package recipe

import (
	"context"
	"errors"
	"fmt"

	"git.huangwc.com/pig/pig-farm-controller/internal/infra/logs"
	"git.huangwc.com/pig/pig-farm-controller/internal/infra/models"
	"git.huangwc.com/pig/pig-farm-controller/internal/infra/repository"

	"gorm.io/gorm"
)

// 定义领域特定的错误
var (
	ErrRecipeNotFound     = fmt.Errorf("配方不存在")
	ErrRecipeNameConflict = fmt.Errorf("配方名称已存在")
)

// RecipeCoreService 定义了配方领域的核心业务服务接口
type RecipeCoreService interface {
	CreateRecipe(ctx context.Context, recipe *models.Recipe) (*models.Recipe, error)
	GetRecipeByID(ctx context.Context, id uint32) (*models.Recipe, error)
	GetRecipeByName(ctx context.Context, name string) (*models.Recipe, error)
	UpdateRecipe(ctx context.Context, recipe *models.Recipe) (*models.Recipe, error)
	DeleteRecipe(ctx context.Context, id uint32) error
	ListRecipes(ctx context.Context, opts repository.RecipeListOptions, page, pageSize int) ([]models.Recipe, int64, error)
	UpdateRecipeIngredients(ctx context.Context, recipeID uint32, ingredients []models.RecipeIngredient) error
}

// recipeCoreServiceImpl 是 RecipeCoreService 的实现
type recipeCoreServiceImpl struct {
	ctx        context.Context
	uow        repository.UnitOfWork
	recipeRepo repository.RecipeRepository
}

// NewRecipeCoreService 创建一个新的 RecipeCoreService 实例
func NewRecipeCoreService(ctx context.Context, uow repository.UnitOfWork, recipeRepo repository.RecipeRepository) RecipeCoreService {
	return &recipeCoreServiceImpl{
		ctx:        ctx,
		uow:        uow,
		recipeRepo: recipeRepo,
	}
}

// CreateRecipe 实现了创建配方的核心业务逻辑
func (s *recipeCoreServiceImpl) CreateRecipe(ctx context.Context, recipe *models.Recipe) (*models.Recipe, error) {
	serviceCtx := logs.AddFuncName(ctx, s.ctx, "CreateRecipe")

	// 检查名称是否已存在
	existing, err := s.recipeRepo.GetRecipeByName(serviceCtx, recipe.Name)
	if err != nil && !errors.Is(err, gorm.ErrRecordNotFound) {
		return nil, fmt.Errorf("检查配方名称失败: %w", err)
	}
	if existing != nil {
		return nil, ErrRecipeNameConflict
	}

	if err := s.recipeRepo.CreateRecipe(serviceCtx, recipe); err != nil {
		return nil, fmt.Errorf("创建配方失败: %w", err)
	}
	return recipe, nil
}

// GetRecipeByID 实现了获取单个配方的逻辑
func (s *recipeCoreServiceImpl) GetRecipeByID(ctx context.Context, id uint32) (*models.Recipe, error) {
	serviceCtx := logs.AddFuncName(ctx, s.ctx, "GetRecipeByID")
	recipe, err := s.recipeRepo.GetRecipeByID(serviceCtx, id)
	if err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, ErrRecipeNotFound
		}
		return nil, fmt.Errorf("获取配方失败: %w", err)
	}
	return recipe, nil
}

// GetRecipeByName 实现了根据名称获取单个配方的逻辑
func (s *recipeCoreServiceImpl) GetRecipeByName(ctx context.Context, name string) (*models.Recipe, error) {
	serviceCtx := logs.AddFuncName(ctx, s.ctx, "GetRecipeByName")
	recipe, err := s.recipeRepo.GetRecipeByName(serviceCtx, name)
	if err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, ErrRecipeNotFound
		}
		return nil, fmt.Errorf("获取配方失败: %w", err)
	}
	return recipe, nil
}

// UpdateRecipe 实现了更新配方的核心业务逻辑
func (s *recipeCoreServiceImpl) UpdateRecipe(ctx context.Context, recipe *models.Recipe) (*models.Recipe, error) {
	serviceCtx := logs.AddFuncName(ctx, s.ctx, "UpdateRecipe")

	// 检查要更新的实体是否存在
	existingRecipe, err := s.recipeRepo.GetRecipeByID(serviceCtx, recipe.ID)
	if err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, ErrRecipeNotFound
		}
		return nil, fmt.Errorf("获取待更新的配方失败: %w", err)
	}

	// 如果名称有变动，检查新名称是否与其它记录冲突
	if existingRecipe.Name != recipe.Name {
		existing, err := s.recipeRepo.GetRecipeByName(serviceCtx, recipe.Name)
		if err != nil && !errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, fmt.Errorf("检查新的配方名称失败: %w", err)
		}
		if existing != nil && existing.ID != recipe.ID {
			return nil, ErrRecipeNameConflict
		}
	}

	if err := s.recipeRepo.UpdateRecipe(serviceCtx, recipe); err != nil {
		return nil, fmt.Errorf("更新配方失败: %w", err)
	}
	return recipe, nil
}

// DeleteRecipe 实现了删除配方的核心业务逻辑
func (s *recipeCoreServiceImpl) DeleteRecipe(ctx context.Context, id uint32) error {
	serviceCtx := logs.AddFuncName(ctx, s.ctx, "DeleteRecipe")

	// 检查实体是否存在
	_, err := s.recipeRepo.GetRecipeByID(serviceCtx, id)
	if err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return ErrRecipeNotFound
		}
		return fmt.Errorf("获取待删除的配方失败: %w", err)
	}

	if err := s.recipeRepo.DeleteRecipe(serviceCtx, id); err != nil {
		return fmt.Errorf("删除配方失败: %w", err)
	}
	return nil
}

// ListRecipes 实现了列出配方的逻辑
func (s *recipeCoreServiceImpl) ListRecipes(ctx context.Context, opts repository.RecipeListOptions, page, pageSize int) ([]models.Recipe, int64, error) {
	serviceCtx := logs.AddFuncName(ctx, s.ctx, "ListRecipes")
	recipes, total, err := s.recipeRepo.ListRecipes(serviceCtx, opts, page, pageSize)
	if err != nil {
		return nil, 0, fmt.Errorf("获取配方列表失败: %w", err)
	}
	return recipes, total, nil
}

// UpdateRecipeIngredients 实现了全量更新配方原料的业务逻辑
func (s *recipeCoreServiceImpl) UpdateRecipeIngredients(ctx context.Context, recipeID uint32, ingredients []models.RecipeIngredient) error {
	serviceCtx := logs.AddFuncName(ctx, s.ctx, "UpdateRecipeIngredients")

	// 1. 检查配方是否存在
	if _, err := s.recipeRepo.GetRecipeByID(serviceCtx, recipeID); err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return ErrRecipeNotFound
		}
		return fmt.Errorf("获取待更新原料的配方失败: %w", err)
	}

	// 2. 在事务中执行替换操作
	err := s.uow.ExecuteInTransaction(serviceCtx, func(tx *gorm.DB) error {
		// 2.1. 删除旧的关联记录
		if err := s.recipeRepo.DeleteRecipeIngredientsByRecipeIDTx(serviceCtx, tx, recipeID); err != nil {
			return err // 错误已在仓库层封装，直接返回
		}

		// 2.2. 创建新的关联记录
		// 确保每个原料都设置了正确的 RecipeID
		for i := range ingredients {
			ingredients[i].RecipeID = recipeID
		}
		if err := s.recipeRepo.CreateBatchRecipeIngredientsTx(serviceCtx, tx, ingredients); err != nil {
			return err // 错误已在仓库层封装，直接返回
		}

		return nil
	})

	if err != nil {
		return fmt.Errorf("更新配方原料事务执行失败: %w", err)
	}

	// 3. 操作成功，直接返回 nil
	return nil
}