package service

import (
	"electricity_bill_calc/cache"
	"electricity_bill_calc/global"
	"electricity_bill_calc/model"

	"xorm.io/builder"
)

type _RegionService struct{}

var RegionService _RegionService

func (_RegionService) FetchSubRegions(parent string) ([]model.Region, error) {
	if regions, _ := cache.RetreiveSearch[[]model.Region]("region", "parent", parent); regions != nil {
		return *regions, nil
	}
	regions := make([]model.Region, 0)
	err := global.DBConn.Where(builder.Eq{"parent": parent}).Asc("code").Find(&regions)
	if err != nil {
		return make([]model.Region, 0), err
	}
	cache.CacheSearch(regions, "region", "region", "parent", parent)
	return regions, err
}

func (r _RegionService) FetchAllParentRegions(code string) ([]model.Region, error) {
	regions := make([]model.Region, 0)
	region, err := r.fetchRegion(code)
	if err != nil {
		return regions, err
	}
	regions = append(regions, *region)
	for region.Level > 1 {
		region, err = r.fetchRegion(region.Parent)
		if err != nil {
			return make([]model.Region, 0), nil
		}
		regions = append(regions, *region)
	}
	return regions, nil
}

func (_RegionService) fetchRegion(code string) (*model.Region, error) {
	if cachedRegion, _ := cache.RetreiveSearch[model.Region]("region", code); cachedRegion != nil {
		return cachedRegion, nil
	}
	region := new(model.Region)
	has, err := global.DBConn.ID(code).NoAutoCondition().Get(region)
	if has {
		cache.CacheSearch(region, "region", "region", code)
	}
	return _postProcessSingle(region, has, err)
}