Refactor code for extensability

Refactor code for extensability

src/handlers/resourceHandlers.ts

@@ -0,0 +1,66 @@
+import { dbAll } from '../db/index.js';
+import { getDatabasePath } from '../db/index.js';
+
+/**
+ * Handle listing resources request
+ * @returns List of available resources
+ */
+export async function handleListResources() {
+  try {
+    const databasePath = getDatabasePath();
+    const resourceBaseUrl = new URL(`sqlite:///${databasePath}`);
+    const SCHEMA_PATH = "schema";
+
+    const result = await dbAll(
+      "SELECT name FROM sqlite_master WHERE type='table' AND name NOT LIKE 'sqlite_%'"
+    );
+    
+    return {
+      resources: result.map((row: any) => ({
+        uri: new URL(`${row.name}/${SCHEMA_PATH}`, resourceBaseUrl).href,
+        mimeType: "application/json",
+        name: `"${row.name}" database schema`,
+      })),
+    };
+  } catch (error: any) {
+    throw new Error(`Error listing resources: ${error.message}`);
+  }
+}
+
+/**
+ * Handle reading a specific resource
+ * @param uri URI of the resource to read
+ * @returns Resource contents
+ */
+export async function handleReadResource(uri: string) {
+  try {
+    const resourceUrl = new URL(uri);
+    const SCHEMA_PATH = "schema";
+
+    const pathComponents = resourceUrl.pathname.split("/");
+    const schema = pathComponents.pop();
+    const tableName = pathComponents.pop();
+
+    if (schema !== SCHEMA_PATH) {
+      throw new Error("Invalid resource URI");
+    }
+
+    // Query to get column information for a table
+    const result = await dbAll(`PRAGMA table_info("${tableName}")`);
+
+    return {
+      contents: [
+        {
+          uri,
+          mimeType: "application/json",
+          text: JSON.stringify(result.map((column: any) => ({
+            column_name: column.name,
+            data_type: column.type
+          })), null, 2),
+        },
+      ],
+    };
+  } catch (error: any) {
+    throw new Error(`Error reading resource: ${error.message}`);
+  }
+} 

src/handlers/toolHandlers.ts

@@ -0,0 +1,170 @@
+import { formatErrorResponse } from '../utils/formatUtils.js';
+
+// Import all tool implementations
+import { readQuery, writeQuery, exportQuery } from '../tools/queryTools.js';
+import { createTable, alterTable, dropTable, listTables, describeTable } from '../tools/schemaTools.js';
+import { appendInsight, listInsights } from '../tools/insightTools.js';
+
+/**
+ * Handle listing available tools
+ * @returns List of available tools
+ */
+export function handleListTools() {
+  return {
+    tools: [
+      {
+        name: "read_query",
+        description: "Execute SELECT queries to read data from the database",
+        inputSchema: {
+          type: "object",
+          properties: {
+            query: { type: "string" },
+          },
+          required: ["query"],
+        },
+      },
+      {
+        name: "write_query",
+        description: "Execute INSERT, UPDATE, or DELETE queries",
+        inputSchema: {
+          type: "object",
+          properties: {
+            query: { type: "string" },
+          },
+          required: ["query"],
+        },
+      },
+      {
+        name: "create_table",
+        description: "Create new tables in the database",
+        inputSchema: {
+          type: "object",
+          properties: {
+            query: { type: "string" },
+          },
+          required: ["query"],
+        },
+      },
+      {
+        name: "alter_table",
+        description: "Modify existing table schema (add columns, rename tables, etc.)",
+        inputSchema: {
+          type: "object",
+          properties: {
+            query: { type: "string" },
+          },
+          required: ["query"],
+        },
+      },
+      {
+        name: "drop_table",
+        description: "Remove a table from the database with safety confirmation",
+        inputSchema: {
+          type: "object",
+          properties: {
+            table_name: { type: "string" },
+            confirm: { type: "boolean" },
+          },
+          required: ["table_name", "confirm"],
+        },
+      },
+      {
+        name: "export_query",
+        description: "Export query results to various formats (CSV, JSON)",
+        inputSchema: {
+          type: "object",
+          properties: {
+            query: { type: "string" },
+            format: { type: "string", enum: ["csv", "json"] },
+          },
+          required: ["query", "format"],
+        },
+      },
+      {
+        name: "list_tables",
+        description: "Get a list of all tables in the database",
+        inputSchema: {
+          type: "object",
+          properties: {},
+        },
+      },
+      {
+        name: "describe_table",
+        description: "View schema information for a specific table",
+        inputSchema: {
+          type: "object",
+          properties: {
+            table_name: { type: "string" },
+          },
+          required: ["table_name"],
+        },
+      },
+      {
+        name: "append_insight",
+        description: "Add a business insight to the memo",
+        inputSchema: {
+          type: "object",
+          properties: {
+            insight: { type: "string" },
+          },
+          required: ["insight"],
+        },
+      },
+      {
+        name: "list_insights",
+        description: "List all business insights in the memo",
+        inputSchema: {
+          type: "object",
+          properties: {},
+        },
+      },
+    ],
+  };
+}
+
+/**
+ * Handle tool call requests
+ * @param name Name of the tool to call
+ * @param args Arguments for the tool
+ * @returns Tool execution result
+ */
+export async function handleToolCall(name: string, args: any) {
+  try {
+    switch (name) {
+      case "read_query":
+        return await readQuery(args.query);
+      
+      case "write_query":
+        return await writeQuery(args.query);
+      
+      case "create_table":
+        return await createTable(args.query);
+      
+      case "alter_table":
+        return await alterTable(args.query);
+      
+      case "drop_table":
+        return await dropTable(args.table_name, args.confirm);
+      
+      case "export_query":
+        return await exportQuery(args.query, args.format);
+      
+      case "list_tables":
+        return await listTables();
+      
+      case "describe_table":
+        return await describeTable(args.table_name);
+      
+      case "append_insight":
+        return await appendInsight(args.insight);
+      
+      case "list_insights":
+        return await listInsights();
+      
+      default:
+        throw new Error(`Unknown tool: ${name}`);
+    }
+  } catch (error: any) {
+    return formatErrorResponse(error);
+  }
+}