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

interface SessionCache {
	knowledge_suggested: boolean;
	first_triggered: string;
	match_reason: string;
}

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

		// Check for Claude Code related keywords (case insensitive)
		const claudeCodeKeywords = ['claude code', 'claudecode', 'claude-code'];

		// Check for standalone "claude" but be more selective to avoid false positives
		const standaloneClaudePatterns = [
			/\bclaude\b(?!\s+sonnet|\s+opus|\s+haiku)/i, // "claude" not followed by model names
			/how\s+(?:do|does|can)\s+claude/i, // "how do/does/can claude..."
			/can\s+claude/i, // "can claude..."
			/does\s+claude/i, // "does claude..."
			/is\s+claude/i, // "is claude..."
			/tell\s+claude/i, // "tell claude..."
			/ask\s+claude/i, // "ask claude..."
		];

		// Additional Claude Code related patterns
		const claudeCodePatterns = [
			/\bhook/i,
			/\bmcp\s+server/i,
			/\bskill/i,
			/slash\s+command/i,
			/claude.*setting/i,
			/claude.*config/i,
			/claude.*feature/i,
			/claude.*capability/i,
			/how\s+(?:do|does)\s+(?:i|claude).*(hook|mcp|skill|command)/i,
		];

		let isMatch = false;
		let matchReason = '';

		// Check for exact keyword matches
		for (const keyword of claudeCodeKeywords) {
			if (prompt.includes(keyword)) {
				isMatch = true;
				matchReason = `Detected "${keyword}"`;
				break;
			}
		}

		// Check for standalone Claude mentions
		if (!isMatch) {
			for (const pattern of standaloneClaudePatterns) {
				if (pattern.test(prompt)) {
					isMatch = true;
					matchReason = 'Detected Claude Code question';
					break;
				}
			}
		}

		// Check for Claude Code feature patterns
		if (!isMatch) {
			for (const pattern of claudeCodePatterns) {
				if (pattern.test(prompt)) {
					isMatch = true;
					matchReason = 'Detected Claude Code feature mention';
					break;
				}
			}
		}

		// Generate context injection if match found
		if (isMatch) {
			// Check session cache - only suggest once per session
			const cache = readSessionCache<SessionCache>(
				'claude-code-knowledge',
				data.cwd,
				data.session_id
			);

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

			// Use JSON output method for explicit control
			let context = '<plugin-claude-code-knowledge-suggestion>\n';
			context += `Detected Claude Code question: ${matchReason}\n\n`;
			context += 'ESSENTIAL SKILL:\n';
			context += '  → claude-code-knowledge:claude-code-knowledge\n';
			context += '</plugin-claude-code-knowledge-suggestion>';

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

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

			// Mark as suggested in session cache
			writeSessionCache<SessionCache>('claude-code-knowledge', data.cwd, data.session_id, {
				knowledge_suggested: true,
				first_triggered: new Date().toISOString(),
				match_reason: matchReason,
			});
		}

		// Exit 0 = success, additionalContext is added to context
		process.exit(0);
	} catch (err) {
		console.error('Error in claude-code-prompt hook:', err);
		process.exit(1);
	}
}

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