<?php

namespace App\Models\Products;

use App\Models\Materials\Material;
use App\Models\Orders\ClientGroup;
use App\Traits\BelongsToTenant;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Database\Eloquent\Relations\HasMany;
use Illuminate\Database\Eloquent\SoftDeletes;

/**
 * 단가 마스터 모델
 *
 * @property int $id
 * @property int $tenant_id
 * @property string $item_type_code
 * @property int $item_id
 * @property int|null $client_group_id
 * @property float|null $purchase_price
 * @property float|null $processing_cost
 * @property float|null $loss_rate
 * @property float|null $margin_rate
 * @property float|null $sales_price
 * @property string $rounding_rule
 * @property int $rounding_unit
 * @property string|null $supplier
 * @property \Carbon\Carbon $effective_from
 * @property \Carbon\Carbon|null $effective_to
 * @property string|null $note
 * @property string $status
 * @property bool $is_final
 * @property \Carbon\Carbon|null $finalized_at
 * @property int|null $finalized_by
 */
class Price extends Model
{
    use BelongsToTenant, SoftDeletes;

    protected $fillable = [
        'tenant_id',
        'item_type_code',
        'item_id',
        'client_group_id',
        'purchase_price',
        'processing_cost',
        'loss_rate',
        'margin_rate',
        'sales_price',
        'rounding_rule',
        'rounding_unit',
        'supplier',
        'effective_from',
        'effective_to',
        'note',
        'status',
        'is_final',
        'finalized_at',
        'finalized_by',
        'created_by',
        'updated_by',
        'deleted_by',
    ];

    protected $casts = [
        'purchase_price' => 'decimal:4',
        'processing_cost' => 'decimal:4',
        'loss_rate' => 'decimal:2',
        'margin_rate' => 'decimal:2',
        'sales_price' => 'decimal:4',
        'rounding_unit' => 'integer',
        'effective_from' => 'date',
        'effective_to' => 'date',
        'is_final' => 'boolean',
        'finalized_at' => 'datetime',
    ];

    /**
     * 고객 그룹 관계
     */
    public function clientGroup(): BelongsTo
    {
        return $this->belongsTo(ClientGroup::class, 'client_group_id');
    }

    /**
     * 리비전 이력 관계
     */
    public function revisions(): HasMany
    {
        return $this->hasMany(PriceRevision::class, 'price_id')->orderBy('revision_number', 'desc');
    }

    /**
     * 품목 관계 (Polymorphic - item_type_code에 따라)
     */
    public function item()
    {
        if ($this->item_type_code === 'PRODUCT') {
            return $this->belongsTo(Product::class, 'item_id');
        } elseif ($this->item_type_code === 'MATERIAL') {
            return $this->belongsTo(Material::class, 'item_id');
        }

        return null;
    }

    /**
     * 제품 관계 (item_type_code = PRODUCT인 경우)
     */
    public function product(): BelongsTo
    {
        return $this->belongsTo(Product::class, 'item_id');
    }

    /**
     * 자재 관계 (item_type_code = MATERIAL인 경우)
     */
    public function material(): BelongsTo
    {
        return $this->belongsTo(Material::class, 'item_id');
    }

    // ========== 스코프 ==========

    /**
     * 특정 품목 필터
     */
    public function scopeForItem($query, string $itemType, int $itemId)
    {
        return $query->where('item_type_code', $itemType)
            ->where('item_id', $itemId);
    }

    /**
     * 고객 그룹 필터
     */
    public function scopeForClientGroup($query, ?int $clientGroupId)
    {
        return $query->where('client_group_id', $clientGroupId);
    }

    /**
     * 특정 일자에 유효한 단가
     */
    public function scopeValidAt($query, $date)
    {
        return $query->where('effective_from', '<=', $date)
            ->where(function ($q) use ($date) {
                $q->whereNull('effective_to')
                    ->orWhere('effective_to', '>=', $date);
            });
    }

    /**
     * 상태 필터
     */
    public function scopeStatus($query, string $status)
    {
        return $query->where('status', $status);
    }

    /**
     * 활성 단가만
     */
    public function scopeActive($query)
    {
        return $query->where('status', 'active');
    }

    /**
     * 확정된 단가만
     */
    public function scopeFinalized($query)
    {
        return $query->where('is_final', true);
    }

    // ========== 계산 메서드 ==========

    /**
     * 총원가 계산
     * 총원가 = (매입단가 + 가공비) × (1 + LOSS율/100)
     */
    public function calculateTotalCost(): float
    {
        $baseCost = ($this->purchase_price ?? 0) + ($this->processing_cost ?? 0);
        $lossMultiplier = 1 + (($this->loss_rate ?? 0) / 100);

        return $baseCost * $lossMultiplier;
    }

    /**
     * 판매단가 계산 (마진율 기반)
     * 판매단가 = 반올림(총원가 × (1 + 마진율/100), 반올림단위, 반올림규칙)
     */
    public function calculateSalesPrice(): float
    {
        $totalCost = $this->calculateTotalCost();
        $marginMultiplier = 1 + (($this->margin_rate ?? 0) / 100);
        $rawPrice = $totalCost * $marginMultiplier;

        return $this->applyRounding($rawPrice);
    }

    /**
     * 반올림 적용
     */
    private function applyRounding(float $value): float
    {
        $unit = $this->rounding_unit ?: 1;

        return match ($this->rounding_rule) {
            'ceil' => ceil($value / $unit) * $unit,
            'floor' => floor($value / $unit) * $unit,
            default => round($value / $unit) * $unit, // 'round'
        };
    }

    /**
     * 확정 가능 여부
     */
    public function canFinalize(): bool
    {
        return ! $this->is_final && in_array($this->status, ['draft', 'active']);
    }

    /**
     * 수정 가능 여부
     */
    public function canEdit(): bool
    {
        return ! $this->is_final;
    }

    /**
     * 스냅샷 생성 (리비전용)
     */
    public function toSnapshot(): array
    {
        return [
            'purchase_price' => $this->purchase_price,
            'processing_cost' => $this->processing_cost,
            'loss_rate' => $this->loss_rate,
            'margin_rate' => $this->margin_rate,
            'sales_price' => $this->sales_price,
            'rounding_rule' => $this->rounding_rule,
            'rounding_unit' => $this->rounding_unit,
            'supplier' => $this->supplier,
            'effective_from' => $this->effective_from?->format('Y-m-d'),
            'effective_to' => $this->effective_to?->format('Y-m-d'),
            'status' => $this->status,
            'is_final' => $this->is_final,
            'note' => $this->note,
        ];
    }
}