<?php

namespace App\Services\Pricing;

use App\Models\Orders\Client;
use App\Models\Products\PriceHistory;
use App\Services\Service;
use Carbon\Carbon;

class PricingService extends Service
{
    /**
     * 특정 항목(제품/자재)의 단가를 조회
     *
     * @param  string  $itemType  'PRODUCT' | 'MATERIAL'
     * @param  int  $itemId  제품/자재 ID
     * @param  int|null  $clientId  고객 ID (NULL이면 기본 가격)
     * @param  string|null  $date  기준일 (NULL이면 오늘)
     * @return array ['price' => float|null, 'price_history_id' => int|null, 'client_group_id' => int|null, 'warning' => string|null]
     */
    public function getItemPrice(string $itemType, int $itemId, ?int $clientId = null, ?string $date = null): array
    {
        $date = $date ?? Carbon::today()->format('Y-m-d');
        $clientGroupId = null;

        // 1. 고객의 그룹 ID 확인
        if ($clientId) {
            $client = Client::where('tenant_id', $this->tenantId())
                ->where('id', $clientId)
                ->first();

            if ($client) {
                $clientGroupId = $client->client_group_id;
            }
        }

        // 2. 가격 조회 (우선순위대로)
        $priceHistory = null;

        // 1순위: 고객 그룹별 매출단가
        if ($clientGroupId) {
            $priceHistory = $this->findPrice($itemType, $itemId, $clientGroupId, $date);
        }

        // 2순위: 기본 매출단가 (client_group_id = NULL)
        if (! $priceHistory) {
            $priceHistory = $this->findPrice($itemType, $itemId, null, $date);
        }

        // 3순위: NULL (경고)
        if (! $priceHistory) {
            return [
                'price' => null,
                'price_history_id' => null,
                'client_group_id' => null,
                'warning' => __('error.price_not_found', [
                    'item_type' => $itemType,
                    'item_id' => $itemId,
                    'date' => $date,
                ]),
            ];
        }

        return [
            'price' => (float) $priceHistory->price,
            'price_history_id' => $priceHistory->id,
            'client_group_id' => $priceHistory->client_group_id,
            'warning' => null,
        ];
    }

    /**
     * 가격 이력에서 유효한 가격 조회
     */
    private function findPrice(string $itemType, int $itemId, ?int $clientGroupId, string $date): ?PriceHistory
    {
        return PriceHistory::where('tenant_id', $this->tenantId())
            ->forItem($itemType, $itemId)
            ->forClientGroup($clientGroupId)
            ->salePrice()
            ->validAt($date)
            ->orderBy('started_at', 'desc')
            ->first();
    }

    /**
     * 여러 항목의 단가를 일괄 조회
     *
     * @param  array  $items  [['item_type' => 'PRODUCT', 'item_id' => 1], ...]
     * @return array ['prices' => [...], 'warnings' => [...]]
     */
    public function getBulkItemPrices(array $items, ?int $clientId = null, ?string $date = null): array
    {
        $prices = [];
        $warnings = [];

        foreach ($items as $item) {
            $result = $this->getItemPrice(
                $item['item_type'],
                $item['item_id'],
                $clientId,
                $date
            );

            $prices[] = array_merge($item, [
                'price' => $result['price'],
                'price_history_id' => $result['price_history_id'],
                'client_group_id' => $result['client_group_id'],
            ]);

            if ($result['warning']) {
                $warnings[] = $result['warning'];
            }
        }

        return [
            'prices' => $prices,
            'warnings' => $warnings,
        ];
    }

    /**
     * 가격 등록/수정
     */
    public function upsertPrice(array $data): PriceHistory
    {
        $data['tenant_id'] = $this->tenantId();
        $data['created_by'] = $this->apiUserId();
        $data['updated_by'] = $this->apiUserId();

        // 중복 확인: 동일 조건(item, client_group, date 범위)의 가격이 이미 있는지
        $existing = PriceHistory::where('tenant_id', $data['tenant_id'])
            ->where('item_type_code', $data['item_type_code'])
            ->where('item_id', $data['item_id'])
            ->where('price_type_code', $data['price_type_code'])
            ->where('client_group_id', $data['client_group_id'] ?? null)
            ->where('started_at', $data['started_at'])
            ->first();

        if ($existing) {
            $existing->update($data);

            return $existing->fresh();
        }

        return PriceHistory::create($data);
    }

    /**
     * 가격 이력 조회 (페이지네이션)
     *
     * @return \Illuminate\Contracts\Pagination\LengthAwarePaginator
     */
    public function listPrices(array $filters = [], int $perPage = 15)
    {
        $query = PriceHistory::where('tenant_id', $this->tenantId());

        if (isset($filters['item_type_code'])) {
            $query->where('item_type_code', $filters['item_type_code']);
        }

        if (isset($filters['item_id'])) {
            $query->where('item_id', $filters['item_id']);
        }

        if (isset($filters['price_type_code'])) {
            $query->where('price_type_code', $filters['price_type_code']);
        }

        if (isset($filters['client_group_id'])) {
            $query->where('client_group_id', $filters['client_group_id']);
        }

        if (isset($filters['date'])) {
            $query->validAt($filters['date']);
        }

        return $query->orderBy('started_at', 'desc')
            ->orderBy('created_at', 'desc')
            ->paginate($perPage);
    }

    /**
     * 가격 삭제 (Soft Delete)
     */
    public function deletePrice(int $id): bool
    {
        $price = PriceHistory::where('tenant_id', $this->tenantId())
            ->findOrFail($id);

        $price->deleted_by = $this->apiUserId();
        $price->save();

        return $price->delete();
    }
}