#!/usr/bin/env bash
# Wrapper to prompt user to select an item from a list.
# Uses rofi on linux, and choose-gui on mac
# https://github.com/davatorium/rofi
# https://github.com/chipsenkbeil/choose

declare -a linux_options
linux_options=()

usage() {
	echo "Usage: command | picker [-p PROMPT]

Accepts [-p PROMPT] to pass to rofi. Ignored on mac.
Reads lines from STDIN and uses rofi/choose-gui to pick one"
	exit "${1:-0}"
}

if [[ "$1" == '-h' ]]; then
	usage
fi

# get user input from STDIN
STDIN="$(cat)" || exit $?

if [[ -z "$STDIN" ]]; then
	echo -e 'picker: No input received from STDIN\n' >&2
	usage 1
fi

## read options
while getopts "p:" OPT; do
	case "$OPT" in
	p)
		linux_options+=("-${OPT}" "$OPTARG")
		;;
	*)
		usage 1
		;;
	esac
done
shift $((OPTIND - 1))

# if this succeeds, it exits the script. Otherwise, uses fzf
os_specific() {
	case "${ON_OS:=$(on_machine)}" in
	linux*)
		havecmd -V 'linux picker uses rofi: https://github.com/davatorium/rofi' rofi || return 0
		declare LINES
		LINES="$(wc -l <<<"$STDIN")"
		# if STDIN is less than 15 lines, limit the list view to that number
		((LINES < 15)) && linux_options+=(-lines "$LINES")
		printf '%s' "$STDIN" | rofi -i -dmenu "${linux_options[@]}" || exit $?
		exit 0
		;;
	mac*)
		havecmd -V 'mac picker uses choose: https://github.com/chipsenkbeil/choose' choose || return 0
		printf '%s' "$STDIN" | choose -c 9400D3 -b 1C1C1C -u || exit $?
		exit 0
		;;
	esac
}

os_specific || true
if havecmd fzf; then
	fzf <<<"$STDIN" || exit $?
else
	echo 'fzf not found, not sure how to prompt' >&2
	exit 1
fi