#!/usr/bin/env bun
import { existsSync, readFileSync } from 'node:fs';
import { basename, dirname, join } from 'node:path';
import type { PostToolUseHookInput, SyncHookJSONOutput } from '@anthropic-ai/claude-agent-sdk';

async function main() {
	try {
		// Read input from stdin
		const input = readFileSync(0, 'utf-8');
		const data: PostToolUseHookInput = JSON.parse(input);

		// Check if the tool was Read
		if (data.tool_name !== 'Read') {
			process.exit(0);
		}

		// Get the file path from tool input
		const toolInput = data.tool_input as Record<string, unknown>;
		const filePath = toolInput.file_path as string;
		if (!filePath) {
			process.exit(0);
		}

		// Check if it's a TypeScript file (but not already a test file)
		const isTypeScriptFile =
			(filePath.endsWith('.ts') || filePath.endsWith('.tsx')) &&
			!filePath.endsWith('.test.ts') &&
			!filePath.endsWith('.test.tsx') &&
			!filePath.endsWith('.spec.ts') &&
			!filePath.endsWith('.spec.tsx');

		if (!isTypeScriptFile) {
			process.exit(0);
		}

		// Look for corresponding test files
		const dir = dirname(filePath);
		const file = basename(filePath);
		const nameWithoutExt = file.replace(/\.tsx?$/, '');

		const testPatterns = [
			`${nameWithoutExt}.test.ts`,
			`${nameWithoutExt}.test.tsx`,
			`${nameWithoutExt}.spec.ts`,
			`${nameWithoutExt}.spec.tsx`,
		];

		const foundTestFiles: string[] = [];
		for (const pattern of testPatterns) {
			const testPath = join(dir, pattern);
			if (existsSync(testPath)) {
				foundTestFiles.push(testPath);
			}
		}

		// If test files were found, suggest them
		if (foundTestFiles.length > 0) {
			let context = '<plugin-langs-suggestion>\n';
			context += `Source file: ${filePath}\n\n`;
			context += 'Related test file(s):\n';
			for (const testFile of foundTestFiles) {
				context += `  → ${testFile}\n`;
			}
			context += '</plugin-langs-suggestion>';

			// Return JSON with hookSpecificOutput for PostToolUse
			const output: SyncHookJSONOutput = {
				hookSpecificOutput: {
					hookEventName: 'PostToolUse',
					additionalContext: context,
				},
			};

			console.log(JSON.stringify(output));
		}

		// Exit 0 = success
		process.exit(0);
	} catch (err) {
		console.error('Error in test-file-suggest hook:', err);
		process.exit(1);
	}
}

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