"use strict";

const fs = require("fs");
const _ = require("underscore");
const settings = require("../settings");

const featureNamePattern = /^feature-(\d+)(?:-[a-zA-Z0-9]+)+$/;
const versionNamePattern = /^v\d+(\.\d+)*$/;
const masterNamePattern = /^master$/;

const writeComment = (options, message, callback) => options.github.issues.createComment({
	owner: options.baseRepoOptions.owner,
	repo: options.baseRepoOptions.reponame,
	number: options.number,
	body: message
}, callback);

const closePullRequest = (options, message, callback) => writeComment(options, message, (err) => {
	if (err) {
		return callback(err);
	}

	return options.github.issues.edit({
		owner: options.baseRepoOptions.owner,
		repo: options.baseRepoOptions.reponame,
		number: options.number,
		state: "closed"
	}, callback);
});

const checkHasIssue = (options, issueNumber, callback) => options.github.issues.get({
	owner: options.baseRepoOptions.owner,
	repo: options.baseRepoOptions.reponame,
	number: issueNumber
}, (err, result) => {
	if (err && err.code !== 404) {
		return callback(err);
	}

	if (err || result.number.toString() !== issueNumber) {
		return callback(undefined, false);
	}

	if (result.pull_request && result.pull_request.url) {
		return callback(undefined, false);
	}

	return callback(undefined, true, result.title);
});

const checkHasReleases = (options, callback) => options.github.repos.getReleases({
	owner: options.baseRepoOptions.owner,
	repo: options.baseRepoOptions.reponame,
	per_page: 1
}, (err, result) => {
	if (err) {
		return callback(err);
	}

	return callback(undefined, result && result.length);
});

const checkPullRequest = (options, callback) => {
	const head = options.headRepoOptions;
	const base = options.baseRepoOptions;

	if (head.reponame !== base.reponame) {
		return closePullRequest(options, "Base and head repository names should match", callback);
	}

	if (head.owner === base.owner) {
		if (!versionNamePattern.test(head.branchname) || !masterNamePattern.test(base.branchname)) {
			return closePullRequest(options, "Only merging from version to master is allowed", callback);
		}

		return checkHasReleases(options, (err, hasReleases) => {
			if (err) {
				return writeComment(options, "Unable to check for releases", callback);
			}

			if (!hasReleases) {
				return closePullRequest(options, "Merging from version to master is only allowed for repositories with releases", callback);
			}

			if (options.action === "opened") {
				return writeComment(options, "Switching master branch to " + head.branchname + " release", callback);
			}

			return process.nextTick(callback);
		});
	}

	if (!featureNamePattern.test(head.branchname)) {
		return closePullRequest(options, "Only merging from feature branch is allowed (pattern: `" + featureNamePattern.toString() + "`)", callback);
	}

	if (!versionNamePattern.test(base.branchname) && !masterNamePattern.test(base.branchname)) {
		return closePullRequest(options, "Only merging to master or version branch is allowed; merging to '" + base.branchname + "'  is not supported", callback);
	}

	const issueNumber = featureNamePattern.exec(head.branchname)[1];
	return checkHasIssue(options, issueNumber, (err, hasIssue, issueTitle) => {
		if (err) {
			return writeComment(options, "Unable to check for issue:\r\n\r\n" + err.message, callback);
		}

		if (!hasIssue) {
			return closePullRequest(options, "Unable to find issue #" + issueNumber, callback);
		}

		const shouldHaveReleases = versionNamePattern.test(base.branchname);
		return checkHasReleases(options, (err, hasReleases) => {
			if (err) {
				return writeComment(options, "Unable to check for releases", callback);
			}

			if (shouldHaveReleases && !hasReleases) {
				return closePullRequest(options, "Merging from feature to version is only allowed for repositories with releases", callback);
			}

			if (!shouldHaveReleases && hasReleases) {
				return closePullRequest(options, "Merging from feature to master is only allowed for repositories without releases", callback);
			}

			if (options.action === "opened") {
				return writeComment(options, "Merging feature #" + issueNumber + " (" + issueTitle + ") to " + base.branchname + (shouldHaveReleases ? " release" : ""), callback);
			}

			return process.nextTick(callback);
		});
	});
};

const getStatusMessageFromRelease = (app, options, callback) => {
	const releaseDir = app.get("releasepath") + "/" + options.owner + "/" + options.reponame + "/" + options.branch + "/" + options.rev;
	const reportFile = releaseDir + "/report.json";

	options.attemptsGetReport = (options.attemptsGetReport || 0) + 1;

	fs.exists(reportFile, (exists) => {
		if (!exists) {
			return setTimeout(() => fs.exists(releaseDir, (dirExists) => {
				if (!dirExists) {
					return callback("Release directory not found. Probably repository hooks are not configured");
				}
				if (options.attemptsGetReport > 100) {
					return callback("Report file not found");
				}

				//maybe it is building right now
				return setTimeout(() => getStatusMessageFromRelease(app, options, callback), 10000);
			}), 2000);
		}

		return setTimeout(() => fs.readFile(reportFile, (err, dataBuffer) => {
			if (err) {
				return callback(err);
			}
			const data = dataBuffer.toString();
			if (!data) {
				return callback("Report file not found");
			}
			const report = JSON.parse(data);

			if (report.result === "MBSNotFound") {
				return callback("mbs.json is not found");
			}
			if (report.result && ((report.result.errors || {}).$allMessages || []).length + ((report.result.warns || {}).$allMessages || []).length > 0) {
				return callback(_.map(
					(report.result.errors || {}).$allMessages || [], (message) => "ERR: " + message.message
				).concat(_.map(
					(report.result.warns || {}).$allMessages || [], (message) => "WARN: " + message.message
				)).join("\r\n"));
			}
			if (!report.result || report.err) {
				return callback("CRITICAL ERROR: " + report.err);
			}
			if ((report.result.infos.$allMessages || []).length > 0) {
				return callback(undefined, report.result.infos.$allMessages[report.result.infos.$allMessages.length-1].message);
			}
			return callback(undefined, "OK");
		}), 1000);
	});
};

exports.commentOnPullRequest = (options, callback) => {
	options.github = settings.createGithub(options.baseRepoOptions.owner);
	return checkPullRequest(options, (err, successMessage) => getStatusMessageFromRelease(options.app, options.headRepoOptions, (err, successMessage) => {
		const message = err ? ("Was not built:\r\n\r\n```\r\n" + err.substring(0, 64000).replace(/```/g, "` ` `") + "\r\n```\r\n\r\nDO NOT MERGE!") : ("Build OK\r\n\r\n" + successMessage);
		const statusUrlMessage = "Build status URL: " + settings.siteRoot + "status/" + options.headRepoOptions.owner + "/" + options.headRepoOptions.reponame + "/" + options.headRepoOptions.rev + "\r\n\r\n";
		return writeComment(options, message + "\r\n\r\n" + statusUrlMessage, callback);
	}));
};