<?php

namespace App\Services;

use Illuminate\Http\Client\PendingRequest;
use Illuminate\Http\Client\RequestException;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\Http;

class QuestionServiceApi
{
    public function __construct(
        protected string $baseUrl = '',
        protected int $timeout = 10,
        protected int $cacheTtl = 300,
    ) {
        $this->baseUrl = rtrim($this->baseUrl ?: config('question_bank.api_base', 'http://localhost:5015'), '/');
        $this->timeout = (int) config('question_bank.timeout', 10);
        $this->cacheTtl = (int) config('question_bank.cache_ttl', 300);
    }

    /**
     * 获取所有题目（分页）
     */
    public function listQuestions(int $page = 1, int $perPage = 50, array $filters = []): array
    {
        $cacheKey = sprintf(
            'questions-list-%d-%d-%s',
            $page,
            $perPage,
            md5(json_encode($filters))
        );

        return Cache::remember(
            $cacheKey,
            now()->addSeconds($this->cacheTtl),
            function () use ($page, $perPage, $filters): array {
                $query = array_filter([
                    'page' => $page,
                    'per_page' => $perPage,
                    'kp_code' => $filters['kp_code'] ?? null,
                    'difficulty' => $filters['difficulty'] ?? null,
                    'skill' => $filters['skill'] ?? null,
                    'search' => $filters['search'] ?? null,
                ], fn ($value) => filled($value));

                $response = $this->request('GET', '/questions', $query);

                return [
                    'data' => $response['data'] ?? [],
                    'meta' => $response['meta'] ?? [
                        'page' => $page,
                        'per_page' => $perPage,
                        'total' => is_array($response) ? count($response) : 0,
                        'total_pages' => 1,
                    ],
                ];
            }
        );
    }

    /**
     * 获取题目统计信息
     */
    public function getStatistics(): array
    {
        $cacheKey = 'question-statistics';

        return Cache::remember(
            $cacheKey,
            now()->addSeconds($this->cacheTtl),
            function (): array {
                $response = $this->request('GET', '/questions/statistics');

                return $response ?? [
                    'total' => 0,
                    'by_difficulty' => [],
                    'by_kp' => [],
                    'by_source' => [],
                ];
            }
        );
    }

    /**
     * 根据 kp_code 获取题目
     */
    public function getQuestionsByKpCode(string $kpCode, int $limit = 100): array
    {
        return $this->request('GET', '/questions', [
            'kp_code' => $kpCode,
            'limit' => $limit,
        ]);
    }

    /**
     * 语义搜索题目
     */
    public function searchQuestions(string $query, int $limit = 20): array
    {
        $cacheKey = sprintf('question-search-%s-%d', md5($query), $limit);

        return Cache::remember(
            $cacheKey,
            now()->addSeconds($this->cacheTtl),
            function () use ($query, $limit): array {
                try {
                    $response = $this->request('POST', '/questions/search', [
                        'query' => $query,
                        'limit' => $limit,
                    ]);

                    return $response ?? [];
                } catch (\Exception $e) {
                    \Log::error('Question search failed: ' . $e->getMessage());
                    return [];
                }
            }
        );
    }

    /**
     * 获取单个题目详情
     */
    public function getQuestionById(int $id): ?array
    {
        $cacheKey = "question-{$id}";

        return Cache::remember(
            $cacheKey,
            now()->addSeconds($this->cacheTtl),
            function () use ($id): ?array {
                try {
                    $response = $this->request('GET', "/questions/{$id}");
                    return $response ?: null;
                } catch (\Exception $e) {
                    \Log::error("Failed to get question {$id}: " . $e->getMessage());
                    return null;
                }
            }
        );
    }

    /**
     * 创建题目（通过 AI 生成）
     */
    public function generateQuestions(array $params): array
    {
        try {
            $response = $this->request('POST', '/questions/generate', $params);

            return $response ?? [
                'success' => false,
                'message' => '生成失败',
            ];
        } catch (\Exception $e) {
            \Log::error('Question generation failed: ' . $e->getMessage());
            return [
                'success' => false,
                'message' => '生成失败：' . $e->getMessage(),
            ];
        }
    }

    /**
     * 导入题目（JSON 批量导入）
     */
    public function importQuestions(array $questions): array
    {
        try {
            $response = $this->request('POST', '/questions/import', [
                'questions' => $questions,
            ]);

            return $response ?? [
                'success' => false,
                'message' => '导入失败',
            ];
        } catch (\Exception $e) {
            \Log::error('Question import failed: ' . $e->getMessage());
            return [
                'success' => false,
                'message' => '导入失败：' . $e->getMessage(),
            ];
        }
    }

    /**
     * 删除题目
     */
    public function deleteQuestion(int $id): bool
    {
        try {
            $response = $this->request('DELETE', "/questions/{$id}");
            return $response['success'] ?? false;
        } catch (\Exception $e) {
            \Log::error("Failed to delete question {$id}: " . $e->getMessage());
            return false;
        }
    }

    /**
     * 获取知识点选项（从知识图谱服务）
     */
    public function getKnowledgePointOptions(): array
    {
        try {
            $knowledgeService = app(KnowledgeServiceApi::class);
            $points = $knowledgeService->listKnowledgePoints(limit: 1000);

            return $points->pluck('cn_name', 'kp_code')
                ->sort()
                ->all();
        } catch (\Exception $e) {
            \Log::error('Failed to get knowledge points: ' . $e->getMessage());
            return [];
        }
    }

    /**
     * 获取提示词模板列表
     */
    public function listPrompts(?string $type = null, ?string $active = null): array
    {
        $cacheKey = sprintf(
            'prompts-list-%s-%s',
            $type ?: 'all',
            $active ?: 'all'
        );

        return Cache::remember(
            $cacheKey,
            now()->addSeconds($this->cacheTtl),
            function () use ($type, $active): array {
                $query = array_filter([
                    'type' => $type,
                    'active' => $active,
                ], fn ($value) => filled($value));

                try {
                    $response = $this->request('GET', '/prompts', $query);
                    return $response ?? [];
                } catch (\Exception $e) {
                    \Log::error('Failed to get prompts: ' . $e->getMessage());
                    return [];
                }
            }
        );
    }

    /**
     * @throws RequestException
     * @return mixed
     */
    protected function request(string $method, string $path, array $params = []): mixed
    {
        $response = $this->http()->send($method, ltrim($path, '/'), [
            'query' => $method === 'GET' ? $params : null,
            'json' => $method !== 'GET' ? $params : null,
        ]);

        return $response->throw()->json();
    }

    protected function http(): PendingRequest
    {
        return Http::baseUrl($this->baseUrl)
            ->acceptJson()
            ->timeout($this->timeout)
            ->retry(2, 200)
            ->withHeaders([
                'User-Agent' => 'Laravel/' . (app()->version()),
                'Accept' => 'application/json',
            ]);
    }
}