'use strict';

const React = require('react');
const create = require('create-react-class');
const Promise = require('bluebird');
const urllib = require('url');

const createApiRequester = require("../lib/api-request");

let login = create({
	displayName: "Login",

	getInitialState: function() {
		return {
			error: null,
			formState: {
				user: "",
				pass: "",
				hs: ""
			},
			hs: {
				prompt: false,
				error: null,
				valid: false
			}
		};
	},

	login: function() {
		return Promise.try(() => {
			this.setState({error: ""});
	
			if (this.state.hs.valid) {
				return this.doLogin();
			}
	
			let parts = this.state.formState.user.split(':');
			if (parts.length != 2) {
				return this.setState({error: "Please enter a full mxid, like username:homeserver.tld"});
			}
	
			let hostname = urllib.parse("https://" + parts[1]);
			
			return Promise.try(() => {
				return getApiServer(hostname);
			}).then((homeserverUrl) => {
				console.log("Using API server", homeserverUrl);

				this.setState({
					apiUrl: homeserverUrl,
					apiRequest: createApiRequester(homeserverUrl),
					formState: Object.assign(this.state.formState, {
						user: parts[0],
						hs: homeserverUrl
					}),
					hs: Object.assign(this.state.hs, {
						valid: true
					})
				});

				return this.doLogin();
			}).catch((error) => {
				/* FIXME: Error filtering */
				console.log("ERROR fetching homeserver url", error);

				this.setState({
					hs: Object.assign(this.state.hs, {
						error: error,
						valid: false,
						prompt: true
					})
				});
			});
		});
	},

	doLogin: function() {
		return Promise.try(() => {
			console.log("Logging in");
			let user = this.state.formState.user.replace('@', '');
			let password = this.state.formState.pass;
			let homeserverUrl = this.state.apiUrl;
			
			return Promise.try(() => {
				return this.state.apiRequest("/_matrix/client/r0/login", {
					user: user,
					password: password,
					type: "m.login.password",
					initial_device_display_name: "Neo v4",
				});
			}).then((responseJson) => {
				console.log("got access token", responseJson);

				this.setState({ json: responseJson });

				if(responseJson.access_token != undefined) {
					this.props.callback(responseJson.user_id, responseJson.access_token, homeserverUrl);
				} else {
					this.setState({ error: responseJson.error });
				}
			}).catch((error) => {
				/* FIXME: Why are errors being swallowed here? */
				console.error(error);
			});
		});
	},

	handleUserChange: function(e) {
		let formState = this.state.formState;
		let user = e.target.value;
		formState.user = e.target.value;
		let parts = user.split(':');
		if (parts.length == 2) {
			formState.hs = parts[1];
			let hsState = Object.assign(this.state.hs, {error: null, valid: false});
			this.setState({hs: hsState});
		}
		this.setState({formState: formState});
	},

	handlePassChange: function(e) {
		let formState = this.state.formState;
		formState.pass = e.target.value;
		this.setState({formState: formState});
	},

	handleHomeserverChange: function(e) {
		let formState = this.state.formState;
		formState.hs = e.target.value;
		this.setState({formState: formState});
		this.setState({hs: {error: null, valid: false, prompt: true, changed: true}});
	},

	render: function() {
		let hsState = "inactive";
		if (this.state.hs.prompt) {
			hsState = "active";
		}
		if (this.state.hs.error != null) {
			hsState = "error";
		}
		if (this.state.hs.valid) {
			hsState = "validated";
		}

		return (
			<div className="loginwrapper">
				<img src="./neo.png"/>
				<div className="errorMessage">{this.state.error}</div>
				<div className="login">
					<label htmlFor="user">Username: </label>
					<input type="text" id="user" placeholder="@user:homeserver.tld" value={this.state.formState["user"]} onChange={this.handleUserChange}/>

					<label htmlFor="pass">Password: </label>
					<input type="password" id="pass" placeholder="password" value={this.state.formState["pass"]} onChange={this.handlePassChange}/>

					<label htmlFor="hs" className={hsState}>Homeserver: </label>
					{this.state.hs.prompt ? (
						<>
							<input type="text" id="hs" value={this.state.formState["hs"]} onChange={this.handleHomeserverChange}/>
						</>
					) : (
						<span id="hs">{this.state.formState["hs"]}</span>
					)}

					<button onClick={()=>this.login()}>Log in</button>
				</div>
			</div>
		);
	}
});

function getApiServer(parsedUrl) {
	return Promise.try(() => {
		console.log("Checking for api server from mxid", urllib.format(parsedUrl));

		return checkApi(parsedUrl);
	}).then(() => {
		// Hostname is a valid api server
		return buildUrl(parsedUrl, "");
	}).catch(() => {
		/* FIXME: Error filtering */
		console.log("trying .well-known");

		return Promise.try(() => {
			return tryWellKnown(parsedUrl);
		}).then((hostname) => {
			console.log("got .well-known host", hostname);

			return hostname;
		}).catch((_err) => {
			/* FIXME: Error chaining */
			throw new Error("Fatal error trying to get API host");
		});
	});
}

function checkApi(host) {
	return Promise.try(() => {
		let versionUrl = buildUrl(host, "/_matrix/client/versions");
		
		return Promise.try(() => {
			return fetch(versionUrl);
		}).then((response) => {
			if (response.status != 200) {
				console.log("Invalid homeserver url", versionUrl);
	
				/* FIXME: Error types */
				throw new Error("Invalid homeserver URL");
			}
		});
	});
}

function tryWellKnown(host) {
	let wellKnownUrl = urllib.format(Object.assign(host, {
		pathname: "/.well-known/matrix/client"
	}));

	console.log("Trying", wellKnownUrl, "for .well-known");

	return Promise.try(() => {
		return fetch(wellKnownUrl);
	}).tap((response) => {
		if (response.status != 200) {
			console.log("no well-known in use");

			/* FIXME: Error type */
			throw new Error("No homeserver found");
		}
	}).catch((_error) => {
		/* FIXME: Error chaining */
		throw new Error("can't fetch .well-known");
	}).then((response) => {
		return response.json();
	}).then((json) => {
		console.log("Parsed json", json);

		if (json['m.homeserver'] != null && json['m.homeserver'].base_url != null) {
			return json['m.homeserver'].base_url;
		} else {
			/* FIXME: Error type */
			throw new Error("No homeserver specified in .well-known");
		}
	}).catch((err) => {
		/* FIXME: Error filtering? */
		console.log("Error in json", err);

		/* FIXME: Error chaining */
		throw new Error("Error while parsing .well-known");
	});
}

function buildUrl(parsedUrl, path) {
	return urllib.format(Object.assign(parsedUrl, {
		pathname: path
	}));
}

module.exports = login;