<?php

namespace App\Services;

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

class MistakeBookService
{
    protected string $learningAnalyticsBase;
    protected string $questionBankBase;
    protected int $timeout;

    public function __construct(
        ?string $learningAnalyticsBase = null,
        ?string $questionBankBase = null,
        ?int $timeout = null
    ) {
        $this->learningAnalyticsBase = rtrim(
            $learningAnalyticsBase
                ?: config('services.learning_analytics.url', env('LEARNING_ANALYTICS_API_BASE', 'http://localhost:5016')),
            '/'
        );

        $this->questionBankBase = rtrim(
            $questionBankBase
                ?: config('services.question_bank.base_url', env('QUESTION_BANK_API_BASE', 'http://localhost:5015')),
            '/'
        );

        $this->timeout = $timeout ?? (int) config('services.learning_analytics.timeout', 20);
    }

    /**
     * 获取错题列表（支持多维筛选）
     */
    public function listMistakes(array $params = []): array
    {
        $query = array_filter([
            'student_id' => $params['student_id'] ?? null,
            'kp_ids' => $this->implodeIfArray($params['kp_ids'] ?? null),
            'skill_ids' => $this->implodeIfArray($params['skill_ids'] ?? null),
            'error_types' => $this->implodeIfArray($params['error_types'] ?? null),
            'time_range' => $params['time_range'] ?? null,
            'start_date' => $params['start_date'] ?? null,
            'end_date' => $params['end_date'] ?? null,
            'incorrect_only' => true, // ✅ 只获取错误记录（错题本的核心功能）
            'page' => $params['page'] ?? 1,
            'per_page' => $params['per_page'] ?? 20,
        ], fn ($value) => filled($value));

        try {
            $response = Http::timeout($this->timeout)
                ->get($this->learningAnalyticsBase . '/api/mistake-book', $query);

            if ($response->successful()) {
                info("MistakeBookService::listMistakes", [$response->json()]);
                $body = $response->json();
                $result = is_array($body) ? $body : ['data' => $body];

                // 补充知识点名称、技能信息和难度
                $result = $this->enrichMistakeData($result);

                // 获取统计数据
                if (!empty($params['student_id'])) {
                    $summary = $this->summarize($params['student_id']);
                    $result['statistics'] = [
                        'total_mistakes' => $summary['total'] ?? 0,
                        'this_week' => $summary['this_week'] ?? 0,
                        'pending_review' => $summary['pending_review'] ?? 0,
                        'mastery_rate' => $summary['mastery_rate'] ?? 0.0,
                    ];
                }

                return $result;
            }

            Log::warning('MistakeBook list failed', [
                'status' => $response->status(),
                'body' => $response->body(),
                'query' => $query,
            ]);
        } catch (\Throwable $e) {
            Log::error('MistakeBook list exception', [
                'error' => $e->getMessage(),
                'query' => $query,
            ]);
        }

        return [
            'data' => [],
            'meta' => ['total' => 0, 'page' => 1, 'per_page' => $query['per_page'] ?? 20],
        ];
    }

    /**
     * 获取单条错题详情（可选带学生ID保证隔离）
     */
    public function getMistakeDetail(string $mistakeId, ?string $studentId = null): array
    {
        $query = array_filter([
            'student_id' => $studentId,
        ], fn ($value) => filled($value));

        try {
            $response = Http::timeout($this->timeout)
                ->get($this->learningAnalyticsBase . '/api/mistake-book/' . $mistakeId, $query);

            if ($response->successful()) {
                $body = $response->json();
                $result = is_array($body) ? $body : [];

                // 补充知识点名称和技能信息
                $result = $this->enrichSingleMistakeData($result);

                return $result;
            }

            Log::warning('Mistake detail request failed', [
                'mistake_id' => $mistakeId,
                'status' => $response->status(),
                'body' => $response->body(),
            ]);

            // 兼容：LearningAnalytics 当前未提供单条详情接口时，从列表中过滤
            if ($studentId) {
                $fallback = $this->listMistakes([
                    'student_id' => $studentId,
                    'per_page' => 100, // 兼容后端限制（<=100）
                ]);

                $matched = collect($fallback['data'] ?? [])->firstWhere('id', (int) $mistakeId);
                if ($matched) {
                    return $matched;
                }
            }
        } catch (\Throwable $e) {
            Log::error('Mistake detail request exception', [
                'mistake_id' => $mistakeId,
                'student_id' => $studentId,
                'error' => $e->getMessage(),
            ]);
        }

        return [];
    }

    /**
     * 获取错题统计概要
     */
    public function summarize(string $studentId): array
    {
        try {
            $response = Http::timeout($this->timeout)
                ->get($this->learningAnalyticsBase . '/api/mistake-book/summary', [
                    'student_id' => $studentId,
                ]);

            if ($response->successful()) {
                $body = $response->json();
                return is_array($body) ? $body : [];
            }

            Log::warning('MistakeBook summary failed', [
                'status' => $response->status(),
                'body' => $response->body(),
                'student_id' => $studentId,
            ]);
        } catch (\Throwable $e) {
            Log::error('MistakeBook summary exception', [
                'student_id' => $studentId,
                'error' => $e->getMessage(),
            ]);
        }

        // fallback 返回一个空结构，避免前端崩溃
        return [
            'total' => 0,
            'this_week' => 0,
            'pending_review' => 0,
            'mastery_rate' => null,
        ];
    }

    /**
     * 获取错误模式与推荐路径
     */
    public function getMistakePatterns(string $studentId): array
    {
        try {
            $response = Http::timeout($this->timeout)
                ->get($this->learningAnalyticsBase . '/api/analytics/mistake-pattern', [
                    'student_id' => $studentId,
                ]);

            if ($response->successful()) {
                $body = $response->json();
                return is_array($body) ? $body : [];
            }

            Log::warning('Mistake pattern request failed', [
                'status' => $response->status(),
                'body' => $response->body(),
                'student_id' => $studentId,
            ]);
        } catch (\Throwable $e) {
            Log::error('Mistake pattern request exception', [
                'student_id' => $studentId,
                'error' => $e->getMessage(),
            ]);
        }

        return [];
    }

    /**
     * 收藏/取消收藏错题
     */
    public function toggleFavorite(string $mistakeId, bool $favorite = true): bool
    {
        try {
            $response = Http::timeout($this->timeout)
                ->post($this->learningAnalyticsBase . '/api/mistake-book/' . $mistakeId . '/favorite', [
                    'favorite' => $favorite,
                ]);

            return $response->successful();
        } catch (\Throwable $e) {
            Log::error('Toggle favorite failed', [
                'mistake_id' => $mistakeId,
                'favorite' => $favorite,
                'error' => $e->getMessage(),
            ]);
        }

        return false;
    }

    /**
     * 标记已复习（向后兼容）
     */
    public function markReviewed(string $mistakeId): bool
    {
        try {
            $response = Http::timeout($this->timeout)
                ->post($this->learningAnalyticsBase . '/api/mistake-book/' . $mistakeId . '/review');

            return $response->successful();
        } catch (\Throwable $e) {
            Log::error('Mark reviewed failed', [
                'mistake_id' => $mistakeId,
                'error' => $e->getMessage(),
            ]);
        }

        return false;
    }

    /**
     * 修改复习状态
     *
     * @param string $mistakeId 错题ID
     * @param string $action 操作类型：'increment' 或 'reset'
     * @param bool $forceReview 是否强制复习（仅对 increment 有效）
     * @return array 复习状态信息
     */
    public function updateReviewStatus(string $mistakeId, string $action = 'increment', bool $forceReview = false): array
    {
        try {
            $payload = array_filter([
                'action' => $action,
                'force_review' => $forceReview,
            ]);

            $response = Http::timeout($this->timeout)
                ->post($this->learningAnalyticsBase . '/api/mistake-book/' . $mistakeId . '/review-status', $payload);

            if ($response->successful()) {
                $body = $response->json();
                return is_array($body) ? $body : [];
            }

            Log::warning('Update review status failed', [
                'mistake_id' => $mistakeId,
                'action' => $action,
                'force_review' => $forceReview,
                'status' => $response->status(),
                'body' => $response->body(),
            ]);
        } catch (\Throwable $e) {
            Log::error('Update review status exception', [
                'mistake_id' => $mistakeId,
                'action' => $action,
                'force_review' => $forceReview,
                'error' => $e->getMessage(),
            ]);
        }

        return [
            'success' => false,
            'error' => '更新复习状态失败',
        ];
    }

    /**
     * 获取复习状态
     *
     * @param string $mistakeId 错题ID
     * @return array 复习状态信息
     */
    public function getReviewStatus(string $mistakeId): array
    {
        try {
            $response = Http::timeout($this->timeout)
                ->get($this->learningAnalyticsBase . '/api/mistake-book/' . $mistakeId . '/review-status');

            if ($response->successful()) {
                $body = $response->json();
                return is_array($body) ? $body : [];
            }

            Log::warning('Get review status failed', [
                'mistake_id' => $mistakeId,
                'status' => $response->status(),
                'body' => $response->body(),
            ]);
        } catch (\Throwable $e) {
            Log::error('Get review status exception', [
                'mistake_id' => $mistakeId,
                'error' => $e->getMessage(),
            ]);
        }

        return [
            'success' => false,
            'error' => '获取复习状态失败',
        ];
    }

    /**
     * 增加复习次数
     *
     * @param string $mistakeId 错题ID
     * @param bool $forceReview 是否强制复习
     * @return array 复习状态信息
     */
    public function incrementReviewCount(string $mistakeId, bool $forceReview = false): array
    {
        return $this->updateReviewStatus($mistakeId, 'increment', $forceReview);
    }

    /**
     * 重置为强制复习状态
     *
     * @param string $mistakeId 错题ID
     * @return array 复习状态信息
     */
    public function resetReviewStatus(string $mistakeId): array
    {
        return $this->updateReviewStatus($mistakeId, 'reset');
    }

    /**
     * 添加到重练清单
     */
    public function addToRetryList(string $mistakeId): bool
    {
        try {
            $response = Http::timeout($this->timeout)
                ->post($this->learningAnalyticsBase . '/api/mistake-book/' . $mistakeId . '/retry-list');

            return $response->successful();
        } catch (\Throwable $e) {
            Log::error('Add to retry list failed', [
                'mistake_id' => $mistakeId,
                'error' => $e->getMessage(),
            ]);
        }

        return false;
    }

    /**
     * 基于错题推荐练习题
     */
    public function recommendPractice(string $studentId, array $kpIds = [], array $skillIds = []): array
    {
        $payload = array_filter([
            'student_id' => $studentId,
            'kp_ids' => array_values(array_unique($kpIds)),
            'skill_ids' => array_values(array_unique($skillIds)),
        ], fn ($value) => $value !== null);

        try {
            $response = Http::timeout($this->timeout)
                ->post($this->questionBankBase . '/api/questions/recommend', $payload);

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

            Log::warning('Recommend practice failed', [
                'status' => $response->status(),
                'body' => $response->body(),
                'payload' => $payload,
            ]);
        } catch (\Throwable $e) {
            Log::error('Recommend practice exception', [
                'payload' => $payload,
                'error' => $e->getMessage(),
            ]);
        }

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

    /**
     * 为学生仪表板提供快照数据
     */
    public function getPanelSnapshot(string $studentId, int $limit = 5): array
    {
        $list = $this->listMistakes([
            'student_id' => $studentId,
            'per_page' => $limit,
        ]);

        $patterns = $this->getMistakePatterns($studentId);
        $summary = $this->summarize($studentId);

        return [
            'recent' => $list['data'] ?? [],
            'weak_skills' => $patterns['top_skills'] ?? [],
            'weak_kps' => $patterns['top_kps'] ?? [],
            'error_types' => $patterns['error_types'] ?? [],
            'recommend_path' => $patterns['recommend_path'] ?? [],
            'stats' => [
                'total' => $summary['total'] ?? Arr::get($list, 'meta.total', 0),
                'this_week' => $summary['this_week'] ?? null,
                'pending_review' => $summary['pending_review'] ?? null,
                'mastery_rate' => $summary['mastery_rate'] ?? null,
            ],
        ];
    }

    private function implodeIfArray($value): ?string
    {
        if (is_array($value)) {
            return implode(',', array_filter($value));
        }

        return $value;
    }

    /**
     * 获取题目的全体正确率（LearningAnalytics 聚合）
     */
    public function getQuestionAccuracy(string $questionId): ?float
    {
        try {
            $response = Http::timeout($this->timeout)
                ->get($this->learningAnalyticsBase . '/api/analytics/question/' . $questionId . '/accuracy');

            if ($response->successful()) {
                $body = $response->json();
                return isset($body['accuracy']) ? floatval($body['accuracy']) : null;
            }
        } catch (\Throwable $e) {
            Log::warning('Get question accuracy failed', [
                'question_id' => $questionId,
                'error' => $e->getMessage(),
            ]);
        }

        return null;
    }

    /**
     * 补充错题数据中的知识点名称、技能信息和难度
     */
    private function enrichMistakeData(array $result): array
    {
        Log::info('MistakeBookService::enrichMistakeData - Starting enrichment', [
            'data_count' => count($result['data'] ?? []),
        ]);

        if (!isset($result['data']) || !is_array($result['data'])) {
            Log::warning('MistakeBookService::enrichMistakeData - No data to enrich');
            return $result;
        }

        // 获取所有知识点代码
        $kpCodes = [];
        foreach ($result['data'] as $item) {
            if (!empty($item['question']['kp_code'])) {
                $kpCodes[] = $item['question']['kp_code'];
            }
            if (!empty($item['kp_ids']) && is_array($item['kp_ids'])) {
                $kpCodes = array_merge($kpCodes, $item['kp_ids']);
            }
        }
        $kpCodes = array_unique(array_filter($kpCodes));

        Log::info('MistakeBookService::enrichMistakeData - Found kp_codes', [
            'kp_codes' => $kpCodes,
        ]);

        // 从KnowledgeService获取知识点详细信息
        $kpDetailMap = [];
        foreach ($kpCodes as $kpCode) {
            $detail = $this->getKnowledgePointDetail($kpCode);
            if (!empty($detail)) {
                $kpDetailMap[$kpCode] = $detail;
            }
        }

        Log::info('MistakeBookService::enrichMistakeData - Retrieved kp details', [
            'kp_detail_map_keys' => array_keys($kpDetailMap),
        ]);

        // 补充数据
        foreach ($result['data'] as &$item) {
            // 补充知识点名称和技能信息
            if (isset($item['question']['kp_code'])) {
                $kpCode = $item['question']['kp_code'];
                if (isset($kpDetailMap[$kpCode])) {
                    $detail = $kpDetailMap[$kpCode];
                    $item['question']['kp_name'] = $detail['cn_name'] ?? $detail['en_name'] ?? $kpCode;
                    $item['question']['skills'] = array_column($detail['skills'] ?? [], 'skill_name');
                    Log::info('MistakeBookService::enrichMistakeData - Enriched item', [
                        'kp_code' => $kpCode,
                        'kp_name' => $item['question']['kp_name'],
                        'skills' => $item['question']['skills'],
                    ]);
                } else {
                    // 如果没有找到详细信息，使用代码作为名称
                    $item['question']['kp_name'] = $kpCode;
                    $item['question']['skills'] = [];
                    Log::warning('MistakeBookService::enrichMistakeData - No detail found for kp', [
                        'kp_code' => $kpCode,
                    ]);
                }
            }

            // 确保kp_ids数组存在且不为空
            if (!isset($item['kp_ids']) || !is_array($item['kp_ids'])) {
                $item['kp_ids'] = [];
            }

            // 如果kp_ids为空但有kp_code，则添加
            if (empty($item['kp_ids']) && !empty($item['question']['kp_code'])) {
                $item['kp_ids'] = [$item['question']['kp_code']];
            }

            // 确保skill_ids数组存在
            if (!isset($item['skill_ids']) || !is_array($item['skill_ids'])) {
                $item['skill_ids'] = [];
            }

            // 如果skill_ids为空但有skills，则使用skills
            if (empty($item['skill_ids']) && !empty($item['question']['skills'])) {
                $item['skill_ids'] = $item['question']['skills'];
            }

            // 补充难度值（如果缺失）
            if (!isset($item['question']['difficulty']) && isset($item['question']['kp_code'])) {
                $kpCode = $item['question']['kp_code'];
                if (isset($kpDetailMap[$kpCode])) {
                    $detail = $kpDetailMap[$kpCode];
                    // 使用importance作为难度（1-10）
                    $item['question']['difficulty'] = ($detail['importance'] ?? 5) / 10.0;
                    Log::info('MistakeBookService::enrichMistakeData - Set difficulty', [
                        'kp_code' => $kpCode,
                        'difficulty' => $item['question']['difficulty'],
                        'importance' => $detail['importance'] ?? 5,
                    ]);
                }
            }
        }

        Log::info('MistakeBookService::enrichMistakeData - Completed enrichment', [
            'processed_count' => count($result['data']),
        ]);

        return $result;
    }

    /**
     * 补充单条错题数据中的知识点名称、技能信息和难度
     */
    private function enrichSingleMistakeData(array $item): array
    {
        if (empty($item)) {
            return $item;
        }

        // 从KnowledgeService获取知识点详细信息
        $kpDetail = null;
        if (isset($item['question']['kp_code'])) {
            $kpCode = $item['question']['kp_code'];
            $kpDetail = $this->getKnowledgePointDetail($kpCode);
        }

        // 补充知识点名称和技能信息
        if (isset($item['question']['kp_code']) && $kpDetail) {
            $item['question']['kp_name'] = $kpDetail['cn_name'] ?? $kpDetail['en_name'] ?? $item['question']['kp_code'];
            $item['question']['skills'] = array_column($kpDetail['skills'] ?? [], 'skill_name');
        } else {
            if (isset($item['question']['kp_code'])) {
                $item['question']['kp_name'] = $item['question']['kp_code'];
            }
            $item['question']['skills'] = [];
        }

        // 确保kp_ids数组存在且不为空
        if (!isset($item['kp_ids']) || !is_array($item['kp_ids'])) {
            $item['kp_ids'] = [];
        }

        // 如果kp_ids为空但有kp_code，则添加
        if (empty($item['kp_ids']) && !empty($item['question']['kp_code'])) {
            $item['kp_ids'] = [$item['question']['kp_code']];
        }

        // 确保skill_ids数组存在
        if (!isset($item['skill_ids']) || !is_array($item['skill_ids'])) {
            $item['skill_ids'] = [];
        }

        // 如果skill_ids为空但有skills，则使用skills
        if (empty($item['skill_ids']) && !empty($item['question']['skills'])) {
            $item['skill_ids'] = $item['question']['skills'];
        }

        // 补充难度值（如果缺失）
        if (!isset($item['question']['difficulty']) && $kpDetail) {
            // 使用importance作为难度（1-10）
            $item['question']['difficulty'] = ($kpDetail['importance'] ?? 5) / 10.0;
        }

        return $item;
    }

    /**
     * 从QuestionBank服务获取知识点详细信息
     */
    private function getKnowledgePointDetail(string $kpCode): ?array
    {
        Log::info('MistakeBookService::getKnowledgePointDetail - Fetching detail from QuestionBank', [
            'kp_code' => $kpCode,
        ]);

        try {
            // 获取QuestionBank中的题目来获取知识点信息
            $response = Http::timeout($this->timeout)
                ->get($this->questionBankBase . '/api/questions', [
                    'kp_code' => $kpCode,
                    'limit' => 1,
                ]);

            Log::info('MistakeBookService::getKnowledgePointDetail - Response from QuestionBank', [
                'status' => $response->status(),
                'has_body' => !empty($response->body()),
            ]);

            if ($response->successful()) {
                $data = $response->json();
                $questions = $data['data'] ?? [];
                if (!empty($questions)) {
                    $question = $questions[0];
                    $detail = [
                        'kp_code' => $kpCode,
                        'cn_name' => $question['kp_name'] ?? $kpCode,
                        'skills' => [],
                        'importance' => null,
                    ];

                    // 提取技能信息
                    if (!empty($question['skills'])) {
                        foreach ($question['skills'] as $skillCode) {
                            $detail['skills'][] = [
                                'skill_code' => $skillCode,
                                'skill_name' => $skillCode,
                            ];
                        }
                    }

                    // 从difficulty计算importance（0-1转为1-10）
                    if (isset($question['difficulty'])) {
                        $detail['importance'] = intval($question['difficulty'] * 10);
                    }

                    Log::info('MistakeBookService::getKnowledgePointDetail - Success', [
                        'kp_code' => $kpCode,
                        'kp_name' => $detail['cn_name'],
                        'skills_count' => count($detail['skills']),
                        'importance' => $detail['importance'],
                    ]);

                    return $detail;
                }
            }
        } catch (\Throwable $e) {
            Log::error('Get knowledge point detail from QuestionBank failed', [
                'kp_code' => $kpCode,
                'error' => $e->getMessage(),
            ]);
        }

        return null;
    }
}