const express = require("express");
const axios = require("axios");
const { log } = require("./logger");
const { saveToken, getToken, deleteToken } = require("./tokenStore");

const router = express.Router();

const CLIENT_ID = process.env.SHOPIFY_CLIENT_ID;
const CLIENT_SECRET = process.env.SHOPIFY_CLIENT_SECRET;

router.get("/auth/login", (req, res) => {
  const { shop } = req.query;

  if (!shop) {
    return res.status(400).json({ error: "Missing shop query parameter." });
  }

  const redirectUri = process.env.SHOPIFY_REDIRECT_URI || `${process.env.APP_URL || "http://localhost:3002"}/auth/callback`;
  const scopes = process.env.SHOPIFY_SCOPES || "write_products,write_files,write_inventory,write_publications";
  const installUrl = `https://${shop}/admin/oauth/authorize?client_id=${CLIENT_ID}&scope=${encodeURIComponent(scopes)}&redirect_uri=${encodeURIComponent(redirectUri)}`;

  return res.redirect(installUrl);
});

router.get("/auth/callback", async (req, res) => {
  const { shop, code } = req.query;

  if (!shop || !code) {
    log("general", `Missing shop or code in callback: ${JSON.stringify(req.query)}`);
    return res.status(400).send("Missing shop or code parameter.");
  }

  try {
    log(shop, "Exchanging OAuth code for access token");
    const resp = await axios.post(
      `https://${shop}/admin/oauth/access_token`,
      {
        client_id: CLIENT_ID,
        client_secret: CLIENT_SECRET,
        code,
      },
      {
        headers: { "Content-Type": "application/json" },
      }
    );

    const { access_token, scope } = resp.data;
    saveToken(shop, access_token, scope);
    log(shop, "Token saved to data/tokens.json");

    // Fetch the store's primary location ID (requires read_locations scope)
    try {
      const locResp = await axios.post(
        `https://${shop}/admin/api/${process.env.SHOPIFY_API_VERSION || "2025-10"}/graphql.json`,
        { query: '{ locations(first: 10, includeInactive: false) { nodes { id name fulfillsOnlineOrders } } }' },
        { headers: { "X-Shopify-Access-Token": access_token, "Content-Type": "application/json" } }
      );
      const nodes = locResp.data?.data?.locations?.nodes || [];
      // Prefer the location that fulfills online orders (the real shop location)
      const node = nodes.find((l) => l.fulfillsOnlineOrders) || nodes[0];
      if (node?.id) {
        saveToken(shop, access_token, scope, null, node.id);
        log(shop, `Primary location saved: ${node.name} (${node.id})`);
      } else {
        log(shop, `No location returned — add read_locations to SHOPIFY_SCOPES and re-auth.`);
      }
    } catch (locErr) {
      log(shop, `Could not fetch primary location: ${locErr.message}`);
    }

    const finalToken = getToken(shop);
    log(shop, `Auth complete. Stored token:\n${JSON.stringify(finalToken, null, 2)}`);

    const redirectTarget = process.env.SHOPIFY_AFTER_AUTH_REDIRECT || "https://admin.shopify.com";
    return res.redirect(redirectTarget);
  } catch (err) {
    const errMsg = err.response?.data || err.message;
    log(shop, `OAuth error: ${JSON.stringify(errMsg)}`);
    return res.status(500).send("Failed to get access token");
  }
});

router.post("/auth/logout", (req, res) => {
  const { shop } = req.body || {};
  if (!shop) {
    return res.status(400).json({ error: "Missing shop." });
  }

  deleteToken(shop);
  log(shop, "Shop token removed");
  return res.json({ ok: true, shop });
});

module.exports = router;