#!/usr/bin/env bash
#shellcheck disable=SC2155

error() {
	echo "error: $*" >&2
}

escape() {
	jq -Rr @html
}

_json_str() {
	printf '%s' "$1" | jq -Rr @json
}

_json_str_opt() {
	if [[ "${1:+x}" == 'x' ]]; then
		_json_str "$1"
	else
		printf 'null'
	fi
}

#shellcheck disable=SC2153
metadata() {
	local title=$(_json_str "${TITLE?}")
	local description=$(_json_str "${DESCRIPTION?}")
	local author=$(_json_str "${AUTHOR:-$(id -un)}")
	local icon=$(_json_str_opt "$ICON")
	local icon_alt=$(_json_str_opt "$ICON_ALT")
	local color=$(_json_str_opt "$COLOR")
	local created_at=$(_json_str_opt "$CREATED_AT")
	local modified_at=$(_json_str_opt "$MODIFIED_AT")
	local tags=$(for tag in "${TAGS[@]}"; do printf '%s' "$tag" | jq -Rs .; done | jq -sr @json)
	local dont_cache=false
	[[ "${DONT_CACHE:+x}" == 'x' ]] && dont_cache=true

	printf '{"title":%s,"description":%s,"author":%s,"icon":%s,"icon_alt":%s,"color":%s,"created_at":%s,"modified_at":%s,"tags":%s,"dont_cache":%s}\n' \
		"$title" "$description" "$author" \
		"$icon" "$icon_alt" "$color" \
		"$created_at" "$modified_at" \
		"$tags" "$dont_cache"

}

header() {
	level=${1?need header level}
	if ! (( level >= 1 && level <= 5 )); then
		error "header level must be a number from 1 to 5"
		return 1
	fi
	printf '<h%d>%s</h%d>' "$level" "$(</dev/stdin)" "$level"
}

paragraph() {
	printf '<p>%s</p>' "$(</dev/stdin)"
}

image() {
	src=${1?need src}
	alt=${2?need alt}
	printf '<img src="%s" alt="%s">' "$(printf '%s' "$src" | escape)" "$(printf '%s' "$alt" | escape)"
}

link() {
	href=${1?need href}
	printf '<a href="%s">%s</a>' "$(printf '%s' "$href" | escape)" "$(</dev/stdin)"
}

br() {
	echo '<br>'
}

br_lines() {
	read -r first_line
	echo "$first_line"
	while read -r line; do
		printf '<br>%s\n' "$line"
	done
}

codeblock() {
	printf '<pre><code>'
	escape
	printf '</code></pre>'
}

render() {
	local birth=$(stat -c'%W' "$1")
	if (( birth > 0 )); then
		CREATED_AT=$(date --rfc-3339=seconds -d "@$birth")
	fi
	MODIFIED_AT=$(date --rfc-3339=seconds -d "@$(stat -c '%Y' "$1")")

	#shellcheck disable=SC1090
	( . "$1"; ) # the moment you've all been waiting for
}



print_help() {
	echo "Usage: $0 <SCRIPT>
       $0 -h|--help"
}


if ! ( return &>/dev/null ); then
	script=$1

	if [[ "${script:+x}" != 'x' ]]; then
		print_help
		exit 1
	elif [[ "$script" == "--help"
		|| "$script" == "-h" ]]; then
		print_help
	else
		render "$script"
	fi
fi