/**
 * @license
 * Copyright 2018-2020 Balena Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import { BalenaSDK } from 'balena-sdk';
import * as Bluebird from 'bluebird';
import { stripIndent } from 'common-tags';
import Dockerode = require('dockerode');
import * as _ from 'lodash';
import { fs } from 'mz';
import * as path from 'path';
import { Composition } from 'resin-compose-parse';
import * as MultiBuild from 'resin-multibuild';
import { Readable } from 'stream';
import * as tar from 'tar-stream';

import { ExpectedError } from '../errors';
import { DeviceInfo } from './device/api';
import Logger = require('./logger');

export interface RegistrySecrets {
	[registryAddress: string]: {
		username: string;
		password: string;
	};
}

const compositionFileNames = ['docker-compose.yml', 'docker-compose.yaml'];

/**
 * high-level function resolving a project and creating a composition out
 * of it in one go. if image is given, it'll create a default project for
 * that without looking for a project. falls back to creating a default
 * project if none is found at the given projectPath.
 */
export async function loadProject(
	logger: Logger,
	opts: import('./compose').ComposeOpts,
	image?: string,
): Promise<import('./compose').ComposeProject> {
	const compose = await import('resin-compose-parse');
	const { createProject } = await import('./compose');
	let composeName: string;
	let composeStr: string;

	logger.logDebug('Loading project...');

	if (image) {
		logger.logInfo(`Creating default composition with image: "${image}"`);
		composeStr = compose.defaultComposition(image);
	} else {
		logger.logDebug('Resolving project...');
		[composeName, composeStr] = await resolveProject(logger, opts.projectPath);
		if (composeName) {
			if (opts.dockerfilePath) {
				logger.logWarn(
					`Ignoring alternative dockerfile "${opts.dockerfilePath}" because composition file "${composeName}" exists`,
				);
			}
		} else {
			logger.logInfo(
				`Creating default composition with source: "${opts.projectPath}"`,
			);
			composeStr = compose.defaultComposition(undefined, opts.dockerfilePath);
		}
	}
	logger.logDebug('Creating project...');
	return createProject(opts.projectPath, composeStr, opts.projectName);
}

/**
 * Look into the given directory for valid compose files and return
 * the contents of the first one found.
 */
async function resolveProject(
	logger: Logger,
	projectRoot: string,
): Promise<[string, string]> {
	let composeFileName = '';
	let composeFileContents = '';
	for (const fname of compositionFileNames) {
		const fpath = path.join(projectRoot, fname);
		if (await fs.exists(fpath)) {
			logger.logDebug(`${fname} file found at "${projectRoot}"`);
			composeFileName = fname;
			try {
				composeFileContents = await fs.readFile(fpath, 'utf-8');
			} catch (err) {
				logger.logError(`Error reading composition file "${fpath}":\n${err}`);
				throw err;
			}
			break;
		}
	}
	if (!composeFileName) {
		logger.logInfo(`No "docker-compose.yml" file found at "${projectRoot}"`);
	}
	return [composeFileName, composeFileContents];
}

/**
 * Load the ".balena/balena.yml" file (or resin.yml, or yaml or json),
 * which contains "build metadata" for features like "build secrets" and
 * "build variables".
 * @returns Pair of metadata object and metadata file path
 */
async function loadBuildMetatada(
	sourceDir: string,
): Promise<[MultiBuild.ParsedBalenaYml, string]> {
	let metadataPath = '';
	let rawString = '';

	outer: for (const fName of ['balena', 'resin']) {
		for (const fExt of ['yml', 'yaml', 'json']) {
			metadataPath = path.join(sourceDir, `.${fName}`, `${fName}.${fExt}`);
			try {
				rawString = await fs.readFile(metadataPath, 'utf8');
				break outer;
			} catch (err) {
				if (err.code === 'ENOENT') {
					// file not found, try the next name.extension combination
					continue;
				} else {
					throw err;
				}
			}
		}
	}
	if (!rawString) {
		return [{}, ''];
	}
	let buildMetadata: MultiBuild.ParsedBalenaYml;
	try {
		if (metadataPath.endsWith('json')) {
			buildMetadata = JSON.parse(rawString);
		} else {
			buildMetadata = require('js-yaml').safeLoad(rawString);
		}
	} catch (err) {
		throw new ExpectedError(
			`Error parsing file "${metadataPath}":\n ${err.message}`,
		);
	}
	return [buildMetadata, metadataPath];
}

/**
 * Check whether the "build secrets" feature is being used and, if so,
 * verify that the target docker daemon is balenaEngine. If the
 * requirement is not satisfied, reject with an ExpectedError.
 * @param docker Dockerode instance
 * @param sourceDir Project directory where to find .balena/balena.yml
 */
export async function checkBuildSecretsRequirements(
	docker: Dockerode,
	sourceDir: string,
) {
	const [metaObj, metaFilename] = await loadBuildMetatada(sourceDir);
	if (metaObj && !_.isEmpty(metaObj['build-secrets'])) {
		const dockerUtils = await import('./docker');
		const isBalenaEngine = await dockerUtils.isBalenaEngine(docker);
		if (!isBalenaEngine) {
			throw new ExpectedError(stripIndent`
				The "build secrets" feature currently requires balenaEngine, but a standard Docker
				daemon was detected. Please use command-line options to specify the hostname and
				port number (or socket path) of a balenaEngine daemon, running on a balena device
				or a virtual machine with balenaOS. If the build secrets feature is not required,
				comment out or delete the 'build-secrets' entry in the file:
				"${metaFilename}"
				`);
		}
	}
}

export async function getRegistrySecrets(
	sdk: BalenaSDK,
	inputFilename?: string,
): Promise<RegistrySecrets> {
	if (inputFilename != null) {
		return await parseRegistrySecrets(inputFilename);
	}

	const directory = await sdk.settings.get('dataDirectory');
	const potentialPaths = [
		path.join(directory, 'secrets.yml'),
		path.join(directory, 'secrets.yaml'),
		path.join(directory, 'secrets.json'),
	];

	for (const potentialPath of potentialPaths) {
		if (await fs.exists(potentialPath)) {
			return await parseRegistrySecrets(potentialPath);
		}
	}

	return {};
}

async function parseRegistrySecrets(
	secretsFilename: string,
): Promise<RegistrySecrets> {
	try {
		let isYaml = false;
		if (/.+\.ya?ml$/i.test(secretsFilename)) {
			isYaml = true;
		} else if (!/.+\.json$/i.test(secretsFilename)) {
			throw new Error('Filename must end with .json, .yml or .yaml');
		}
		const raw = (await fs.readFile(secretsFilename)).toString();
		const registrySecrets = new MultiBuild.RegistrySecretValidator().validateRegistrySecrets(
			isYaml ? require('js-yaml').safeLoad(raw) : JSON.parse(raw),
		);
		MultiBuild.addCanonicalDockerHubEntry(registrySecrets);
		return registrySecrets;
	} catch (error) {
		throw new ExpectedError(
			`Error validating registry secrets file "${secretsFilename}":\n${error.message}`,
		);
	}
}

/**
 * Create a BuildTask array of "resolved build tasks" by calling multibuild
 * .splitBuildStream() and performResolution(), and add build stream error
 * handlers and debug logging.
 * Both `balena build` and `balena deploy` call this function.
 */
export async function makeBuildTasks(
	composition: Composition,
	tarStream: Readable,
	deviceInfo: DeviceInfo,
	logger: Logger,
	projectName: string,
	releaseHash: string = 'unavailable',
): Promise<MultiBuild.BuildTask[]> {
	const buildTasks = await MultiBuild.splitBuildStream(composition, tarStream);

	logger.logDebug('Found build tasks:');
	_.each(buildTasks, task => {
		let infoStr: string;
		if (task.external) {
			infoStr = `image pull [${task.imageName}]`;
		} else {
			infoStr = `build [${task.context}]`;
		}
		logger.logDebug(`    ${task.serviceName}: ${infoStr}`);
	});

	logger.logDebug(
		`Resolving services with [${deviceInfo.deviceType}|${deviceInfo.arch}]`,
	);

	await performResolution(buildTasks, deviceInfo, projectName, releaseHash);

	logger.logDebug('Found project types:');
	_.each(buildTasks, task => {
		if (task.external) {
			logger.logDebug(`    ${task.serviceName}: External image`);
		} else {
			logger.logDebug(`    ${task.serviceName}: ${task.projectType}`);
		}
	});

	return buildTasks;
}

async function performResolution(
	tasks: MultiBuild.BuildTask[],
	deviceInfo: DeviceInfo,
	appName: string,
	releaseHash: string,
): Promise<MultiBuild.BuildTask[]> {
	const { cloneTarStream } = require('tar-utils');

	return await new Promise<MultiBuild.BuildTask[]>((resolve, reject) => {
		const buildTasks = MultiBuild.performResolution(
			tasks,
			deviceInfo.arch,
			deviceInfo.deviceType,
			{ error: [reject] },
			{
				BALENA_RELEASE_HASH: releaseHash,
				BALENA_APP_NAME: appName,
			},
		);
		// Do one task at a time (Bluebird.each instead of Bluebird.all)
		// in order to reduce peak memory usage. Resolves to buildTasks.
		Bluebird.each(buildTasks, buildTask => {
			// buildStream is falsy for "external" tasks (image pull)
			if (!buildTask.buildStream) {
				return buildTask;
			}
			// Consume each task.buildStream in order to trigger the
			// resolution events that define fields like:
			//     task.dockerfile, task.dockerfilePath,
			//     task.projectType, task.resolved
			// This mimics what is currently done in `resin-builder`.
			return cloneTarStream(buildTask.buildStream).then(
				(clonedStream: tar.Pack) => {
					buildTask.buildStream = clonedStream;
					if (!buildTask.external && !buildTask.resolved) {
						throw new Error(
							`Project type for service "${buildTask.serviceName}" could not be determined. Missing a Dockerfile?`,
						);
					}
					return buildTask;
				},
			);
		}).then(resolve, reject);
	});
}

/**
 * Enforce that, for example, if 'myProject/MyDockerfile.template' is specified
 * as an alternativate Dockerfile name, then 'myProject/MyDockerfile' must not
 * exist.
 * Return the tar stream path (Posix, normalized) for the given dockerfilePath.
 * For example, on Windows, given a dockerfilePath of 'foo\..\bar\Dockerfile',
 * return 'bar/Dockerfile'. On Linux, given './bar/Dockerfile', return 'bar/Dockerfile'.
 *
 * @param projectPath The project source folder (-s command-line option)
 * @param dockerfilePath The alternative Dockerfile specified by the user
 * @return A normalized posix representation of dockerfilePath
 */
async function validateSpecifiedDockerfile(
	projectPath: string,
	dockerfilePath: string,
): Promise<string> {
	const { contains, toNativePath, toPosixPath } = MultiBuild.PathUtils;

	const nativeProjectPath = path.normalize(projectPath);
	const nativeDockerfilePath = path.normalize(toNativePath(dockerfilePath));

	// reminder: native windows paths may start with a drive specificaton,
	// e.g. 'C:\absolute' or 'C:relative'.
	if (path.isAbsolute(nativeDockerfilePath)) {
		throw new ExpectedError(stripIndent`
			Error: the specified Dockerfile cannot be an absolute path. The path must be
			relative to, and not a parent folder of, the project's source folder.
			Specified dockerfile: "${nativeDockerfilePath}"
			Project's source folder: "${nativeProjectPath}"
		`);
	}

	// note that path.normalize('a/../../b') results in '../b'
	if (nativeDockerfilePath.startsWith('..')) {
		throw new ExpectedError(stripIndent`
			Error: the specified Dockerfile cannot be in a parent folder of the project's
			source folder. Note that the path should be relative to the project's source
			folder, not the current folder.
			Specified dockerfile: "${nativeDockerfilePath}"
			Project's source folder: "${nativeProjectPath}"
		`);
	}

	const fullDockerfilePath = path.join(nativeProjectPath, nativeDockerfilePath);

	if (!(await fs.exists(fullDockerfilePath))) {
		throw new ExpectedError(stripIndent`
			Error: specified Dockerfile not found:
			Specified dockerfile: "${fullDockerfilePath}"
			Project's source folder: "${nativeProjectPath}"
			Note that the specified Dockerfile path should be relative to the source folder.
		`);
	}

	if (!contains(nativeProjectPath, fullDockerfilePath)) {
		throw new ExpectedError(stripIndent`
			Error: the specified Dockerfile must be in a subfolder of the source folder:
			Specified dockerfile: "${fullDockerfilePath}"
			Project's source folder: "${nativeProjectPath}"
		`);
	}

	return toPosixPath(nativeDockerfilePath);
}

export interface ProjectValidationResult {
	dockerfilePath: string;
	registrySecrets: RegistrySecrets;
}

/**
 * Perform "sanity checks" on the project directory, e.g. for the existence
 * of a 'Dockerfile[.*]' or 'docker-compose.yml' file or 'package.json' file.
 * Also validate registry secrets if any, and perform checks around an
 * alternative specified dockerfile (--dockerfile) if any.
 *
 * Return the parsed registry secrets if any, and the "tar stream path" for
 * an alternative specified Dockerfile if any (see validateSpecifiedDockerfile()).
 */
export async function validateProjectDirectory(
	sdk: BalenaSDK,
	opts: {
		dockerfilePath?: string;
		noParentCheck: boolean;
		projectPath: string;
		registrySecretsPath?: string;
	},
): Promise<ProjectValidationResult> {
	if (
		!(await fs.exists(opts.projectPath)) ||
		!(await fs.stat(opts.projectPath)).isDirectory()
	) {
		throw new ExpectedError(
			`Could not access source folder: "${opts.projectPath}"`,
		);
	}

	const result: ProjectValidationResult = {
		dockerfilePath: opts.dockerfilePath || '',
		registrySecrets: {},
	};

	if (opts.dockerfilePath) {
		result.dockerfilePath = await validateSpecifiedDockerfile(
			opts.projectPath,
			opts.dockerfilePath,
		);
	} else {
		const files = await fs.readdir(opts.projectPath);
		const projectMatch = (file: string) =>
			/^(Dockerfile|Dockerfile\.\S+|docker-compose.ya?ml|package.json)$/.test(
				file,
			);
		if (!_.some(files, projectMatch)) {
			throw new ExpectedError(stripIndent`
				Error: no "Dockerfile[.*]", "docker-compose.yml" or "package.json" file
				found in source folder "${opts.projectPath}"
			`);
		}
		if (!opts.noParentCheck) {
			const checkCompose = async (folder: string) => {
				return _.some(
					await Promise.all(
						compositionFileNames.map(filename =>
							fs.exists(path.join(folder, filename)),
						),
					),
				);
			};
			const [hasCompose, hasParentCompose] = await Promise.all([
				checkCompose(opts.projectPath),
				checkCompose(path.join(opts.projectPath, '..')),
			]);
			if (!hasCompose && hasParentCompose) {
				Logger.getLogger().logWarn(stripIndent`
					"docker-compose.y[a]ml" file found in parent directory: please check
					that the correct folder was specified. (Suppress with '--noparent-check'.)
				`);
			}
		}
	}
	result.registrySecrets = await getRegistrySecrets(
		sdk,
		opts.registrySecretsPath,
	);

	return result;
}