<?php

namespace App\Services;

use App\Models\CompetitorBrand;
use App\Models\CompetitorPost;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Log;
use Carbon\Carbon;

class CompetitorDataFetchService
{
    /**
     * Fetch posts for a competitor brand from all connected platforms.
     *
     * @param CompetitorBrand $competitor
     * @param Carbon|null $since
     * @return array
     */
    public function fetchCompetitorPosts(CompetitorBrand $competitor, ?Carbon $since = null): array
    {
        $since = $since ?? now()->subDays(30);
        $results = [];

        $socialHandles = $competitor->social_handles ?? [];

        foreach ($socialHandles as $platform => $handle) {
            try {
                $posts = $this->fetchPlatformPosts($platform, $handle, $since);
                $results[$platform] = $this->storePosts($competitor, $platform, $posts);
            } catch (\Exception $e) {
                Log::error("Failed to fetch {$platform} posts for competitor {$competitor->id}: {$e->getMessage()}");
                $results[$platform] = ['error' => $e->getMessage()];
            }
        }

        $competitor->update(['last_synced_at' => now()]);

        return $results;
    }

    /**
     * Fetch posts from a specific platform.
     *
     * @param string $platform
     * @param string $handle
     * @param Carbon $since
     * @return array
     */
    protected function fetchPlatformPosts(string $platform, string $handle, Carbon $since): array
    {
        // This is a placeholder implementation
        // In production, you would integrate with actual social media APIs
        // or use a third-party service that provides competitor data
        
        return match($platform) {
            'instagram' => $this->fetchInstagramPosts($handle, $since),
            'facebook' => $this->fetchFacebookPosts($handle, $since),
            'twitter' => $this->fetchTwitterPosts($handle, $since),
            'tiktok' => $this->fetchTikTokPosts($handle, $since),
            'linkedin' => $this->fetchLinkedInPosts($handle, $since),
            default => [],
        };
    }

    /**
     * Fetch Instagram posts (placeholder - requires actual API integration).
     *
     * @param string $handle
     * @param Carbon $since
     * @return array
     */
    protected function fetchInstagramPosts(string $handle, Carbon $since): array
    {
        // NOTE: This is a placeholder implementation
        // In production, you would use Instagram Graph API or a third-party service
        // that provides public competitor data (respecting platform rules)
        
        // Example structure of what the API should return:
        return [
            // [
            //     'platform_post_id' => 'unique_id',
            //     'post_type' => 'reel',
            //     'caption' => 'Post caption',
            //     'media' => ['url1', 'url2'],
            //     'permalink' => 'https://instagram.com/p/...',
            //     'published_at' => '2025-09-25 10:00:00',
            //     'metrics' => [
            //         'likes' => 1000,
            //         'comments' => 50,
            //         'shares' => 20,
            //         'views' => 10000,
            //         'saves' => 100,
            //     ],
            //     'hashtags' => ['#marketing', '#socialmedia'],
            //     'mentions' => ['@brand1', '@brand2'],
            // ]
        ];
    }

    /**
     * Fetch Facebook posts (placeholder).
     *
     * @param string $handle
     * @param Carbon $since
     * @return array
     */
    protected function fetchFacebookPosts(string $handle, Carbon $since): array
    {
        // Placeholder - implement Facebook Graph API integration
        return [];
    }

    /**
     * Fetch Twitter posts (placeholder).
     *
     * @param string $handle
     * @param Carbon $since
     * @return array
     */
    protected function fetchTwitterPosts(string $handle, Carbon $since): array
    {
        // Placeholder - implement Twitter API integration
        return [];
    }

    /**
     * Fetch TikTok posts (placeholder).
     *
     * @param string $handle
     * @param Carbon $since
     * @return array
     */
    protected function fetchTikTokPosts(string $handle, Carbon $since): array
    {
        // Placeholder - implement TikTok API integration
        return [];
    }

    /**
     * Fetch LinkedIn posts (placeholder).
     *
     * @param string $handle
     * @param Carbon $since
     * @return array
     */
    protected function fetchLinkedInPosts(string $handle, Carbon $since): array
    {
        // Placeholder - implement LinkedIn API integration
        return [];
    }

    /**
     * Store fetched posts in the database.
     *
     * @param CompetitorBrand $competitor
     * @param string $platform
     * @param array $posts
     * @return array
     */
    protected function storePosts(CompetitorBrand $competitor, string $platform, array $posts): array
    {
        $stored = 0;
        $updated = 0;
        $errors = 0;

        foreach ($posts as $postData) {
            try {
                $post = CompetitorPost::updateOrCreate(
                    [
                        'competitor_brand_id' => $competitor->id,
                        'platform_post_id' => $postData['platform_post_id'],
                    ],
                    [
                        'platform' => $platform,
                        'post_type' => $postData['post_type'] ?? null,
                        'caption' => $postData['caption'] ?? null,
                        'content' => $postData['content'] ?? null,
                        'media' => $postData['media'] ?? null,
                        'permalink' => $postData['permalink'] ?? null,
                        'published_at' => $postData['published_at'] ?? null,
                        'metrics' => $postData['metrics'] ?? null,
                        'hashtags' => $postData['hashtags'] ?? null,
                        'mentions' => $postData['mentions'] ?? null,
                        'raw_data' => $postData,
                        'last_checked_at' => now(),
                    ]
                );

                // Calculate engagement rate
                if ($post->metrics) {
                    $post->engagement_rate = $post->calculateEngagementRate();
                    $post->save();
                }

                if ($post->wasRecentlyCreated) {
                    $stored++;
                } else {
                    $updated++;
                }
            } catch (\Exception $e) {
                Log::error("Failed to store competitor post: {$e->getMessage()}");
                $errors++;
            }
        }

        return [
            'stored' => $stored,
            'updated' => $updated,
            'errors' => $errors,
            'total' => count($posts),
        ];
    }

    /**
     * Update metrics for existing posts.
     *
     * @param CompetitorBrand $competitor
     * @param int $daysBack
     * @return array
     */
    public function updatePostMetrics(CompetitorBrand $competitor, int $daysBack = 7): array
    {
        $posts = $competitor->posts()
            ->where('published_at', '>=', now()->subDays($daysBack))
            ->get();

        $updated = 0;
        $errors = 0;

        foreach ($posts as $post) {
            try {
                // Fetch updated metrics from platform
                $updatedMetrics = $this->fetchPostMetrics($post->platform, $post->platform_post_id);
                
                if ($updatedMetrics) {
                    $post->update([
                        'metrics' => $updatedMetrics,
                        'engagement_rate' => $this->calculateEngagementRate($updatedMetrics),
                        'last_checked_at' => now(),
                    ]);
                    $updated++;
                }
            } catch (\Exception $e) {
                Log::error("Failed to update metrics for post {$post->id}: {$e->getMessage()}");
                $errors++;
            }
        }

        return [
            'updated' => $updated,
            'errors' => $errors,
            'total' => $posts->count(),
        ];
    }

    /**
     * Fetch updated metrics for a specific post.
     *
     * @param string $platform
     * @param string $postId
     * @return array|null
     */
    protected function fetchPostMetrics(string $platform, string $postId): ?array
    {
        // Placeholder - implement actual API calls to fetch updated metrics
        return null;
    }

    /**
     * Calculate engagement rate from metrics.
     *
     * @param array $metrics
     * @return float
     */
    protected function calculateEngagementRate(array $metrics): float
    {
        $views = $metrics['views'] ?? 0;
        if ($views <= 0) {
            return 0;
        }

        $engagement = ($metrics['likes'] ?? 0) + 
                     ($metrics['comments'] ?? 0) + 
                     ($metrics['shares'] ?? 0) + 
                     ($metrics['saves'] ?? 0);

        return round(($engagement / $views) * 100, 2);
    }
}