package business

import (
	"context"
	"encoding/json"
	"kra/internal/biz/business"
	"kra/internal/service/dto"
	"math"
	"strconv"
	"strings"
	"unicode/utf8"
)

type AlertRuleUsecase interface {
	List(context.Context, business.AlertRuleFilter, ...business.ListOption) ([]*business.AlertRule, int64, error)
	Find(context.Context, uint64) (*business.AlertRule, error)
	Types(context.Context) ([]string, error)
	Save(context.Context, *business.AlertRule) (uint64, error)
	Delete(context.Context, uint64) error
	Toggle(context.Context, uint64, int) error
}
type AlertRuleService struct{ uc AlertRuleUsecase }

func NewAlertRuleService(uc *business.AlertRuleUsecase) *AlertRuleService {
	return &AlertRuleService{uc: uc}
}
func alertRuleResponse(r *business.AlertRule) *dto.AlertRuleResponse {
	var threshold *json.Number
	if r.MomThreshold != nil {
		n := json.Number(*r.MomThreshold)
		threshold = &n
	}
	return &dto.AlertRuleResponse{ID: r.ID, RuleName: r.Name, RuleType: r.Type, RuleTypeLabel: business.AlertRuleTypeLabel(r.Type), MonitorMetric: r.Metric, MonitorMetricLabel: business.AlertMetricLabel(r.Metric), StatPeriodDays: r.StatPeriodDays, MomDirection: r.MomDirection, MomDirectionLabel: business.AlertDirectionLabel(r.MomDirection), MomThreshold: threshold, UnloginDays: r.UnloginDays, MonitorScope: r.MonitorScope, WarningColor: r.WarningColor, CreatorID: r.CreatorID, CreatorName: r.CreatorName, Enabled: r.Enabled, CreatedAt: localTime(&r.CreatedAt), UpdatedAt: localTime(&r.UpdatedAt), RuleDescription: r.Description()}
}
func (s *AlertRuleService) List(ctx context.Context, req *dto.AlertRuleQuery) (*dto.AlertRulePage, error) {
	if req == nil {
		return nil, business.ErrAlertRuleInput
	}
	filter := business.AlertRuleFilter{Name: req.RuleName, Type: req.RuleType}
	if req.MonitorMetric != "" {
		n, err := strconv.Atoi(req.MonitorMetric)
		if err != nil || n < 1 || n > 3 {
			return nil, business.ErrAlertRuleInput
		}
		filter.Metric = &n
	}
	page, size := req.Page, req.PageSize
	if page < 1 {
		page = 1
	}
	if size < 1 {
		size = 10
	}
	if size > 500 {
		size = 500
	}
	if page > int(^uint(0)>>1)/size {
		return nil, business.ErrAlertRuleInput
	}
	rows, total, err := s.uc.List(ctx, filter, business.ListOffset((page-1)*size), business.ListLimit(size))
	if err != nil {
		return nil, err
	}
	out := &dto.AlertRulePage{Rows: make([]*dto.AlertRuleResponse, 0, len(rows)), Total: total}
	for _, r := range rows {
		out.Rows = append(out.Rows, alertRuleResponse(r))
	}
	return out, nil
}
func (s *AlertRuleService) Find(ctx context.Context, id uint64) (*dto.AlertRuleResponse, error) {
	if id == 0 {
		return nil, business.ErrAlertRuleInput
	}
	rule, err := s.uc.Find(ctx, id)
	if err != nil {
		return nil, err
	}
	return alertRuleResponse(rule), nil
}
func (s *AlertRuleService) Types(ctx context.Context) ([]string, error) { return s.uc.Types(ctx) }
func (s *AlertRuleService) Save(ctx context.Context, req *dto.AlertRuleRequest) (uint64, error) {
	if req == nil || strings.TrimSpace(req.RuleName) == "" || utf8.RuneCountInString(req.RuleName) > 100 || strings.TrimSpace(req.RuleType) == "" || strings.TrimSpace(req.WarningColor) == "" || len(req.WarningColor) > 20 {
		return 0, business.ErrAlertRuleInput
	}
	for _, n := range []*int{req.StatPeriodDays, req.UnloginDays} {
		if n != nil && (*n > math.MaxInt32 || *n < math.MinInt32) {
			return 0, business.ErrAlertRuleInput
		}
	}
	rule := &business.AlertRule{ID: req.ID, Name: req.RuleName, Type: req.RuleType, Metric: req.MonitorMetric, StatPeriodDays: req.StatPeriodDays, MomDirection: req.MomDirection, UnloginDays: req.UnloginDays, WarningColor: req.WarningColor}
	if req.MomThreshold != nil {
		value := req.MomThreshold.String()
		rule.MomThreshold = &value
	}
	return s.uc.Save(ctx, rule)
}
func (s *AlertRuleService) Delete(ctx context.Context, id uint64) error {
	if id == 0 {
		return business.ErrAlertRuleInput
	}
	return s.uc.Delete(ctx, id)
}
func (s *AlertRuleService) Toggle(ctx context.Context, id uint64, enabled int) error {
	if id == 0 {
		return business.ErrAlertRuleInput
	}
	return s.uc.Toggle(ctx, id, enabled)
}