/$6.png" ]]; then
        rm -f "/tmp$PWD/$6.png"
    elif  [[ -d "/tmp$PWD/$6/" ]]; then
        rm -rf "/tmp$PWD/$6/"
    fi
}

function preview() {
    declare -p -A cmd=([action]=add [identifier]="$ID_PREVIEW"
        [x]="$2" [y]="$3" [width]="$4" [height]="$5" \
        [path]="$PWD/$6") \
        > "$FIFO_UEBERZUG"
}

function previewvideo() {
    if [[ ! -f "/tmp$PWD/$6.png" ]]; then
        ffmpegthumbnailer -i "$PWD/$6" -o "/tmp$PWD/$6.png" -s 0 -q 10
    fi
    declare -p -A cmd=([action]=add [identifier]="$ID_PREVIEW"
        [x]="$2" [y]="$3" [width]="$4" [height]="$5" \
        [path]="/tmp$PWD/$6.png") \
        > "$FIFO_UEBERZUG"
}

function previewepub() {
    if [[ ! -f "/tmp$PWD/$6.png" ]]; then
        epub-thumbnailer "$6" "/tmp$PWD/$6.png" 1024
    fi
    declare -p -A cmd=([action]=add [identifier]="$ID_PREVIEW"
        [x]="$2" [y]="$3" [width]="$4" [height]="$5" \
        [path]="/tmp$PWD/$6.png") \
        > "$FIFO_UEBERZUG"
}

function previewgif() {
    if [[ ! -d "/tmp$PWD/$6/" ]]; then
        mkdir -p "/tmp$PWD/$6/"
        convert -coalesce "$PWD/$6" "/tmp$PWD/$6/$6.png"
    fi
    if [[ ! -z "$PLAY_GIF" ]]; then
        for frame in $(ls -1 /tmp$PWD/$6/$6*.png | sort -V); do
            declare -p -A cmd=([action]=add [identifier]="$ID_PREVIEW"
                [x]="$2" [y]="$3" [width]="$4" [height]="$5" \
                [path]="$frame") \
                > "$FIFO_UEBERZUG"
            # Sleep between frames to make the animation smooth.
            sleep .07
        done
    else
            declare -p -A cmd=([action]=add [identifier]="$ID_PREVIEW"
                [x]="$2" [y]="$3" [width]="$4" [height]="$5" \
                [path]="/tmp$PWD/$6/$6-0.png") \
                > "$FIFO_UEBERZUG"
    fi
}

function previewpdf() {
    if [[ ! "$6" == "$PDF_FILE" ]]; then
        PDF_PAGE=1
        echo 1 > $PDF_PAGE_CONFIG
        rm -f "/tmp$PWD/$6.png"
    fi

    if [[ ! "$PDF_PAGE" == "1" ]] && [[ -f "/tmp$PWD/$6.png" ]]; then
        rm -f "/tmp$PWD/$6.png"
    fi

    if [[ ! -f "/tmp$PWD/$6.png" ]]; then
        pdftoppm -png -f $PDF_PAGE -singlefile "$6" "/tmp$PWD/$6"
    fi
    echo "$6" > $PDF_FILE_CONFIG

    declare -p -A cmd=([action]=add [identifier]="$ID_PREVIEW"
        [x]="$2" [y]="$3" [width]="$4" [height]="$5" \
        [path]="/tmp$PWD/$6.png") \
        > "$FIFO_UEBERZUG"
}


function previewmagick() {
    if [[ ! -f "/tmp$PWD/$6.png" ]]; then
        convert -thumbnail $(identify -format "%wx%h" "$6") "$PWD/$6" "/tmp$PWD/$6.png"
    fi
    declare -p -A cmd=([action]=add [identifier]="$ID_PREVIEW"
        [x]="$2" [y]="$3" [width]="$4" [height]="$5" \
        [path]="/tmp$PWD/$6.png") \
        > "$FIFO_UEBERZUG"
}



function main() {
    case "$1" in
        "inc") inc "$@" ;;
        "dec") dec "$@" ;;
        "clear") previewclear "$@" ;;
        "clean") fileclean "$@" ;;
        "draw") preview "$@" ;;
        "videopreview") previewvideo "$@" ;;
        "epubpreview") previewepub "$@" ;;
        "gifpreview") previewgif "$@" ;;
        "pdfpreview") previewpdf "$@" ;;
        "magickpreview") previewmagick "$@" ;;
        "*") echo "Unknown command: '$@'" ;;
    esac
}
main "$@"