// TODO: could get path constants from DOM in jinja template
const FOLDER_CONTENTS_PATH = '/pvdb/file_listing/folder_contents_json/';
const QUERY_PATH = '/pvdb/tmdb/query_media_json';
const CREATE_MAPPING_PATH = '/pvdb/tmdb/create_path_mapping';
const PATH_PATH = '/pvdb/tmdb/query_path_json';
const VIDEO_PREFIX = '/video/';


// NOTE: create links for folder contents
function addContents(node, json) {
	let li = document.createElement('li');
	let a = document.createElement('a');
	a.href = window.location;
	a.dataset.base_name = json.base_name;
	a.dataset.file_extension = json.file_extension;
	a.dataset.is_dir = json.is_dir;
	a.dataset.rel_path = json.rel_path;

	if (json.is_dir)
		a.classList.add('folder');
	else
		if (json.in_db)
			a.classList.add('file_stored');
		else
			a.classList.add('file');

	a.appendChild(document.createTextNode(json.base_name));
	li.appendChild(a);
	node.appendChild(li);

	a.addEventListener('click', function(e) {
		e.preventDefault();
		let element = e.target.parentNode; // NOTE: the parent 'li' element
		let ul_node = element.querySelector('li > ul');
		let div_node = element.querySelector('li > .search_result');

		if (ul_node != null) {
			element.removeChild(ul_node);
		} else if (div_node != null) {
			element.removeChild(div_node);
		} else {
			if (a.dataset.is_dir == 'true') {
				fetchJSON(FOLDER_CONTENTS_PATH + a.dataset.rel_path, parseResponse, element);
			} else {
				if (a.className == 'file_stored')
					openInfoCard(a.dataset, e.target);
				else // 'file'
					openQueryDialog(a.dataset, e.target);
			}
		}
	});
}

// NOTE: display an 'info card' for a path that has already been stored
function openInfoCard(dataset, element) {
	query_str = PATH_PATH + '?rel_path=' + dataset.rel_path;
	fetchJSON(query_str, function(json) {
		if (json.errors) {
			for (let e of json.errors)
				logError(e)
		} else {
			blurb = createBlurb(json);
			// NOTE: don't need the mapping link here
			let p = blurb.querySelector('.mapping_link').parentNode;
			p.parentNode.removeChild(p);

			// NOTE: add play link
			let a = document.createElement('a');
			a.classList.add('play_link');
			a.href = VIDEO_PREFIX + dataset.rel_path;
			a.appendChild(document.createTextNode('play'));
			let div = blurb.querySelector('.search_result');
			div.insertBefore(a, div.firstChild);

			element.parentNode.appendChild(blurb);
		}
	});
}

// NOTE: create query results dialog from html templates
function openQueryDialog(dataset, element) {
	query_str = QUERY_PATH
		+ '?query=' + dataset.base_name
		+ '&rel_path=' + dataset.rel_path;
	fetchJSON(query_str, function(json) {

		console.log('openQueryDialog(), ' + query_str);
		console.log(json);

		if (json.errors) {
			for (let e of json.errors)
				logError(e)
		} else {
			let tcontainer = document.querySelector('#query_results');
			let tclone = document.importNode(tcontainer.content, true);
			let close = tclone.querySelector('#query_close');
			close.addEventListener('click', function(e) {
				e.preventDefault();
				document.querySelector('body').removeChild(e.target.parentNode);
			});

			for (let result of json) {
				blurb = createBlurb(result);
				blurb.querySelector('.mapping_link').addEventListener('click', function(e) {
					submitFileMapping(e, result.detail_id, dataset.rel_path, element);
				});
				tclone.querySelector('#query_result_container').appendChild(blurb);
			}

			document.querySelector('body').appendChild(tclone);
		}
	});
}

function createBlurb(details) {
	let qt = document.querySelector('#query_result');
	let qtclone = document.importNode(qt.content, true);

	let title_link = qtclone.querySelector('h3 > a');
	title_link.href = details.tmdb_link;
	title_link.appendChild(document.createTextNode(details.title));

	let date = qtclone.querySelector('.query_release_date');
	date.appendChild(document.createTextNode(details.release_date));

	let description = qtclone.querySelector('.query_description');
	description.appendChild(document.createTextNode(details.overview));

	return qtclone;
}

async function submitFileMapping(click_event, detail_id, rel_path, element) {
	click_event.preventDefault();
	// NOTE: remove the query box
	document.querySelector('body').removeChild(document.querySelector('#query_result_container'));
	query_str = CREATE_MAPPING_PATH;
	params = new FormData();
	params.append('detail_id', detail_id);
	params.append('rel_path', rel_path);

	let json = null;
	const response = await fetch(CREATE_MAPPING_PATH, { body: params, method: 'POST' });
	try {
		json = await response.json();
	} catch (e) {
		logError('error in submitFileMapping(), ' + e);
	}

	if (json != null && json.errors.length == 0) {
		// NOTE: display success dialog
		let map_temp = document.querySelector('#mapping_success');
		let clone = document.importNode(map_temp.content, true);
		clone.querySelector('div > p').appendChild(document.createTextNode(json.message));
		let body = document.querySelector('body');
		body.appendChild(clone);
		window.setTimeout(function() {
			body.removeChild(document.querySelector('.success_container'));
		}, 500);
		// NOTE: update the displayed link class
		element.className = 'file_stored';
	}
}

function parseResponse(json, node) {
	if (node == null) {
		logError('parent node cannot be null');
		return;
	}

	if (json.errors.length > 0) {
		for (let err of json.errors)
			logError(err);
	} else {
		let frag = document.createDocumentFragment();
		let ul = document.createElement('ul');
		frag.appendChild(ul);

		for (let path of json.paths)
			addContents(ul, path);

		node.appendChild(frag);
	}
}

window.onload = function() {
	document.querySelector('#noscript').style.display = 'none';
	let error_box = document.querySelector('#js_errors');
	error_box.style.display = 'none';

	if (!('fetch' in window)) {
		logError('Unsupported Browser, No fetch API');
		return;
	}

	if ((!'content' in document.createElement('template'))) {
		logError('Unsupported Browser, No template support');
		return;
	}

	fetchJSON(FOLDER_CONTENTS_PATH, parseResponse, document.querySelector('.content'));
}


function logError(s) {
	console.log(s);
	let error_box = document.querySelector('#js_errors');
	let p = document.createElement('p');
	p.appendChild(document.createTextNode(s));
	error_box.appendChild(p);
	error_box.style.display = 'block';
}

function removeAllChildren(node) {
	while(node.hasChildNodes())
		node.removeChild(node.lastChild);
}

function fetchJSON(url, responseFunc, node=null) {
	fetch(url)
	.then(function(response) {
		if (!response.ok)
			throw Error(response.statusText);

		return response.json();
	})
	.catch(function(error) {
		logError('fetch error: ' + error);
		return null;
	})
	.then(function(json) {
		if (json != null)
			(node == null) ? responseFunc(json) : responseFunc(json, node);
	});
}