<?php

namespace App\Services;

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

class QuestionBankService
{
    protected string $baseUrl;

    public function __construct()
    {
        // 从配置文件读取base_url
        $this->baseUrl = config('services.question_bank.base_url', env('QUESTION_BANK_API_BASE', 'http://localhost:5015'));
        $this->baseUrl = rtrim($this->baseUrl, '/');
    }

    /**
     * 获取题目列表
     */
    public function listQuestions(int $page = 1, int $perPage = 50, array $filters = []): array
    {
        try {
            $response = Http::timeout(10)
                ->get($this->baseUrl . '/questions', [
                    'page' => $page,
                    'per_page' => $perPage,
                    ...$filters
                ]);

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

            Log::warning('题库API调用失败', [
                'status' => $response->status()
            ]);
        } catch (\Exception $e) {
            Log::error('获取题目列表失败', [
                'error' => $e->getMessage()
            ]);
        }

        return ['data' => [], 'meta' => ['total' => 0]];
    }

    /**
     * 筛选题目 (支持 kp_codes, skills 等高级筛选)
     */
    public function filterQuestions(array $params): array
    {
        try {
            $response = Http::timeout(30)
                ->get($this->baseUrl . '/questions', $params);

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

            Log::warning('筛选题目API调用失败', [
                'status' => $response->status(),
                'params' => $params
            ]);
        } catch (\Exception $e) {
            Log::error('筛选题目异常', [
                'error' => $e->getMessage(),
                'params' => $params
            ]);
        }

        return ['data' => []];
    }

    /**
     * 批量获取题目详情（根据题目 ID 列表）
     */
    public function getQuestionsByIds(array $ids): array
    {
        if (empty($ids)) {
            return ['data' => []];
        }
        try {
            $response = Http::timeout(15)
                ->get($this->baseUrl . '/questions', [
                    'ids' => implode(',', $ids),
                ]);
            if ($response->successful()) {
                return $response->json();
            }
            Log::warning('批量获取题目失败', [
                'ids' => $ids,
                'status' => $response->status(),
            ]);
        } catch (\Exception $e) {
            Log::error('批量获取题目异常', [
                'ids' => $ids,
                'error' => $e->getMessage(),
            ]);
        }
        return ['data' => []];
    }

    /**
     * 智能生成题目（异步模式）
     */
    public function generateIntelligentQuestions(array $params, ?string $callbackUrl = null): array
    {
        try {
            // 添加回调 URL
            if ($callbackUrl) {
                $params['callback_url'] = $callbackUrl;
            }

            $response = Http::timeout(10)
                ->post($this->baseUrl . '/generate-intelligent-questions', $params);

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

            Log::warning('题目生成API调用失败', [
                'status' => $response->status()
            ]);
        } catch (\Exception $e) {
            Log::error('题目生成异常', [
                'error' => $e->getMessage()
            ]);
        }

        return ['success' => false, 'message' => '生成失败'];
    }

    /**
     * 获取任务状态
     */
    public function getTaskStatus(string $taskId): ?array
    {
        try {
            $response = Http::timeout(10)
                ->get($this->baseUrl . '/tasks/' . $taskId);

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

            Log::warning('获取任务状态失败', [
                'task_id' => $taskId,
                'status' => $response->status()
            ]);
        } catch (\Exception $e) {
            Log::error('获取任务状态异常', [
                'task_id' => $taskId,
                'error' => $e->getMessage()
            ]);
        }

        return null;
    }

    /**
     * 获取任务列表
     */
    public function listTasks(?string $status = null, int $page = 1, int $perPage = 10): array
    {
        try {
            $params = [
                'page' => $page,
                'per_page' => $perPage
            ];

            if ($status) {
                $params['status'] = $status;
            }

            $response = Http::timeout(10)
                ->get($this->baseUrl . '/tasks', $params);

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

            Log::warning('获取任务列表失败', [
                'status' => $response->status()
            ]);
        } catch (\Exception $e) {
            Log::error('获取任务列表异常', [
                'error' => $e->getMessage()
            ]);
        }

        return ['data' => [], 'meta' => ['total' => 0]];
    }

    /**
     * 获取题目统计信息
     */
    public function getStatistics(): array
    {
        try {
            $response = Http::timeout(10)
                ->get($this->baseUrl . '/questions/statistics');

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

            Log::warning('获取题目统计失败', [
                'status' => $response->status()
            ]);
        } catch (\Exception $e) {
            Log::error('获取题目统计异常', [
                'error' => $e->getMessage()
            ]);
        }

        return [
            'total' => 0,
            'by_difficulty' => [],
            'by_kp' => [],
            'by_source' => []
        ];
    }

    /**
     * 根据知识点获取题目
     */
    public function getQuestionsByKpCode(string $kpCode, int $limit = 100): array
    {
        try {
            $response = Http::timeout(10)
                ->get($this->baseUrl . '/questions', [
                    'kp_code' => $kpCode,
                    'limit' => $limit
                ]);

            if ($response->successful()) {
                return $response->json();
            }
        } catch (\Exception $e) {
            Log::error('根据知识点获取题目失败', [
                'kp_code' => $kpCode,
                'error' => $e->getMessage()
            ]);
        }

        return [];
    }

    /**
     * 删除题目
     */
    public function deleteQuestion(string $questionCode): bool
    {
        try {
            $response = Http::timeout(10)
                ->delete($this->baseUrl . "/questions/{$questionCode}");

            // 只有返回204（删除成功）才返回true，404（不存在）返回false
            if ($response->status() === 204) {
                return true;
            }

            if ($response->status() === 404) {
                Log::warning('尝试删除不存在的题目', ['question_code' => $questionCode]);
                return false;
            }

            return false;
        } catch (\Exception $e) {
            Log::error('删除题目失败', [
                'question_code' => $questionCode,
                'error' => $e->getMessage()
            ]);
            return false;
        }
    }

    /**
     * 智能选择试卷题目
     */
    public function selectQuestionsForExam(int $totalQuestions, array $filters): array
    {
        try {
            $response = Http::timeout(30)
                ->post($this->baseUrl . '/exam/select-questions', [
                    'total_questions' => $totalQuestions,
                    'filters' => $filters
                ]);

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

            Log::warning('智能选题API调用失败', [
                'status' => $response->status()
            ]);
        } catch (\Exception $e) {
            Log::error('智能选题异常', [
                'error' => $e->getMessage()
            ]);
        }

        return [];
    }

    /**
     * 保存试卷到数据库（本地 papers 表）
     */
    public function saveExamToDatabase(array $examData): ?string
    {
        try {
            // 生成试卷ID
            $paperId = 'paper_' . time() . '_' . bin2hex(random_bytes(4));
            
            // 保存到 papers 表
            \Illuminate\Support\Facades\DB::table('papers')->insert([
                'paper_id' => $paperId,
                'student_id' => $examData['student_id'] ?? '',
                'teacher_id' => $examData['teacher_id'] ?? '',
                'paper_name' => $examData['paper_name'] ?? '未命名试卷',
                'paper_type' => 'auto_generated',
                'question_count' => $examData['total_questions'] ?? 0,
                'total_score' => $examData['total_score'] ?? 0,
                'status' => 'draft',
                'difficulty_category' => $examData['difficulty_category'] ?? '基础',
                'created_at' => now(),
                'updated_at' => now(),
            ]);
            
            // 如果有题目列表，保存到 paper_questions 表
            if (!empty($examData['questions'])) {
                foreach ($examData['questions'] as $index => $question) {
                    // 处理难度字段：如果是字符串则转换为数字
                    $difficultyValue = $question['difficulty'] ?? 0.5;
                    if (is_string($difficultyValue)) {
                        // 将中文难度转换为数字
                        if (strpos($difficultyValue, '基础') !== false || strpos($difficultyValue, '简单') !== false) {
                            $difficultyValue = 0.3;
                        } elseif (strpos($difficultyValue, '中等') !== false || strpos($difficultyValue, '一般') !== false) {
                            $difficultyValue = 0.6;
                        } elseif (strpos($difficultyValue, '拔高') !== false || strpos($difficultyValue, '困难') !== false) {
                            $difficultyValue = 0.9;
                        } else {
                            $difficultyValue = 0.5;
                        }
                    }

                    // 确保 knowledge_point 有值
                    $knowledgePoint = $question['kp'] ?? $question['kp_code'] ?? $question['knowledge_point'] ?? $question['knowledge_point_code'] ?? '';
                    if (empty($knowledgePoint) && isset($question['kp_code'])) {
                        $knowledgePoint = $question['kp_code'];
                    }

                    // 获取题目类型
                    $questionType = $question['question_type'] ?? 'answer';
                    if (!$questionType) {
                        // 如果没有类型，根据内容推断
                        $content = $question['stem'] ?? $question['content'] ?? '';
                        if (is_string($content)) {
                            // 1. 优先检查填空题（下划线）
                            if (strpos($content, '____') !== false || strpos($content, '______') !== false) {
                                $questionType = 'fill';
                            }
                            // 2. 检查选择题（必须有选项 A. B. C. D.）
                            elseif (preg_match('/[A-D]\s*\./', $content) || preg_match('/\([A-D]\)/', $content)) {
                                if (preg_match('/A\./', $content) && preg_match('/B\./', $content)) {
                                    $questionType = 'choice';
                                } else {
                                    // 只有括号没有选项，可能是填空
                                    if (strpos($content, '（）') !== false || strpos($content, '()') !== false) {
                                        $questionType = 'fill';
                                    } else {
                                        $questionType = 'answer';
                                    }
                                }
                            }
                            // 3. 检查纯括号填空
                            elseif (strpos($content, '（）') !== false || strpos($content, '()') !== false) {
                                $questionType = 'fill';
                            }
                            else {
                                $questionType = 'answer';
                            }
                        } else {
                            $questionType = 'answer';
                        }
                    }

                    \Illuminate\Support\Facades\DB::table('paper_questions')->insert([
                        'id' => $paperId . '_q' . ($index + 1),
                        'paper_id' => $paperId,
                        'question_bank_id' => $question['id'] ?? $question['question_id'] ?? 0,
                        'knowledge_point' => $knowledgePoint,
                        'question_type' => $questionType,
                        'difficulty' => $difficultyValue,
                        'score' => $question['score'] ?? 5, // 默认5分
                        'estimated_time' => $question['estimated_time'] ?? 300,
                        'question_number' => $index + 1,
                    ]);
                }
            }
            
            Log::info('试卷保存成功', ['paper_id' => $paperId, 'question_count' => count($examData['questions'] ?? [])]);
            return $paperId;
            
        } catch (\Exception $e) {
            Log::error('保存试卷到数据库失败', [
                'error' => $e->getMessage(),
                'trace' => $e->getTraceAsString()
            ]);
            return null;
        }
    }

    /**
     * 获取试卷列表
     */
    public function listExams(int $page = 1, int $perPage = 20): array
    {
        try {
            $response = Http::timeout(10)
                ->get($this->baseUrl . '/exam/list', [
                    'page' => $page,
                    'per_page' => $perPage
                ]);

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

            Log::warning('获取试卷列表失败', [
                'status' => $response->status()
            ]);
        } catch (\Exception $e) {
            Log::error('获取试卷列表异常', [
                'error' => $e->getMessage()
            ]);
        }

        return ['data' => [], 'meta' => ['total' => 0]];
    }

    /**
     * 获取试卷详情
     */
    public function getExamById(string $paperId): ?array
    {
        try {
            $response = Http::timeout(10)
                ->get($this->baseUrl . '/exam/' . $paperId);

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

            Log::warning('获取试卷详情失败', [
                'paper_id' => $paperId,
                'status' => $response->status()
            ]);
        } catch (\Exception $e) {
            Log::error('获取试卷详情异常', [
                'paper_id' => $paperId,
                'error' => $e->getMessage()
            ]);
        }

        return null;
    }

    /**
     * 导出试卷为PDF
     */
    public function exportExamToPdf(string $paperId): ?string
    {
        try {
            $response = Http::timeout(60)
                ->get($this->baseUrl . '/exam/' . $paperId . '/export/pdf');

            if ($response->successful()) {
                // 返回PDF文件路径或URL
                return $response->json('pdf_url', null);
            }

            Log::warning('导出PDF失败', [
                'paper_id' => $paperId,
                'status' => $response->status()
            ]);
        } catch (\Exception $e) {
            Log::error('导出PDF异常', [
                'paper_id' => $paperId,
                'error' => $e->getMessage()
            ]);
        }

        return null;
    }

    /**
     * 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) {
            Log::error('题库服务健康检查失败', [
                'error' => $e->getMessage()
            ]);
            return false;
        }
    }
}