import fastify, { FastifyInstance } from 'fastify';
import etags from '@fastify/etag';
import compress, { FastifyCompressOptions } from '@fastify/compress';
import formbody from '@fastify/formbody';
import { pino } from 'pino';

export type ServerStatus = 'unstarted' | 'starting' | 'ready' | 'closing' | 'closed';

export interface HttpConfig {
	address: string;
	port: number;
	tls: false | {
		key: string;
		cert: string;
	};
	exposed_url?: string;
	etag?: boolean;
	compress?: false | FastifyCompressOptions['encodings'];
	cache_control?: {
		static_assets: string;
	};
}

export interface BaseHttpDependencies {
	logger: pino.Logger;
}

export interface RegisterHttpEndpoint<Deps extends BaseHttpDependencies> {
	(server: FastifyInstance, conf: HttpConfig, deps: Deps): void;
}

export interface ContentParser {
	(server: FastifyInstance, media_types: string[]): void;
}

export interface HttpParams<Deps extends BaseHttpDependencies> {
	content_parsers: Record<string, ContentParser>;
	endpoints: RegisterHttpEndpoint<Deps>[];
}

export function create_http_server<Deps extends BaseHttpDependencies>(conf: HttpConfig, deps: Deps, params: HttpParams<Deps>) {
	const server = fastify({
		logger: deps.logger
	});

	// Register error handlers
	// todo: register error handlers...

	// Register endpoints
	for (const endpoint of params.endpoints) {
		endpoint(server, conf, deps);
	}

	let resolve: () => void;
	let status: ServerStatus = 'unstarted';

	const ready = new Promise<void>((onResolve) => {
		resolve = onResolve;
	});

	return {
		server,
		ready,
		get status() {
			return status;
		},

		// 
		async setup_plugins() {
			await Promise.all([
				server.register(formbody),
				conf.etag ? server.register(etags) : null,
				conf.compress ? server.register(compress, { encodings: conf.compress }) : null,
			]);
		},

		async listen() {
			status = 'starting';
			
			try {
				await server.listen({ port: conf.port, host: conf.address });
			}

			catch (error) {
				server.log.error(error);
				process.exit(1);
			}

			await server.ready();
			status = 'ready';
			resolve();
		},
		async close() {
			status = 'closing';
			await server.close();
			status = 'closed';
		},
	};
}