#!/usr/bin/env bash

set -euo pipefail
command_check() {
	local MISSING=()
	for cmd in "$@"; do 
		if ! command -v "$cmd" >/dev/null 2>&1; then
			MISSING+=("$cmd")
		fi
	done
	if [[ ${#MISSING[*]} -gt 0 ]]; then
		echo "Error: Missing required programs:" >&2
		for cmd in "${MISSING[@]}"; do
			echo "  - $cmd" >&2
		done
		exit 1
	fi
}
command_check curl jq
if [[ ! -t 0 ]]; then
	QUERY="$(cat)"
elif [[ $# -gt 0 ]]; then
	QUERY="$*"
else
	printf "Create a map link for a location.\n"
	printf "Address? "
	read -r QUERY
fi
ENCODED_QUERY="${QUERY// /%20}"
LOCATION_JSON="$(curl -s "https://nominatim.openstreetmap.org/search?q=$ENCODED_QUERY&limit=2&format=json")"
if ! jq empty <<<"$LOCATION_JSON" 2>/dev/null; then
	echo "Error: Something wrong, invalid JSON for location query." >&2
	exit 1
fi
coordinate() {
	local COOR="$1"
	local VALUE
	VALUE="$(jq -r ".[0].$COOR" <<<"$LOCATION_JSON")"
	if [[ "$VALUE" =~ ^-?[0-9]+([.][0-9]+)?$ ]]; then
		echo "$VALUE"
	else
		echo "Error: Not a number" >&2
		echo "Usage: $0 <address>" >&2
		echo "Query was: $QUERY" >&2
		echo "Encoded query was: $ENCODED_QUERY" >&2
		echo "Location JSON was: $LOCATION_JSON" >&2
		exit 1
	fi
}
LAT="$(coordinate lat)"
LON="$(coordinate lon)"
echo "https://www.openstreetmap.org/?mlat=$LAT&mlon=$LON#map=16/$LAT/$LON"