const obsidian = require('obsidian');
const Plugin = obsidian.Plugin;
const ItemView = obsidian.ItemView;

const DateFormat = {
	week: "y[0-9]{2}w[0-9]{2}",
	days: ["zo", "ma", "di", "wo", "do", "vrij", "za"],
	time: "[0-9]{2}:[0-9]{2}[ap]m",
	date: ""
}
DateFormat.date = "(?:" + DateFormat.week + ")?(?: ?(?:" + DateFormat.days.join('|') + ") ?)?(?:" + DateFormat.time + ")?";

function parseSingleDate(d, defal)
{
	let year = -1, week = -1, dow = -1, time = defal;

	d = d.toLowerCase();

	// year
	let res = d.match(/y([0-9]{2})/);
	if (res !== null)
	{
		year = parseInt(res[1]) + 2000;
	}
	else
	{
		year = defal.isoWeekYear();
	}

	// week
	res = d.match(/w([0-9]{2})/);
	if (res !== null)
	{
		week = parseInt(res[1]);
	}
	else
	{
		week = defal.isoWeek();
	}

	// day of week
	res = d.split(' ');
	for (const p in res)
	{
		let i = DateFormat.days.indexOf(res[p]);
		if (i != -1){
			dow = i;
			break;
		}
	}
	if (dow == -1)
	{
		dow = defal.day()
	}

	// time
	res = d.match(/([0-9]{2}:[0-9]{2}[ap]m)/);
	if (res !== null)
	{
		time = moment(res[1], "hh:mma");
	}
	
	// combine
	time.day(dow);
	time.isoWeek(week);
	time.isoWeekYear(year);
	return time;
}

function stringifySingleDate(date)
{
	let week = date.format("[y]GG[w]WW");
	let dow = DateFormat.days[date.day()];
	let time = date.format("hh:mma");
	return [week, dow, time].join(' ');
}

function stringifyDate(date)
{
	let res = stringifySingleDate(date[0]);
	if (date[1].diff(date[0]) > 1000)
	{
		res += "-" + stringifySingleDate(date[1])
	}
	return res;
}

function parseDate(d, defal)
{
	let start, end;
	let res = d.match(/([^-]+)-([^-]+)/);
	if (res !== null)
	{
		start = parseSingleDate(res[1], defal);
		end = parseSingleDate(res[2], start);
	}
	else
	{
		start = parseSingleDate(d, defal);
		end = start;
	}
	return [start, end]
}

function findDate(line, defal)
{
	let res = line.match("\\[(" + DateFormat.date + "(?:-" + DateFormat.date + ")?)\\]");
	if (res !== null)
	{
		res[1] = parseDate(res[1], defal);
	}
	return {
		"line": line,
		"dateRemoved": (res === null) ? line : line.replace(res[0], ''),
		'date': (res === null) ? null : res[1]
	}
}

function scanFile(editor, data)
{
	let lineNum = 0, lineCount = editor.lineCount();
	let defal = parseSingleDate("00:00am", moment());

	while ((lineNum < lineCount))
	{
		let res, line = editor.getLine(lineNum);

		res = line.match("weekboek: \"?(" + DateFormat.date + ")\"?");
		if (res != null)
		{
			defal = parseSingleDate(res[1], defal);
		}

		res = [...line.matchAll("\\[(" + DateFormat.date + "(?:-" + DateFormat.date + ")?)\\]")];
		if (res.length > 0)
		{
			if (res[0][0] == "[-]" && res.length > 1)
			{
				res[0] = res[1];
			}
			if (res[0][0] != "[-]")
			{
				res = res[0]
				res[1] = parseDate(res[1], defal);
				let procesed = processLine(line, line.replace(res[0], ''), res[1], data);
				data = procesed['data'];
				editor.setLine(lineNum, procesed['line']);
			}
		}

		lineNum++;
	}
	return data;
}

function processLine(line, noDate, date, data)
{
	let res;
	let item = {
		"id": null,
		"date": stringifyDate(date),
		"title": "Untitled",
		"group": "default",
		"location": null,
		"state": "reminder"
	};

	// id
	res = noDate.match(/<([a-z0-9]+)\/>/);
	if (res != null)
	{
		item["id"] = res[1];
		noDate = noDate.replace(res[0], '');
	}
	else
	{
		item["id"] = generateId();
		line += " <" + item["id"] + "/>";
	}

	// location
	res = noDate.match(/\{([^\}\{]+)\}/);
	if (res != null)
	{
		item["location"] = res[1];
		noDate = noDate.replace(res[0], '');
	}

	// state (checkbox)
	res = noDate.match(/^[ \t]*- \[(.)\] /);
	if (res != null)
	{
		switch (res[1])
		{
			case ' ':
				item["state"] = "task";
				break;
			case 'x':
				item["state"] = "done";
				break;
			case '-':
				item["state"] = "canceled";
				break;
			case '>':
				item["state"] = "moved";
				break;
			case '/':
				item["state"] = "partly finished";
				break;
			default:
				item['state'] = res[1];
				break;
		}
		noDate = noDate.replace('[' + res[1] + '] ', '');
	}
	
	noDate = noDate.replace(/[ \t][ \t]+/g, ' '); // remve multeple spaces/tabs in a row

	// title and group
	res = noDate.match(/^ ?- ([^\[\]<>{}]*) - ([^\[\]<>{}]*)/);
	if (res != null)
	{
		item["group"] = res[1];
		item["title"] = res[2];
	}
	else
	{
		// no group look for only title
		res = noDate.match(/^ ?- ([^\[\]<>\{\}]*)/);
		if (res != null)
		{
			item["title"] = res[1];
		}
		else
		{
			item["title"] = noDate;
		}
	}
	// remove leading and ending spaces
	item["title"] = item['title'].replaceAll(/(^ +)?( +$)?/g, '')
	item["group"] = item['group'].replaceAll(/(^ +)?( +$)?/g, '')

	// add/update to database
	if (data == null) data = {};
	data[item["id"]] = item;

	return { line: line, data: data};
}

function generateId()
{
	let id = '';
	const chars = 'abcdefghijklmnopqrstuvwxyz0123456789';
	let l = 0;
	while (l < 10) {
	  id += chars.charAt(Math.floor(Math.random() * chars.length));
	  l += 1;
	}
	return id;
}

const VIEW_TYPE_CALENDAR = "fr-calendar"

class CalendarView extends ItemView 
{
	constructor(leaf, plugin)
	{
		super(leaf);
		this.plugin = plugin;
		this.week = stringifySingleDate(moment()).match(DateFormat.week)[0];
		this.zoom = 30/60; // in px/min
	}

	getViewType()
	{
	  return VIEW_TYPE_CALENDAR;
	}

	getDisplayText()
	{
	  return "Calender " + this.week;
	}

	async onOpen()
	{
		const container = this.containerEl.children[1];
		container.empty();
		this.eventsEls = {};

		// month
		this.monthEl = container.createEl("div", { cls: "frcal__month" });

		this.monthEl.createEl("div", { cls: "frcal__time" });
		this.mountFirstEl = this.monthEl.createEl("div", { cls: "frcal__month_first", attr: { style: "flex: 70" } });
		this.mountFirstSpanEl = this.mountFirstEl.createEl("span");
		this.mountSecondEl = this.monthEl.createEl("div", { cls: "frcal__month_second", attr: { style: "flex: 0" } });
		this.mountSecondSpanEl = this.mountSecondEl.createEl("span");

		// day header
		this.headEl = container.createEl("div", { cls: "frcal__days frcal__day_head" });

		this.weekNumEl = this.headEl.createEl("div", { cls: "frcal__time" });
		this.dayHeads = [null, null, null, null, null, null, null];
		for (let i = 0; i < 7; i++)
		{
			let dayEl = this.headEl.createEl("div", { cls: "frcal__day frcal__day_head_item" });
			this.dayHeads[i] = dayEl.createEl("span");
		}

		// all day events
		this.alldayEl = container.createEl("div", { cls: "frcal__days frcal__day_allday" });

		this.alldayEl.createEl("div", { cls: "frcal__time" });
		this.allday = [null, null, null, null, null, null, null];
		for (let i = 0; i < 7; i++)
		{
			this.allday[i] = this.alldayEl.createEl("div", { cls: "frcal__day frcal__day_allday_item" });
		}

		// timed events
		this.timedEl = container.createEl("div", { cls: "frcal__days frcal__day_timed" });

		let timed = this.timedEl.createEl("div", { cls: "frcal__time" });
		let median = "am"
		for (let i = 1; i <= 12; i++)
		{
			timed.createEl("div", { cls: "frcal__hour " + median, text: i.toString() });
			if (i == 12 && median == "am"){
				i = 0;
				median = "pm";
			}
		}
		this.timed = [null, null, null, null, null, null, null];
		for (let i = 0; i < 7; i++)
		{
			this.timed[i] = this.timedEl.createEl("div", { cls: "frcal__day frcal__timed_item" });
		}

		this.addEvents();
		this.updateWeek();
	}
 
	async onClose()
	{
	  // Nothing to clean up.
	}

	addEvents()
	{
		this.backButtonEl.ariaDisabled = "false";
		this.backButtonEl.addEventListener('click', this.gotoPreviusWeek.bind(this));
		this.forwardButtonEl.ariaDisabled = "false";
		this.forwardButtonEl.addEventListener('click', this.gotoNextWeek.bind(this));
	}

	gotoPreviusWeek()
	{
		let date = parseSingleDate(this.week + ' ma 12:00am', null).subtract(7, 'days');
		this.week = stringifySingleDate(date).match(DateFormat.week)[0];
		this.updateWeek();
	}

	gotoNextWeek()
	{
		let date = parseSingleDate(this.week + ' ma 12:00am', null).add(7, 'days');
		this.week = stringifySingleDate(date).match(DateFormat.week)[0];
		this.updateWeek();
	}

	updateWeek()
	{
		let months = ["januarie", "februarie", "maart", "april", "mei", "juni", "juli", "augustis", "september", "oktober", "november", "december"];
		let monthF = parseSingleDate(this.week + " ma 00:00am",).month();
		this.mountFirstSpanEl.innerText = (monthF+1).toString() + " - " + months[monthF];

		this.weekNumEl.innerText = this.week.match(/[0-9]+$/)[0];

		let zoDate = parseSingleDate(this.week + " zo 00:00am");
		let monthS = zoDate.month();
		if (monthF != monthS)
		{
			this.mountSecondSpanEl.innerText = (monthS+1).toString() + " - " + months[monthS];
			
			let dow = zoDate.date();

			this.mountFirstEl.setAttr("style", "flex: " + ((7-dow)*10).toString());
			this.mountSecondEl.setAttr("style", "flex: " + ((dow)*10).toString())
		}
		else
		{
			this.mountSecondSpanEl.innerText = "";
			this.mountFirstEl.setAttr("style", "flex: 70")
			this.mountSecondEl.setAttr("style", "flex: 0")
		}


		let days = ["Maandag", "Dinsdag", "Woensdag", "Donderdag", "Vrijdag", "Zaterdag", "Zondag"];
		for (let day = 0; day < 7; day++)
		{
			let date = parseSingleDate(this.week + " " + DateFormat.days[(day + 1) % 7] + " 12:00pm");
			this.dayHeads[day].innerHTML = days[day] + "<br/>" + date.date().toString();
		}

		this.updateEvents();
	}

	updateEvents()
	{
		// let item = {
		// 	"id": null,
		// 	"date": stringifyDate(date),
		// 	"allDay": false,
		// 	"title": "Untitled",
		// 	"group": "default",
		// 	"location": null,
		// 	"state": "reminder"
		// };
		
		// clear events
		for (let day = 0; day < 7; day++)
		{
			this.allday[day].innerHTML = "";
			this.timed[day].innerHTML = "";
		}

		let start = parseSingleDate(this.week + " ma 00:00am");
		let end = parseSingleDate(this.week + " zo 11:59pm");
		for (let event in this.plugin.data)
		{
			event = this.plugin.data[event];
			let date = parseDate(event['date'])
			if (
				(date[0] > start && date[0] < end)
				|| (date[1] > start && date[1] < end)
			)
			{
				let day = date[0].day() - 1
				day = (day == -1) ? 6 : day;
				if (event.date.match(DateFormat.time)[0] == '12:00am')
				{
					this.renderEvent(event, this.allday[day]);
				}
				else
				{
					this.renderEvent(event, this.timed[day]);
				}
			}
		}
	}

	renderEvent(event, container)
	{
		let time = parseDate(event.date);
		time[0] = time[0].hour()*60 + time[0].minute();
		time[1] = time[1].hour()*60 + time[1].minute();
		let el = container.createEl('div', {
			cls: 'frcal__event',
			id: "fr_event_" + event.id,
			attr: {
				'data-group': event.group,
				'data-state': event.state,
				'data-start': time[0].toString(),
				'data-duration': (time[1] - time[0]).toString(),
				'style': 'top:' + (time[0]*this.zoom).toString() + 'px'
			},
		});
		el.createEl('span', { 
			text: event.title,
			attr: {
				'style': 'min-height:' + ((time[1] - time[0]) * this.zoom).toString() + 'px'
			}
		});
		return el;
	}
}


class FRCalander extends Plugin
{
	async onload()
	{
		this.registerView(VIEW_TYPE_CALENDAR, (leaf) => { return new CalendarView(leaf, this) });

		this.addCommand({
			id: 'calnder-scan',
			name: 'scan active file',
			editorCallback: (editor) => {
				//TODO: check if editor is valid
				if (this.data == null) this.data = this.loadData();
				this.data = scanFile(editor, this.data);
				this.saveData(this.data);
			}
		});
		//TODO: scan folder; with DataAdapter
		// this.addCommand({
		// 	id: 'calnder-save',
		// 	name: 'save the calander',
		// 	editorCallback: () => {
		// 		this.saveData(data);
		// 	}
		// });
		// this.addCommand({
		// 	id: 'calnder-load',
		// 	name: 'save the calander',
		// 	editorCallback: () => {
		// 		data = this.loadData();
		// 	}
		// });


		this.addRibbonIcon("calendar", "show fr calender", () => {
			let leaf = app.workspace.getLeavesOfType(VIEW_TYPE_CALENDAR);
			if (leaf.length > 0)
			{
				leaf = leaf[0];
			}
			else
			{
				leaf = app.workspace.getLeavesOfType('empty');
				if (leaf.length > 0)
				{
					leaf = leaf[0];
				}
				else
				{
					leaf = app.workspace.getLeaf('tab');
				}
			}

			leaf.setViewState({ type: VIEW_TYPE_CALENDAR });
			app.workspace.setActiveLeaf(leaf);
		});

		this.data = await this.loadData();
	}
}

module.exports = FRCalander;