#!/usr/bin/env node
import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import { z } from "zod";
// zod is a peer dep of @modelcontextprotocol/sdk
import { checkMigration } from "./checker.js";
import { ALL_CHECK_DEFINITIONS } from "./checks.js";

const server = new McpServer({
  name: "pg-safe-migrate",
  version: "1.0.0",
});

server.tool(
  "check_migration",
  "Check a PostgreSQL migration SQL string for unsafe operations that could cause downtime or data loss.",
  {
    sql: z.string().describe("The migration SQL to check"),
  },
  async ({ sql }) => {
    const result = checkMigration(sql);
    return {
      content: [
        {
          type: "text",
          text: JSON.stringify(result, null, 2),
        },
      ],
    };
  }
);

server.tool(
  "list_checks",
  "List all available safety checks with their severity, description, and suggested fix.",
  {},
  async () => {
    return {
      content: [
        {
          type: "text",
          text: JSON.stringify(ALL_CHECK_DEFINITIONS, null, 2),
        },
      ],
    };
  }
);

server.tool(
  "explain_check",
  "Get a detailed explanation of a specific safety check by name.",
  {
    checkName: z.string().describe("The check name, e.g. 'create_index_without_concurrently'"),
  },
  async ({ checkName }) => {
    const def = ALL_CHECK_DEFINITIONS.find((d) => d.name === checkName);
    if (!def) {
      return {
        content: [
          {
            type: "text",
            text: `Check '${checkName}' not found. Use list_checks to see all available checks.`,
          },
        ],
      };
    }
    return {
      content: [
        {
          type: "text",
          text: JSON.stringify(def, null, 2),
        },
      ],
    };
  }
);

async function main() {
  const transport = new StdioServerTransport();
  await server.connect(transport);
}

main().catch((err) => {
  console.error(err);
  process.exit(1);
});