chore: init backend and ignore local artifacts

routes/tiles.js

@@ -0,0 +1,79 @@
+const express = require("express");
+const Database = require("better-sqlite3");
+const path = require("path");
+
+const router = express.Router();
+
+// =======================
+// MBTiles DB (READONLY)
+// =======================
+const mbtilesPath = path.join(__dirname, "..", "data", "map.mbtiles");
+const tileDb = new Database(mbtilesPath, { readonly: true });
+
+// =======================
+// 📊 METADATA
+// =======================
+const metadataRows = tileDb.prepare("SELECT name, value FROM metadata").all();
+const metadata = {};
+
+for (const row of metadataRows) {
+    metadata[row.name] = row.value;
+}
+
+// decide content-type
+let contentType = "application/octet-stream";
+
+if (metadata.format === "pbf") {
+    contentType = "application/x-protobuf";
+} else if (metadata.format === "png") {
+    contentType = "image/png";
+} else if (metadata.format === "jpg" || metadata.format === "jpeg") {
+    contentType = "image/jpeg";
+}
+
+// =======================
+// METADATA API
+// =======================
+router.get("/metadata/info", (req, res) => {
+    res.json(metadata);
+});
+
+// =======================
+// TILE API (XYZ → TMS)
+// =======================
+router.get("/:z/:x/:y", (req, res) => {
+    const z = Number(req.params.z);
+    const x = Number(req.params.x);
+    const y = Number(req.params.y);
+
+    if (!Number.isInteger(z) || !Number.isInteger(x) || !Number.isInteger(y)) {
+        return res.status(400).send("Invalid tile coordinates");
+    }
+
+    // convert XYZ → TMS
+    const tmsY = (1 << z) - 1 - y;
+
+    const stmt = tileDb.prepare(`
+        SELECT tile_data
+        FROM tiles
+        WHERE zoom_level = ?
+          AND tile_column = ?
+          AND tile_row = ?
+    `);
+
+    const tile = stmt.get(z, x, tmsY);
+
+    if (!tile) {
+        return res.status(404).send("Tile not found");
+    }
+
+    res.setHeader("Content-Type", contentType);
+
+    if (metadata.format === "pbf") {
+        res.setHeader("Content-Encoding", "gzip");
+    }
+
+    res.send(tile.tile_data);
+});
+
+module.exports = router;