<?php

namespace App\Services;

use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Facades\DB;

class LearningAnalyticsService
{
    protected string $baseUrl;
    protected int $timeout = 10;
    protected QuestionBankService $questionBankService;

    public function __construct(QuestionBankService $questionBankService)
    {
        $this->baseUrl = config('services.learning_analytics.url', env('LEARNING_ANALYTICS_API_BASE', 'http://localhost:5016'));
        $this->questionBankService = $questionBankService;
    }

    /**
     * 获取学生掌握度
     */
    public function getStudentMastery(string $studentId, string $kpCode = null): array
    {
        try {
            $endpoint = $kpCode 
                ? "/api/v1/mastery/student/{$studentId}/kp/{$kpCode}"
                : "/api/v1/mastery/student/{$studentId}";

            $response = Http::timeout($this->timeout)->get($this->baseUrl . $endpoint);
            
            if ($response->successful()) {
                return $response->json();
            }

            Log::error('LearningAnalytics API Error', [
                'endpoint' => $endpoint,
                'status' => $response->status(),
                'response' => $response->body()
            ]);

            return [
                'error' => true,
                'message' => 'Failed to fetch mastery data'
            ];
        } catch (\Exception $e) {
            Log::error('LearningAnalytics Service Exception', [
                'error' => $e->getMessage(),
                'trace' => $e->getTraceAsString()
            ]);

            return [
                'error' => true,
                'message' => $e->getMessage()
            ];
        }
    }

    /**
     * 更新学生掌握度
     */
    public function updateMastery(array $data): array
    {
        try {
            $response = Http::timeout($this->timeout)
                ->post($this->baseUrl . '/api/v1/mastery/student/' . $data['student_id'] . '/update', $data);

            if ($response->successful()) {
                return $response->json();
            }

            Log::error('LearningAnalytics Update Error', [
                'data' => $data,
                'status' => $response->status(),
                'response' => $response->body()
            ]);

            return [
                'error' => true,
                'message' => 'Failed to update mastery'
            ];
        } catch (\Exception $e) {
            Log::error('LearningAnalytics Update Exception', [
                'error' => $e->getMessage(),
                'data' => $data
            ]);

            return [
                'error' => true,
                'message' => $e->getMessage()
            ];
        }
    }

    /**
     * 获取老师名下的所有学生
     */
    public function getTeacherStudents(string $teacherId): array
    {
        try {
            // 从本地MySQL获取学生
            $students = DB::table('students as s')
                ->leftJoin('users as u', 's.student_id', '=', 'u.user_id')
                ->where('s.teacher_id', $teacherId)
                ->select(
                    's.student_id',
                    's.name',
                    's.grade',
                    's.class_name',
                    'u.username',
                    'u.email'
                )
                ->get()
                ->toArray();

            return $students;
        } catch (\Exception $e) {
            Log::error('Get Teacher Students Error', [
                'teacher_id' => $teacherId,
                'error' => $e->getMessage()
            ]);

            return [];
        }
    }

    /**
     * 获取学生学习分析
     */
    public function getStudentAnalysis(string $studentId): array
    {
        // 从LearningAnalytics获取掌握度
        $masteryData = $this->getStudentMastery($studentId);
        
        // 从MySQL获取练习历史
        $exercises = DB::table('student_exercises')
            ->where('student_id', $studentId)
            ->orderBy('created_at', 'desc')
            ->limit(50)
            ->get()
            ->toArray();

        // 从MySQL获取掌握度记录
        $masteryRecords = DB::table('student_mastery')
            ->where('student_id', $studentId)
            ->get()
            ->toArray();

        return [
            'student_id' => $studentId,
            'mastery_from_la' => $masteryData,
            'exercises' => $exercises,
            'mastery_records' => $masteryRecords,
            'total_exercises' => count($exercises),
            'total_mastery_records' => count($masteryRecords),
        ];
    }

    /**
     * 生成学习测试数据
     */
    public function generateLearningData(string $studentId, array $params): array
    {
        $results = [];
        
        foreach ($params as $param) {
            $data = [
                'student_id' => $studentId,
                'kp_code' => $param['kp_code'],
                'is_correct' => $param['is_correct'],
                'time_spent_seconds' => $param['time_spent_seconds'] ?? 120,
                'difficulty_level' => $param['difficulty_level'] ?? 3,
            ];
            
            $result = $this->updateMastery($data);
            $results[] = $result;
        }
        
        return $results;
    }

    /**
     * 获取学习推荐
     */
    public function getLearningRecommendations(string $studentId): array
    {
        try {
            $response = Http::timeout($this->timeout)
                ->get($this->baseUrl . "/api/v1/learning-path/student/{$studentId}/recommend");

            if ($response->successful()) {
                return $response->json();
            }

            return ['error' => true, 'message' => 'Failed to fetch recommendations'];
        } catch (\Exception $e) {
            return ['error' => true, 'message' => $e->getMessage()];
        }
    }

    /**
     * 获取知识点列表（从知识图谱API）
     */
    public function getKnowledgePoints(array $filters = []): array
    {
        try {
            $kgBaseUrl = config('services.knowledge_api.base_url', 'http://localhost:5011');
            $response = Http::timeout($this->timeout)
                ->get($kgBaseUrl . '/knowledge-points/', $filters);

            if ($response->successful()) {
                return $response->json()['data'] ?? [];
            }

            return [];
        } catch (\Exception $e) {
            Log::error('LearningAnalytics Knowledge Points Error', [
                'error' => $e->getMessage()
            ]);

            return [];
        }
    }

    /**
     * 获取学生技能熟练度
     */
    public function getStudentSkillProficiency(string $studentId): array
    {
        try {
            $response = Http::timeout($this->timeout)
                ->get($this->baseUrl . "/api/v1/skill/proficiency/student/{$studentId}");

            if ($response->successful()) {
                return $response->json();
            }

            Log::error('LearningAnalytics Skill Proficiency Error', [
                'student_id' => $studentId,
                'status' => $response->status(),
                'response' => $response->body()
            ]);

            return [
                'error' => true,
                'message' => 'Failed to fetch skill proficiency'
            ];
        } catch (\Exception $e) {
            Log::error('LearningAnalytics Skill Proficiency Exception', [
                'student_id' => $studentId,
                'error' => $e->getMessage()
            ]);

            return [
                'error' => true,
                'message' => $e->getMessage()
            ];
        }
    }

    /**
     * 获取学生掌握度列表（别名方法）
     */
    public function getStudentMasteryList(string $studentId): array
    {
        return $this->getStudentMastery($studentId);
    }

    /**
     * 获取知识点依赖关系
     */
    public function getKnowledgeDependencies(): array
    {
        try {
            $response = Http::timeout($this->timeout)
                ->get($this->baseUrl . '/knowledge-dependencies/');

            if ($response->successful()) {
                return $response->json()['data'] ?? [];
            }

            return [];
        } catch (\Exception $e) {
            Log::error('LearningAnalytics Knowledge Dependencies Error', [
                'error' => $e->getMessage()
            ]);

            return [];
        }
    }

    /**
     * 提交学生答题记录
     */
    public function submitAttempt(string $studentId, array $attemptData): array
    {
        try {
            $response = Http::timeout($this->timeout)
                ->post($this->baseUrl . "/api/v1/attempts/student/{$studentId}", $attemptData);

            if ($response->successful()) {
                return $response->json();
            }

            Log::error('Submit Attempt Error', [
                'student_id' => $studentId,
                'data' => $attemptData,
                'status' => $response->status(),
                'response' => $response->body()
            ]);

            return [
                'error' => true,
                'message' => 'Failed to submit attempt'
            ];
        } catch (\Exception $e) {
            Log::error('Submit Attempt Exception', [
                'student_id' => $studentId,
                'error' => $e->getMessage(),
                'data' => $attemptData
            ]);

            return [
                'error' => true,
                'message' => $e->getMessage()
            ];
        }
    }

    /**
     * 检查服务健康状态
     */
    public function checkHealth(): bool
    {
        try {
            $response = Http::timeout(5)->get($this->baseUrl . '/health');
            return $response->successful();
        } catch (\Exception $e) {
            return false;
        }
    }

    /**
     * 获取学生掌握度概览
     */
    public function getStudentMasteryOverview(string $studentId): array
    {
        try {
            $mastery = $this->getStudentMastery($studentId);
            if (isset($mastery['error'])) {
                return [
                    'total_knowledge_points' => 0,
                    'average_mastery_level' => 0,
                    'mastered_knowledge_points' => 0,
                    'good_knowledge_points' => 0,
                    'weak_knowledge_points' => 0,
                    'weak_knowledge_points_list' => [],
                    'details' => []
                ];
            }

            $data = $mastery['data'] ?? [];

            // 过滤出有实际答题记录的知识点
            $attemptedData = array_filter($data, function($item) {
                return ($item['total_attempts'] ?? 0) > 0;
            });

            $total = count($data);  // 总知识点数（包括未学习的）
            $attemptedCount = count($attemptedData);  // 已学习的知识点数
            $average = $attemptedCount > 0
                ? array_sum(array_column($attemptedData, 'mastery_level')) / $attemptedCount
                : 0;

            // 分类知识点（只对有记录的知识点进行分类）
            $mastered = [];     // ≥ 85%
            $good = [];         // 70-84%
            $weak = [];         // < 70%

            foreach ($attemptedData as $item) {
                $level = $item['mastery_level'] ?? 0;
                if ($level >= 0.85) {
                    $mastered[] = $item;
                } elseif ($level >= 0.70) {
                    $good[] = $item;
                } else {
                    $weak[] = $item;
                }
            }

            return [
                'total_knowledge_points' => $total,
                'average_mastery_level' => $average,
                'mastered_knowledge_points' => count($mastered),
                'good_knowledge_points' => count($good),
                'weak_knowledge_points' => count($weak),
                'weak_knowledge_points_list' => $weak,
                'details' => $data
            ];
        } catch (\Exception $e) {
            Log::error('Get Student Mastery Overview Error', [
                'student_id' => $studentId,
                'error' => $e->getMessage()
            ]);
            return [
                'total_knowledge_points' => 0,
                'average_mastery_level' => 0,
                'mastered_knowledge_points' => 0,
                'good_knowledge_points' => 0,
                'weak_knowledge_points' => 0,
                'weak_knowledge_points_list' => [],
                'details' => []
            ];
        }
    }

    /**
     * 获取学生技能摘要
     */
    public function getStudentSkillSummary(string $studentId): array
    {
        try {
            $proficiency = $this->getStudentSkillProficiency($studentId);
            if (isset($proficiency['error'])) {
                return [
                    'total_skills' => 0,
                    'average_proficiency_level' => 0,
                    'total_questions_attempted' => 0,
                    'skill_list' => []
                ];
            }

            $data = $proficiency['data'] ?? [];
            $totalSkills = count($data);
            $averageLevel = $totalSkills > 0 ? array_sum(array_column($data, 'proficiency_level')) / $totalSkills : 0;

            // 计算总答题数
            $totalQuestions = 0;
            foreach ($data as $skill) {
                $totalQuestions += $skill['total_questions_attempted'] ?? 0;
            }

            return [
                'total_skills' => $totalSkills,
                'average_proficiency_level' => $averageLevel,
                'total_questions_attempted' => $totalQuestions,
                'skill_list' => $data
            ];
        } catch (\Exception $e) {
            Log::error('Get Student Skill Summary Error', [
                'student_id' => $studentId,
                'error' => $e->getMessage()
            ]);
            return [
                'total_skills' => 0,
                'average_proficiency_level' => 0,
                'total_questions_attempted' => 0,
                'skill_list' => []
            ];
        }
    }

    /**
     * 获取学生预测数据
     */
    public function getStudentPredictions(string $studentId, int $count = 5): array
    {
        try {
            $response = Http::timeout($this->timeout)
                ->get($this->baseUrl . "/api/v1/prediction/student/{$studentId}?count={$count}");

            if ($response->successful()) {
                $data = $response->json();
                $predictions = $data['predictions'] ?? $data['data'] ?? [];
                return [
                    'predictions' => $predictions
                ];
            }

            return [
                'predictions' => []
            ];
        } catch (\Exception $e) {
            Log::error('Get Student Predictions Error', [
                'student_id' => $studentId,
                'error' => $e->getMessage()
            ]);
            return [
                'predictions' => []
            ];
        }
    }

    /**
     * 获取学生学习路径
     */
    public function getStudentLearningPaths(string $studentId, int $count = 3): array
    {
        try {
            $response = Http::timeout($this->timeout)
                ->get($this->baseUrl . "/api/v1/learning-path/student/{$studentId}?count={$count}");

            if ($response->successful()) {
                $data = $response->json()['data'] ?? [];
                return [
                    'paths' => $data
                ];
            }

            return [
                'paths' => []
            ];
        } catch (\Exception $e) {
            Log::error('Get Student Learning Paths Error', [
                'student_id' => $studentId,
                'error' => $e->getMessage()
            ]);
            return [
                'paths' => []
            ];
        }
    }

    /**
     * 获取预测分析数据
     */
    public function getPredictionAnalytics(string $studentId): array
    {
        try {
            $predictions = $this->getStudentPredictions($studentId, 10);

            if (empty($predictions)) {
                return ['accuracy' => 0, 'trend' => 'stable', 'confidence' => 0];
            }

            $accuracy = 0;
            $confidence = 0;
            if (!empty($predictions)) {
                $accuracy = rand(75, 95); // 模拟准确率
                $confidence = rand(70, 90); // 模拟置信度
            }

            $trend = 'improving'; // improving, stable, declining

            return [
                'accuracy' => $accuracy,
                'trend' => $trend,
                'confidence' => $confidence,
                'sample_size' => count($predictions)
            ];
        } catch (\Exception $e) {
            Log::error('Get Prediction Analytics Error', [
                'student_id' => $studentId,
                'error' => $e->getMessage()
            ]);
            return ['accuracy' => 0, 'trend' => 'stable', 'confidence' => 0];
        }
    }

    /**
     * 获取学习路径分析数据
     */
    public function getLearningPathAnalytics(string $studentId): array
    {
        try {
            $paths = $this->getStudentLearningPaths($studentId, 5);

            if (empty($paths)) {
                return [
                    'active_paths' => 0,
                    'completed_paths' => 0,
                    'average_efficiency_score' => 0,
                    'completion_rate' => 0,
                    'average_time' => 0,
                    'total_paths' => 0
                ];
            }

            $activePaths = 0;
            $completedPaths = 0;
            $efficiencyScores = [];

            foreach ($paths as $path) {
                if (($path['status'] ?? '') === 'active') {
                    $activePaths++;
                }
                if (($path['status'] ?? '') === 'completed') {
                    $completedPaths++;
                }
                if (isset($path['efficiency_score'])) {
                    $efficiencyScores[] = $path['efficiency_score'];
                }
            }

            $averageEfficiency = !empty($efficiencyScores)
                ? array_sum($efficiencyScores) / count($efficiencyScores)
                : rand(60, 85) / 100;

            $completionRate = count($paths) > 0
                ? ($completedPaths / count($paths)) * 100
                : 0;

            $averageTime = rand(30, 60); // 模拟平均时间（分钟）

            return [
                'active_paths' => $activePaths,
                'completed_paths' => $completedPaths,
                'average_efficiency_score' => $averageEfficiency,
                'completion_rate' => $completionRate,
                'average_time' => $averageTime,
                'total_paths' => count($paths)
            ];
        } catch (\Exception $e) {
            Log::error('Get Learning Path Analytics Error', [
                'student_id' => $studentId,
                'error' => $e->getMessage()
            ]);
            return [
                'active_paths' => 0,
                'completed_paths' => 0,
                'average_efficiency_score' => 0,
                'completion_rate' => 0,
                'average_time' => 0,
                'total_paths' => 0
            ];
        }
    }

    /**
     * 快速分数预测
     */
    public function quickScorePrediction(string $studentId): array
    {
        Log::info('开始调用快速预测API', ['student_id' => $studentId]);

        try {
            $response = Http::timeout($this->timeout)
                ->post($this->baseUrl . "/api/v1/prediction/student/{$studentId}/quick-prediction", [
                    'student_id' => $studentId
                ]);

            Log::info('快速预测API响应', [
                'student_id' => $studentId,
                'status' => $response->status(),
                'body' => $response->body()
            ]);

            if ($response->successful()) {
                $data = $response->json();
                Log::info('快速预测API返回数据', ['student_id' => $studentId, 'data' => $data]);

                // API直接返回数据，没有嵌套在'data'键中
                $quickPredictionData = $data['quick_prediction'] ?? [];

                return [
                    'quick_prediction' => [
                        'current_score' => $quickPredictionData['current_score'] ?? 70,
                        'predicted_score' => $quickPredictionData['predicted_score'] ?? 75,
                        'improvement_potential' => $quickPredictionData['improvement_potential'] ?? 5,
                        'estimated_study_hours' => $quickPredictionData['estimated_study_hours'] ?? 15,
                        'confidence_level' => $quickPredictionData['confidence_level'] ?? 0.75,
                        'priority_topics' => $quickPredictionData['priority_topics'] ?? [],
                        'recommended_actions' => $quickPredictionData['recommended_actions'] ?? [],
                        'weak_knowledge_points_count' => $quickPredictionData['weak_knowledge_points_count'] ?? 0,
                        'total_knowledge_points' => $quickPredictionData['total_knowledge_points'] ?? 0
                    ],
                    'predicted_score' => $quickPredictionData['predicted_score'] ?? 75,
                    'confidence' => $quickPredictionData['confidence_level'] ? $quickPredictionData['confidence_level'] * 100 : 75,
                    'time_estimate' => $quickPredictionData['estimated_study_hours'] ?? 15
                ];
            }

            Log::warning('快速预测API调用失败', [
                'student_id' => $studentId,
                'status' => $response->status(),
                'response' => $response->body()
            ]);

            return [
                'quick_prediction' => [
                    'improvement_potential' => 0,
                    'estimated_study_hours' => 0,
                    'confidence_level' => 0
                ],
                'predicted_score' => 0,
                'confidence' => 0,
                'time_estimate' => 0
            ];
        } catch (\Exception $e) {
            Log::error('Quick Score Prediction Error', [
                'student_id' => $studentId,
                'error' => $e->getMessage()
            ]);
            return [
                'quick_prediction' => [
                    'improvement_potential' => 0,
                    'estimated_study_hours' => 0,
                    'confidence_level' => 0
                ],
                'predicted_score' => 0,
                'confidence' => 0,
                'time_estimate' => 0
            ];
        }
    }

    /**
     * 推荐学习路径
     */
    public function recommendLearningPaths(string $studentId, int $count = 3): array
    {
        try {
            $response = Http::timeout($this->timeout)
                ->get($this->baseUrl . "/api/v1/learning-path/recommend/{$studentId}?count={$count}");

            if ($response->successful()) {
                $data = $response->json()['data'] ?? [];
                return [
                    'recommendations' => $data
                ];
            }

            return [
                'recommendations' => []
            ];
        } catch (\Exception $e) {
            Log::error('Recommend Learning Paths Error', [
                'student_id' => $studentId,
                'error' => $e->getMessage()
            ]);
            return [
                'recommendations' => []
            ];
        }
    }

    /**
     * 重新计算掌握度
     */
    public function recalculateMastery(string $studentId, string $kpCode): bool
    {
        try {
            $response = Http::timeout($this->timeout)
                ->post($this->baseUrl . "/api/v1/mastery/recalculate/{$studentId}", [
                    'student_id' => $studentId,
                    'kp_code' => $kpCode
                ]);

            return $response->successful();
        } catch (\Exception $e) {
            Log::error('Recalculate Mastery Error', [
                'student_id' => $studentId,
                'kp_code' => $kpCode,
                'error' => $e->getMessage()
            ]);
            return false;
        }
    }

    /**
     * 批量更新技能熟练度
     */
    public function batchUpdateSkillProficiency(string $studentId): bool
    {
        try {
            $response = Http::timeout($this->timeout)
                ->post($this->baseUrl . "/api/v1/skill/proficiency/student/{$studentId}/batch-update", [
                    'student_id' => $studentId
                ]);

            return $response->successful();
        } catch (\Exception $e) {
            Log::error('Batch Update Skill Proficiency Error', [
                'student_id' => $studentId,
                'error' => $e->getMessage()
            ]);
            return false;
        }
    }

    /**
     * 清空学生所有答题数据
     */
    public function clearStudentData(string $studentId): bool
    {
        try {
            // 清空LearningAnalytics中的数据（通过API）
            $response = Http::timeout($this->timeout)
                ->delete($this->baseUrl . "/api/v1/student/{$studentId}/clear");

            if (!$response->successful()) {
                Log::error('Clear LearningAnalytics Data Failed', [
                    'student_id' => $studentId,
                    'status' => $response->status(),
                    'response' => $response->body()
                ]);
            }

            // 清空MySQL中的数据
            $this->clearStudentMySQLData($studentId);

            Log::info('Student Data Cleared Successfully', [
                'student_id' => $studentId,
                'api_success' => $response->successful()
            ]);

            return true;
        } catch (\Exception $e) {
            Log::error('Clear Student Data Error', [
                'student_id' => $studentId,
                'error' => $e->getMessage()
            ]);

            // 即使API失败，也要尝试清空本地数据
            try {
                $this->clearStudentMySQLData($studentId);
                return true;
            } catch (\Exception $localError) {
                Log::error('Clear Local Data Also Failed', [
                    'student_id' => $studentId,
                    'error' => $localError->getMessage()
                ]);
                return false;
            }
        }
    }

    /**
     * 清空学生MySQL中的答题数据
     */
    private function clearStudentMySQLData(string $studentId): void
    {
        try {
            // 清空student_exercises表
            DB::table('student_exercises')
                ->where('student_id', $studentId)
                ->delete();

            // 清空student_mastery表
            DB::table('student_mastery')
                ->where('student_id', $studentId)
                ->delete();

            Log::info('Student MySQL Data Cleared', [
                'student_id' => $studentId
            ]);
        } catch (\Exception $e) {
            Log::error('Clear Student MySQL Data Error', [
                'student_id' => $studentId,
                'error' => $e->getMessage()
            ]);
            throw $e; // 重新抛出异常，让上层处理
        }
    }

    /**
     * 获取学生列表（供智能出卷使用）
     */
    public function getStudentsList(): array
    {
        try {
            $response = Http::timeout($this->timeout)
                ->get($this->baseUrl . '/api/v1/students/list');

            if ($response->successful()) {
                return $response->json('data', []);
            }

            // 如果API失败，尝试从MySQL直接读取
            return $this->getStudentsFromMySQL();
        } catch (\Exception $e) {
            Log::error('Get Students List Error', [
                'error' => $e->getMessage()
            ]);

            // 返回模拟数据
            return [
                ['student_id' => 'stu_001', 'name' => '张三'],
                ['student_id' => 'stu_002', 'name' => '李四'],
                ['student_id' => 'stu_003', 'name' => '王五'],
            ];
        }
    }

    /**
     * 从MySQL获取学生列表
     */
    private function getStudentsFromMySQL(): array
    {
        try {
            return DB::table('students')
                ->select('student_id', 'name')
                ->limit(100)
                ->get()
                ->toArray();
        } catch (\Exception $e) {
            Log::error('Get Students From MySQL Error', [
                'error' => $e->getMessage()
            ]);
            return [];
        }
    }

    /**
     * 获取学生薄弱点列表
     */
    public function getStudentWeaknesses(string $studentId, int $limit = 10): array
    {
        try {
            $response = Http::timeout($this->timeout)
                ->get($this->baseUrl . "/api/v1/analysis/weaknesses/{$studentId}?limit={$limit}");

            if ($response->successful()) {
                return $response->json('data', []);
            }

            // API失败时，从MySQL直接查询
            return $this->getStudentWeaknessesFromMySQL($studentId, $limit);
        } catch (\Exception $e) {
            Log::error('Get Student Weaknesses Error', [
                'student_id' => $studentId,
                'error' => $e->getMessage()
            ]);
            return [];
        }
    }

    /**
     * 从MySQL获取学生薄弱点
     */
    private function getStudentWeaknessesFromMySQL(string $studentId, int $limit = 10): array
    {
        try {
            $weaknesses = DB::table('student_mastery as sm')
                ->join('knowledge_points as kp', 'sm.kp', '=', 'kp.kp')
                ->where('sm.student_id', $studentId)
                ->where('sm.mastery', '<', 0.7) // 掌握度低于70%视为薄弱点
                ->orderBy('sm.mastery', 'asc')
                ->limit($limit)
                ->select([
                    'sm.kp as kp_code',
                    'kp.cn_name as kp_name',
                    'sm.mastery',
                    'sm.stability'
                ])
                ->get()
                ->toArray();

            return array_map(function ($item) {
                return [
                    'kp_code' => $item->kp_code,
                    'kp_name' => $item->kp_name,
                    'mastery' => (float) $item->mastery,
                    'stability' => (float) $item->stability,
                    'weakness_level' => 1.0 - (float) $item->mastery // 薄弱程度
                ];
            }, $weaknesses);
        } catch (\Exception $e) {
            Log::error('Get Student Weaknesses From MySQL Error', [
                'student_id' => $studentId,
                'error' => $e->getMessage()
            ]);
            return [];
        }
    }

    /**
     * 智能出卷：根据学生掌握度智能选择题目
     */
    public function generateIntelligentExam(array $params): array
    {
        try {
            $studentId = $params['student_id'] ?? null;
            $totalQuestions = $params['total_questions'] ?? 20;
            $kpCodes = $params['kp_codes'] ?? [];
            $skills = $params['skills'] ?? [];
            $questionTypeRatio = $params['question_type_ratio'] ?? [
                '选择题' => 40,
                '填空题' => 30,
                '解答题' => 30,
            ];
            $difficultyRatio = $params['difficulty_ratio'] ?? [
                '基础' => 50,
                '中等' => 35,
                '拔高' => 15,
            ];

            // 1. 如果指定了学生，获取学生的薄弱点
            $weaknessFilter = [];
            if ($studentId) {
                $weaknesses = $this->getStudentWeaknesses($studentId, 20);
                $weaknessFilter = array_column($weaknesses, 'kp_code');

                // 如果用户没有指定知识点，使用学生的薄弱点
                if (empty($kpCodes)) {
                    $kpCodes = $weaknessFilter;
                }
            }

            // 如果仍然没有知识点（例如新学生无薄弱点），根据年级从知识图谱获取知识点
            if (empty($kpCodes)) {
                $filters = [];
                if ($studentId) {
                    $student = \App\Models\Student::find($studentId);
                    if ($student && $student->grade) {
                        $grade = $student->grade;
                        $standardizedGrade = $grade;
                        
                        // 标准化年级名称并更新数据库
                        if ($grade === '初一') {
                            $standardizedGrade = '七年级';
                        } elseif ($grade === '初二') {
                            $standardizedGrade = '八年级';
                        } elseif ($grade === '初三') {
                            $standardizedGrade = '九年级';
                        }

                        if ($standardizedGrade !== $grade) {
                            $student->grade = $standardizedGrade;
                            $student->save();
                            Log::info('Standardized student grade', ['student_id' => $studentId, 'old' => $grade, 'new' => $standardizedGrade]);
                            $grade = $standardizedGrade;
                        }

                        // 映射年级到学段 (phase)
                        if (str_contains($grade, '初') || str_contains($grade, '七年级') || str_contains($grade, '八年级') || str_contains($grade, '九年级')) {
                            $filters['phase'] = '初中';
                        } elseif (str_contains($grade, '高')) {
                            $filters['phase'] = '高中';
                        }
                    }
                }

                // 调用API获取过滤后的知识点
                $filteredKps = $this->getKnowledgePoints($filters);
                
                if (!empty($filteredKps)) {
                    // 随机选择 5 个知识点
                    $kpKeys = array_column($filteredKps, 'kp_code');
                    if (empty($kpKeys)) {
                         $kpKeys = array_column($filteredKps, 'code');
                    }
                    
                    if (!empty($kpKeys)) {
                        $randomKeys = array_rand(array_flip($kpKeys), min(5, count($kpKeys)));
                        $kpCodes = is_array($randomKeys) ? $randomKeys : [$randomKeys];
                        
                        Log::info('Randomly selected KPs for student based on grade (API)', [
                            'student_id' => $studentId, 
                            'grade' => $student->grade ?? 'unknown',
                            'filters' => $filters,
                            'kps' => $kpCodes
                        ]);
                    }
                }
            }

            // 2. 调用题库API获取符合条件的所有题目
            $allQuestions = $this->getQuestionsFromBank($kpCodes, $skills, $studentId);

            if (empty($allQuestions)) {
                return [
                    'success' => false,
                    'message' => '未找到符合条件的题目',
                    'questions' => []
                ];
            }

            // 3. 根据掌握度对题目进行筛选和排序
            $selectedQuestions = $this->selectQuestionsByMastery(
                $allQuestions,
                $studentId,
                $totalQuestions,
                $questionTypeRatio,
                $difficultyRatio,
                $weaknessFilter
            );

            if (empty($selectedQuestions)) {
                return [
                    'success' => false,
                    'message' => '题目筛选失败',
                    'questions' => []
                ];
            }

            return [
                'success' => true,
                'message' => '智能出卷成功',
                'questions' => $selectedQuestions,
                'stats' => [
                    'total_selected' => count($selectedQuestions),
                    'source_questions' => count($allQuestions),
                    'weakness_targeted' => $studentId ? count(array_intersect(array_column($selectedQuestions, 'kp_code'), $weaknessFilter)) : 0
                ]
            ];
        } catch (\Exception $e) {
            Log::error('Generate Intelligent Exam Error', [
                'error' => $e->getMessage(),
                'trace' => $e->getTraceAsString()
            ]);

            return [
                'success' => false,
                'message' => '智能出卷异常: ' . $e->getMessage(),
                'questions' => []
            ];
        }
    }

    /**
     * 从题库获取题目
     */
    private function getQuestionsFromBank(array $kpCodes, array $skills, ?string $studentId): array
    {
        try {
            // 构建查询参数
            $params = [
                'kp_codes' => implode(',', $kpCodes),
                'limit' => 1000 // 获取足够多的题目用于筛选
            ];

            if (!empty($skills)) {
                $params['skills'] = implode(',', $skills);
            }

            if ($studentId) {
                $params['exclude_student_questions'] = $studentId; // 过滤学生做过的题目
            }

            // 调用QuestionBank API
            // 使用 QuestionBankService 获取题目 (使用 filterQuestions 方法以支持 kp_codes)
            $response = $this->questionBankService->filterQuestions($params);
            
            if (!empty($response['data'])) {
                return $response['data'];
            }
            
            Log::warning('Get Questions From Bank Failed or Empty', [
                'params' => $params,
                'response' => $response
            ]);

            return [];
        } catch (\Exception $e) {
            Log::error('Get Questions From Bank Error', [
                'error' => $e->getMessage()
            ]);
        }

        return [];
    }

    /**
     * 根据学生掌握度筛选题目
     */
    private function selectQuestionsByMastery(
        array $questions,
        ?string $studentId,
        int $totalQuestions,
        array $questionTypeRatio,
        array $difficultyRatio,
        array $weaknessFilter
    ): array {
        // 1. 按知识点分组
        $questionsByKp = [];
        foreach ($questions as $question) {
            $kpCode = $question['kp_code'] ?? '';
            if (!isset($questionsByKp[$kpCode])) {
                $questionsByKp[$kpCode] = [];
            }
            $questionsByKp[$kpCode][] = $question;
        }

        // 2. 为每个知识点计算权重
        $kpWeights = [];
        foreach (array_keys($questionsByKp) as $kpCode) {
            if ($studentId) {
                // 获取学生对该知识点的掌握度
                $mastery = $this->getStudentKpMastery($studentId, $kpCode);

                // 薄弱点权重更高
                if (in_array($kpCode, $weaknessFilter)) {
                    $kpWeights[$kpCode] = 2.0; // 薄弱点权重翻倍
                } else {
                    // 掌握度越低，权重越高
                    $kpWeights[$kpCode] = 1.0 + (1.0 - $mastery) * 1.5;
                }
            } else {
                $kpWeights[$kpCode] = 1.0; // 未指定学生时平均分配
            }
        }

        // 3. 按权重分配题目数量
        $totalWeight = array_sum($kpWeights);
        $selectedQuestions = [];

        foreach ($questionsByKp as $kpCode => $kpQuestions) {
            // 计算该知识点应该选择的题目数
            $kpQuestionCount = max(1, round(($totalQuestions * $kpWeights[$kpCode]) / $totalWeight));

            // 打乱题目顺序（避免固定模式）
            shuffle($kpQuestions);

            // 选择题目
            $selectedFromKp = array_slice($kpQuestions, 0, $kpQuestionCount);
            $selectedQuestions = array_merge($selectedQuestions, $selectedFromKp);
        }

        // 4. 如果题目过多，按权重排序后截取
        if (count($selectedQuestions) > $totalQuestions) {
            usort($selectedQuestions, function ($a, $b) use ($kpWeights) {
                $weightA = $kpWeights[$a['kp_code']] ?? 1.0;
                $weightB = $kpWeights[$b['kp_code']] ?? 1.0;
                return $weightB <=> $weightA;
            });
            $selectedQuestions = array_slice($selectedQuestions, 0, $totalQuestions);
        }

        // 5. 按题型和难度进行微调
        return $this->adjustQuestionsByRatio($selectedQuestions, $questionTypeRatio, $difficultyRatio);
    }

    /**
     * 获取学生对特定知识点的掌握度
     */
    private function getStudentKpMastery(string $studentId, string $kpCode): float
    {
        try {
            $mastery = DB::table('student_mastery')
                ->where('student_id', $studentId)
                ->where('kp', $kpCode)
                ->value('mastery');

            return $mastery ? (float) $mastery : 0.5; // 默认0.5（中等掌握度）
        } catch (\Exception $e) {
            Log::error('Get Student Kp Mastery Error', [
                'student_id' => $studentId,
                'kp_code' => $kpCode,
                'error' => $e->getMessage()
            ]);
            return 0.5;
        }
    }

    /**
     * 根据题型和难度配比调整题目
     */
    private function adjustQuestionsByRatio(array $questions, array $typeRatio, array $difficultyRatio): array
    {
        // 这里可以实现更精细的调整逻辑
        // 目前先返回原始题目，后续可以基于question_type和difficulty字段进行调整

        return $questions;
    }
}