<?php

namespace App\Services;

use App\Models\Tenants\AiPricingConfig;
use App\Models\Tenants\AiTokenUsage;

class AiTokenUsageService extends Service
{
    /**
     * 토큰 사용량 목록 + 통계
     */
    public function list(array $params): array
    {
        $tenantId = $this->tenantId();

        $query = AiTokenUsage::where('tenant_id', $tenantId)
            ->when($params['start_date'] ?? null, fn ($q, $d) => $q->whereDate('created_at', '>=', $d))
            ->when($params['end_date'] ?? null, fn ($q, $d) => $q->whereDate('created_at', '<=', $d))
            ->when($params['menu_name'] ?? null, fn ($q, $m) => $q->where('menu_name', $m));

        // 통계 (페이지네이션 전 전체 집계)
        $stats = (clone $query)->selectRaw('
            COUNT(*) as total_count,
            COALESCE(SUM(prompt_tokens), 0) as total_prompt_tokens,
            COALESCE(SUM(completion_tokens), 0) as total_completion_tokens,
            COALESCE(SUM(total_tokens), 0) as total_total_tokens,
            COALESCE(SUM(cost_usd), 0) as total_cost_usd,
            COALESCE(SUM(cost_krw), 0) as total_cost_krw
        ')->first();

        // 목록 (페이지네이션)
        $items = $query->with('creator:id,name')
            ->orderByDesc('created_at')
            ->paginate($params['per_page'] ?? 20);

        // 메뉴명 필터 옵션
        $menuNames = AiTokenUsage::where('tenant_id', $tenantId)
            ->select('menu_name')
            ->distinct()
            ->orderBy('menu_name')
            ->pluck('menu_name');

        return [
            'items' => $items,
            'stats' => [
                'total_count' => (int) $stats->total_count,
                'total_prompt_tokens' => (int) $stats->total_prompt_tokens,
                'total_completion_tokens' => (int) $stats->total_completion_tokens,
                'total_total_tokens' => (int) $stats->total_total_tokens,
                'total_cost_usd' => (float) $stats->total_cost_usd,
                'total_cost_krw' => (float) $stats->total_cost_krw,
            ],
            'menu_names' => $menuNames,
        ];
    }

    /**
     * 단가 설정 조회 (읽기 전용)
     */
    public function getPricing(): array
    {
        $configs = AiPricingConfig::where('is_active', true)
            ->orderBy('provider')
            ->get();

        return [
            'pricing' => $configs,
            'exchange_rate' => AiPricingConfig::getExchangeRate(),
        ];
    }
}