package trafficusage

import (
	"math"
	"time"

	"git.5iot.com/iotlcm-public/iotlcm-admin-svr/internal/model"
)

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

func previousUsageMonth(now time.Time) time.Time {
	now = now.In(historyUsageLocation)
	return time.Date(now.Year(), now.Month(), 1, 0, 0, 0, 0, historyUsageLocation).AddDate(0, -1, 0)
}

func reconcileUsage[T any](keys []*model.SimKey, output []model.SimBaseRes[T], amount func(T) float64) ([]model.SimBaseRes[T], []*model.SimKey) {
	return reconcileUsageWithPeriod(keys, output, amount, func(T) string { return "" }, func(string) (string, bool) { return "", true }, "")
}

func reconcileUsageWithPeriod[T any](keys []*model.SimKey, output []model.SimBaseRes[T], amount func(T) float64, period func(T) string, normalize func(string) (string, bool), expected string) ([]model.SimBaseRes[T], []*model.SimKey) {
	results := make(map[string][]model.SimBaseRes[T])
	for _, item := range output {
		if item.SimKey != nil {
			results[item.SimKey.ICCID] = append(results[item.SimKey.ICCID], item)
		}
	}
	success := make([]model.SimBaseRes[T], 0, len(keys))
	failed := make([]*model.SimKey, 0)
	for _, key := range keys {
		items := results[key.ICCID]
		if len(items) != 1 || items[0].Code != 0 {
			failed = append(failed, key)
			continue
		}
		usage := amount(items[0].ResData)
		if math.IsNaN(usage) || math.IsInf(usage, 0) || usage < 0 {
			failed = append(failed, key)
			continue
		}
		if expected != "" {
			periodValue, ok := normalize(period(items[0].ResData))
			if !ok || periodValue != expected {
				failed = append(failed, key)
				continue
			}
		}
		items[0].SimKey = key
		success = append(success, items[0])
	}
	return success, failed
}

func normalizeUsageDay(value string) (string, bool) {
	for _, layout := range []string{"20060102", "2006-01-02"} {
		parsed, err := time.ParseInLocation(layout, value, historyUsageLocation)
		if err == nil {
			return parsed.Format("20060102"), true
		}
	}
	return "", false
}

func normalizeUsageMonth(value string) (string, bool) {
	for _, layout := range []string{"200601", "2006-01", "20060102", "2006-01-02"} {
		parsed, err := time.ParseInLocation(layout, value, historyUsageLocation)
		if err == nil {
			return parsed.Format("200601"), true
		}
	}
	return "", false
}