#!/usr/bin/env node
/**
 * QR Rápido MCP Server (stdio transport)
 *
 * Environment variables:
 *   QR_API_KEY  — your API key (e.g. qr_xxxx). Get one free at https://qrrapido.site/Developer
 *   QR_BASE_URL — API base URL (default: https://qrrapido.site)
 *   NODE_TLS_REJECT_UNAUTHORIZED=0  — set only for local dev with self-signed cert
 */

import { Server } from "@modelcontextprotocol/sdk/server/index.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import { ListToolsRequestSchema, CallToolRequestSchema } from "@modelcontextprotocol/sdk/types.js";
import { fetch } from "undici";
import { writeFileSync } from "fs";
import { tmpdir } from "os";
import { join } from "path";
import { exec } from "child_process";

const API_KEY  = process.env.QR_API_KEY  || "";
const BASE_URL = process.env.QR_BASE_URL || "https://qrrapido.site";

if (!API_KEY) process.stderr.write("[qrrapido-mcp] WARNING: QR_API_KEY not set\n");

// ── PIX EMV/BRCode builder (port do C# em PagamentoController) ────────────────

function pixField(id, value) {
  const len = String(value.length).padStart(2, "0");
  return `${id}${len}${value}`;
}

function removeAccents(text) {
  return text.toUpperCase()
    .normalize("NFD").replace(/[\u0300-\u036f]/g, "")
    .replace(/[^A-Z0-9 ]/g, " ");
}

function crc16(data) {
  let crc = 0xFFFF;
  for (const ch of data) {
    crc ^= ch.charCodeAt(0) << 8;
    for (let i = 0; i < 8; i++) {
      crc = (crc & 0x8000) ? ((crc << 1) ^ 0x1021) & 0xFFFF : (crc << 1) & 0xFFFF;
    }
  }
  return crc.toString(16).toUpperCase().padStart(4, "0");
}

function buildPixPayload({ pixKey, amount, merchantName, merchantCity, txId = "***" }) {
  const merchantInfo = pixField("00", "br.gov.bcb.pix") + pixField("01", pixKey);
  const addData = pixField("05", txId.substring(0, 25));
  const name = removeAccents(merchantName).substring(0, 25);
  const city = removeAccents(merchantCity).substring(0, 15);

  let payload = pixField("00", "01")
    + pixField("26", merchantInfo)
    + pixField("52", "0000")
    + pixField("53", "986");

  if (amount && amount > 0) {
    payload += pixField("54", amount.toFixed(2));
  }

  payload += pixField("58", "BR")
    + pixField("59", name)
    + pixField("60", city)
    + pixField("62", addData)
    + "6304";

  return payload + crc16(payload);
}

// ── API helper ────────────────────────────────────────────────────────────────

async function callApi(body) {
  const res = await fetch(`${BASE_URL}/api/v1/QRManager/generate`, {
    method: "POST",
    headers: { "X-API-Key": API_KEY, "Content-Type": "application/json" },
    body: JSON.stringify(body)
  });
  return res.json();
}

function errorContent(msg) {
  return { content: [{ type: "text", text: `Error: ${msg}` }], isError: true };
}

function openImage(base64, label = "qr") {
  try {
    const ext = "png";
    const file = join(tmpdir(), `${label}_${Date.now()}.${ext}`);
    writeFileSync(file, Buffer.from(base64, "base64"));
    exec(`start "" "${file}"`);
    return file;
  } catch (e) {
    process.stderr.write(`[qrrapido-mcp] Could not open image: ${e.message}\n`);
    return null;
  }
}

function successContent(data, label = "qr") {
  const file = openImage(data.qrCodeBase64, label);
  return {
    content: [
      { type: "image", data: data.qrCodeBase64, mimeType: data.mimeType || "image/png" },
      {
        type: "text",
        text: [
          `QR code generated successfully`,
          file ? `Opened at: ${file}` : "",
          `Generation time: ${data.generationTimeMs}ms`,
          `Cache: ${data.fromCache ? "hit" : "miss"}`,
          data.monthlyQuotaLimit >= 0
            ? `Monthly quota: ${data.monthlyQuotaRemaining}/${data.monthlyQuotaLimit}`
            : `Monthly quota: unlimited`
        ].filter(Boolean).join("\n")
      }
    ]
  };
}

// ── Server ────────────────────────────────────────────────────────────────────

const server = new Server(
  {
    name: "qrrapido",
    version: "1.0.3",
  },
  { capabilities: { tools: {} } }
);

const QR_OUTPUT_SCHEMA = {
  type: "object",
  properties: {
    content: {
      type: "array",
      description: "Array with the QR code image (base64 PNG) and a text summary.",
      items: {
        oneOf: [
          {
            type: "object",
            description: "Base64-encoded QR code image.",
            properties: {
              type: { type: "string", const: "image" },
              data: { type: "string", description: "Base64-encoded image data." },
              mimeType: { type: "string", description: "MIME type, e.g. image/png." }
            },
            required: ["type", "data", "mimeType"]
          },
          {
            type: "object",
            description: "Text summary with timing, cache status, and quota info.",
            properties: {
              type: { type: "string", const: "text" },
              text: { type: "string" }
            },
            required: ["type", "text"]
          }
        ]
      }
    }
  },
  required: ["content"]
};

// tools/list
server.setRequestHandler(ListToolsRequestSchema, async () => ({
  tools: [
    {
      name: "generate_qr",
      description:
        "Generate a QR code for a URL, Wi-Fi network, vCard contact, WhatsApp message, " +
        "email, SMS, or free text. Returns an inline base64 PNG — no file hosting needed. " +
        "For Brazilian PIX payments use generate_pix_qr instead.",
      annotations: {
        title: "Generate QR Code",
        readOnlyHint: false,
        destructiveHint: false,
        idempotentHint: true,
        openWorldHint: true
      },
      inputSchema: {
        type: "object",
        properties: {
          type: {
            type: "string",
            enum: ["url", "wifi", "vcard", "whatsapp", "email", "sms", "texto"],
            description:
              "QR code type. Use 'url' for websites, 'wifi' for network credentials, " +
              "'vcard' for contacts, 'whatsapp' to open a WhatsApp chat, " +
              "'email' for pre-filled emails, 'sms' for text messages, 'texto' for free text."
          },
          content: {
            type: "string",
            description:
              "Content to encode. Examples by type — " +
              "url: 'https://example.com'; " +
              "wifi: 'WIFI:T:WPA;S:MyNet;P:pass123;;'; " +
              "vcard: 'BEGIN:VCARD\\nFN:John\\nTEL:+1234\\nEND:VCARD'; " +
              "whatsapp: '+5511999998888'; " +
              "email: 'user@example.com'; " +
              "sms: '+5511999998888'; " +
              "texto: any plain text."
          },
          format: {
            type: "string",
            enum: ["png", "webp", "svg"],
            default: "png",
            description: "Output image format. PNG is recommended for broadest compatibility."
          },
          size: {
            type: "number",
            default: 400,
            description: "Image size in pixels (width = height). Range: 100–2000. Default: 400."
          },
          primaryColor: {
            type: "string",
            default: "#000000",
            description: "QR module color as hex, e.g. '#1a1a1a'. Default: black (#000000)."
          },
          backgroundColor: {
            type: "string",
            default: "#FFFFFF",
            description: "Background color as hex, e.g. '#FFFFFF'. Default: white (#FFFFFF)."
          }
        },
        required: ["type", "content"]
      },
      outputSchema: QR_OUTPUT_SCHEMA
    },
    {
      name: "generate_pix_qr",
      description:
        "Generate a Brazilian PIX payment QR code (BRCode/EMV standard). " +
        "Builds the payload automatically from the PIX key, amount, recipient name, and city. " +
        "Returns an inline base64 PNG ready to display or share.",
      annotations: {
        title: "Generate PIX QR Code",
        readOnlyHint: false,
        destructiveHint: false,
        idempotentHint: true,
        openWorldHint: true
      },
      inputSchema: {
        type: "object",
        properties: {
          pixKey: {
            type: "string",
            description:
              "PIX key of the recipient. Accepted formats: " +
              "CPF (digits only, e.g. '12345678901'), " +
              "email (e.g. 'user@example.com'), " +
              "phone with country code (e.g. '+5511987654321'), " +
              "or random key (UUID, e.g. '123e4567-e89b-12d3-a456-426614174000')."
          },
          amount: {
            type: "number",
            description:
              "Payment amount in BRL (e.g. 49.90). " +
              "Omit or set to 0 to create an open-value QR code where the payer enters the amount."
          },
          merchantName: {
            type: "string",
            description:
              "Recipient name as it appears in the payer's banking app. " +
              "Max 25 characters. Accents are stripped automatically. Example: 'RICARDO CARNEIRO'."
          },
          merchantCity: {
            type: "string",
            description:
              "Recipient city. Max 15 characters. Accents are stripped automatically. " +
              "Example: 'SAO PAULO'."
          },
          txId: {
            type: "string",
            default: "***",
            description:
              "Optional transaction identifier for reconciliation. Max 25 characters. " +
              "Use '***' (default) to omit. Example: 'PEDIDO123'."
          },
          size: {
            type: "number",
            default: 400,
            description: "Image size in pixels (width = height). Range: 100–2000. Default: 400."
          },
          primaryColor: {
            type: "string",
            default: "#000000",
            description: "QR module color as hex. Default: black (#000000)."
          },
          backgroundColor: {
            type: "string",
            default: "#FFFFFF",
            description: "Background color as hex. Default: white (#FFFFFF)."
          }
        },
        required: ["pixKey", "merchantName", "merchantCity"]
      },
      outputSchema: QR_OUTPUT_SCHEMA
    }
  ]
}));

// tools/call
server.setRequestHandler(CallToolRequestSchema, async (req) => {
  const { name } = req.params;
  const args = req.params.arguments ?? {};

  // ── generate_pix_qr ──────────────────────────────────────────────────────
  if (name === "generate_pix_qr") {
    const { pixKey, amount, merchantName, merchantCity, txId = "***",
            size = 400, primaryColor = "#000000", backgroundColor = "#FFFFFF" } = args;

    if (!pixKey || !merchantName || !merchantCity)
      return errorContent("pixKey, merchantName and merchantCity are required.");

    let payload;
    try {
      payload = buildPixPayload({ pixKey, amount, merchantName, merchantCity, txId });
    } catch (err) {
      return errorContent(`Failed to build PIX payload: ${err.message}`);
    }

    let data;
    try {
      data = await callApi({ type: "texto", content: payload, size, primaryColor, backgroundColor });
    } catch (err) {
      return errorContent(`API request failed: ${err.message}`);
    }

    if (!data.success) return errorContent(data.message || data.error || "Unknown error");

    const pixFile = openImage(data.qrCodeBase64, "pix");
    return {
      content: [
        { type: "image", data: data.qrCodeBase64, mimeType: data.mimeType || "image/png" },
        {
          type: "text",
          text: [
            `PIX QR code generated successfully`,
            pixFile ? `Opened at: ${pixFile}` : "",
            `PIX key: ${pixKey}`,
            `Amount: ${amount ? `BRL ${amount.toFixed(2)}` : "open (payer chooses)"}`,
            `Recipient: ${merchantName} — ${merchantCity}`,
            `Generation time: ${data.generationTimeMs}ms`
          ].filter(Boolean).join("\n")
        }
      ]
    };
  }

  // ── generate_qr ──────────────────────────────────────────────────────────
  if (name === "generate_qr") {
    const { type, content, format = "png", size = 400,
            primaryColor = "#000000", backgroundColor = "#FFFFFF" } = args;

    if (!type || !content) return errorContent("'type' and 'content' are required.");

    let data;
    try {
      data = await callApi({ type, content, outputFormat: format, size, primaryColor, backgroundColor });
    } catch (err) {
      return errorContent(`API request failed: ${err.message}`);
    }

    if (!data.success) return errorContent(data.message || data.error || "Unknown error");
    return successContent(data);
  }

  return errorContent(`Unknown tool: ${name}`);
});

// ── Start ─────────────────────────────────────────────────────────────────────

const transport = new StdioServerTransport();
await server.connect(transport);
process.stderr.write(`[qrrapido-mcp] Server started. Base URL: ${BASE_URL}\n`);