package models

import (
	"time"

	"gorm.io/gorm"
)

/*
	饲料和饲喂相关的模型
*/

// RawMaterial 代表饲料的原料。
// 建议：所有重量单位统一存储 (例如, 全部使用 'g')，便于计算和避免转换错误。
type RawMaterial struct {
	gorm.Model
	Name        string  `gorm:"size:100;unique;not null;comment:原料名称"`
	Description string  `gorm:"size:255;comment:描述"`
	Quantity    float64 `gorm:"not null;comment:库存总量, 单位: g"`
}

func (RawMaterial) TableName() string {
	return "raw_materials"
}

// RawMaterialPurchase 记录了原料的每一次采购。
type RawMaterialPurchase struct {
	ID            uint        `gorm:"primaryKey"`
	RawMaterialID uint        `gorm:"not null;index;comment:关联的原料ID"`
	RawMaterial   RawMaterial `gorm:"foreignKey:RawMaterialID"`
	Supplier      string      `gorm:"size:100;comment:供应商"`
	Amount        float64     `gorm:"not null;comment:采购数量, 单位: g"`
	UnitPrice     float64     `gorm:"comment:单价"`
	TotalPrice    float64     `gorm:"comment:总价"`
	PurchaseDate  time.Time   `gorm:"primaryKey;comment:采购日期"`
	CreatedAt     time.Time
	UpdatedAt     time.Time
	DeletedAt     gorm.DeletedAt `gorm:"index"`
}

func (RawMaterialPurchase) TableName() string {
	return "raw_material_purchases"
}

// StockLogSourceType 定义了库存日志来源的类型
type StockLogSourceType string

const (
	StockLogSourcePurchase      StockLogSourceType = "采购入库"
	StockLogSourceFeeding       StockLogSourceType = "饲喂出库"
	StockLogSourceDeteriorate   StockLogSourceType = "变质出库"
	StockLogSourceSale          StockLogSourceType = "售卖出库"
	StockLogSourceMiscellaneous StockLogSourceType = "杂用领取"
	StockLogSourceManual        StockLogSourceType = "手动盘点"
)

// RawMaterialStockLog 记录了原料库存的所有变动，提供了完整的追溯链。
type RawMaterialStockLog struct {
	ID            uint               `gorm:"primaryKey"`
	RawMaterialID uint               `gorm:"not null;index;comment:关联的原料ID"`
	ChangeAmount  float64            `gorm:"not null;comment:变动数量, 正数为入库, 负数为出库"`
	SourceType    StockLogSourceType `gorm:"size:50;not null;index;comment:库存变动来源类型"`
	SourceID      uint               `gorm:"not null;index;comment:来源记录的ID (如 RawMaterialPurchase.ID 或 FeedUsageRecord.ID)"`
	HappenedAt    time.Time          `gorm:"primaryKey;comment:业务发生时间"`
	Remarks       string             `gorm:"comment:备注, 如主动领取的理由等"`
	CreatedAt     time.Time
	UpdatedAt     time.Time
	DeletedAt     gorm.DeletedAt `gorm:"index"`
}

func (RawMaterialStockLog) TableName() string {
	return "raw_material_stock_logs"
}

// FeedFormula 代表饲料配方。
// 对于没有配方的外购饲料，可以将其视为一种特殊的 RawMaterial, 并为其创建一个仅包含它自己的 FeedFormula。
type FeedFormula struct {
	gorm.Model
	Name        string                 `gorm:"size:100;unique;not null;comment:配方名称"`
	Description string                 `gorm:"size:255;comment:描述"`
	Components  []FeedFormulaComponent `gorm:"foreignKey:FeedFormulaID"`
}

func (FeedFormula) TableName() string {
	return "feed_formulas"
}

// FeedFormulaComponent 代表配方中的一种原料及其占比。
type FeedFormulaComponent struct {
	gorm.Model
	FeedFormulaID uint        `gorm:"not null;index;comment:外键到 FeedFormula"`
	RawMaterialID uint        `gorm:"not null;index;comment:外键到 RawMaterial"`
	RawMaterial   RawMaterial `gorm:"foreignKey:RawMaterialID"`
	Percentage    float64     `gorm:"not null;comment:该原料在配方中的百分比 (0-1.0)"`
}

func (FeedFormulaComponent) TableName() string {
	return "feed_formula_components"
}

// FeedUsageRecord 代表饲料使用记录。
// 应用层逻辑：当一条使用记录被创建时，应根据其使用的 FeedFormula,
// 计算出每种 RawMaterial 的消耗量，并在 RawMaterialStockLog 中创建对应的出库记录。
type FeedUsageRecord struct {
	ID            uint        `gorm:"primaryKey"`
	PenID         uint        `gorm:"not null;index;comment:关联的猪栏ID"`
	Pen           Pen         `gorm:"foreignKey:PenID"`
	FeedFormulaID uint        `gorm:"not null;index;comment:使用的饲料配方ID"`
	FeedFormula   FeedFormula `gorm:"foreignKey:FeedFormulaID"`
	Amount        float64     `gorm:"not null;comment:使用数量, 单位: g"`
	RecordedAt    time.Time   `gorm:"primaryKey;comment:记录时间"`
	OperatorID    uint        `gorm:"not null;comment:操作员"`
	Remarks       string      `gorm:"comment:备注, 如 '例行喂料, 弱猪补料' 等"`
	CreatedAt     time.Time
	UpdatedAt     time.Time
	DeletedAt     gorm.DeletedAt `gorm:"index"`
}

func (FeedUsageRecord) TableName() string {
	return "feed_usage_records"
}