#!/usr/bin/env bun
import type { PostToolUseHookInput, SyncHookJSONOutput } from '@anthropic-ai/claude-agent-sdk';
import { readSessionCache, writeSessionCache } from '../../../utils/session-cache';
import { readFileSync } from 'node:fs';

interface SessionCache {
	doc_writer_suggested: boolean;
	first_triggered: string;
	triggered_by: string;
}

const PLUGIN_NAME = 'doc-writer';

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 Write, Edit, or MultiEdit
		const relevantTools = ['Write', 'Edit', 'MultiEdit'];
		if (!relevantTools.includes(data.tool_name)) {
			process.exit(0);
		}

		// Check if any markdown files were modified
		let isMarkdownFile = false;
		let filePath = '';

		if (data.tool_name === 'Write' || data.tool_name === 'Edit') {
			// Single file operations
			const toolInput = data.tool_input as Record<string, unknown>;
			filePath = toolInput.file_path as string;
			if (filePath?.toLowerCase().endsWith('.md')) {
				isMarkdownFile = true;
			}
		} else if (data.tool_name === 'MultiEdit') {
			// MultiEdit might have multiple files
			const toolInput = data.tool_input as Record<string, unknown>;
			const edits = toolInput.edits as Array<{ file_path: string }>;
			if (edits && Array.isArray(edits)) {
				for (const edit of edits) {
					if (edit.file_path?.toLowerCase().endsWith('.md')) {
						isMarkdownFile = true;
						filePath = edit.file_path;
						break;
					}
				}
			}
		}

		// If a markdown file was modified, suggest the doc-writer skill
		if (isMarkdownFile) {
			// Check session cache - only suggest once per session
			const session = readSessionCache<SessionCache>(PLUGIN_NAME, data.cwd, data.session_id);

			// If already suggested this session, exit silently
			if (session?.doc_writer_suggested) {
				process.exit(0);
			}

			let context = '<plugin-doc-writer-suggestion>\n';
			context += `Detected markdown file modification: ${filePath}\n\n`;
			context += 'ESSENTIAL SKILL:\n';
			context += '  → doc-writer:writing-documentation\n\n';
			context += 'RECOMMENDED AGENT:\n';
			context += '  → doc-writer:docs-reviewer\n';
			context += '</plugin-doc-writer-suggestion>';

			// Return JSON with hookSpecificOutput for PostToolUse
			// Note: decision is undefined (no blocking), but additionalContext should still be provided
			const output: SyncHookJSONOutput = {
				hookSpecificOutput: {
					hookEventName: 'PostToolUse',
					additionalContext: context,
				},
			};

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

			// Mark as suggested in session cache
			const sessionCache: SessionCache = {
				doc_writer_suggested: true,
				first_triggered: new Date().toISOString(),
				triggered_by: filePath,
			};
			writeSessionCache(PLUGIN_NAME, data.cwd, data.session_id, sessionCache);
		}

		// Exit 0 = success, additionalContext is added to context if provided
		process.exit(0);
	} catch (err) {
		console.error('Error in doc-writer-suggest hook:', err);
		process.exit(1);
	}
}

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