import { Server } from "@modelcontextprotocol/sdk/server/index.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import {
  CallToolRequestSchema,
  ListToolsRequestSchema,
} from "@modelcontextprotocol/sdk/types.js";
import axios from "axios";
import FormData from "form-data";

const BACKEND_URL = process.env.BACKEND_URL || "http://localhost:3000/api";
const ADMIN_USERNAME = process.env.ADMIN_USERNAME || "admin";
const ADMIN_PASSWORD = process.env.ADMIN_PASSWORD || "homaroma123";

let authToken = "";

export const api = axios.create({
  baseURL: BACKEND_URL,
});

api.interceptors.request.use(async (config) => {
  if (!authToken && config.url !== "/auth/login") {
    console.error("[MCP] No token found. Attempting auto-login...");
    await performLogin();
  }
  if (authToken) {
    config.headers.Authorization = `Bearer ${authToken}`;
  }
  return config;
});

async function performLogin() {
  try {
    const res = await axios.post(`${BACKEND_URL}/auth/login`, {
      username: ADMIN_USERNAME,
      password: ADMIN_PASSWORD,
    });
    if (res.data && res.data.token) {
      authToken = res.data.token;
      console.error("[MCP] Successfully logged in to Backend API.");
    }
  } catch (err: any) {
    console.error("[MCP] Auto-login failed:", err.message);
  }
}

const server = new Server(
  {
    name: "homaroma-mcp",
    version: "1.0.0",
  },
  {
    capabilities: {
      tools: {},
    },
  }
);

server.setRequestHandler(ListToolsRequestSchema, async () => {
  return {
    tools: [
      {
        name: "ping_backend",
        description: "Ping the backend to verify connection and authentication",
        inputSchema: { type: "object", properties: {} },
      },
      {
        name: "search_products",
        description: "Search for products and get their basic info",
        inputSchema: {
          type: "object",
          properties: {
            search: { type: "string", description: "Search term" },
            limit: { type: "number", description: "Max results" }
          }
        }
      },
      {
        name: "get_product_detail",
        description: "Get full product details including variants, images, and category",
        inputSchema: {
          type: "object",
          properties: {
            id: { type: "number", description: "Product ID" }
          },
          required: ["id"]
        }
      },
      {
        name: "update_product_content",
        description: "Update product basic content (name, description, details)",
        inputSchema: {
          type: "object",
          properties: {
            id: { type: "number" },
            name: { type: "string" },
            description: { type: "string" },
            details: { type: "string" },
          },
          required: ["id"]
        }
      },
      {
        name: "upload_product_image_from_url",
        description: "Download image from URL, upload to backend, and append to product images",
        inputSchema: {
          type: "object",
          properties: {
            productId: { type: "number" },
            imageUrl: { type: "string", description: "URL of the image to download" }
          },
          required: ["productId", "imageUrl"]
        }
      },
      {
        name: "generate_mock_review",
        description: "Create a dummy review for a product",
        inputSchema: {
          type: "object",
          properties: {
            productId: { type: "number" },
            rating: { type: "number", description: "1-5" },
            comment: { type: "string" },
            customerName: { type: "string", description: "Name of the mock reviewer" }
          },
          required: ["productId", "rating", "customerName"]
        }
      }
    ],
  };
});

server.setRequestHandler(CallToolRequestSchema, async (request) => {
  const params = request.params.arguments as any;

  try {
    switch (request.params.name) {
      case "ping_backend": {
        const res = await api.get("/products?limit=1");
        return { content: [{ type: "text", text: `Connection successful!` }] };
      }
      case "search_products": {
        const search = params.search ? `&search=${encodeURIComponent(params.search)}` : "";
        const limit = params.limit ? `&limit=${params.limit}` : "&limit=10";
        const res = await api.get(`/products?${search}${limit}`);
        return { content: [{ type: "text", text: JSON.stringify(res.data, null, 2) }] };
      }
      case "get_product_detail": {
        const res = await api.get(`/products/${params.id}`);
        return { content: [{ type: "text", text: JSON.stringify(res.data, null, 2) }] };
      }
      case "update_product_content": {
        const payload: any = {};
        if (params.name) payload.name = params.name;
        if (params.description) payload.description = params.description;
        if (params.details) payload.details = params.details;

        const res = await api.patch(`/products/${params.id}`, payload);
        return { content: [{ type: "text", text: JSON.stringify(res.data, null, 2) }] };
      }
      case "upload_product_image_from_url": {
        // 1. Download image
        const imgRes = await axios.get(params.imageUrl, { responseType: 'arraybuffer' });
        const buffer = Buffer.from(imgRes.data, 'binary');
        const ext = params.imageUrl.split('.').pop()?.split('?')[0] || 'jpg';
        
        // 2. Upload to backend
        const formData = new FormData();
        formData.append('file', buffer, { filename: `download.${ext}` });
        
        const uploadRes = await api.post('/upload', formData, {
          headers: formData.getHeaders()
        });
        const uploadedUrl = uploadRes.data.url;

        // 3. Get current product to append image
        const prodRes = await api.get(`/products/${params.productId}`);
        const product = prodRes.data;
        const newImages = [...product.images, { url: uploadedUrl, order: product.images.length }];

        // 4. Update product (using PUT to sync variants and images)
        // Ensure we pass required fields
        const putRes = await api.put(`/products/${params.productId}`, {
          categoryId: product.categoryId,
          description: product.description,
          details: product.details,
          variants: product.variants,
          images: newImages
        });

        return { content: [{ type: "text", text: `Image uploaded and product updated. New image URL: ${uploadedUrl}` }] };
      }
      case "generate_mock_review": {
        const res = await api.post("/reviews", {
          productId: params.productId,
          rating: params.rating,
          comment: params.comment,
          customerName: params.customerName
        });
        return { content: [{ type: "text", text: JSON.stringify(res.data, null, 2) }] };
      }
      default:
        throw new Error(`Unknown tool: ${request.params.name}`);
    }
  } catch (err: any) {
    const errorMsg = err.response?.data ? JSON.stringify(err.response.data) : err.message;
    return {
      content: [{ type: "text", text: `Error executing tool: ${errorMsg}` }],
      isError: true,
    };
  }
});

async function main() {
  await performLogin();
  const transport = new StdioServerTransport();
  await server.connect(transport);
  console.error("HomAroma MCP Server running on stdio");
}

main().catch(console.error);