#!/usr/bin/env node

const { loadArticles } = require("../lib/stats/articles");
const { renderWithPython } = require("../lib/stats/python");

const MONTH_LABELS = ["Jan", "Fev", "Mar", "Avr", "Mai", "Jun", "Jul", "Aou", "Sep", "Oct", "Nov", "Dec"];

function groupByMonthAndYear(articles) {
    const counts = new Map();
    const years = new Set();
    let first = null;
    let last = null;

    for (const article of articles) {
        if (!article.date) continue;
        const year = article.date.year;
        const month = article.date.month; // 1..12
        years.add(year);
        const key = `${year}-${month}`;
        counts.set(key, (counts.get(key) || 0) + 1);
        if (!first || article.date < first) first = article.date;
        if (!last || article.date > last) last = article.date;
    }

    const monthNumbers = Array.from({ length: 12 }, (_, index) => index + 1);
    const labels = monthNumbers.map((month) => MONTH_LABELS[month - 1]);
    const sortedYears = Array.from(years).sort((a, b) => a - b);

    const series = sortedYears.map((year) => {
        return {
            label: String(year),
            values: monthNumbers.map((month) => counts.get(`${year}-${month}`) || 0),
        };
    });

    return { labels, series, first, last };
}

async function run({ contentDir, outputPath, publicPath }) {
    if (!outputPath) {
        throw new Error("outputPath manquant pour articles_per_month");
    }

    const articles = await loadArticles(contentDir || "content");
    const { labels, series, first, last } = groupByMonthAndYear(articles);

    await renderWithPython({
        type: "articles_per_month",
        outputPath,
        data: {
            labels,
            series,
            title: "Articles par mois",
        },
    });

    return {
        image: publicPath,
        meta: {
            from: first ? first.toISODate() : null,
            to: last ? last.toISODate() : null,
            months: labels.length,
        },
    };
}

module.exports = { run };