package model

import (
	"errors"
	"fmt"
	"strconv"
	"strings"
	"time"
)

const QRVersion = 1

// IdentityLink 不透明二维码映射，避免把内部 ID 或个人信息放进二维码。
type IdentityLink struct {
	ID         string    `gorm:"type:uuid;primaryKey;default:gen_random_uuid()" json:"id"`
	PublicID   string    `gorm:"column:public_id;size:64;uniqueIndex" json:"publicId"`
	EntityType string    `gorm:"column:entity_type;size:16;index" json:"entityType"`
	EntityID   string    `gorm:"column:entity_id;size:128;uniqueIndex" json:"entityId"`
	Version    int       `gorm:"default:1" json:"version"`
	CreatedAt  time.Time `gorm:"type:timestamptz" json:"createdAt"`
	UpdatedAt  time.Time `gorm:"type:timestamptz" json:"updatedAt"`
}

func (IdentityLink) TableName() string { return "identity_links" }

// SeedSource 蚕种来源与检疫链。
type SeedSource struct {
	ID             string     `gorm:"type:uuid;primaryKey;default:gen_random_uuid()" json:"id"`
	PublicID       string     `gorm:"column:public_id;size:64;uniqueIndex" json:"publicId"`
	BatchID        *string    `gorm:"column:batch_id;type:uuid;index" json:"batchId,omitempty"`
	ParentID       *string    `gorm:"column:parent_id;type:uuid;index" json:"parentId,omitempty"`
	Supplier       string     `gorm:"size:128" json:"supplier"`
	SeedBatchNo    string     `gorm:"column:seed_batch_no;size:64" json:"seedBatchNo"`
	QuarantineNo   *string    `gorm:"column:quarantine_no;size:64" json:"quarantineNo,omitempty"`
	Variety        *string    `gorm:"size:64" json:"variety,omitempty"`
	CertificateURL *string    `gorm:"column:certificate_url;size:512" json:"certificateUrl,omitempty"`
	EntryAt        *time.Time `gorm:"column:entry_at;type:timestamptz" json:"entryAt,omitempty"`
	Note           *string    `gorm:"type:text" json:"note,omitempty"`
	CreatedBy      *string    `gorm:"column:created_by;type:uuid" json:"createdBy,omitempty"`
	CreatedAt      time.Time  `gorm:"type:timestamptz" json:"createdAt"`
	UpdatedAt      time.Time  `gorm:"type:timestamptz" json:"updatedAt"`
}

func (SeedSource) TableName() string { return "seed_sources" }

// DisinfectionRecord 消毒计划与执行记录。
type DisinfectionRecord struct {
	ID            string     `gorm:"type:uuid;primaryKey;default:gen_random_uuid()" json:"id"`
	RoomID        *string    `gorm:"column:room_id;type:uuid;index" json:"roomId,omitempty"`
	BatchID       *string    `gorm:"column:batch_id;type:uuid;index" json:"batchId,omitempty"`
	Kind          string     `gorm:"size:16;default:plan" json:"kind"` // plan/execution
	PlanID        *string    `gorm:"column:plan_id;type:uuid;index" json:"planId,omitempty"`
	Agent         string     `gorm:"size:128" json:"agent"`
	Concentration string     `gorm:"size:64" json:"concentration"`
	Amount        *string    `gorm:"size:64" json:"amount,omitempty"`
	PlannedAt     *time.Time `gorm:"column:planned_at;type:timestamptz" json:"plannedAt,omitempty"`
	ExecutedAt    *time.Time `gorm:"column:executed_at;type:timestamptz" json:"executedAt,omitempty"`
	ExecutorID    *string    `gorm:"column:executor_id;type:uuid" json:"executorId,omitempty"`
	ReviewedAt    *time.Time `gorm:"column:reviewed_at;type:timestamptz" json:"reviewedAt,omitempty"`
	ReviewerID    *string    `gorm:"column:reviewer_id;type:uuid" json:"reviewerId,omitempty"`
	PhotoURL      *string    `gorm:"column:photo_url;size:512" json:"photoUrl,omitempty"`
	Note          *string    `gorm:"type:text" json:"note,omitempty"`
	CreatedBy     *string    `gorm:"column:created_by;type:uuid" json:"createdBy,omitempty"`
	CreatedAt     time.Time  `gorm:"type:timestamptz" json:"createdAt"`
	UpdatedAt     time.Time  `gorm:"type:timestamptz" json:"updatedAt"`
}

func (DisinfectionRecord) TableName() string { return "disinfection_records" }

// EncodeQRPayload 生成不透明二维码载荷。
func EncodeQRPayload(entityType, publicID string, version int) string {
	return fmt.Sprintf("silk:v1:%s:%s:%d", entityType, publicID, version)
}

// ParseQRPayload 解析并校验二维码载荷。
func ParseQRPayload(payload string) (string, string, int, error) {
	parts := strings.Split(strings.TrimSpace(payload), ":")
	if len(parts) != 5 || parts[0] != "silk" || parts[1] != "v1" {
		return "", "", 0, errors.New("二维码格式不正确")
	}
	entityType := parts[2]
	publicID := parts[3]
	version, err := strconv.Atoi(parts[4])
	if err != nil || version <= 0 {
		return "", "", 0, errors.New("二维码版本不正确")
	}
	if !ValidQRIdentityType(entityType) || publicID == "" {
		return "", "", 0, errors.New("二维码身份无效")
	}
	return entityType, publicID, version, nil
}

// ValidQRIdentityType 当前二维码支持的实体类型。
func ValidQRIdentityType(entityType string) bool {
	switch entityType {
	case "batch", "tray", "sample":
		return true
	default:
		return false
	}
}

// ValidateSeedSource 种源必填项。
func ValidateSeedSource(source SeedSource) error {
	if strings.TrimSpace(source.Supplier) == "" {
		return errors.New("供应商不能为空")
	}
	if strings.TrimSpace(source.SeedBatchNo) == "" {
		return errors.New("蚕种批号不能为空")
	}
	return nil
}

// ValidateDisinfectionRecord 消毒必填项。
func ValidateDisinfectionRecord(record DisinfectionRecord) error {
	if record.Kind != "plan" && record.Kind != "execution" {
		return errors.New("kind 仅支持 plan/execution")
	}
	if strings.TrimSpace(record.Agent) == "" {
		return errors.New("消毒药剂不能为空")
	}
	if strings.TrimSpace(record.Concentration) == "" {
		return errors.New("消毒浓度不能为空")
	}
	return nil
}

// SeedSourceCycleError 检测种源链是否形成循环。
func SeedSourceCycleError(chain map[string]string, id, parentID string) error {
	seen := map[string]bool{id: true}
	current := parentID
	for current != "" {
		if seen[current] {
			return errors.New("种源链不能形成循环")
		}
		seen[current] = true
		next := chain[current]
		if next == current {
			return errors.New("种源链不能自引用")
		}
		current = next
	}
	return nil
}