<?php

namespace app\common;

use think\Db;

/**
 * AI 写作模版句规则匹配（t_ai_template_sentence）
 */
class AiTemplateSentenceService
{
    /** @var array<int,array>|null */
    private static $ruleCache;

    /**
     * 按稿件分节统计模版句出现次数
     *
     * @param array<string,string> $sectionTexts 键：abstract/introduction/methods/results/discussion/conclusion
     * @return array{total_matches:int,matched_rule_count:int,items:array,by_section:array}
     */
    public function countInManuscript(array $sectionTexts): array
    {
        $rules = $this->loadActiveRules();
        if (empty($rules)) {
            return [
                'total_matches'       => 0,
                'matched_rule_count'  => 0,
                'items'               => [],
                'by_section'          => [],
            ];
        }

        $normalizedSections = [];
        foreach ($sectionTexts as $key => $text) {
            $sectionKey = strtolower(trim((string) $key));
            if ($sectionKey === '') {
                continue;
            }
            $normalizedSections[$sectionKey] = $this->normalizeText((string) $text);
        }

        $allText = $this->normalizeText(implode("\n\n", array_filter($normalizedSections)));

        $items = [];
        $bySection = [];

        foreach ($rules as $rule) {
            $ruleSection = strtolower(trim((string) ($rule['section'] ?? '')));
            $pattern = trim((string) ($rule['sentence_pattern'] ?? ''));
            if ($pattern === '') {
                continue;
            }

            $targetText = '';
            if ($ruleSection === 'all') {
                $targetText = $allText;
            } elseif (isset($normalizedSections[$ruleSection])) {
                $targetText = $normalizedSections[$ruleSection];
            } else {
                continue;
            }

            if ($targetText === '') {
                continue;
            }

            $count = $this->countPatternMatches($targetText, $pattern);
            if ($count <= 0) {
                continue;
            }

            $item = [
                'id'               => intval($rule['id'] ?? 0),
                'section'          => $ruleSection,
                'sentence_pattern' => $pattern,
                'count'            => $count,
                'risk_level'       => intval($rule['risk_level'] ?? 0),
                'weight'           => intval($rule['weight'] ?? 0),
                'remark'           => (string) ($rule['remark'] ?? ''),
            ];
            $items[] = $item;

            if (!isset($bySection[$ruleSection])) {
                $bySection[$ruleSection] = [
                    'total_matches'      => 0,
                    'matched_rule_count' => 0,
                    'items'              => [],
                ];
            }
            $bySection[$ruleSection]['items'][] = $item;
            $bySection[$ruleSection]['total_matches'] += $count;
            $bySection[$ruleSection]['matched_rule_count']++;
        }

        usort($items, function ($a, $b) {
            if ($a['count'] !== $b['count']) {
                return $b['count'] - $a['count'];
            }
            if ($a['weight'] !== $b['weight']) {
                return $b['weight'] - $a['weight'];
            }
            return $a['id'] - $b['id'];
        });

        foreach ($bySection as &$sectionStats) {
            usort($sectionStats['items'], function ($a, $b) {
                if ($a['count'] !== $b['count']) {
                    return $b['count'] - $a['count'];
                }
                return $b['weight'] - $a['weight'];
            });
        }
        unset($sectionStats);

        $totalMatches = 0;
        foreach ($items as $item) {
            $totalMatches += intval($item['count']);
        }

        return [
            'total_matches'      => $totalMatches,
            'matched_rule_count' => count($items),
            'items'              => $items,
            'by_section'         => $bySection,
        ];
    }

    /**
     * @return array<int,array>
     */
    private function loadActiveRules(): array
    {
        if (self::$ruleCache !== null) {
            return self::$ruleCache;
        }

        try {
            self::$ruleCache = Db::name('ai_template_sentence')
                ->where('status', 1)
                ->field('id,sentence_pattern,section,language,risk_level,weight,remark,article_type,version')
                ->order('section asc,id asc')
                ->select();
        } catch (\Throwable $e) {
            self::$ruleCache = [];
        }

        return self::$ruleCache;
    }

    private function normalizeText(string $text): string
    {
        return ManuscriptTextCleanService::clean($text);
    }

    private function countPatternMatches(string $text, string $pattern): int
    {
        if ($text === '' || $pattern === '') {
            return 0;
        }

        $regex = '#' . $pattern . '#iu';
        $error = null;
        set_error_handler(function ($errno, $errstr) use (&$error) {
            $error = $errstr;
            return true;
        });
        $count = preg_match_all($regex, $text, $matches);
        restore_error_handler();

        if ($count === false || $error !== null) {
            return 0;
        }

        return intval($count);
    }
}