import "dotenv/config";
import express, { Request, Response, NextFunction } from "express";
import multer from "multer";
import { config } from "./config";
import { scanShelfPhoto } from "./shelf";
import { scanPantryPhoto } from "./pantry";
import { extractProductInfo } from "./enrich";
import { getCount } from "./chroma";

const ALLOWED_MIMES = new Set([
  "image/jpeg",
  "image/png",
  "image/webp",
  "image/gif",
  "image/heic",
  "image/heif",
]);

const app = express();

const upload = multer({
  storage: multer.memoryStorage(),
  limits: {
    fileSize: config.maxFileSize,
    files: 1,
  },
  fileFilter: (_req, file, cb) => {
    if (ALLOWED_MIMES.has(file.mimetype)) {
      cb(null, true);
    } else {
      cb(new Error("Invalid file type. Allowed: JPEG, PNG, WebP, GIF, HEIC, HEIF"));
    }
  },
});

// --- Health check ---

app.get("/health", async (_req: Request, res: Response) => {
  const status: Record<string, unknown> = {
    status: "ok",
    vision_model: config.visionAiModel,
  };

  // Check vision model
  try {
    const visionUrl = config.visionAiUrl.replace("/v1/chat/completions", "/v1/models");
    const resp = await fetch(visionUrl, { signal: AbortSignal.timeout(5000) });
    status.vision = resp.ok ? "connected" : `status ${resp.status}`;
  } catch (err) {
    status.vision = `unreachable: ${err instanceof Error ? err.message : err}`;
    status.status = "degraded";
  }

  // Check Ollama
  try {
    const resp = await fetch(`${config.ollamaHost}/api/tags`, {
      signal: AbortSignal.timeout(5000),
    });
    status.ollama = resp.ok ? "connected" : `status ${resp.status}`;
  } catch (err) {
    status.ollama = `unreachable: ${err instanceof Error ? err.message : err}`;
    status.status = "degraded";
  }

  // Check ChromaDB
  try {
    const count = await getCount();
    status.chroma = "connected";
    status.chroma_count = count;
  } catch (err) {
    status.chroma = `unreachable: ${err instanceof Error ? err.message : err}`;
    status.status = "degraded";
  }

  res.json(status);
});

// --- Scan endpoints ---

app.post(
  "/scan/shelf",
  upload.single("image"),
  async (req: Request, res: Response, next: NextFunction) => {
    try {
      const file = req.file;
      if (!file) {
        res.status(400).json({ error: "No image provided" });
        return;
      }

      const storeName = req.body?.store_name;
      if (!storeName) {
        res.status(400).json({ error: "store_name is required" });
        return;
      }

      const result = await scanShelfPhoto(file.buffer, storeName);
      res.json(result);
    } catch (err) {
      next(err);
    }
  }
);

app.post(
  "/scan/pantry",
  upload.single("image"),
  async (req: Request, res: Response, next: NextFunction) => {
    try {
      const file = req.file;
      if (!file) {
        res.status(400).json({ error: "No image provided" });
        return;
      }

      const result = await scanPantryPhoto(file.buffer);
      res.json(result);
    } catch (err) {
      next(err);
    }
  }
);

// --- Product enrichment ---

app.post(
  "/enrich/product",
  upload.single("image"),
  async (req: Request, res: Response, next: NextFunction) => {
    try {
      const file = req.file;
      if (!file) {
        res.status(400).json({ error: "No image provided" });
        return;
      }

      const result = await extractProductInfo(file.buffer);
      res.json(result);
    } catch (err) {
      next(err);
    }
  }
);

// --- 404 ---

app.use((_req: Request, res: Response) => {
  res.status(404).json({ error: "Not found" });
});

// --- Error handler ---

app.use((err: Error, _req: Request, res: Response, _next: NextFunction) => {
  if (err instanceof multer.MulterError && err.code === "LIMIT_FILE_SIZE") {
    res.status(413).json({ error: `File too large. Maximum size is ${config.maxFileSize / 1024 / 1024}MB.` });
    return;
  }

  if (err.message.startsWith("Invalid file type")) {
    res.status(400).json({ error: err.message });
    return;
  }

  console.error("Scan error:", err.message);
  res.status(502).json({ error: "Failed to process image" });
});

// --- Start ---

app.listen(config.port, "0.0.0.0", () => {
  console.log(`Vision Scanner Service listening on port ${config.port}`);
  console.log(`Vision AI: ${config.visionAiUrl} (model: ${config.visionAiModel})`);
  console.log(`Ollama: ${config.ollamaHost} (embed: ${config.ollamaEmbedModel})`);
  console.log(`ChromaDB: ${config.chromaHost}`);
});