<?php
/**
 * JARVIS Knowledge Base + Intent Engine
 * Matches user input against intent patterns, substitutes live facts from kb_facts.
 * Returns a response if matched, or null to escalate to Ollama/Claude.
 */

class KBEngine {

    /**
     * Try to match the input against known intents.
     * Returns ['reply' => string, 'intent' => string] or null if no match.
     */
    public static function match(string $input): ?array {
        $intents = JarvisDB::query(
            'SELECT * FROM kb_intents WHERE active=1 ORDER BY priority DESC, id ASC'
        );
        if (!$intents) return null;

        foreach ($intents as $intent) {
            $pat = '~' . $intent['pattern'] . '~';
            if (@preg_match($pat, $input)) {
                $reply = self::fillTemplate(
                    $intent['response_template'],
                    $intent['fact_category']
                );
                return [
                    'reply'  => $reply,
                    'intent' => $intent['intent_name'],
                    'action' => $intent['action_type'],
                ];
            }
        }
        return null;
    }

    /**
     * Replace {placeholder} tokens in a template with values from kb_facts,
     * plus built-in dynamic tokens like {current_time}.
     */
    private static function fillTemplate(string $template, ?string $category): string {
        // Built-in tokens
        $builtins = [
            'current_time' => date('g:i A'),
            'current_date' => date('l, F j Y'),
        ];

        // Fetch all facts for this category (and null-category universal facts)
        $facts = [];
        if ($category) {
            $rows = JarvisDB::query(
                'SELECT fact_key, fact_value FROM kb_facts
                 WHERE category = ?',
                [$category]
            );
            foreach ($rows as $r) {
                $facts[$r['fact_key']] = $r['fact_value'];
            }
        }
        // Also pull network facts for network tokens used in any template
        if (strpos($template, '{online_count}') !== false || strpos($template, '{total_count}') !== false) {
            $netRows = JarvisDB::query(
                "SELECT fact_key, fact_value FROM kb_facts
                 WHERE category='network'"
            );
            foreach ($netRows as $r) {
                $facts[$r['fact_key']] = $r['fact_value'];
            }
        }

        $allTokens = array_merge($builtins, $facts);

        // Replace placeholders
        return preg_replace_callback('/\{([a-z0-9_]+)\}/', function ($m) use ($allTokens) {
            return $allTokens[$m[1]] ?? '[unknown]';
        }, $template);
    }

    /**
     * Store a fact in kb_facts (upsert).
     */
    public static function storeFact(
        string $category,
        string $key,
        string $value,
        string $host = 'local',
        ?int $ttlSeconds = null
    ): void {
        $expires = $ttlSeconds ? gmdate('Y-m-d H:i:s', time() + $ttlSeconds) : null;
        JarvisDB::execute(
            'INSERT INTO kb_facts (category, fact_key, fact_value, host, expires_at)
             VALUES (?,?,?,?,?)
             ON DUPLICATE KEY UPDATE fact_value=VALUES(fact_value), expires_at=VALUES(expires_at)',
            [$category, $key, $value, $host, $expires]
        );
    }

    /**
     * Learn from conversation — store interesting facts the user mentions.
     */
    public static function learnFromConversation(string $input, string $reply): void {
        // Preference learning: user states a preference
        if (preg_match('/(?i)i (prefer|like|want|always)\s+(.+?)(?:\.|$)/', $input, $m)) {
            $pref = trim($m[2]);
            if (strlen($pref) < 120) {
                JarvisDB::execute(
                    'INSERT INTO kb_preferences (pref_key, pref_value)
                     VALUES (?,?)
                     ON DUPLICATE KEY UPDATE pref_value=VALUES(pref_value)',
                    ['learned_' . md5($pref), $pref]
                );
            }
        }
    }

    /**
     * Return a summary of what the KB knows (for system prompt injection).
     */
    public static function getContextSummary(): string {
        // Exclude entity_map — too large for Ollama 1B tokenizer
        $facts = JarvisDB::query(
            "SELECT category, fact_key, fact_value FROM kb_facts
             WHERE fact_key != 'entity_map'
             ORDER BY category, updated_at DESC"
        );
        if (!$facts) return '';

        $byCategory = [];
        foreach ($facts as $f) {
            $byCategory[$f['category']][] = "{$f['fact_key']}={$f['fact_value']}";
        }

        $lines = [];
        foreach ($byCategory as $cat => $items) {
            $lines[] = strtoupper($cat) . ': ' . implode(', ', array_slice($items, 0, 8));
        }
        return implode("\n", $lines);
    }
}