class Navi {
	api;
	connected = false;
	icon;
	info;
	theme;
	world;

	#init;
	#listeners = new Map();
	#socket;
	#secret;
	#world;

	constructor(api = window.location.origin, secret = '') {
		this.api = api.replace(/\/$/, '');
		this.icon = `${this.api}/favicon.png`;
		this.#secret = secret;
	}

	async init() {
		if(this.#init) return this.#init;
		this.#init = new Promise(async (res, rej) => {
			try {
				this.info = await fetch(`${this.api}/api/info`, {
					headers: this.#secret ? {'Authorization': `Bearer ${this.#secret}`} : {}
				}).then(resp => {
					if(!resp.ok) throw new Error(`Invalid Navi API: ${this.api}`);
					return resp.json();
				});
				this.theme = this.info.theme;

				this.#socket = io(this.api, {auth: this.#secret ? {token: this.#secret} : null});

				this.#socket.on('llm-stream', (chunk) => {
					if(this.llmCallback) this.llmCallback(chunk);
					this.emit('llm:stream', chunk);
				});

				this.#socket.on('llm-response', (data) => {
					if(this.llmResolve) this.llmResolve(data);
					this.emit('llm:response', data);
					this.llmCallback = null;
					this.llmResolve = null;
					this.llmReject = null;
				});

				this.#socket.on('llm-error', (error) => {
					if(this.llmReject) this.llmReject(error);
					this.emit('llm:error', error);
					this.llmCallback = null;
					this.llmResolve = null;
					this.llmReject = null;
				});

				this.connected = true;
				this.emit('init');
				res(this);
			} catch(err) {
				rej(err);
			}
		});
		return this.#init;
	}

	// ============================================
	// EVENT SYSTEM
	// ============================================

	on(event, callback) {
		if(!this.#listeners.has(event)) this.#listeners.set(event, []);
		this.#listeners.get(event).push(callback);
		return () => this.off(event, callback);
	}

	off(event, callback) {
		const callbacks = this.#listeners.get(event);
		if(callbacks) {
			const index = callbacks.indexOf(callback);
			if(index > -1) callbacks.splice(index, 1);
		}
	}

	emit(event, data) {
		const callbacks = this.#listeners.get(event) || [];
		callbacks.forEach(cb => cb(data));
	}

	// ============================================
	// REST API
	// ============================================

	async sendUserMessage(userId, message) {
		const response = await fetch(`${this.api}/api/message`, {
			method: 'POST',
			headers: {'Content-Type': 'application/json'},
			body: JSON.stringify({message})
		});
		if(!response.ok) throw new Error('Message failed to send bestie');

		const result = await response.json();
		this.emit('message:sent', {
			userId,
			message,
			result
		});
		return result;
	}

	async linkPet(petId, targetApiUrl) {
		const response = await fetch(`${this.api}/api/link`, {
			method: 'POST',
			headers: {'Content-Type': 'application/json'},
			body: JSON.stringify({targetApiUrl})
		});
		if(!response.ok) throw new Error('Link connection is bussin (negatively)');

		const result = await response.json();
		this.emit('pet:linked', {
			petId,
			targetApiUrl,
			result
		});
		return result;
	}

	// ============================================
	// WORLD SOCKET
	// ============================================

	connect(apiOrWorld, world) {
		let api;
		if(world) {
			api = apiOrWorld;
		} else {
			api = this.api;
			world = apiOrWorld;
		}

		if(!this.world) this.world = {};
		if(this.#world && this.world.api !== api) {
			this.#world.disconnect();
			this.#world = null;
		}
		if(!this.#world) this.#world = io(`${api}/world`, {auth: this.#secret ? {token: this.#secret} : null});
		this.world.api = api;
		this.world.data = null;
		this.world.name = world;
		this.world.players = new Map();

		const callbacks = {
			move: (x, y) => {
				this.#world.emit('move', {
					x,
					y
				});
			},
			leave: () => {
				this.#world.disconnect();
				this.world = null;
			},
			onData: (data) => {
			},
			onPlayers: (players) => {
			},
			onJoined: (player) => {
			},
			onMoved: (player) => {
			},
			onLeft: (player) => {
			},
			onError: (error) => {
			}
		};

		this.#world.on('data', (data) => {
			this.world.data = data;
			callbacks.onData(data);
			this.emit('world:data', data);
		});

		this.#world.on('players', (players) => {
			this.world.players.clear();
			players.forEach(p => this.world.players.set(p.socketId, p));
			callbacks.onPlayers(players);
			this.emit('world:players', players);
		});

		this.#world.on('joined', (player) => {
			this.world.players.set(player.socketId, player);
			callbacks.onJoined(player);
			this.emit('world:joined', player);
		});

		this.#world.on('moved', (data) => {
			const player = this.world.players.get(data.socketId);
			if(player) {
				player.x = data.x;
				player.y = data.y;
			}
			callbacks.onMoved(player);
			this.emit('world:moved', player);
		});

		this.#world.on('left', (data) => {
			const player = this.world.players.get(data.socketId);
			this.world.players.delete(data.socketId);
			callbacks.onLeft(player);
			this.emit('world:left', player);
		});

		this.#world.on('error', (error) => {
			console.error('World error:', error);
			callbacks.onError(error);
			this.emit('world:error', error);
		});

		this.#world.emit('join', {
			world,
			api
		});

		this.emit('world:join', world);
		return callbacks;
	}

	// ============================================
	// LLM
	// ============================================

	ask(message, stream) {
		this.llmCallback = stream;
		const promise = new Promise((resolve, reject) => {
			this.llmResolve = resolve;
			this.llmReject = reject;
			this.#socket.emit('llm-ask', {message});
			this.emit('llm:ask');
		});

		promise.abort = () => {
			this.#socket.emit('llm-abort');
			if(this.llmReject) this.llmReject(new Error('Aborted by user'));
			this.llmCallback = null;
			this.llmResolve = null;
			this.llmReject = null;
			this.emit('llm:abort');
		};

		return promise;
	}

	clearChat() {
		if(this.#socket) this.#socket.emit('llm-clear');
		this.emit('llm:clear');
	}

	// ============================================
	// UTILITY
	// ============================================

	disconnect() {
		this.connected = false;
		this.icon = this.info = this.theme = this.world = this.#init = this.#secret = null;
		if(this.#world) {
			this.#world.disconnect();
			this.#world = null;
		}
		if(this.#socket) {
			this.#socket.disconnect();
			this.#socket = null;
		}
		this.emit('disconnected');
	}
}

export default Navi;