package model

import (
	"encoding/json"
	"errors"
	"time"
)

// DiseaseEvent 独立发病事件，作为处置、会诊、溯源和效果评估主线。
type DiseaseEvent struct {
	ID              string          `gorm:"type:uuid;primaryKey;default:gen_random_uuid()" json:"id"`
	SourceKey       string          `gorm:"column:source_key;size:128;uniqueIndex" json:"sourceKey,omitempty"`
	RoomID          *string         `gorm:"column:room_id;type:uuid;index" json:"roomId,omitempty"`
	BatchID         *string         `gorm:"column:batch_id;type:uuid;index" json:"batchId,omitempty"`
	DetectionTaskID *string         `gorm:"column:detection_task_id;type:uuid;index" json:"detectionTaskId,omitempty"`
	LampTestID      *string         `gorm:"column:lamp_test_id;type:uuid;index" json:"lampTestId,omitempty"`
	ConsultationID  *string         `gorm:"column:consultation_id;type:uuid;index" json:"consultationId,omitempty"`
	InspectionID    *string         `gorm:"column:inspection_id;type:uuid;index" json:"inspectionId,omitempty"`
	Disease         string          `gorm:"size:64" json:"disease"`
	Status          string          `gorm:"size:16;default:suspected;index" json:"status"`
	Evidence        json.RawMessage `gorm:"type:jsonb" json:"evidence,omitempty"`
	ConfirmedAt     *time.Time      `gorm:"column:confirmed_at;type:timestamptz" json:"confirmedAt,omitempty"`
	ConfirmedBy     *string         `gorm:"column:confirmed_by;type:uuid" json:"confirmedBy,omitempty"`
	LossSummary     *string         `gorm:"column:loss_summary;type:text" json:"lossSummary,omitempty"`
	Measure         *string         `gorm:"type:text" json:"measure,omitempty"`
	Note            *string         `gorm:"type:text" json:"note,omitempty"`
	CreatedAt       time.Time       `gorm:"type:timestamptz" json:"createdAt"`
	UpdatedAt       time.Time       `gorm:"type:timestamptz" json:"updatedAt"`
	RoomName        *string         `gorm:"-" json:"roomName,omitempty"`
}

func (DiseaseEvent) TableName() string { return "disease_events" }

// ValidDiseaseEventTransition 状态机：suspected/confirmed/controlled/closed/reopened。
func ValidDiseaseEventTransition(from, to string) bool {
	switch from {
	case "suspected":
		return to == "confirmed" || to == "closed"
	case "confirmed":
		return to == "controlled" || to == "closed"
	case "controlled":
		return to == "closed" || to == "reopened"
	case "closed":
		return to == "reopened"
	case "reopened":
		return to == "confirmed" || to == "controlled" || to == "closed"
	default:
		return false
	}
}

// ValidateDiseaseEventEvidence 确诊必须有证据，不能仅凭状态字段确认。
func ValidateDiseaseEventEvidence(event DiseaseEvent) error {
	if event.Status == "confirmed" && len(event.Evidence) == 0 {
		return errors.New("确诊发病事件必须提供证据")
	}
	return nil
}