<?php

namespace App\Services;

use App\Models\Setting;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Str;

class LinkedInService
{
    protected string $clientId;
    protected string $clientSecret;
    protected string $organizationId;
    protected string $redirectUri;

    public function __construct()
    {
        $this->clientId = config('linkedin.client_id', '');
        $this->clientSecret = config('linkedin.client_secret', '');
        $this->organizationId = config('linkedin.organization_id', '35611757');
        $this->redirectUri = config('linkedin.redirect_uri', url('/admin/linkedin/callback'));
    }

    /**
     * Generate OAuth 2.0 Authorization URL for admin redirect
     */
    public function getAuthorizationUrl(): string
    {
        $scopes = implode(' ', config('linkedin.scopes', [
            'openid',
            'profile',
            'email',
            'w_member_social',
            'w_organization_social',
            'r_organization_admin',
            'rw_organization_admin',
        ]));

        $state = Str::random(32);
        session(['linkedin_oauth_state' => $state]);

        $queryParams = http_build_query([
            'response_type' => 'code',
            'client_id' => $this->clientId,
            'redirect_uri' => $this->redirectUri,
            'state' => $state,
            'scope' => $scopes,
        ]);

        return "https://www.linkedin.com/oauth/v2/authorization?" . $queryParams;
    }

    /**
     * Handle OAuth Callback and exchange authorization code for access token
     */
    public function handleCallback(string $code): array
    {
        try {
            $response = Http::asForm()->post('https://www.linkedin.com/oauth/v2/accessToken', [
                'grant_type' => 'authorization_code',
                'code' => $code,
                'redirect_uri' => $this->redirectUri,
                'client_id' => $this->clientId,
                'client_secret' => $this->clientSecret,
            ]);

            if ($response->failed()) {
                Log::error('LinkedIn OAuth Token Exchange Failed', [
                    'status' => $response->status(),
                    'body' => $response->body(),
                ]);
                return [
                    'success' => false,
                    'message' => 'LinkedIn Access Token alınamadı: ' . ($response->json('error_description') ?? $response->body()),
                ];
            }

            $data = $response->json();
            $accessToken = $data['access_token'] ?? null;
            $expiresIn = $data['expires_in'] ?? 5184000; // Default 60 days in seconds

            if (!$accessToken) {
                return [
                    'success' => false,
                    'message' => 'LinkedIn Access Token yanıt içinde bulunamadı.',
                ];
            }

            $expiresAt = now()->addSeconds($expiresIn)->toDateTimeString();

            // Save in Setting model
            Setting::updateOrCreate(
                ['key' => 'linkedin_access_token'],
                ['value' => $accessToken, 'type' => 'text', 'group' => 'social_media', 'label' => 'LinkedIn Access Token']
            );

            Setting::updateOrCreate(
                ['key' => 'linkedin_token_expires_at'],
                ['value' => $expiresAt, 'type' => 'datetime', 'group' => 'social_media', 'label' => 'LinkedIn Token Expiration']
            );

            return [
                'success' => true,
                'message' => 'LinkedIn hesabınız başarıyla bağlandı! Access Token kaydedildi.',
                'expires_at' => $expiresAt,
            ];
        } catch (\Throwable $e) {
            Log::error('LinkedIn Callback Error: ' . $e->getMessage());
            return [
                'success' => false,
                'message' => 'Hata oluştu: ' . $e->getMessage(),
            ];
        }
    }

    /**
     * Check if valid LinkedIn Access Token exists
     */
    public function isAuthorized(): bool
    {
        $token = Setting::get('linkedin_access_token');
        $expiresAt = Setting::get('linkedin_token_expires_at');

        if (!$token) {
            return false;
        }

        if ($expiresAt && now()->greaterThanOrEqualTo($expiresAt)) {
            return false;
        }

        return true;
    }

    /**
     * Get remaining days of Access Token
     */
    public function getTokenExpirationStatus(): array
    {
        $expiresAt = Setting::get('linkedin_token_expires_at');

        if (!$expiresAt) {
            return [
                'is_valid' => false,
                'message' => 'Yetkilendirme yapılmadı.',
            ];
        }

        $date = \Carbon\Carbon::parse($expiresAt);
        $diff = now()->diffInDays($date, false);

        if ($diff <= 0) {
            return [
                'is_valid' => false,
                'message' => 'Erişim anahtarının süresi doldu (' . $date->format('d.m.Y H:i') . '). Yeniden yetkilendirin.',
            ];
        }

        return [
            'is_valid' => true,
            'days_left' => $diff,
            'expires_at' => $date->format('d.m.Y H:i'),
            'message' => "Erişim anahtarı aktif. Kalan süre: {$diff} gün ({$date->format('d.m.Y H:i')}).",
        ];
    }

    /**
     * Share a post to LinkedIn Company Page
     */
    public function sharePost(string $title, string $text, ?string $url = null, ?string $imageUrl = null): array
    {
        if (!$this->isAuthorized()) {
            return [
                'success' => false,
                'message' => 'LinkedIn yetkilendirmesi bulunamadı veya süresi dolmuş.',
            ];
        }

        $token = Setting::get('linkedin_access_token');
        $authorUrn = "urn:li:organization:{$this->organizationId}";

        // Prepare UGC Post payload
        $shareCommentary = trim($title . "\n\n" . $text);
        if ($url) {
            $shareCommentary .= "\n\n" . $url;
        }

        $mediaContent = [];
        if ($url) {
            $mediaItem = [
                'status' => 'READY',
                'originalUrl' => $url,
                'title' => [
                    'text' => Str::limit($title, 200),
                ],
                'description' => [
                    'text' => Str::limit(strip_tags($text), 250),
                ],
            ];
            $mediaContent[] = $mediaItem;
        }

        $shareContent = [
            'shareCommentary' => [
                'text' => $shareCommentary,
            ],
            'shareMediaCategory' => !empty($mediaContent) ? 'ARTICLE' : 'NONE',
        ];

        if (!empty($mediaContent)) {
            $shareContent['media'] = $mediaContent;
        }

        $payload = [
            'author' => $authorUrn,
            'lifecycleState' => 'PUBLISHED',
            'specificContent' => [
                'com.linkedin.ugc.ShareContent' => $shareContent,
            ],
            'visibility' => [
                'com.linkedin.ugc.ShareProductVisibility' => 'PUBLIC',
            ],
        ];

        try {
            $response = Http::withHeaders([
                'Authorization' => 'Bearer ' . $token,
                'X-Restli-Protocol-Version' => '2.0.0',
                'Content-Type' => 'application/json',
            ])->post('https://api.linkedin.com/v2/ugcPosts', $payload);

            if ($response->successful()) {
                $postId = $response->header('x-restli-id') ?? $response->json('id');
                Log::info('LinkedIn post published successfully', [
                    'organization_id' => $this->organizationId,
                    'post_id' => $postId,
                ]);

                return [
                    'success' => true,
                    'message' => 'LinkedIn gönderisi başarıyla paylaşıldı!',
                    'post_id' => $postId,
                ];
            }

            Log::error('LinkedIn Share API Failed', [
                'status' => $response->status(),
                'body' => $response->body(),
            ]);

            return [
                'success' => false,
                'message' => 'LinkedIn gönderisi paylaşılamadı: ' . ($response->json('message') ?? $response->body()),
            ];
        } catch (\Throwable $e) {
            Log::error('LinkedIn Share Post Exception: ' . $e->getMessage());
            return [
                'success' => false,
                'message' => 'Gönderi paylaşılırken bir hata oluştu: ' . $e->getMessage(),
            ];
        }
    }
}