package upstreamapi

import (
	"strings"
	"time"
)

const (
	historicalMonthLayout      = "200601"
	historicalDailyLayout      = "20060102"
	historicalMonthFormatError = "queryDate格式错误，应为yyyyMM"
	historicalMonthRangeError  = "月流量仅支持查询已结束月份；本月累计流量请调用 /sim/query/sim-datausage"
	historicalDailyFormatError = "queryDate格式错误，应为yyyyMMdd"
	historicalDailyRangeError  = "日流量仅支持查询已结束日期，不支持当天或未来日期"
)

var historicalPeriodLocation = time.FixedZone("UTC+8", 8*60*60)

const currentBatchMonthRangeError = "电信月批量接口仅支持当月；历史月份请调用 /sim/query/sim-datausage-monthly"

func validateCurrentBatchMonth(queryDate string, now time.Time) string {
	queryDate = strings.TrimSpace(queryDate)
	if _, err := time.ParseInLocation(historicalMonthLayout, queryDate, historicalPeriodLocation); err != nil {
		return historicalMonthFormatError
	}
	if queryDate != now.In(historicalPeriodLocation).Format(historicalMonthLayout) {
		return currentBatchMonthRangeError
	}
	return ""
}

func validateHistoricalMonth(queryDate string, now time.Time) string {
	queryDate = strings.TrimSpace(queryDate)
	if len(queryDate) != len(historicalMonthLayout) {
		return historicalMonthFormatError
	}
	if _, err := time.ParseInLocation(historicalMonthLayout, queryDate, historicalPeriodLocation); err != nil {
		return historicalMonthFormatError
	}
	if queryDate >= now.In(historicalPeriodLocation).Format(historicalMonthLayout) {
		return historicalMonthRangeError
	}
	return ""
}

func validateHistoricalDay(queryDate string, now time.Time) string {
	queryDate = strings.TrimSpace(queryDate)
	if len(queryDate) != len(historicalDailyLayout) {
		return historicalDailyFormatError
	}
	if _, err := time.ParseInLocation(historicalDailyLayout, queryDate, historicalPeriodLocation); err != nil {
		return historicalDailyFormatError
	}
	if queryDate >= now.In(historicalPeriodLocation).Format(historicalDailyLayout) {
		return historicalDailyRangeError
	}
	return ""
}