<?php

namespace App\Controllers;

use App\Core\Request;
use App\Core\Response;
use App\Core\Database;
use App\Models\CompanySubscription;

class SuperAdminController extends BaseController
{
    /**
     * Helper to verify if the requester is the Super Admin (Company ID 1 and role Admin)
     */
    private function verifySuperAdmin(Request $request, Response $response): bool
    {
        if ((int)$request->company_id !== 1 || $request->role !== 'admin') {
            $response->status(403)->json(['error' => 'Forbidden: Super Admin privileges required.']);
            return false;
        }
        return true;
    }

    /**
     * Get platform statistics and companies list
     * GET /api/admin/stats
     */
    public function getStats(Request $request, Response $response): void
    {
        if (!$this->verifySuperAdmin($request, $response)) {
            return;
        }

        try {
            // Overall stats
            $companiesCount = Database::selectOne("SELECT COUNT(*) as count FROM companies")['count'] ?? 0;
            $sessionsCount = Database::selectOne("SELECT COUNT(*) as count FROM whatsapp_sessions")['count'] ?? 0;
            $connectedSessions = Database::selectOne("SELECT COUNT(*) as count FROM whatsapp_sessions WHERE status = 'connected'")['count'] ?? 0;
            
            // Detailed list of all companies and their current subscriptions
            $companies = Database::select("
                SELECT 
                    c.id, 
                    c.name, 
                    c.status as company_status, 
                    c.created_at,
                    cs.plan_id, 
                    cs.status as sub_status, 
                    cs.starts_at, 
                    cs.ends_at, 
                    cs.payment_method, 
                    cs.receipt_reference,
                    p.name as plan_name,
                    (SELECT COUNT(*) FROM whatsapp_sessions WHERE company_id = c.id) as sessions_count,
                    (SELECT COUNT(*) FROM whatsapp_sessions WHERE company_id = c.id AND status = 'connected') as active_sessions,
                    COALESCE(cu.request_count, 0) as request_usage,
                    COALESCE(cu.voice_count, 0) as voice_usage,
                    COALESCE(cu.ocr_count, 0) as ocr_usage
                FROM companies c
                LEFT JOIN company_subscriptions cs ON c.id = cs.company_id AND cs.status IN ('active', 'trialing', 'pending_approval')
                LEFT JOIN subscription_plans p ON cs.plan_id = p.id
                LEFT JOIN company_subscription_usage cu ON cu.company_id = c.id 
                    AND cu.billing_start <= CURRENT_DATE() 
                    AND cu.billing_end >= CURRENT_DATE()
                ORDER BY c.created_at DESC
            ");

            $pendingApprovals = [];
            $activeCompanies = [];

            foreach ($companies as $c) {
                if ($c['sub_status'] === 'pending_approval') {
                    $pendingApprovals[] = $c;
                } else {
                    $activeCompanies[] = $c;
                }
            }

            // 4. Fetch all available plans to allow admin to upgrade them manually
            $plans = Database::select("SELECT id, name, price FROM subscription_plans ORDER BY price ASC");

            $response->json([
                'status' => 'success',
                'data' => [
                    'stats' => [
                        'total_companies' => (int)$companiesCount,
                        'total_sessions' => (int)$sessionsCount,
                        'connected_sessions' => (int)$connectedSessions
                    ],
                    'companies' => $activeCompanies,
                    'pending_approvals' => $pendingApprovals,
                    'plans' => $plans
                ]
            ]);

        } catch (\Exception $e) {
            error_log("[SuperAdminController Error] " . $e->getMessage());
            $response->status(500)->json(['error' => 'Failed to fetch platform stats: ' . $e->getMessage()]);
        }
    }

    /**
     * Subscribe or upgrade a company to a plan
     * POST /api/admin/companies/subscribe
     */
    public function subscribeCompany(Request $request, Response $response): void
    {
        if (!$this->verifySuperAdmin($request, $response)) {
            return;
        }

        $body = $request->getBody();
        $targetCompanyId = isset($body['company_id']) ? (int)$body['company_id'] : null;
        $planId = isset($body['plan_id']) ? (int)$body['plan_id'] : null;
        $durationDays = isset($body['duration_days']) ? (int)$body['duration_days'] : 30;

        if (!$targetCompanyId || !$planId) {
            $response->status(400)->json(['error' => 'Missing company_id or plan_id']);
            return;
        }

        // Verify company exists
        $companyExists = Database::selectOne("SELECT id FROM companies WHERE id = ?", [$targetCompanyId]);
        if (!$companyExists) {
            $response->status(404)->json(['error' => 'Company not found']);
            return;
        }

        // Verify plan exists
        $planExists = Database::selectOne("SELECT id FROM subscription_plans WHERE id = ?", [$planId]);
        if (!$planExists) {
            $response->status(404)->json(['error' => 'Subscription plan not found']);
            return;
        }

        try {
            // Subscribe the company
            $subId = CompanySubscription::subscribeCompany($targetCompanyId, $planId, $durationDays, 'manual_admin', 'admin_' . $request->user_id);

            // Clean active subscription cache for the company
            if (class_exists('App\Core\Cache')) {
                \App\Core\Cache::delete("company_subscription:{$targetCompanyId}");
                \App\Core\Cache::delete("company_subscription_{$targetCompanyId}");
            }

            $response->json([
                'status' => 'success',
                'message' => 'Subscription updated successfully',
                'subscription_id' => $subId
            ]);
        } catch (\Exception $e) {
            error_log("[SuperAdminController Error] " . $e->getMessage());
            $response->status(500)->json(['error' => 'Failed to update subscription: ' . $e->getMessage()]);
        }
    }

    /**
     * Approve a pending billing request
     * POST /api/admin/companies/approve-billing
     */
    public function approveBilling(Request $request, Response $response): void
    {
        $body = $request->getBody();
        $targetCompanyId = isset($body['company_id']) ? (int)$body['company_id'] : null;

        if (!$targetCompanyId) {
            $response->status(400)->json(['error' => 'Missing company_id']);
            return;
        }

        try {
            // Find the pending subscription
            $pending = Database::selectOne("SELECT * FROM company_subscriptions WHERE company_id = ? AND status = 'pending_approval' ORDER BY id DESC LIMIT 1", [$targetCompanyId]);
            if (!$pending) {
                $response->status(404)->json(['error' => 'No pending approval found for this company']);
                return;
            }

            // Deactivate other active/trialing subscriptions
            Database::execute("UPDATE company_subscriptions SET status = 'expired' WHERE company_id = ? AND status IN ('active', 'trialing')", [$targetCompanyId]);

            // Mark the pending one as active
            Database::execute("UPDATE company_subscriptions SET status = 'active' WHERE id = ?", [$pending['id']]);

            // Clear active subscription cache for the company
            if (class_exists('App\Core\Cache')) {
                \App\Core\Cache::delete("company_subscription_{$targetCompanyId}");
            }

            $response->json([
                'status' => 'success',
                'message' => 'Billing approved and subscription activated successfully'
            ]);
        } catch (\Exception $e) {
            $response->status(500)->json(['error' => 'Failed to approve billing: ' . $e->getMessage()]);
        }
    }
}