// Major Australian city centers and their coordinates const CITIES: Record = { "2": { lat: -33.8688, lon: 151.2093, name: "SYDNEY" }, "3": { lat: -37.8136, lon: 144.9631, name: "MELBOURNE" }, "4": { lat: -27.4698, lon: 153.0251, name: "BRISBANE" }, "5": { lat: -34.9285, lon: 138.6007, name: "ADELAIDE" }, "6": { lat: -31.9505, lon: 115.8605, name: "PERTH" }, "7": { lat: -42.8821, lon: 147.3272, name: "HOBART" }, "0": { lat: -12.4634, lon: 130.8456, name: "DARWIN" }, }; export default async function (req: Request): Promise { if (req.method !== "GET") { return new Response("Method not allowed", { status: 405 }); } const url = new URL(req.url); const format = url.searchParams.get("format") || "image"; const postcode = url.searchParams.get("postcode") || "3000"; // Validate postcode and get city info const cityPrefix = postcode.charAt(0); const city = CITIES[cityPrefix]; if (!city || !/^\d{4}$/.test(postcode)) { return new Response(`Invalid postcode: ${postcode}`, { status: 400 }); } const { lat, lon, name } = city; // Fetch AQI data for the given location const response = await fetch( `https://air-quality-api.open-meteo.com/v1/air-quality?latitude=${lat}&longitude=${lon}&hourly=us_aqi` ); const data = await response.json(); // Get the latest non-null AQI value and metadata const aqiValues = data.hourly.us_aqi; const times = data.hourly.time; let latestAqi = null; let latestTime = null; for (let i = aqiValues.length - 1; i >= 0; i--) { if (aqiValues[i] !== null) { latestAqi = aqiValues[i]; latestTime = times[i]; break; } } // Determine AQI category and styling const getAQIInfo = (aqi: number | null) => { if (aqi === null) return { color: "#6B7280", gradient: ["#1F2937", "#374151"], category: "Unknown" }; if (aqi <= 50) return { color: "#10B981", gradient: ["#065F46", "#059669"], category: "Good" }; if (aqi <= 100) return { color: "#F59E0B", gradient: ["#92400E", "#D97706"], category: "Moderate" }; if (aqi <= 150) return { color: "#F97316", gradient: ["#9A3412", "#EA580C"], category: "Unhealthy for Sensitive Groups" }; if (aqi <= 200) return { color: "#EF4444", gradient: ["#991B1B", "#DC2626"], category: "Unhealthy" }; if (aqi <= 300) return { color: "#A855F7", gradient: ["#6B21A8", "#9333EA"], category: "Very Unhealthy" }; return { color: "#991B1B", gradient: ["#7F1D1D", "#991B1B"], category: "Hazardous" }; }; const aqiInfo = getAQIInfo(latestAqi); const timestamp = latestTime ? new Date(latestTime).toLocaleString('en-AU', { timeZone: 'Australia/Melbourne', dateStyle: 'medium', timeStyle: 'short' }) : ""; // Return JSON if requested if (format === "json") { return new Response(JSON.stringify({ location: name, postcode, aqi: latestAqi, timestamp: latestTime, category: aqiInfo.category, color: aqiInfo.color, coordinates: { lat, lon }, updated_at: timestamp }), { headers: { "content-type": "application/json", "cache-control": "no-cache, no-store, must-revalidate", }, }); } // Set dimensions for SVG const width = 600; const height = 180; // Update the location text in the SVG to show postcode const locationText = `${name} ${postcode} [${lat}°, ${lon}°]`; // Generate SVG const svg = ` `; return new Response(svg, { headers: { "content-type": "image/svg+xml", "cache-control": "no-cache, no-store, must-revalidate", "content-disposition": "inline", "access-control-allow-origin": "*", "x-content-type-options": "nosniff" }, }); }

airSource