import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { readFile, access, constants } from "node:fs/promises";
import { resolve, extname } from "node:path";
import { z } from "zod";
import {
createErrorResponse,
debugLog,
} from "../../helpers.js";
import { analyzeJsonStructure } from "./json-analyzer.js";
export const registerAnalyzeJsonFromFile = (server: McpServer) => {
/**
* Tool: analyze_json_from_file
* Reads JSON from a local file and analyzes its structure for Searchcraft schema generation
*/
server.tool(
"analyze_json_from_file",
"Read JSON data from a local file and analyze its structure to understand field types and patterns for Searchcraft index schema generation",
{
path: z.string().describe("Local file path to the JSON data"),
sample_size: z.number().int().positive().optional().default(10).describe("For arrays, number of items to analyze (default: 10)"),
},
async ({ path, sample_size = 10 }) => {
debugLog("[Tool Call] analyze_json_from_file");
try {
// Trim whitespace from path
const trimmedPath = path.trim();
// Resolve and validate file path
const filePath = resolve(trimmedPath);
// Security check - ensure file path doesn't contain dangerous patterns
if (filePath.includes("..") || filePath.includes("~")) {
return createErrorResponse("File path contains potentially unsafe characters");
}
// Check if file exists and is readable
try {
await access(filePath, constants.R_OK);
} catch {
return createErrorResponse(`File not found or not readable: ${trimmedPath}`);
}
// Validate file extension
const ext = extname(filePath).toLowerCase();
if (![".json", ".jsonl", ".ndjson"].includes(ext)) {
debugLog(`Warning: File extension ${ext} is not typically JSON`);
}
debugLog(`Reading JSON from file: ${filePath}`);
// Read file content
let fileContent: string;
try {
fileContent = await readFile(filePath, "utf-8");
} catch (readError) {
return createErrorResponse(
`Failed to read file: ${readError instanceof Error ? readError.message : "Read error"}`
);
}
if (fileContent.trim().length === 0) {
return createErrorResponse("File is empty");
}
// Parse JSON
let jsonData: any;
try {
// Handle JSONL/NDJSON files (one JSON object per line)
if ([".jsonl", ".ndjson"].includes(ext)) {
const lines = fileContent.trim().split("\n");
jsonData = lines
.filter(line => line.trim().length > 0)
.map(line => JSON.parse(line));
if (jsonData.length === 0) {
return createErrorResponse("No valid JSON objects found in JSONL file");
}
// For JSONL, we'll analyze as an array of objects
debugLog(`Parsed ${jsonData.length} JSON objects from JSONL file`);
} else {
jsonData = JSON.parse(fileContent);
}
} catch (parseError) {
return createErrorResponse(
`Invalid JSON in file: ${parseError instanceof Error ? parseError.message : "Parse error"}`
);
}
// Analyze the JSON structure
const analysis = analyzeJsonStructure(jsonData, sample_size);
return {
content: [
{
type: "resource",
resource: {
uri: `searchcraft://json-analysis-file/${encodeURIComponent(trimmedPath)}/${Date.now()}`,
mimeType: "application/json",
text: JSON.stringify({
source: {
type: "file",
path: trimmedPath,
resolved_path: filePath,
analyzed_at: new Date().toISOString(),
file_size: fileContent.length,
file_extension: ext,
},
analysis,
}, null, 2),
},
},
],
};
} catch (error) {
const errorMessage =
error instanceof Error
? error.message
: "Unknown error occurred";
return createErrorResponse(
`Failed to analyze JSON from file: ${errorMessage}`
);
}
},
);
};
