<?php

namespace App\Services;

use App\Models\UsageLog;
use App\Models\GatewayUser;
use Illuminate\Support\Facades\DB;

class StatisticsService
{
    /**
     * Get dashboard overview statistics
     */
    public function getDashboardStats()
    {
        return [
            'total_users' => GatewayUser::count(),
            'active_users' => GatewayUser::active()->count(),
            'blocked_users' => GatewayUser::blocked()->count(),
            'total_requests_today' => UsageLog::today()->count(),
            'total_spend_today' => UsageLog::today()->sum('cost') ?? 0,
            'total_tokens_today' => UsageLog::today()->sum('total_tokens') ?? 0,
            'total_spend_month' => UsageLog::whereMonth('timestamp', now()->month)->sum('cost') ?? 0,
            'total_requests_month' => UsageLog::whereMonth('timestamp', now()->month)->count(),
        ];
    }

    /**
     * Get usage breakdown by provider
     */
    public function getUsageByProvider($days = 30)
    {
        return UsageLog::selectRaw('provider, COUNT(*) as count, SUM(cost) as total_cost')
            ->where('timestamp', '>=', now()->subDays($days))
            ->groupBy('provider')
            ->orderByDesc('count')
            ->get();
    }

    /**
     * Get usage breakdown by model
     */
    public function getUsageByModel($days = 30)
    {
        return UsageLog::selectRaw('model, COUNT(*) as count, SUM(total_tokens) as tokens, SUM(cost) as total_cost')
            ->where('timestamp', '>=', now()->subDays($days))
            ->groupBy('model')
            ->orderByDesc('count')
            ->limit(10)
            ->get();
    }

    /**
     * Get daily usage chart data
     */
    public function getDailyUsageChart($days = 30)
    {
        return UsageLog::selectRaw('DATE(timestamp) as date, COUNT(*) as requests, SUM(cost) as cost, SUM(total_tokens) as tokens')
            ->where('timestamp', '>=', now()->subDays($days))
            ->groupBy('date')
            ->orderBy('date')
            ->get();
    }

    /**
     * Get top users by spend
     */
    public function getTopUsers($limit = 10)
    {
        return GatewayUser::withCount('usageLogs')
            ->withSum('usageLogs', 'cost')
            ->orderByDesc('usage_logs_sum_cost')
            ->limit($limit)
            ->get();
    }

    /**
     * Get recent activity
     */
    public function getRecentActivity($limit = 20)
    {
        return UsageLog::with(['gatewayUser', 'apiKey'])
            ->orderByDesc('timestamp')
            ->limit($limit)
            ->get();
    }

    /**
     * Get user statistics
     */
    public function getUserStatistics($userId, $days = 30)
    {
        return UsageLog::where('user_id', $userId)
            ->where('timestamp', '>=', now()->subDays($days))
            ->selectRaw('
                COUNT(*) as total_requests,
                SUM(prompt_tokens) as total_prompt_tokens,
                SUM(completion_tokens) as total_completion_tokens,
                SUM(total_tokens) as total_tokens,
                SUM(cost) as total_cost,
                AVG(total_tokens) as avg_tokens_per_request
            ')
            ->first();
    }
}