package models

import (
	"time"

	"gorm.io/gorm"
)

/*
	和猪只、猪群本身相关的模型
*/

// PigBatchStatus 定义了猪批次所处的不同阶段或状态
type PigBatchStatus string

const (
	BatchStatusWeaning   PigBatchStatus = "保育" // 从断奶到保育结束
	BatchStatusGrowing   PigBatchStatus = "生长" // 生长育肥阶段
	BatchStatusFinishing PigBatchStatus = "育肥" // 最后的育肥阶段
	BatchStatusForSale   PigBatchStatus = "待售" // 达到出栏标准
	BatchStatusSold      PigBatchStatus = "已出售"
	BatchStatusArchived  PigBatchStatus = "已归档" // 批次结束（如全群淘汰等）
)

// PigBatchOriginType 定义了猪批次的来源
type PigBatchOriginType string

const (
	OriginTypeSelfFarrowed PigBatchOriginType = "自繁"
	OriginTypePurchased    PigBatchOriginType = "外购"
)

// PigBatch 是猪批次的核心模型，代表了一群被共同管理的猪
type PigBatch struct {
	gorm.Model
	BatchNumber      string             `gorm:"size:50;not null;uniqueIndex;comment:批次编号,如 2024-W25-A01"`
	OriginType       PigBatchOriginType `gorm:"size:20;not null;comment:批次来源 (自繁, 外购)"`
	StartDate        time.Time          `gorm:"not null;comment:批次开始日期 (如转入日或购买日)"`
	InitialCount     int                `gorm:"not null;comment:初始数量"`
	CurrentCount     int                `gorm:"not null;comment:当前存栏数量"`
	CurrentSickCount int                `gorm:"not null;default:0;comment:当前病猪数量"`
	AverageWeight    float64            `gorm:"comment:平均体重 (kg)"`
	Status           PigBatchStatus     `gorm:"size:20;not null;index;comment:批次状态"`
	Pens             []Pen              `gorm:"foreignKey:PigBatchID;comment:所在圈舍ID"`
}

func (PigBatch) TableName() string {
	return "pig_batches"
}

// LogChangeType 定义了猪批次数量变更的类型
type LogChangeType string

const (
	ChangeTypeDeath       LogChangeType = "死亡"
	ChangeTypeCull        LogChangeType = "淘汰"
	ChangeTypeSale        LogChangeType = "销售"
	ChangeTypeTransferIn  LogChangeType = "转入"
	ChangeTypeTransferOut LogChangeType = "转出"
	ChangeTypeTreatment   LogChangeType = "治疗" // 仅改变健康状态，不改变总数
	ChangeTypeRecovering  LogChangeType = "康复" // 仅改变健康状态，不改变总数
	ChangeTypeCorrection  LogChangeType = "盘点校正"
)

// PigBatchLog 记录了猪批次数量或状态的每一次变更
type PigBatchLog struct {
	ID              uint          `gorm:"primaryKey"`
	PigBatchID      uint          `gorm:"not null;index;comment:关联的猪批次ID"`
	ChangeType      LogChangeType `gorm:"size:20;not null;comment:变更类型"`
	ChangeCount     int           `gorm:"not null;comment:数量变化,负数表示减少"`
	Reason          string        `gorm:"size:255;comment:变更原因描述"`
	BeforeCount     int           `gorm:"not null;comment:变更前总数"`
	AfterCount      int           `gorm:"not null;comment:变更后总数"`
	BeforeSickCount int           `gorm:"not null;comment:变更前病猪数"`
	AfterSickCount  int           `gorm:"not null;comment:变更后病猪数"`
	Operator        string        `gorm:"size:50;comment:操作员"`
	HappenedAt      time.Time     `gorm:"primaryKey;comment:事件发生时间"`
	CreatedAt       time.Time
	UpdatedAt       time.Time
	DeletedAt       gorm.DeletedAt `gorm:"index"`
}

func (PigBatchLog) TableName() string {
	return "pig_batch_logs"
}