import axios from "axios";
import 'dotenv/config';
import express from 'express';

const app = express();
const PORT = process.env.PORT;

app.get('/metrics', async (req, res) => { 
    try {
        const metrics = await fetchAndParsePrometheusData();
        res.json(metrics);
    } catch (error) {
        res.status(500).json({ error: 'Server error', details: error.message });
    }
})


app.listen(PORT, () => {
    console.log(`Server running on http://localhost:${PORT}`);
});  

function parseKumaMetrics(metricsString) {
    const lines = metricsString.split("\n").map(line => line.trim()).filter(line => line);
    const result = {};
    let currentHelp = null;
    let currentType = null;
  
    for (const line of lines) {
        if (line.startsWith("# HELP")) {
            const [, metricName, description] = line.match(/^# HELP (\S+) (.+)$/) || [];
            if (metricName) {
                currentHelp = description;
                result[metricName] = { help: currentHelp, type: currentType, metrics: [] };
            }
        } else if (line.startsWith("# TYPE")) {
            const [, metricName, type] = line.match(/^# TYPE (\S+) (\S+)$/) || [];
            if (metricName) {
                currentType = type;
                if (!result[metricName]) {
                    result[metricName] = { help: currentHelp, type: currentType, metrics: [] };
                } else {
                    result[metricName].type = type;
                }
            }
        } else {
            const metricRegex = /^(\w+)(?:\{([^}]*)\})?\s+([\d.e+-]+)$/;
            const match = line.match(metricRegex);
  
            if (match) {
                const [, metricName, labels, value] = match;
                const labelObject = {};
  
                if (labels) {
                    labels.split(",").forEach(pair => {
                        const [key, val] = pair.split("=");
                        labelObject[key.trim()] = val.trim().replace(/^"|"$/g, '');
                    });
                }
  
                if (!result[metricName]) {
                    result[metricName] = { help: currentHelp, type: currentType, metrics: [] };
                }
  
                result[metricName].metrics.push({ labels: labelObject, value: parseFloat(value) });
            }
        }
    }
  
    return result;
  }

async function fetchAndParsePrometheusData() {
  const URI = process.env.URI
  const PASS = process.env.PASS
    try {
        const response = await axios.get(URI, {
            auth: {
                username: "", // Empty username
                password: PASS
            }
        });

        const prometheusData = response.data; 
        // console.log("Metrics Data:", prometheusData); 

        const jsonData = parseKumaMetrics(prometheusData);
        // console.log(JSON.stringify(jsonData, null, 2));
        return jsonData;
    } catch (error) {
        console.error("Error fetching metrics:", error.message);
    }
}