import { isProKey } from "../services/keys.js";
import logger from "../services/logger.js";
import pool from "../services/db.js";
const FREE_TIER_LIMIT = 100;
// In-memory cache, periodically synced to PostgreSQL
let usage = new Map();
function getMonthKey() {
    const d = new Date();
    return `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, "0")}`;
}
export async function loadUsageData() {
    try {
        const result = await pool.query("SELECT key, count, month_key FROM usage");
        usage = new Map();
        for (const row of result.rows) {
            usage.set(row.key, { count: row.count, monthKey: row.month_key });
        }
        logger.info(`Loaded usage data for ${usage.size} keys from PostgreSQL`);
    }
    catch (error) {
        logger.info("No existing usage data found, starting fresh");
        usage = new Map();
    }
}
async function saveUsageEntry(key, record) {
    try {
        await pool.query(`INSERT INTO usage (key, count, month_key) VALUES ($1, $2, $3)
       ON CONFLICT (key) DO UPDATE SET count = $2, month_key = $3`, [key, record.count, record.monthKey]);
    }
    catch (error) {
        logger.error({ err: error }, "Failed to save usage data");
    }
}
export function usageMiddleware(req, res, next) {
    const keyInfo = req.apiKeyInfo;
    const key = keyInfo?.key || "unknown";
    const monthKey = getMonthKey();
    if (isProKey(key)) {
        trackUsage(key, monthKey);
        next();
        return;
    }
    const record = usage.get(key);
    if (record && record.monthKey === monthKey && record.count >= FREE_TIER_LIMIT) {
        res.status(429).json({
            error: "Free tier limit reached",
            limit: FREE_TIER_LIMIT,
            used: record.count,
            upgrade: "Upgrade to Pro for unlimited conversions: https://docfast.dev/pricing",
        });
        return;
    }
    trackUsage(key, monthKey);
    next();
}
function trackUsage(key, monthKey) {
    const record = usage.get(key);
    if (!record || record.monthKey !== monthKey) {
        const newRecord = { count: 1, monthKey };
        usage.set(key, newRecord);
        saveUsageEntry(key, newRecord).catch((err) => logger.error({ err }, "Failed to save usage entry"));
    }
    else {
        record.count++;
        saveUsageEntry(key, record).catch((err) => logger.error({ err }, "Failed to save usage entry"));
    }
}
export function getUsageStats(apiKey) {
    const stats = {};
    if (apiKey) {
        const record = usage.get(apiKey);
        if (record) {
            const masked = apiKey.slice(0, 8) + "...";
            stats[masked] = { count: record.count, month: record.monthKey };
        }
    }
    return stats;
}