/*
 * Copyright 2016 Resin.io
 *
 * 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.
 */

/**
 * @module Versionist.Tags
 */

import * as _ from 'lodash';

/**
 * @summary Is line a tag line?
 * @function
 * @public
 *
 * @param {String} line - commit line
 * @returns {Boolean} whether the line represents a tag line
 *
 * @example
 * if (tags.isTagLine('Foo: bar')) {
 *   console.log('This line represents a tag');
 * }
 */
export const isTagLine = (line: string): boolean => {
	return _.some([
		/^[\w-]+(\s+)?:[^//]/.test(line),
		/^[\w-]+(\s+)?:$/.test(line),
	]);
};

/**
 * @summary Parse a tag line
 * @function
 * @private
 *
 * @param {String} line - commit line
 * @returns {Object} parsed tag
 *
 * @example
 * const parsedTag = tags.parseTagLine('Foo: bar');
 *
 * console.log(parsedTag.key);
 * > Foo
 * console.log(parsedTag.value);
 * > bar
 */
export const parseTagLine = (line: string) => {
	const firstColonIndex = _.indexOf(line, ':');

	return {
		key: line.slice(0, firstColonIndex).trim(),
		value: line.slice(firstColonIndex + 1).trim() || undefined,
	};
};

/**
 * @summary Parse footer tags lines
 * @function
 * @public
 *
 * @param {String[]} footerTagLines - footer tag lines
 * @param {Object} [options={}] - options
 * @param {Boolean} [options.lowerCaseFooterTags=false] - lowercase footer tag keys
 * @returns {Object} parsed tags
 *
 * @example
 * const footer = tags.parseFooterTagLines([
 *   'Foo: bar',
 *   'Bar: baz'
 * ]);
 *
 * console.log(footer.Foo);
 * > bar
 *
 * console.log(footer.Bar);
 * > baz
 */
export const parseFooterTagLines = (
	footerTagLines: string[],
	options: { lowerCaseFooterTags?: boolean } = {},
): _.Dictionary<string> => {
	return _.chain(footerTagLines)
		.reject((line) => {
			line = line.trim();
			return (
				_.isEmpty(line) ||
				/^\(cherry\spicked\sfrom\scommit\s[0-9a-f]{7,40}\)$/.test(line)
			);
		})
		.reduce((tags: Array<[string, string?]>, tagLine) => {
			const tag = parseTagLine(tagLine);

			tags.push([tag.key, tag.value]);

			if (options.lowerCaseFooterTags) {
				tags.push([tag.key.toLowerCase(), tag.value]);
			}

			return tags;
		}, [])
		.fromPairs()
		.value();
};