<?php

namespace App\Support;

use App\Models\LoginEvent;
use App\Models\OAuthAuthorizationEvent;
use App\Models\User;
use Illuminate\Support\Carbon;
use Illuminate\Support\Facades\DB;
use Laravel\Passport\Passport;
use Laravel\Passport\Token;

/**
 * Agregación compartida por Admin\AnalyticsController (sesión) y
 * Api\AnalyticsController (token) — misma data, dos superficies de auth.
 */
class AnalyticsSummary
{
    public static function build(int $days = 30): array
    {
        $since = Carbon::now()->subDays($days - 1)->startOfDay();

        return [
            'kpis' => [
                'total_users' => User::count(),
                'active_sessions' => Token::query()->where('revoked', false)->where('expires_at', '>', now())->count(),
                'logins_today' => LoginEvent::successful()->whereDate('created_at', today())->count(),
                'logins_7d' => LoginEvent::successful()->where('created_at', '>=', now()->subDays(7))->count(),
                'login_failures_7d' => LoginEvent::where('type', 'session')->where('outcome', 'failure')->where('created_at', '>=', now()->subDays(7))->count(),
                'login_failure_rate_7d' => self::loginFailureRate(now()->subDays(7)),
            ],
            'logins_by_day' => self::loginsByDay($since, $days),
            'logins_by_app' => self::loginsByApp($since),
            'top_users' => self::topUsers($since),
            'recent' => self::recent(),
            'oauth_funnel' => self::oauthFunnel($since),
            'oauth_funnel_by_client' => self::oauthFunnelByClient($since),
            'active_tokens_by_client' => self::activeTokensByClient(),
            'scope_usage' => self::scopeUsage($since),
        ];
    }

    private static function loginFailureRate(Carbon $since): float
    {
        $success = LoginEvent::where('type', 'session')->where('outcome', 'success')->where('created_at', '>=', $since)->count();
        $failure = LoginEvent::where('type', 'session')->where('outcome', 'failure')->where('created_at', '>=', $since)->count();
        $total = $success + $failure;

        return $total === 0 ? 0.0 : round(($failure / $total) * 100, 1);
    }

    private static function oauthFunnel(Carbon $since): array
    {
        $counts = OAuthAuthorizationEvent::query()
            ->where('created_at', '>=', $since)
            ->selectRaw('outcome, count(*) as count')
            ->groupBy('outcome')
            ->pluck('count', 'outcome');

        $attempted = (int) ($counts['attempted'] ?? 0);
        $approved = (int) ($counts['approved'] ?? 0);
        $denied = (int) ($counts['denied'] ?? 0);

        return [
            'attempted' => $attempted,
            'approved' => $approved,
            'denied' => $denied,
            'approval_rate' => $attempted === 0 ? 0.0 : round(($approved / $attempted) * 100, 1),
        ];
    }

    private static function oauthFunnelByClient(Carbon $since): array
    {
        return OAuthAuthorizationEvent::query()
            ->join('oauth_clients', 'oauth_clients.id', '=', 'oauth_authorization_events.client_id')
            ->where('oauth_authorization_events.created_at', '>=', $since)
            ->groupBy('oauth_clients.id', 'oauth_clients.name')
            ->orderByDesc('attempted')
            ->limit(8)
            ->get([
                'oauth_clients.name as client_name',
                DB::raw("sum(case when outcome = 'attempted' then 1 else 0 end) as attempted"),
                DB::raw("sum(case when outcome = 'approved' then 1 else 0 end) as approved"),
                DB::raw("sum(case when outcome = 'denied' then 1 else 0 end) as denied"),
            ])
            ->map(fn ($row) => [
                'client_name' => $row->client_name,
                'attempted' => (int) $row->attempted,
                'approved' => (int) $row->approved,
                'denied' => (int) $row->denied,
            ])
            ->toArray();
    }

    private static function activeTokensByClient(): array
    {
        return Token::query()
            ->join('oauth_clients', 'oauth_clients.id', '=', 'oauth_access_tokens.client_id')
            ->where('oauth_access_tokens.revoked', false)
            ->where('oauth_access_tokens.expires_at', '>', now())
            ->groupBy('oauth_clients.id', 'oauth_clients.name')
            ->orderByDesc('count')
            ->limit(8)
            ->get(['oauth_clients.name as client_name', DB::raw('count(*) as count')])
            ->toArray();
    }

    private static function scopeUsage(Carbon $since): array
    {
        $descriptions = Passport::scopes()->keyBy('id');

        $counts = [];
        Token::query()
            ->where('oauth_access_tokens.created_at', '>=', $since)
            ->where('revoked', false)
            ->pluck('scopes')
            ->each(function ($raw) use (&$counts) {
                $scopes = is_array($raw) ? $raw : (json_decode($raw ?? '[]', true) ?? []);

                foreach ($scopes as $scope) {
                    $counts[$scope] = ($counts[$scope] ?? 0) + 1;
                }
            });

        arsort($counts);

        return collect($counts)
            ->take(8)
            ->map(fn ($count, $scope) => [
                'scope' => $scope,
                'description' => $descriptions->get($scope)?->description ?? $scope,
                'count' => $count,
            ])
            ->values()
            ->toArray();
    }

    private static function loginsByDay(Carbon $since, int $days): array
    {
        $rows = LoginEvent::query()
            ->selectRaw("date(created_at) as day, type, count(*) as count")
            ->where('outcome', 'success')
            ->where('created_at', '>=', $since)
            ->groupBy('day', 'type')
            ->get()
            ->groupBy('day');

        $out = [];
        for ($i = 0; $i < $days; $i++) {
            $date = $since->copy()->addDays($i)->toDateString();
            $dayRows = $rows->get($date, collect());

            $out[] = [
                'date' => $date,
                'session' => (int) $dayRows->firstWhere('type', 'session')?->count,
                'oauth' => (int) $dayRows->firstWhere('type', 'oauth')?->count,
            ];
        }

        return $out;
    }

    private static function loginsByApp(Carbon $since): array
    {
        return LoginEvent::query()
            ->join('oauth_clients', 'oauth_clients.id', '=', 'login_events.client_id')
            ->where('login_events.type', 'oauth')
            ->where('login_events.outcome', 'success')
            ->where('login_events.created_at', '>=', $since)
            ->groupBy('oauth_clients.id', 'oauth_clients.name')
            ->orderByDesc('count')
            ->limit(8)
            ->get(['oauth_clients.name as client_name', DB::raw('count(*) as count')])
            ->toArray();
    }

    private static function topUsers(Carbon $since): array
    {
        return LoginEvent::query()
            ->join('users', 'users.id', '=', 'login_events.user_id')
            ->where('login_events.outcome', 'success')
            ->where('login_events.created_at', '>=', $since)
            ->groupBy('users.id', 'users.name', 'users.email')
            ->orderByDesc('count')
            ->limit(8)
            ->get(['users.name', 'users.email', DB::raw('count(*) as count')])
            ->toArray();
    }

    private static function recent(int $limit = 15): array
    {
        return LoginEvent::with(['user:id,name,email', 'client:id,name'])
            ->where('outcome', 'success')
            ->latest('created_at')
            ->limit($limit)
            ->get()
            ->map(fn (LoginEvent $event) => [
                'user_name' => $event->user?->name,
                'user_email' => $event->user?->email,
                // null para logins de sesión (el frontend lo traduce como "Panel admin"/"Admin
                // panel" según el idioma) y para apps borradas (el frontend traduce ese caso
                // también) — así el backend no filtra texto sin traducir a la UI.
                'client_name' => $event->type === 'session' ? null : $event->client?->name,
                'type' => $event->type,
                'ip_address' => $event->ip_address,
                'created_at' => $event->created_at,
            ])
            ->toArray();
    }
}