const path = require("path");
const { DateTime } = require("luxon");
const { collectMarkdownFiles, collectSectionIndexDirs } = require("../content");
const { readFrontmatter } = require("../weather/frontmatter");

function parseDate(value) {
    if (!value) return null;

    if (value instanceof Date) {
        return DateTime.fromJSDate(value);
    }

    if (typeof value === "string") {
        let parsed = DateTime.fromISO(value);

        if (!parsed.isValid) {
            parsed = DateTime.fromRFC2822(value);
        }

        return parsed.isValid ? parsed : null;
    }

    return null;
}

function countWords(body) {
    if (!body) return 0;

    const cleaned = body
        .replace(/```[\s\S]*?```/g, " ") // fenced code blocks
        .replace(/`[^`]*`/g, " ") // inline code
        .replace(/<[^>]+>/g, " "); // html tags

    const words = cleaned.match(/[\p{L}\p{N}'-]+/gu);
    return words ? words.length : 0;
}

async function loadArticles(contentDir) {
    const files = await collectMarkdownFiles(contentDir);
    const sectionDirs = await collectSectionIndexDirs(contentDir);
    const rootDir = path.resolve(contentDir);
    const articles = [];

    function resolveSection(filePath) {
        const absolute = path.resolve(filePath);
        let current = path.dirname(absolute);

        while (current.startsWith(rootDir)) {
            if (sectionDirs.has(current)) {
                return path.relative(rootDir, current).replace(/\\/g, "/") || ".";
            }
            const parent = path.dirname(current);
            if (parent === current) break;
            current = parent;
        }

        return null;
    }

    for (const file of files) {
        const frontmatter = await readFrontmatter(file);
        if (!frontmatter) continue;

        const date = parseDate(frontmatter.doc.get("date"));
        const title = frontmatter.doc.get("title") || path.basename(file, ".md");
        const body = frontmatter.body.trim();
        const wordCount = countWords(body);
        const relativePath = path.relative(contentDir, file);
        const section = resolveSection(file);

        articles.push({
            path: file,
            relativePath,
            title,
            date,
            body,
            wordCount,
            section,
            frontmatter: frontmatter.doc.toJS ? frontmatter.doc.toJS() : frontmatter.doc.toJSON(),
        });
    }

    return articles;
}

module.exports = {
    collectMarkdownFiles,
    countWords,
    loadArticles,
    parseDate,
};