package logic

import (
	"context"
	"errors"

	"bj_power_mes/ent"
	"bj_power_mes/ent/alert"
	"bj_power_mes/ent/alertrule"
)

// CreateAlertRule 新增预警规则
func (s *Service) CreateAlertRule(ctx context.Context, name, typ string, threshold float64, receiver string, enabled bool, createdBy string) error {
	if name == "" || typ == "" {
		return errors.New("规则名称与类型必填")
	}
	_, err := s.ctx.EntClient.AlertRule.Create().
		SetName(name).SetType(typ).SetThreshold(threshold).
		SetReceiver(receiver).SetEnabled(enabled).SetCreatedBy(createdBy).Save(ctx)
	return err
}

// UpdateAlertRule 修改预警规则
func (s *Service) UpdateAlertRule(ctx context.Context, id int, name, typ string, threshold float64, receiver string, enabled bool) error {
	if id <= 0 {
		return errors.New("规则ID无效")
	}
	if name == "" || typ == "" {
		return errors.New("规则名称与类型必填")
	}
	_, err := s.ctx.EntClient.AlertRule.UpdateOneID(id).
		SetName(name).SetType(typ).SetThreshold(threshold).
		SetReceiver(receiver).SetEnabled(enabled).Save(ctx)
	return err
}

// DeleteAlertRule 删除预警规则
func (s *Service) DeleteAlertRule(ctx context.Context, id int) error {
	if id <= 0 {
		return errors.New("规则ID无效")
	}
	return s.ctx.EntClient.AlertRule.DeleteOneID(id).Exec(ctx)
}

// ListAlertRules 查询全部预警规则
func (s *Service) ListAlertRules(ctx context.Context) ([]*ent.AlertRule, error) {
	return s.ctx.EntClient.AlertRule.Query().
		Order(ent.Desc(alertrule.FieldCreatedAt), ent.Desc(alertrule.FieldID)).All(ctx)
}

// ListAlerts 查询预警消息（status 空=全部）
func (s *Service) ListAlerts(ctx context.Context, status string) ([]*ent.Alert, error) {
	q := s.ctx.EntClient.Alert.Query()
	if status != "" {
		q = q.Where(alert.Status(status))
	}
	return q.Order(ent.Desc(alert.FieldCreatedAt), ent.Desc(alert.FieldID)).All(ctx)
}

// UnreadAlertCount 未读预警数
func (s *Service) UnreadAlertCount(ctx context.Context) (int, error) {
	return s.ctx.EntClient.Alert.Query().Where(alert.Status("UNREAD")).Count(ctx)
}

// MarkAlertRead 标记预警已读
func (s *Service) MarkAlertRead(ctx context.Context, id int) error {
	if id <= 0 {
		return errors.New("预警ID无效")
	}
	_, err := s.ctx.EntClient.Alert.UpdateOneID(id).SetStatus("READ").Save(ctx)
	return err
}

// alertDirection 阈值比较方向：inventory_low 为 <=，其余为 >=
func alertDirection(typ string) int {
	if typ == "inventory_low" {
		return -1
	}
	return 1
}

// Evaluate 预警规则评估：遍历启用且类型匹配的规则，命中阈值则写 alert 消息。
// 由业务事件触发（如拧紧不合格），也可手动调用。
func (s *Service) Evaluate(ctx context.Context, typ string, value float64, title, content, refType, refId string) {
	rules, err := s.ctx.EntClient.AlertRule.Query().
		Where(alertrule.Type(typ), alertrule.Enabled(true)).All(ctx)
	if err != nil || len(rules) == 0 {
		return
	}
	dir := alertDirection(typ)
	for _, r := range rules {
		hit := (dir == 1 && value >= r.Threshold) || (dir == -1 && value <= r.Threshold)
		if !hit {
			continue
		}
		_ = s.createAlert(ctx, r.ID, typ, title, content, refType, refId, r.Receiver)
	}
}

func (s *Service) createAlert(ctx context.Context, ruleId int, typ, title, content, refType, refId, receiver string) error {
	_, err := s.ctx.EntClient.Alert.Create().
		SetRuleId(ruleId).SetType(typ).SetTitle(title).
		SetContent(content).SetRefType(refType).SetRefId(refId).
		SetReceiver(receiver).SetStatus("UNREAD").Save(ctx)
	return err
}