/*!
 * Copyright 2019-2020 Lime Technology Inc. All rights reserved.
 * Written by: Alexis Tyler
 */

import get from 'lodash.get';
import { v4 as uuid } from 'uuid';
import * as core from '../core';
// eslint-disable-next-line @typescript-eslint/no-duplicate-imports
import { bus, apiManager, graphqlLogger, config, pluginManager, modules, coreLogger, log, paths, pubsub } from '../core';
import { AppError, FatalAppError, PluginError } from '../core/errors';
import { usersState } from '../core/states';
import { makeExecutableSchema, SchemaDirectiveVisitor } from 'graphql-tools';
import { mergeTypeDefs } from '@graphql-tools/merge';
import gql from 'graphql-tag';
import dee from '@gridplus/docker-events';
import { run, publish } from '../run';
import { typeDefs } from './schema';
import * as resolvers from './resolvers';
import { wsHasConnected, wsHasDisconnected } from '../ws';
import { MOTHERSHIP_RELAY_WS_LINK } from '../consts';
import { isNodeError } from '../core/utils';
import { User } from '../core/types';

const internalServiceUser: User = { id: '-1', description: 'Internal service account', name: 'internal', role: 'admin', password: false };

const baseTypes = [gql`
	scalar JSON
	scalar Long
	scalar UUID
	scalar DateTime

	directive @func(
		module: String
		data: JSON
		query: JSON
		result: String
		extractFromResponse: String
	) on FIELD_DEFINITION

	directive @subscription(
		channel: String!
	) on FIELD_DEFINITION

	type Welcome {
		message: String!
	}

	type Query {
		# This should always be available even for guest users
		welcome: Welcome! @func(module: "getWelcome")
		online: Boolean!
		info: Info!
		pluginModule(plugin: String!, module: String!, params: JSON, result: String): JSON @func(result: "json")
	}

	type Mutation {
		login(username: String!, password: String!): String

		shutdown: String
		reboot: String
	}

	type Subscription {
		ping: String!
		info: Info!
		pluginModule(plugin: String!, module: String!, params: JSON, result: String): JSON!
		online: Boolean!
	}
`];

// Add test defs in dev mode
if (process.env.NODE_ENV === 'development') {
	const testDefs = gql`
		# Test query
		input testQueryInput {
			state: String!
			optional: Boolean
		}
		type Query {
			testQuery(id: String!, input: testQueryInput): JSON @func(module: "getContext")
		}

		# Test mutation
		input testMutationInput {
			state: String!
		}
		type Mutation {
			testMutation(id: String!, input: testMutationInput): JSON @func(module: "getContext")
		}

		# Test subscription
		type Subscription {
			testSubscription: String!
		}
	`;
	baseTypes.push(testDefs);
}

// Add debug defs to all envs apart from production
if (process.env.NODE_ENV !== 'production') {
	const debugDefs = gql`
		# Debug query
		type Context {
			query: JSON
			params: JSON
			data: JSON
			user: JSON
		}

		type Query {
			context: Context @func(module: "getContext")
		}
	`;
	baseTypes.push(debugDefs);
}

const types = mergeTypeDefs([
	...baseTypes,
	typeDefs
]);

const getCoreModule = (moduleName: string) => {
	if (!Object.keys(modules).includes(moduleName)) {
		throw new FatalAppError(`"${moduleName}" is not a valid core module.`);
	}

	return modules[moduleName];
};

const getPluginModule = (pluginName: string, pluginModuleName: string) => {
	if (!pluginManager.isInstalled(pluginName, pluginModuleName)) {
		throw new PluginError('Plugin not installed.');
	}

	if (!pluginManager.isActive(pluginName, pluginModuleName)) {
		throw new PluginError('Plugin disabled.');
	}

	if (!pluginModuleName) {
		return pluginManager.get(pluginName);
	}

	return pluginManager.get(pluginName, pluginModuleName);
};

/**
 * Func directive
 *
 * @see https://github.com/smooth-code/graphql-directive/blob/master/README.md#directive-resolver-function-signature
 *
 * @param {object} obj
 * The result returned from the resolver on the parent field, or, in the case of a top-level Query field,
 * the rootValue passed from the server configuration.
 * @param {object} directiveArgs
 * An object with the arguments passed into the directive in the query or schema.
 * For example, if the directive was called with `@dateFormat(format: "DD/MM/YYYY")`,
 * the args object would be: `{ "format": "DD/MM/YYYY" }`.
 * @param {object} context
 * This is an object shared by all resolvers in a particular query,
 * and is used to contain per-request state, including authentication information,
 * dataloader instances, and anything else that should be taken into account when resolving the query.
 * @param {object} info
 * This argument should only be used in advanced cases,
 * but it contains information about the execution state of the query,
 * including the field name, path to the field from the root, and more.
 */
class FuncDirective extends SchemaDirectiveVisitor {
	visitFieldDefinition(field: Record<string, any>) {
		const { args } = this;
		field.resolve = async function (_source, directiveArgs: {
			[key: string]: string | any;
			plugin: string;
			module: string;
			result: string;
			input: Record<string, any>;
			query: Record<string, any>;
		}, { user }, info: Record<string, any>) {
			const { module: moduleName, result: resultType } = args as {
				module: string;
				result: string;
			};
			const { plugin: pluginName, module: pluginModuleName, result: pluginType, input, ...params } = directiveArgs;
			const operationType = info.operation.operation;
			const query = {
				...directiveArgs.query,
				...(operationType === 'query' ? input : {})
			};
			const data = {
				...directiveArgs.data,
				...(operationType === 'mutation' ? input : {})
			};
			// If query    @func(param_1, param_2, input: query?)
			// If mutation @func(param_1, param_2, input: data)
			const context = {
				query,
				params,
				data,
				user
			};

			// Resolve func
			let func;
			try {
				if (pluginName) {
					// @ts-expect-error
					const { filePath } = getPluginModule(pluginName, pluginModuleName);
					// eslint-disable-next-line @typescript-eslint/no-var-requires
					const pluginModule = require(filePath);
					// The file will either use a default export or a named one
					// If it's named it should be the same as a module name
					func = typeof pluginModule === 'function' ? pluginModule : pluginModule[pluginModuleName];
				} else {
					func = getCoreModule(moduleName);
				}
			} catch (error: unknown) {
				if (isNodeError(error, AppError)) {
					// Rethrow clean error message about module being missing
					if (error.code === 'MODULE_NOT_FOUND') {
						throw new AppError(`Cannot find ${pluginName ? `Plugin: "${pluginName}" ` : ''}Module: "${pluginName ? pluginModuleName : moduleName}"`);
					}
				}

				// In production let's just throw an internal error
				if (process.env.NODE_ENV === 'production') {
					throw new AppError('Internal error occurred');
				}

				// Otherwise re-throw actual error
				throw error;
			}

			const pluginOrModule = pluginName ? 'Plugin:' : 'Module:';
			const pluginOrModuleName = pluginModuleName || moduleName;

			// Run function
			const [error, coreMethodResult] = await Promise.resolve(func(context, core))
				.then(result => [undefined, result])
				.catch(error_ => {
					// Ensure we aren't leaking anything in production
					if (process.env.NODE_ENV === 'production') {
						graphqlLogger.error(pluginOrModule, pluginOrModuleName, 'Error:', error_.message);
						return [new Error(error_.message)];
					}

					return [error_];
				});

			// Bail if we can't get the method to run
			if (error) {
				return error;
			}

			// Get wanted result type or fallback to json
			let result = coreMethodResult[pluginType || resultType || 'json'];

			// Allow fields to be extracted
			if (directiveArgs.extractFromResponse) {
				return get(result, directiveArgs.extractFromResponse);
			}

			return result;
		};
	}
}

const schema = makeExecutableSchema({
	typeDefs: types,
	resolvers,
	schemaDirectives: {
		func: FuncDirective
	}
});

const ensureApiKey = async (apiKeyToCheck: string) => {
	// No my servers key is loaded into memory
	if (core.apiManager.getValidKeys().filter(key => key.name === 'my_servers').length === 0) {
		const configPath = paths.get('myservers-config')!;
		await apiManager.checkKey(configPath, true);
	}

	// Check there is a valid key
	// If there were no keys when we entered this method
	// the above should have tried forcefully reloading them
	if (core.apiManager.getValidKeys().filter(key => key.name === 'my_servers').length !== 0) {
		if (!apiKeyToCheck) {
			throw new AppError('Missing API key.', 403);
		}

		if (!apiManager.isValid(apiKeyToCheck)) {
			throw new AppError('Invalid API key.', 403);
		}
	} else if (process.env.NODE_ENV !== 'development') {
		throw new AppError('No valid API keys active.', 401);
	}
};

const debug = config.get('debug');

const apiKeyToUser = async (apiKey: string) => {
	try {
		await ensureApiKey(apiKey);
	} catch (error: unknown) {
		log.debug('Failed looking up API key with "%s"', (error as Error).message);

		return { name: 'guest', role: 'guest' };
	}

	try {
		const keyName = apiManager.getNameFromKey(apiKey);

		log.silly('Found key "%s".', keyName);

		// Force upc into it's own group that's not a user group
		if (keyName && keyName === 'upc') {
			return { id: -1, description: 'UPC service account', name: 'upc', role: 'upc' };
		}

		// Force my_servers into it's own group that's not a user group
		if (keyName && keyName === 'my_servers') {
			return { id: -1, description: 'My servers service account', name: 'my_servers', role: 'my_servers' };
		}

		if (keyName) {
			const id = apiManager.getKey(keyName)?.userId;
			const foundUser = usersState.findOne({ id });
			if (foundUser) {
				return foundUser;
			}
		}
	} catch (error: unknown) {
		log.debug('Failed looking up API key with "%s"', (error as Error).message);
	}

	return { id: -1, description: 'A guest user', name: 'guest', role: 'guest' };
};

// Update array values when slots change
bus.on('slots', async () => {
	coreLogger.silly('slots updated: running getArray');
	await run('array', 'UPDATED', {
		moduleToRun: modules.getArray,
		context: {
			user: internalServiceUser
		}
	});
});

let hostname: string;

// Update info/hostname when hostname changes
bus.on('var', async data => {
	// Publish var changes
	await pubsub.publish('vars', {
		vars: data.var.node
	});

	// Hostname changed
	if (hostname !== data.var.node.name) {
		// Update cache
		hostname = data.var.node.name;

		// Publish new hostname
		await pubsub.publish('info', {
			info: {
				os: {
					hostname
				}
			}
		});
	}
});

// On Docker event update info with { apps: { installed, started } }
dee.on('*', async (data: { Type: string }) => {
	// Only listen to container events
	if (data.Type !== 'container') {
		return;
	}

	const user: User = { id: '-1', description: 'Internal service account', name: 'internal', role: 'admin', password: false };
	const { json } = await modules.getAppCount({ user });
	await publish('info', 'UPDATED', {
		apps: json
	});
});

dee.listen();

// OS uptime
run('uptime', 'UPDATED', {
	moduleToRun: modules.getUptime,
	context: {
		user: internalServiceUser
	},
	loop: Infinity
}).catch((error: unknown) => {
	log.error('Failed getting "uptime" with "%s".', (error as Error).message);
});

// Services
run('services', 'UPDATED', {
	moduleToRun: modules.getServices,
	context: {
		user: internalServiceUser
	},
	loop: Infinity
}).catch((error: unknown) => {
	log.error('Failed getting "services" with "%s".', (error as Error).message);
});

export const graphql = {
	debug,
	introspection: debug,
	playground: debug ? {
		subscriptionEndpoint: '/graphql'
	} : false,
	schema,
	types,
	resolvers,
	subscriptions: {
		keepAlive: 10000,
		onConnect: async (connectionParams: Record<string, string>) => {
			const apiKey = connectionParams['x-api-key'];
			const user = await apiKeyToUser(apiKey);
			const websocketId = uuid();

			graphqlLogger.debug(`<ws> ${user.name}[${websocketId}] connected.`);

			// Update ws connection count and other needed values
			wsHasConnected(websocketId);

			return {
				user,
				websocketId
			};
		},
		onDisconnect: async (_, websocketContext) => {
			const context = await websocketContext.initPromise;

			// This is the internal mothership connection
			// This should only disconnect if mothership restarts
			// or the network link reconnects
			if (websocketContext.socket.url === MOTHERSHIP_RELAY_WS_LINK) {
				graphqlLogger.debug('Mothership disconnected.');
				return;
			}

			// The websocket has disconnected before init event has resolved
			// @see: https://github.com/apollographql/subscriptions-transport-ws/issues/349
			if (context === true || context === false) {
				// This seems to also happen if a tab is left open and then a server starts up
				// The tab hits the server over and over again without sending init
				graphqlLogger.debug('<ws> unknown[unknown] disconnected.');
				return;
			}

			const { user, websocketId } = context as {
				user: {
					name: string;
				};
				websocketId: string;
			};
			graphqlLogger.debug(`<ws> ${user.name}[${websocketId}] disconnected.`);

			// Update ws connection count and other needed values
			wsHasDisconnected(websocketId);
		}
	},
	context: async ({ req, connection }) => {
		// Normal Websocket connection
		if (connection && Object.keys(connection.context).length >= 1) {
			// Check connection for metadata
			return {
				...connection.context
			};
		}

		// Normal HTTP connection
		if (req) {
			const apiKey = req.headers['x-api-key'];
			const user = await apiKeyToUser(apiKey);

			return {
				user
			};
		}

		throw new Error('Invalid');
	}
};