// Copyright 2021 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
//go:build plus

package models

import (
	"github.com/TeaOSLab/EdgeCommon/pkg/dnsconfigs"
	"github.com/iwind/TeaGo/types"
)

func RouteIdString(routeId int64) string {
	return "id:" + types.String(routeId)
}

type RouteRecords struct {
	routeRecordsMap map[string]*RecordIds // routeCode => { recordId1, recordId2, ... }
	recordsMap      map[int64]*NSRecord   // recordId => *NSRecord
}

func NewRouteRecords() *RouteRecords {
	return &RouteRecords{
		routeRecordsMap: map[string]*RecordIds{},
		recordsMap:      map[int64]*NSRecord{},
	}
}

func (this *RouteRecords) Add(record *NSRecord) {
	// 先删除
	this.remove(record.Id)

	// 添加记录
	this.recordsMap[record.Id] = record

	// 添加线路
	var routeIds = record.RouteIds
	if len(routeIds) == 0 || (len(routeIds) == 1 && routeIds[0] == "") {
		routeIds = []string{"default"}
	}

	for _, routeId := range routeIds {
		recordIds, ok := this.routeRecordsMap[routeId]
		if !ok {
			recordIds = NewRecordIds()
			this.routeRecordsMap[routeId] = recordIds
		}
		recordIds.Add(record.Id, record.Weight)
	}
}

// Find 查找与线路匹配的记录
// strictMode 表示是否严格匹配线路
func (this *RouteRecords) Find(routeCodes []string, config *dnsconfigs.NSAnswerConfig, strictMode bool) (records []*NSRecord, routeCode string) {
	if config == nil {
		config = dnsconfigs.DefaultNSAnswerConfig()
	}

	var maxSize = int(config.MaxSize)
	if maxSize <= 0 {
		maxSize = dnsconfigs.NSAnswerDefaultSize
	}

	// 查找匹配的线路
	for _, routeId := range routeCodes {
		recordIds, ok := this.routeRecordsMap[routeId]
		if ok && !recordIds.IsEmpty() {
			return this.recordsWithIds(recordIds, config.Mode, maxSize), routeId
		}
	}

	// 查找默认线路
	recordIds, ok := this.routeRecordsMap["default"]
	if ok && !recordIds.IsEmpty() {
		return this.recordsWithIds(recordIds, config.Mode, maxSize), "default"
	}

	// 随机一个
	if !strictMode {
		for _, record := range this.recordsMap {
			return []*NSRecord{record}, "default"
		}
	}

	return nil, ""
}

func (this *RouteRecords) Remove(recordId int64) {
	this.remove(recordId)
}

func (this *RouteRecords) IsEmpty() bool {
	return len(this.recordsMap) == 0
}

func (this *RouteRecords) remove(recordId int64) {
	oldRecord, ok := this.recordsMap[recordId]
	if !ok {
		return
	}

	delete(this.recordsMap, recordId)

	var oldRouteIds = oldRecord.RouteIds
	if len(oldRouteIds) == 0 || (len(oldRouteIds) == 1 && oldRouteIds[0] == "") {
		oldRouteIds = []string{"default"}
	}

	for _, routeId := range oldRouteIds {
		recordIds, ok := this.routeRecordsMap[routeId]
		if ok {
			recordIds.Remove(recordId)
			if recordIds.IsEmpty() {
				delete(this.routeRecordsMap, routeId)
			}
		}
	}
}

func (this *RouteRecords) recordsWithIds(recordIds *RecordIds, mode dnsconfigs.NSAnswerMode, maxSize int) (records []*NSRecord) {
	// round-robin
	if mode == dnsconfigs.NSAnswerModeRoundRobin {
		var recordId = recordIds.NextId()
		if recordId > 0 {
			return []*NSRecord{this.recordsMap[recordId]}
		}
	}

	// random
	var randomIds = recordIds.RandomIds(maxSize)
	for _, randomId := range randomIds {
		records = append(records, this.recordsMap[randomId])
	}

	return
}