var { app } = require('./app.js');
var Note = require('lib/models/Note.js');
var Folder = require('lib/models/Folder.js');
var Tag = require('lib/models/Tag.js');
var { cliUtils } = require('./cli-utils.js');
var yargParser = require('yargs-parser');
var fs = require('fs-extra');

async function handleAutocompletionPromise(line) {
	// Auto-complete the command name
	const names = await app().commandNames();
	let words = getArguments(line);
	//If there is only one word and it is not already a command name then you
	//should look for commmands it could be
	if (words.length == 1) {
		if (names.indexOf(words[0]) === -1) {
			let x = names.filter((n) => n.indexOf(words[0]) === 0);
			if (x.length === 1) {
				return x[0] + ' ';
			}
			return x.length > 0 ? x.map((a) => a + ' ') : line;
		} else {
			return line;
		}
	}
	//There is more than one word and it is a command
	const metadata = (await app().commandMetadata())[words[0]];
	//If for some reason this command does not have any associated metadata
	//just don't autocomplete. However, this should not happen.
	if (metadata === undefined) {
		return line;
	}
	//complete an option
	let next = words.length > 1 ? words[words.length - 1] : '';
	let l = [];
	if (next[0] === '-') {
		for (let i = 0; i<metadata.options.length; i++) {
			const options = metadata.options[i][0].split(' ');
		//if there are multiple options then they will be seperated by comma and
			//space. The comma should be removed
			if (options[0][options[0].length - 1] === ',') {
				options[0] = options[0].slice(0, -1);
			}
			if (words.includes(options[0]) || words.includes(options[1])) {
				continue;
			}
			//First two elements are the flag and the third is the description
			//Only autocomplete long
			if (options.length > 1 && options[1].indexOf(next) === 0) {
				l.push(options[1]);
			} else if (options[0].indexOf(next) === 0) {
				l.push(options[0]);
			}
		}
		if (l.length === 0) {
			return line;
		}
		let ret = l.map(a=>toCommandLine(a));
		ret.prefix = toCommandLine(words.slice(0, -1)) + ' ';
		return ret;
	}
	//Complete an argument
	//Determine the number of positional arguments by counting the number of
	//words that don't start with a - less one for the command name
	const positionalArgs = words.filter((a)=>a.indexOf('-') !== 0).length - 1;

	let cmdUsage = yargParser(metadata.usage)['_'];
	cmdUsage.splice(0, 1);

	if (cmdUsage.length >= positionalArgs) {

		let argName = cmdUsage[positionalArgs - 1];
		argName = cliUtils.parseCommandArg(argName).name;

		const currentFolder = app().currentFolder();

		if (argName == 'note' || argName == 'note-pattern') {
			const notes = currentFolder ? await Note.previews(currentFolder.id, { titlePattern: next + '*' }) : [];
			l.push(...notes.map((n) => n.title));
		}

		if (argName == 'notebook') {
			const folders = await Folder.search({ titlePattern: next + '*' });
			l.push(...folders.map((n) => n.title));
		}

		if (argName == 'item') {
			const notes = currentFolder ? await Note.previews(currentFolder.id, { titlePattern: next + '*' }) : [];
			const folders = await Folder.search({ titlePattern: next + '*' });
			l.push(...notes.map((n) => n.title), folders.map((n) => n.title));
		}

		if (argName == 'tag') {
			let tags = await Tag.search({ titlePattern: next + '*' });
			l.push(...tags.map((n) => n.title));
		}

		if (argName == 'file') {
			let files = await fs.readdir('.');
			l.push(...files);
		}

		if (argName == 'tag-command') {
			let c = filterList(['add', 'remove', 'list'], next);
			l.push(...c);
		}

		if (argName == 'todo-command') {
			let c = filterList(['toggle', 'clear'], next);
			l.push(...c);
		}
	}
	if (l.length === 1) {
		return toCommandLine([...words.slice(0, -1), l[0]]);
	} else if (l.length > 1) {
		let ret = l.map(a=>toCommandLine(a));
		ret.prefix = toCommandLine(words.slice(0, -1)) + ' ';
		return ret;
	}
	return line;

}
function handleAutocompletion(str, callback) {
	handleAutocompletionPromise(str).then(function(res) {
		callback(undefined, res);
	});
}
function toCommandLine(args) {
	if (Array.isArray(args)) {
		return args.map(function(a) {
			if(a.indexOf('"') !== -1 || a.indexOf(' ') !== -1) {
				return "'" + a + "'";
			} else if (a.indexOf("'") !== -1) {
				return '"' + a + '"';
			} else {
				return a;
			}
		}).join(' ');
	} else {
		if(args.indexOf('"') !== -1 || args.indexOf(' ') !== -1) {
			return "'" + args + "' ";
		} else if (args.indexOf("'") !== -1) {
			return '"' + args + '" ';
		} else {
			return args + ' ';
		}
	}
}
function getArguments(line) {
	let inSingleQuotes = false;
	let inDoubleQuotes = false;
	let currentWord = '';
	let parsed = [];
	for(let i = 0; i<line.length; i++) {
		if(line[i] === '"') {
			if(inDoubleQuotes) {
				inDoubleQuotes = false;
				//maybe push word to parsed?
				//currentWord += '"';
			} else {
				inDoubleQuotes = true;
				//currentWord += '"';
			}
		} else if(line[i] === "'") {
			if(inSingleQuotes) {
				inSingleQuotes = false;
				//maybe push word to parsed?
				//currentWord += "'";
			} else {
				inSingleQuotes = true;
				//currentWord += "'";
			}
		} else if (/\s/.test(line[i]) &&
			!(inDoubleQuotes || inSingleQuotes)) {
			if (currentWord !== '') {
				parsed.push(currentWord);
				currentWord = '';
			}
		} else {
			currentWord += line[i];
		}
	}
	if (!(inSingleQuotes || inDoubleQuotes) && /\s/.test(line[line.length - 1])) {
		parsed.push('');
	} else {
		parsed.push(currentWord);
	}
	return parsed;
}
function filterList(list, next) {
	let output = [];
	for (let i = 0; i < list.length; i++) {
		if (list[i].indexOf(next) !== 0) continue;
		output.push(list[i]);
	}
	return output;
}

module.exports = { handleAutocompletion };