<?php

namespace App\Services\Design;

use App\Models\Design\DesignModel;
use App\Models\Design\ModelParameter;
use App\Models\Design\ModelFormula;
use App\Models\Design\BomConditionRule;
use App\Models\Design\BomTemplate;
use App\Models\Design\BomTemplateItem;
use App\Models\Product;
use App\Models\Material;
use App\Services\Service;
use Illuminate\Support\Facades\DB;
use Illuminate\Validation\ValidationException;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;

class BomResolverService extends Service
{
    protected ModelParameterService $parameterService;
    protected ModelFormulaService $formulaService;
    protected BomConditionRuleService $ruleService;

    public function __construct(
        ModelParameterService $parameterService,
        ModelFormulaService $formulaService,
        BomConditionRuleService $ruleService
    ) {
        $this->parameterService = $parameterService;
        $this->formulaService = $formulaService;
        $this->ruleService = $ruleService;
    }

    /**
     * 매개변수 기반 BOM 해석 (전체 프로세스)
     */
    public function resolveBom(int $modelId, array $inputParameters, ?int $templateId = null): array
    {
        $tenantId = $this->tenantId();

        // 1. 모델 존재 확인
        $model = DesignModel::where('tenant_id', $tenantId)->where('id', $modelId)->first();
        if (!$model) {
            throw new NotFoundHttpException(__('error.model_not_found'));
        }

        // 2. 매개변수 검증 및 기본값 적용
        $validatedParameters = $this->parameterService->validateParameters($modelId, $inputParameters);

        // 3. 공식 계산 실행
        $calculatedValues = $this->formulaService->calculateFormulas($modelId, $validatedParameters);

        // 4. 조건 규칙 평가
        $ruleResults = $this->ruleService->evaluateRules($modelId, $calculatedValues);

        // 5. 기본 BOM 템플릿 조회 (지정된 템플릿 또는 최신 버전)
        $baseBom = $this->getBaseBomTemplate($modelId, $templateId);

        // 6. 조건 규칙 적용으로 BOM 변환
        $resolvedBom = $this->applyRulesToBom($baseBom, $ruleResults['bom_actions'], $calculatedValues);

        // 7. BOM 아이템 정보 보강 (재료/제품 세부정보)
        $enrichedBom = $this->enrichBomItems($resolvedBom);

        return [
            'model' => [
                'id' => $model->id,
                'code' => $model->code,
                'name' => $model->name,
            ],
            'input_parameters' => $validatedParameters,
            'calculated_values' => $calculatedValues,
            'matched_rules' => $ruleResults['matched_rules'],
            'base_bom_template_id' => $baseBom['template_id'] ?? null,
            'resolved_bom' => $enrichedBom,
            'summary' => $this->generateBomSummary($enrichedBom),
        ];
    }

    /**
     * BOM 해석 미리보기 (저장하지 않음)
     */
    public function previewBom(int $modelId, array $inputParameters, ?int $templateId = null): array
    {
        return $this->resolveBom($modelId, $inputParameters, $templateId);
    }

    /**
     * 매개변수 변경에 따른 BOM 차이 분석
     */
    public function compareBomByParameters(int $modelId, array $parameters1, array $parameters2, ?int $templateId = null): array
    {
        // 두 매개변수 세트로 각각 BOM 해석
        $bom1 = $this->resolveBom($modelId, $parameters1, $templateId);
        $bom2 = $this->resolveBom($modelId, $parameters2, $templateId);

        return [
            'parameters_diff' => [
                'set1' => $parameters1,
                'set2' => $parameters2,
                'changed' => array_diff_assoc($parameters2, $parameters1),
            ],
            'calculated_values_diff' => [
                'set1' => $bom1['calculated_values'],
                'set2' => $bom2['calculated_values'],
                'changed' => array_diff_assoc($bom2['calculated_values'], $bom1['calculated_values']),
            ],
            'bom_diff' => $this->compareBomItems($bom1['resolved_bom'], $bom2['resolved_bom']),
            'summary_diff' => [
                'set1' => $bom1['summary'],
                'set2' => $bom2['summary'],
            ],
        ];
    }

    /**
     * 기본 BOM 템플릿 조회
     */
    private function getBaseBomTemplate(int $modelId, ?int $templateId = null): array
    {
        $tenantId = $this->tenantId();

        if ($templateId) {
            // 지정된 템플릿 사용
            $template = BomTemplate::where('tenant_id', $tenantId)
                ->where('id', $templateId)
                ->first();
        } else {
            // 해당 모델의 최신 버전에서 BOM 템플릿 찾기
            $template = BomTemplate::query()
                ->where('tenant_id', $tenantId)
                ->whereHas('modelVersion', function ($q) use ($modelId) {
                    $q->where('model_id', $modelId)
                        ->where('status', 'RELEASED');
                })
                ->orderByDesc('created_at')
                ->first();
        }

        if (!$template) {
            // 기본 템플릿이 없으면 빈 BOM 반환
            return [
                'template_id' => null,
                'items' => [],
            ];
        }

        $items = BomTemplateItem::query()
            ->where('bom_template_id', $template->id)
            ->orderBy('order')
            ->get()
            ->map(function ($item) {
                return [
                    'target_type' => $item->ref_type,
                    'target_id' => $item->ref_id,
                    'quantity' => $item->quantity,
                    'waste_rate' => $item->waste_rate,
                    'reason' => 'base_template',
                ];
            })
            ->toArray();

        return [
            'template_id' => $template->id,
            'items' => $items,
        ];
    }

    /**
     * 조건 규칙을 BOM에 적용
     */
    private function applyRulesToBom(array $baseBom, array $bomActions, array $calculatedValues): array
    {
        $currentBom = $baseBom['items'];

        foreach ($bomActions as $action) {
            switch ($action['action_type']) {
                case 'INCLUDE':
                    // 새 아이템 추가 (중복 체크)
                    $exists = collect($currentBom)->contains(function ($item) use ($action) {
                        return $item['target_type'] === $action['target_type'] &&
                               $item['target_id'] === $action['target_id'];
                    });

                    if (!$exists) {
                        $currentBom[] = [
                            'target_type' => $action['target_type'],
                            'target_id' => $action['target_id'],
                            'quantity' => $action['quantity_multiplier'] ?? 1,
                            'waste_rate' => 0,
                            'reason' => $action['rule_name'],
                        ];
                    }
                    break;

                case 'EXCLUDE':
                    // 아이템 제외
                    $currentBom = array_filter($currentBom, function ($item) use ($action) {
                        return !($item['target_type'] === $action['target_type'] &&
                                $item['target_id'] === $action['target_id']);
                    });
                    break;

                case 'MODIFY_QUANTITY':
                    // 수량 변경
                    foreach ($currentBom as &$item) {
                        if ($item['target_type'] === $action['target_type'] &&
                            $item['target_id'] === $action['target_id']) {

                            $multiplier = $action['quantity_multiplier'] ?? 1;

                            // 공식으로 계산된 값이 있으면 그것을 사용
                            if (isset($calculatedValues['quantity_' . $action['target_id']])) {
                                $item['quantity'] = $calculatedValues['quantity_' . $action['target_id']];
                            } else {
                                $item['quantity'] = $item['quantity'] * $multiplier;
                            }

                            $item['reason'] = $action['rule_name'];
                        }
                    }
                    break;
            }
        }

        return array_values($currentBom); // 인덱스 재정렬
    }

    /**
     * BOM 아이템 정보 보강
     */
    private function enrichBomItems(array $bomItems): array
    {
        $tenantId = $this->tenantId();
        $enriched = [];

        foreach ($bomItems as $item) {
            $enrichedItem = $item;

            if ($item['target_type'] === 'MATERIAL') {
                $material = Material::where('tenant_id', $tenantId)
                    ->where('id', $item['target_id'])
                    ->first();

                if ($material) {
                    $enrichedItem['target_info'] = [
                        'id' => $material->id,
                        'code' => $material->code,
                        'name' => $material->name,
                        'unit' => $material->unit,
                        'type' => 'material',
                    ];
                }
            } elseif ($item['target_type'] === 'PRODUCT') {
                $product = Product::where('tenant_id', $tenantId)
                    ->where('id', $item['target_id'])
                    ->first();

                if ($product) {
                    $enrichedItem['target_info'] = [
                        'id' => $product->id,
                        'code' => $product->code,
                        'name' => $product->name,
                        'unit' => $product->unit,
                        'type' => 'product',
                    ];
                }
            }

            // 실제 필요 수량 계산 (폐기율 적용)
            $baseQuantity = $enrichedItem['quantity'];
            $wasteRate = $enrichedItem['waste_rate'] ?? 0;
            $enrichedItem['actual_quantity'] = $baseQuantity * (1 + $wasteRate / 100);

            $enriched[] = $enrichedItem;
        }

        return $enriched;
    }

    /**
     * BOM 요약 정보 생성
     */
    private function generateBomSummary(array $bomItems): array
    {
        $totalItems = count($bomItems);
        $materialCount = 0;
        $productCount = 0;
        $totalValue = 0; // 나중에 가격 정보 추가 시 사용

        foreach ($bomItems as $item) {
            if ($item['target_type'] === 'MATERIAL') {
                $materialCount++;
            } elseif ($item['target_type'] === 'PRODUCT') {
                $productCount++;
            }
        }

        return [
            'total_items' => $totalItems,
            'material_count' => $materialCount,
            'product_count' => $productCount,
            'total_estimated_value' => $totalValue,
            'generated_at' => now()->toISOString(),
        ];
    }

    /**
     * BOM 아이템 비교
     */
    private function compareBomItems(array $bom1, array $bom2): array
    {
        $added = [];
        $removed = [];
        $modified = [];

        // BOM1에 있던 아이템들 체크
        foreach ($bom1 as $item1) {
            $key = $item1['target_type'] . '_' . $item1['target_id'];
            $found = false;

            foreach ($bom2 as $item2) {
                if ($item2['target_type'] === $item1['target_type'] &&
                    $item2['target_id'] === $item1['target_id']) {
                    $found = true;

                    // 수량이 변경되었는지 체크
                    if ($item1['quantity'] != $item2['quantity']) {
                        $modified[] = [
                            'target_type' => $item1['target_type'],
                            'target_id' => $item1['target_id'],
                            'target_info' => $item1['target_info'] ?? null,
                            'old_quantity' => $item1['quantity'],
                            'new_quantity' => $item2['quantity'],
                            'change' => $item2['quantity'] - $item1['quantity'],
                        ];
                    }
                    break;
                }
            }

            if (!$found) {
                $removed[] = $item1;
            }
        }

        // BOM2에 새로 추가된 아이템들
        foreach ($bom2 as $item2) {
            $found = false;

            foreach ($bom1 as $item1) {
                if ($item1['target_type'] === $item2['target_type'] &&
                    $item1['target_id'] === $item2['target_id']) {
                    $found = true;
                    break;
                }
            }

            if (!$found) {
                $added[] = $item2;
            }
        }

        return [
            'added' => $added,
            'removed' => $removed,
            'modified' => $modified,
            'summary' => [
                'added_count' => count($added),
                'removed_count' => count($removed),
                'modified_count' => count($modified),
            ],
        ];
    }

    /**
     * BOM 해석 결과 저장 (향후 주문/견적 연계용)
     */
    public function saveBomResolution(int $modelId, array $inputParameters, array $bomResolution, string $purpose = 'ESTIMATION'): array
    {
        $tenantId = $this->tenantId();
        $userId = $this->apiUserId();

        return DB::transaction(function () use ($tenantId, $userId, $modelId, $inputParameters, $bomResolution, $purpose) {
            // BOM 해석 결과를 데이터베이스에 저장
            // 향후 order_items, quotation_items 등과 연계할 수 있도록 구조 준비

            $resolutionRecord = [
                'tenant_id' => $tenantId,
                'model_id' => $modelId,
                'input_parameters' => json_encode($inputParameters),
                'calculated_values' => json_encode($bomResolution['calculated_values']),
                'resolved_bom' => json_encode($bomResolution['resolved_bom']),
                'matched_rules' => json_encode($bomResolution['matched_rules']),
                'summary' => json_encode($bomResolution['summary']),
                'purpose' => $purpose,
                'created_by' => $userId,
                'created_at' => now(),
            ];

            // 실제 테이블이 있다면 저장, 없으면 파일이나 캐시에 임시 저장
            $resolutionId = md5(json_encode($resolutionRecord));

            // 임시로 캐시에 저장 (1시간)
            cache()->put("bom_resolution_{$resolutionId}", $resolutionRecord, 3600);

            return [
                'resolution_id' => $resolutionId,
                'saved_at' => now()->toISOString(),
                'purpose' => $purpose,
            ];
        });
    }

    /**
     * 저장된 BOM 해석 결과 조회
     */
    public function getBomResolution(string $resolutionId): ?array
    {
        return cache()->get("bom_resolution_{$resolutionId}");
    }

    /**
     * KSS01 시나리오 테스트용 빠른 실행
     */
    public function resolveKSS01(array $parameters): array
    {
        // KSS01 모델이 있다고 가정하고 하드코딩된 로직
        $defaults = [
            'W0' => 800,
            'H0' => 600,
            'screen_type' => 'FABRIC',
            'install_type' => 'WALL',
        ];

        $params = array_merge($defaults, $parameters);

        // 공식 계산 시뮬레이션
        $calculated = [
            'W1' => $params['W0'] + 100,
            'H1' => $params['H0'] + 100,
        ];
        $calculated['area'] = ($calculated['W1'] * $calculated['H1']) / 1000000;

        // 조건 규칙 시뮬레이션
        $bom = [];

        // 스크린 타입에 따른 자재
        if ($params['screen_type'] === 'FABRIC') {
            $bom[] = ['target_type' => 'MATERIAL', 'target_id' => 1, 'quantity' => $calculated['area'], 'target_info' => ['name' => '패브릭 스크린']];
        } else {
            $bom[] = ['target_type' => 'MATERIAL', 'target_id' => 2, 'quantity' => $calculated['area'], 'target_info' => ['name' => '스틸 스크린']];
        }

        // 브라켓 개수 (폭에 따라)
        $bracketCount = $calculated['W1'] > 1000 ? 3 : 2;
        $bom[] = ['target_type' => 'PRODUCT', 'target_id' => 10, 'quantity' => $bracketCount, 'target_info' => ['name' => '브라켓']];

        // 가이드레일
        $railLength = ($calculated['W1'] + $calculated['H1']) * 2 / 1000; // m 단위
        $bom[] = ['target_type' => 'MATERIAL', 'target_id' => 3, 'quantity' => $railLength, 'target_info' => ['name' => '가이드레일']];

        return [
            'model' => ['code' => 'KSS01', 'name' => '기본 스크린 시스템'],
            'input_parameters' => $params,
            'calculated_values' => $calculated,
            'resolved_bom' => $bom,
            'summary' => ['total_items' => count($bom)],
        ];
    }
}