<?php

namespace app\common;

/**
 * 编辑辅助：AI 辅助写作风险综合分析
 */
class AiWritingRiskAnalysisService
{
    /**
     * @param array $parsedData parseManuscriptStructure 的 data 字段
     */
    public function buildReport(array $parsedData): array
    {
        $templateStats = (array) ($parsedData['template_sentence_stats'] ?? []);
        $repeatedStats = (array) ($parsedData['repeated_phrases'] ?? []);
        $sentenceStats = (array) ($parsedData['sentence_stats'] ?? []);

        $dimensions = [
            $this->analyzeTemplateSentenceRisk($templateStats),
            $this->analyzeRepeatedPhraseRisk($repeatedStats),
            $this->analyzeSentenceLengthRisk($sentenceStats),
        ];

        $overallScore = 0;
        $levelRank = ['low' => 1, 'medium' => 2, 'high' => 3];
        $maxRank = 1;
        $flags = [];

        foreach ($dimensions as $dimension) {
            $overallScore += intval($dimension['score'] ?? 0);
            $rank = $levelRank[$dimension['level'] ?? 'low'] ?? 1;
            if ($rank > $maxRank) {
                $maxRank = $rank;
            }
            foreach ((array) ($dimension['flags'] ?? []) as $flag) {
                if ($flag !== '') {
                    $flags[] = $flag;
                }
            }
        }

        $overallLevel = array_search($maxRank, $levelRank, true) ?: 'low';

        return [
            'overall_level' => $overallLevel,
            'overall_score' => min(100, $overallScore),
            'summary'       => $this->buildSummary($overallLevel, $dimensions, $flags),
            'dimensions'    => $dimensions,
            'flags'         => array_values(array_unique($flags)),
        ];
    }

    private function analyzeTemplateSentenceRisk(array $stats): array
    {
        $items = (array) ($stats['items'] ?? []);
        $totalMatches = intval($stats['total_matches'] ?? 0);
        $matchedRuleCount = intval($stats['matched_rule_count'] ?? 0);

        $score = 0;
        $flags = [];
        foreach ($items as $item) {
            $count = intval($item['count'] ?? 0);
            $riskLevel = max(1, intval($item['risk_level'] ?? 1));
            $weight = max(1, intval($item['weight'] ?? 1));
            $score += $count * $riskLevel * $weight;

            if ($count > 0) {
                $section = (string) ($item['section'] ?? '');
                $remark = trim((string) ($item['remark'] ?? ''));
                $label = $remark !== '' ? $remark : (string) ($item['sentence_pattern'] ?? '');
                $flags[] = sprintf('%s段命中模版句：%s（%d次）', $section, $label, $count);
            }
        }

        $level = $this->scoreToLevel($score, 15, 40);

        return [
            'key'     => 'template_sentence',
            'name'    => '模版句特征',
            'level'   => $level,
            'score'   => min(100, $score),
            'summary' => $totalMatches > 0
                ? sprintf('命中 %d 条模版句规则，共 %d 处', $matchedRuleCount, $totalMatches)
                : '未检测到典型 AI 模版句',
            'metrics' => [
                'total_matches'      => $totalMatches,
                'matched_rule_count' => $matchedRuleCount,
            ],
            'details' => $stats,
            'flags'   => array_slice($flags, 0, 8),
        ];
    }

    private function analyzeRepeatedPhraseRisk(array $stats): array
    {
        $items = (array) ($stats['suspicious_items'] ?? []);
        if (empty($items)) {
            $items = array_values(array_filter((array) ($stats['items'] ?? []), function ($item) {
                return ($item['category'] ?? '') === 'suspicious';
            }));
        }
        $uniqueCount = count($items);
        $expectedCount = count((array) ($stats['expected_topic_items'] ?? []));
        $topCount = 0;
        $flags = [];

        foreach (array_slice($items, 0, 5) as $item) {
            $count = intval($item['count'] ?? 0);
            if ($count > $topCount) {
                $topCount = $count;
            }
            if ($count >= 4) {
                $flags[] = sprintf('可疑重复短语「%s」出现 %d 次', (string) ($item['phrase'] ?? ''), $count);
            }
        }

        $score = min(100, $uniqueCount * 3 + max(0, $topCount - 3) * 6);
        $level = 'low';
        if ($uniqueCount >= 10 || $topCount >= 8) {
            $level = 'high';
        } elseif ($uniqueCount >= 4 || $topCount >= 5) {
            $level = 'medium';
        }

        $summary = '未发现可疑机械重复短语';
        if ($uniqueCount > 0) {
            $summary = sprintf('发现 %d 组可疑重复短语，最高重复 %d 次', $uniqueCount, $topCount);
        } elseif ($expectedCount > 0) {
            $summary = sprintf('主题词正常重复 %d 组，未触发可疑短语', $expectedCount);
        }

        return [
            'key'     => 'repeated_phrase',
            'name'    => '重复短语',
            'level'   => $level,
            'score'   => $score,
            'summary' => $summary,
            'metrics' => [
                'suspicious_count' => $uniqueCount,
                'expected_topic_count' => $expectedCount,
                'top_count'      => $topCount,
            ],
            'details' => $stats,
            'flags'   => $flags,
        ];
    }

    private function analyzeSentenceLengthRisk(array $stats): array
    {
        $avg = floatval($stats['avg'] ?? 0);
        $std = floatval($stats['std'] ?? 0);
        $max = intval($stats['max'] ?? 0);
        $sentenceCount = intval($stats['sentence_count'] ?? 0);

        $score = 0;
        $flags = [];
        $level = 'low';

        if ($sentenceCount >= 8) {
            if ($avg >= 32) {
                $score += 20;
                $flags[] = sprintf('平均句长偏高（%.1f 词/句）', $avg);
            }
            if ($std > 0 && $std <= 5 && $avg >= 12 && $avg <= 28) {
                $score += 25;
                $flags[] = sprintf('句长分布过于均匀（均值 %.1f，标准差 %.1f）', $avg, $std);
            }
            if ($max >= 50) {
                $score += 10;
                $flags[] = sprintf('存在超长句（最长 %d 词）', $max);
            }
        }

        $level = $this->scoreToLevel($score, 10, 25);

        return [
            'key'     => 'sentence_length',
            'name'    => '句长特征',
            'level'   => $level,
            'score'   => min(100, $score),
            'summary' => $sentenceCount > 0
                ? sprintf('平均句长 %.1f，标准差 %.1f，共 %d 句', $avg, $std, $sentenceCount)
                : '正文句长数据不足',
            'metrics' => [
                'avg'             => $avg,
                'std'             => $std,
                'max'             => $max,
                'min'             => intval($stats['min'] ?? 0),
                'sentence_count'  => $sentenceCount,
            ],
            'details' => $stats,
            'flags'   => $flags,
        ];
    }

    private function scoreToLevel(int $score, int $mediumThreshold, int $highThreshold): string
    {
        if ($score >= $highThreshold) {
            return 'high';
        }
        if ($score >= $mediumThreshold) {
            return 'medium';
        }
        return 'low';
    }

    private function buildSummary(string $overallLevel, array $dimensions, array $flags): string
    {
        $levelText = [
            'low'    => '低风险',
            'medium' => '中等风险',
            'high'   => '较高风险',
        ];
        $parts = [$levelText[$overallLevel] ?? '低风险'];

        foreach ($dimensions as $dimension) {
            if (($dimension['level'] ?? 'low') === 'low') {
                continue;
            }
            $parts[] = $dimension['name'] . '需关注';
        }

        if (!empty($flags)) {
            $parts[] = '重点：' . $flags[0];
        }

        return implode('；', $parts);
    }
}