import { existsSync } from "node:fs";
import { join } from "node:path";
import cors from "cors";
import "dotenv/config";
import express from "express";
import { z } from "zod";
import { AzureImageService } from "./azure-service";
import { TemplateService } from "./template-service";

const queryLocation = z.object({ location: z.string().min(1) });
const queryOffer = z.object({ location: z.string().min(1), publisher: z.string().min(1) });
const querySku = z.object({ location: z.string().min(1), publisher: z.string().min(1), offer: z.string().min(1) });
const queryVersion = z.object({ location: z.string().min(1), publisher: z.string().min(1), offer: z.string().min(1), sku: z.string().min(1) });

const renderBody = z.object({
  templateFile: z.string().min(1),
  selection: z.object({
    location: z.string().min(1),
    publisher: z.string().min(1),
    offer: z.string().min(1),
    sku: z.string().min(1),
    version: z.string().min(1)
  })
});

const makeApp = () => {
  const app = express();
  const port = Number.parseInt(process.env.PORT ?? "3000", 10);
  const subscriptionId = process.env.AZURE_SUBSCRIPTION_ID;

  app.use(cors());
  app.use(express.json());

  if (!subscriptionId) {
    app.get("/api/health", (_req, res) => {
      res.status(500).json({
        status: "error",
        message: "Missing AZURE_SUBSCRIPTION_ID"
      });
    });

    return { app, port };
  }

  const azure = new AzureImageService(subscriptionId);
  const templates = new TemplateService();

  app.get("/api/health", (_req, res) => {
    res.json({ status: "ok" });
  });

  app.get("/api/locations", async (_req, res, next) => {
    try {
      res.json(await azure.getLocations());
    } catch (error) {
      next(error);
    }
  });

  app.get("/api/publishers", async (req, res, next) => {
    try {
      const { location } = queryLocation.parse(req.query);
      res.json(await azure.getPublishers(location));
    } catch (error) {
      next(error);
    }
  });

  app.get("/api/offers", async (req, res, next) => {
    try {
      const { location, publisher } = queryOffer.parse(req.query);
      res.json(await azure.getOffers(location, publisher));
    } catch (error) {
      next(error);
    }
  });

  app.get("/api/skus", async (req, res, next) => {
    try {
      const { location, publisher, offer } = querySku.parse(req.query);
      res.json(await azure.getSkus(location, publisher, offer));
    } catch (error) {
      next(error);
    }
  });

  app.get("/api/versions", async (req, res, next) => {
    try {
      const { location, publisher, offer, sku } = queryVersion.parse(req.query);
      res.json(await azure.getVersions(location, publisher, offer, sku));
    } catch (error) {
      next(error);
    }
  });

  app.get("/api/templates", (_req, res) => {
    res.json(templates.getTemplates());
  });

  app.post("/api/render", (req, res, next) => {
    try {
      const payload = renderBody.parse(req.body);
      const rendered = templates.render(payload.templateFile, payload.selection);
      res.json({ rendered });
    } catch (error) {
      next(error);
    }
  });

  app.get("/api/sku-export", async (req, res, next) => {
    try {
      const { location, publisher, offer } = querySku.parse(req.query);
      const skus = await azure.getSkus(location, publisher, offer);
      res.json({ rendered: templates.buildSkuExport(skus) });
    } catch (error) {
      next(error);
    }
  });

  app.use((err: unknown, _req: express.Request, res: express.Response, _next: express.NextFunction) => {
    if (err instanceof z.ZodError) {
      res.status(400).json({ message: "Invalid request", issues: err.issues });
      return;
    }

    const message = err instanceof Error ? err.message : "Unexpected error";
    res.status(500).json({ message });
  });

  const frontendRoot = join(process.cwd(), "dist/frontend");
  if (existsSync(frontendRoot)) {
    app.use(express.static(frontendRoot));
    app.get(/^(?!\/api).*/, (_req, res) => {
      res.sendFile(join(frontendRoot, "index.html"));
    });
  }

  return { app, port };
};

if (require.main === module) {
  const { app, port } = makeApp();
  app.listen(port, () => {
    // eslint-disable-next-line no-console
    console.log(`azure-image-chooser listening on ${port}`);
  });
}

export { makeApp };