#!/usr/bin/env bash

cacheDir=${XDG_CACHE_HOME:-"$HOME/.cache"}
configDir=${XDG_CONFIG_HOME:-"$HOME/.config"}/clauncher
cacheFile="$cacheDir/launcher_opts"
historyFile="$cacheDir/launcher_opts_history"

update_cache() {
    if ! [[ -f "$cacheFile" ]] || [[ "$1" == "force" ]]; then

	if [ -f "$customLocationsFile" ]; then
            while IFS= read -r location; do
                locations+=("$location")
            done < "$customLocationsFile"
	else
	    locations=(
	      "$HOME/Applications"
	      "/System/Applications"
	      "/Applications"
	    )
        fi

	find . "${locations[@]}" -maxdepth 2 -name "*.app" -type d | gxargs -d '\n' basename | sed 's/\.app$//' | ({ [ -f "$configDir/.open_ignore" ] && grep -v -f "$configDir/.open_ignore"; } || cat -) | ([ -f "$configDir/.open_add" ] && cat "$configDir/.open_add"; cat -) | sort -u > "$cacheFile"
    fi
}

run_launcher() {
    local launcher
    if [ "$1" = "fzf" ]; then
        launcher="fzf -e --tiebreak=index"
    else
        shift
        launcher="dmenu"
    fi

    gawk -v histfile="$historyFile" '
        BEGIN {
            while( (getline < histfile) > 0 ) {
                sub("^[0-9]+\t","")
                print
                x[$0]=1
            }
        } !x[$0]++ ' "$cacheFile" \
        | $launcher \
        | gawk -v histfile="$historyFile" '
            BEGIN {
                FS=OFS="\t"
                while ( (getline < histfile) > 0 ) {
                    count=$1
                    sub("^[0-9]+\t","")
                    fname=$0
                    history[fname]=count
                }
                close(histfile)
            }

            {
                history[$0]++
                print
            }

            END {
                if(!NR) exit
                for (f in history)
                    print history[f],f | "sort -t '\t' -k1rn >" histfile
            }
        ' \
        | xargs -I {} open -a "{}"
}

usage() {
    cat << EOF
usage: ${0##*/} [command]
    update      - Update program list
    help        - Display this help message
EOF
}

runScript() {
    if [ "$#" -eq 0 ]; then
        update_cache
        run_launcher fzf
    elif [ "$1" == "dmenu" ]; then
        update_cache
        run_launcher dmenu
    elif [ "$1" == "update" ]; then
        update_cache force
    elif [ "$1" == "help" ]; then
        usage
	exit 0
    else
        echo "Invalid command. Use 'help' to see available commands."
        exit 1
    fi
}

runScript "$@"