import * as changelogConfig from "./changelogConfig.js";

const REGEX_CHANGELOG_LINE = /^(\w+): (.+)$/;

const CHANGELOG_KEYS_TO_ENTRY = {};
for (const [types, entry] of changelogConfig.CHANGELOG_ENTRIES) {
	const entryWithChangelogKey = {
		...entry,
		changelogKey: types[0],
	};

	for (const type of types) {
		CHANGELOG_KEYS_TO_ENTRY[type] = entryWithChangelogKey;
	}
}

function parseChangelogBody(lines, openTag) {
	const [changelogOpening] = lines.splice(0, 1);

	const author =
		changelogOpening.substring(openTag.length).trim() || undefined;

	const changelog = {
		author,
		changes: [],
	};

	for (const line of lines) {
		if (line.trim().length === 0) {
			continue;
		}

		for (const closeTag of changelogConfig.CHANGELOG_CLOSE_TAGS) {
			if (line.startsWith(closeTag)) {
				return changelog;
			}
		}

		const match = line.match(REGEX_CHANGELOG_LINE);
		if (match) {
			const [_, type, description] = match;

			const entry = CHANGELOG_KEYS_TO_ENTRY[type] || CHANGELOG_KEYS_TO_ENTRY["rscadd"];

			if (entry.placeholders.includes(description)) {
				continue;
			}

			if (entry) {
				changelog.changes.push({
					type: entry,
					description,
				});
			}
		} else {
			const lastChange = changelog.changes[changelog.changes.length - 1];
			if (lastChange) {
				lastChange.description += `\n${line}`;
			}
		}
	}

	return changelog;
}

export function parseChangelog(text) {
	const lines = text.split("\n").map((line) => line.trim());

	for (let index = 0; index < lines.length; index++) {
		const line = lines[index];

		for (const openTag of changelogConfig.CHANGELOG_OPEN_TAGS) {
			if (line.startsWith(openTag)) {
				return parseChangelogBody(lines.slice(index), openTag);
			}
		}
	}

	return undefined;
}