#!/usr/bin/env nodejs
'use strict';

// 20260730 - Hyperling
// Generate .ics files with entries to be imported in a shared calendar.

/*** Parameters ***/

const args = process.argv;

const cmdExec = args[0];
const cmdPath = args[1];
const startDate = args[2];
const endDate = args[3];
const DEBUG = args[4];

console.log(`Running ${cmdPath} with ${cmdExec}...`);
console.log("Start Date: " + startDate);
console.log("  End Date: " + endDate);

console.log("Converting strings to dates...");
const dayStart = new Date(startDate);
const dayEnd = new Date(endDate);
console.log("...done!");

/*** Setup ***/

// Local Vars

const name = "Hyperling's Moonth Calendar";
const domain = "cloud.hyperling.com";

// iCalendar Library

// https://www.npmjs.com/package/ical-generator
import ical, { ICalCalendarMethod } from 'ical-generator';
const cal =
	ical({
		domain: "$domain",
		name: "$name"
	})
;

// File System Reading

import fs from "fs";
function readFile (file) {
	try {
		const text = fs.readFileSync(file, "utf8");
		console.log(file + " loaded!");
		return text;
	} catch (e) {
		console.error("ERROR: Could not read " + file + ": ", e);
	}
}
function writeFile (name, text) {
	try {
	fs.writeFileSync(name, text);
		console.log(name + " written successfully");
	} catch (e) {
		console.error("Error writing " + name + ": ", e);
	}
}

const templateTitle = readFile("templates/TITLE.txt")
const templateDesc = readFile("templates/DESCRIPTION.txt");

/*** Main ***/

const dayOne = new Date("2026-04-01");
const dayLength = 1000 * 60 * 60 * 24;
function getNumDaysBetween (date1, date2) {
	return Math.abs((date1-date2)/dayLength);
}

for (
	let dayCurr = dayStart;
	dayCurr <= dayEnd;
	dayCurr.setDate(dayCurr.getDate() + 1)
) {

	if (DEBUG) console.log("DEBUG: curr-Apr1 = ", getNumDaysBetween(dayCurr, dayOne));

	// Pull data for UID.
	const year = dayCurr.getFullYear();
	const moonth = dayCurr.getMonth();
	const day = dayCurr.getDate();
	const extra = "00";

	// Reset vars to defaults.
	const title = templateTitle
		.replaceAll("{{MOONTH}}", moonth)
		.replaceAll("{{DAY}}", day)
		.replaceAll("{{YEAR}}", year)
	;
	const description = templateDesc;

	cal.createEvent({
		uid: `${year}${moonth}${day}${extra}@${domain}`,
		start: new Date(dayCurr),
		allDay: true,
		summary: title,
		description: description,
	});
}

/*** Finish ***/

// Create Events
//cal.save('schedule.ics');
writeFile("calendar.ics", cal.toString());