<?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;

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

    /**
     * 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::connection('remote_mysql')
                ->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::connection('remote_mysql')
            ->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::connection('remote_mysql')
            ->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
    {
        try {
            $response = Http::timeout($this->timeout)
                ->get($this->baseUrl . '/knowledge-points/');

            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::connection('remote_mysql')
                ->table('student_exercises')
                ->where('student_id', $studentId)
                ->delete();

            // 清空student_mastery表
            DB::connection('remote_mysql')
                ->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
        }
    }
}