import * as Config from '@taqueria/protocol/Config';
import * as Environment from '@taqueria/protocol/Environment';
import * as PersistentState from '@taqueria/protocol/PersistentState';
import { readFile, stat } from 'fs/promises';
import { join, resolve } from 'path';
import load from '../common';

const getProjectAbsPath = async (search = './'): Promise<string> => {
	const dir = resolve(search);

	// If we've reached / or c:\, then give up
	if (/^(\/|[A-Z]:\\?)$/.test(dir)) {
		throw 'Could not find project directory';
	}

	const filename = join(dir, '.taq', 'config.json');
	try {
		const exists = await stat(filename);

		// TODO: Will this work on Windows?
		// ... I might need to use .taq\config.json
		return filename.replace('.taq/config.json', '');
	} catch {
		// TODO: Will this work on Windows?
		// I might need to do ..\
		return await getProjectAbsPath(join(dir, '../'));
	}
};

const getConfig = async (projectAbspath: string) => {
	try {
		const configAbspath = join(projectAbspath, '.taq', 'config.json');
		const contents = await readFile(configAbspath, 'utf-8');
		const unvalided = JSON.parse(contents);
		return Config.create(unvalided);
	} catch {
		throw 'Could not load .taq/config.json';
	}
};

const getState = async (projectAbspath: string, env?: string) => {
	const configAbspath = join(projectAbspath, '.taq', `${env}-state.json`);
	try {
		const contents = await readFile(configAbspath, 'utf-8');
		const unvalided = JSON.parse(contents);
		return PersistentState.create(unvalided);
	} catch {
		throw `Could not load ${configAbspath}`;
	}
};

export default async (projectDir?: string, selectedEnv?: string) => {
	const projectAbspath = await getProjectAbsPath(projectDir);
	const config = await getConfig(projectAbspath);

	/**
	 * Gets the current environment
	 * @returns {Environment.t}
	 */
	const getCurrentEnv = (): [string, Environment.t] => {
		if (!config.environment) {
			throw 'No environment configuration exists in your .taq/config.json file';
		}

		// Get the name of the current environment
		// If one hasn't been assigned, just pick the first one defined
		const foundName = (selectedEnv || config.environment.default)
			?? Object.keys(config.environment)
				.filter(key => key !== 'storage')
				.shift();

		if (!foundName) throw 'Your environment configuration is invalid in your .taq/config.json file';

		// Treat the name as a string
		const name = String(foundName);

		return [
			name,
			Environment.from(config.environment[name]),
		];
	};

	const currentEnv = selectedEnv || getCurrentEnv()[0];

	const state = await getState(projectAbspath, currentEnv);

	return {
		...load(projectAbspath, config, state, selectedEnv),
		getCurrentEnv,
	};
};