<?php

namespace Tests\Feature\Inventory;

use App\Models\Tenants\Stock;
use App\Models\Tenants\StockLot;
use App\Models\Tenants\StockTransaction;
use App\Services\StockService;
use Tests\TestCase;

class StockApiTest extends TestCase
{
    protected function setUp(): void
    {
        parent::setUp();
        $this->setUpAuthenticatedUser();
    }

    // ==================== API 엔드포인트 ====================

    public function test_재고_목록_조회(): void
    {
        $this->createStockWithLot(50);

        $response = $this->api('get', '/api/v1/stocks');

        $this->assertApiPaginated($response);
    }

    public function test_재고_통계_조회(): void
    {
        // 정상 재고
        $this->createStockWithLot(50, 10);
        // 부족 재고
        $this->createStockWithLot(5, 10);
        // 빈 재고
        $this->createStock(0, 10);

        $response = $this->api('get', '/api/v1/stocks/stats');

        $response->assertStatus(200)
            ->assertJsonStructure(['success', 'data']);
    }

    public function test_품목유형별_통계_조회(): void
    {
        $this->createStockWithLot(30, 10, 'raw_material');
        $this->createStockWithLot(20, 5, 'purchased_part');

        $response = $this->api('get', '/api/v1/stocks/stats-by-type');

        $response->assertStatus(200)
            ->assertJsonStructure(['success', 'data']);
    }

    public function test_재고_상세_존재하지_않는_품목_404(): void
    {
        // Stock API는 Item 기준 조회 → 존재하지 않는 Item ID는 404
        $response = $this->api('get', '/api/v1/stocks/999999');

        $response->assertStatus(404);
    }

    public function test_미인증_요청시_401(): void
    {
        $response = $this->withHeaders([
            'X-API-KEY' => $this->apiKey,
            'Accept' => 'application/json',
        ])->getJson('/api/v1/stocks');

        $response->assertStatus(401);
    }

    // ==================== FIFO 핵심 로직 ====================

    public function test_FIFO_입고시_LOT_생성_및_순서_할당(): void
    {
        $stock = $this->createStock(0, 10);

        // LOT 1 생성 (fifo_order = 1)
        $lot1 = $this->addLot($stock, 30, 1);
        // LOT 2 생성 (fifo_order = 2)
        $lot2 = $this->addLot($stock, 20, 2);

        $stock->refresh();
        $stock->refreshFromLots();

        $this->assertEquals(50, $stock->stock_qty);
        $this->assertEquals(50, $stock->available_qty);
        $this->assertEquals(2, $stock->lot_count);
        $this->assertEquals('normal', $stock->status);
    }

    public function test_FIFO_차감시_오래된_LOT부터_감소(): void
    {
        $stock = $this->createStock(0, 10);
        $lot1 = $this->addLot($stock, 30, 1); // 먼저 입고
        $lot2 = $this->addLot($stock, 20, 2); // 나중 입고
        $stock->refreshFromLots();

        // FIFO 차감: 25개 요청 → LOT1에서 25개 차감
        $service = app(StockService::class);
        $service->setContext($this->tenant->id, $this->user->id);
        $result = $service->decreaseFIFO($stock->item_id, 25, 'shipment', 1);

        $lot1->refresh();
        $lot2->refresh();

        // LOT1: 30 → 5 (25 차감)
        $this->assertEquals(5, $lot1->qty);
        // LOT2: 변화 없음
        $this->assertEquals(20, $lot2->qty);
    }

    public function test_FIFO_차감시_LOT_걸침_처리(): void
    {
        $stock = $this->createStock(0, 10);
        $lot1 = $this->addLot($stock, 10, 1);
        $lot2 = $this->addLot($stock, 20, 2);
        $stock->refreshFromLots();

        // 15개 차감 → LOT1(10) 전부 + LOT2(5) 일부
        $service = app(StockService::class);
        $service->setContext($this->tenant->id, $this->user->id);
        $result = $service->decreaseFIFO($stock->item_id, 15, 'shipment', 2);

        $lot1->refresh();
        $lot2->refresh();

        $this->assertEquals(0, $lot1->qty);
        $this->assertEquals(15, $lot2->qty);
    }

    public function test_재고_부족시_예외_발생(): void
    {
        $stock = $this->createStockWithLot(10);

        $service = app(StockService::class);
        $service->setContext($this->tenant->id, $this->user->id);

        $this->expectException(\Exception::class);
        $service->decreaseFIFO($stock->item_id, 999, 'shipment', 3);
    }

    // ==================== 예약/해제 ====================

    public function test_수주_확정시_재고_예약(): void
    {
        $stock = $this->createStock(0, 10);
        $lot1 = $this->addLot($stock, 50, 1);
        $stock->refreshFromLots();

        $service = app(StockService::class);
        $service->setContext($this->tenant->id, $this->user->id);
        $service->reserve($stock->item_id, 20, 100); // orderId=100

        $lot1->refresh();
        $stock->refresh();

        $this->assertEquals(20, $lot1->reserved_qty);
        $this->assertEquals(30, $lot1->available_qty);
        $this->assertEquals(20, $stock->reserved_qty);
    }

    public function test_수주_취소시_예약_해제(): void
    {
        $stock = $this->createStock(0, 10);
        $lot1 = $this->addLot($stock, 50, 1);
        $stock->refreshFromLots();

        $service = app(StockService::class);
        $service->setContext($this->tenant->id, $this->user->id);

        // 예약
        $service->reserve($stock->item_id, 20, 100);
        // 해제
        $service->releaseReservation($stock->item_id, 20, 100);

        $lot1->refresh();
        $stock->refresh();

        $this->assertEquals(0, $lot1->reserved_qty);
        $this->assertEquals(50, $lot1->available_qty);
        $this->assertEquals(0, $stock->reserved_qty);
    }

    // ==================== 거래 이력 ====================

    public function test_차감시_거래이력_기록(): void
    {
        $stock = $this->createStockWithLot(50);

        $service = app(StockService::class);
        $service->setContext($this->tenant->id, $this->user->id);
        $service->decreaseFIFO($stock->item_id, 10, 'shipment', 5);

        $transaction = StockTransaction::where('stock_id', $stock->id)
            ->where('type', StockTransaction::TYPE_OUT)
            ->first();

        $this->assertNotNull($transaction);
        $this->assertEquals(-10, $transaction->qty);
        $this->assertEquals('shipment', $transaction->reason);
    }

    // ==================== Stock 상태 자동 계산 ====================

    public function test_재고_상태_자동_계산(): void
    {
        // 정상: stock_qty > safety_stock
        $stock = $this->createStockWithLot(50, 10);
        $this->assertEquals('normal', $stock->calculateStatus());

        // 부족: 0 < stock_qty <= safety_stock
        $stock2 = $this->createStockWithLot(5, 10);
        $this->assertEquals('low', $stock2->calculateStatus());

        // 없음: stock_qty = 0
        $stock3 = $this->createStock(0, 10);
        $this->assertEquals('out', $stock3->calculateStatus());
    }

    // ==================== 헬퍼 ====================

    private function createStock(int $qty, int $safetyStock = 10, string $itemType = 'raw_material'): Stock
    {
        return Stock::create([
            'tenant_id' => $this->tenant->id,
            'item_id' => rand(100000, 999999),
            'item_code' => 'ITM-'.uniqid(),
            'item_name' => '테스트 품목',
            'item_type' => $itemType,
            'unit' => 'EA',
            'stock_qty' => $qty,
            'safety_stock' => $safetyStock,
            'reserved_qty' => 0,
            'available_qty' => $qty,
            'lot_count' => 0,
            'status' => $qty > $safetyStock ? 'normal' : ($qty > 0 ? 'low' : 'out'),
            'location' => 'A-01',
            'created_by' => $this->user->id,
            'updated_by' => $this->user->id,
        ]);
    }

    private function createStockWithLot(int $qty, int $safetyStock = 10, string $itemType = 'raw_material'): Stock
    {
        $stock = $this->createStock($qty, $safetyStock, $itemType);
        $this->addLot($stock, $qty, 1);
        $stock->refreshFromLots();

        return $stock;
    }

    private function addLot(Stock $stock, int $qty, int $fifoOrder): StockLot
    {
        return StockLot::create([
            'tenant_id' => $this->tenant->id,
            'stock_id' => $stock->id,
            'lot_no' => 'LOT-'.uniqid(),
            'fifo_order' => $fifoOrder,
            'receipt_date' => now(),
            'qty' => $qty,
            'reserved_qty' => 0,
            'available_qty' => $qty,
            'unit' => 'EA',
            'status' => 'available',
            'created_by' => $this->user->id,
            'updated_by' => $this->user->id,
        ]);
    }
}