/*
Real-time Online/Offline Charging System (OCS) for Telecom & ISP environments
Copyright (C) ITsysCOM GmbH

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>
*/

package engine

import (
	"fmt"
	"sort"
	"time"

	"github.com/cgrates/cgrates/config"
	"github.com/cgrates/cgrates/guardian"
	"github.com/cgrates/cgrates/utils"
)

type AliasEntry struct {
	FieldName string
	Initial   string
	Alias     string
}

type AliasProfile struct {
	Tenant             string
	ID                 string
	FilterIDs          []string
	ActivationInterval *utils.ActivationInterval    // Activation interval
	Aliases            map[string]map[string]string // map[FieldName][InitialValue]AliasValue
	Weight             float64
}

func (als *AliasProfile) TenantID() string {
	return utils.ConcatenatedKey(als.Tenant, als.ID)
}

// AliasProfiles is a sortable list of Alias profiles
type AliasProfiles []*AliasProfile

// Sort is part of sort interface, sort based on Weight
func (aps AliasProfiles) Sort() {
	sort.Slice(aps, func(i, j int) bool { return aps[i].Weight > aps[j].Weight })
}

func NewAliasService(dm *DataManager, filterS *FilterS, indexedFields []string) (*AliasService, error) {
	return &AliasService{dm: dm, filterS: filterS, indexedFields: indexedFields}, nil
}

type AliasService struct {
	dm            *DataManager
	filterS       *FilterS
	indexedFields []string
}

// ListenAndServe will initialize the service
func (alS *AliasService) ListenAndServe(exitChan chan bool) (err error) {
	utils.Logger.Info("Starting Alias service")
	e := <-exitChan
	exitChan <- e // put back for the others listening for shutdown request
	return
}

// Shutdown is called to shutdown the service
func (alS *AliasService) Shutdown() (err error) {
	utils.Logger.Info(fmt.Sprintf("<%s> shutdown initialized", utils.AliasS))
	utils.Logger.Info(fmt.Sprintf("<%s> shutdown complete", utils.AliasS))
	return
}

// matchingSupplierProfilesForEvent returns ordered list of matching resources which are active by the time of the call
func (alS *AliasService) matchingAliasProfilesForEvent(ev *utils.CGREvent) (aPrfls AliasProfiles, err error) {
	matchingAPs := make(map[string]*AliasProfile)
	aPrflIDs, err := matchingItemIDsForEvent(ev.Event, alS.indexedFields,
		alS.dm, utils.AliasProfilesStringIndex+ev.Tenant)
	if err != nil {
		return nil, err
	}
	lockIDs := utils.PrefixSliceItems(aPrflIDs.Slice(), utils.AliasProfilesStringIndex)
	guardian.Guardian.GuardIDs(config.CgrConfig().LockingTimeout, lockIDs...)
	defer guardian.Guardian.UnguardIDs(lockIDs...)
	for apID := range aPrflIDs {
		aPrfl, err := alS.dm.GetAliasProfile(ev.Tenant, apID, false, utils.NonTransactional)
		if err != nil {
			if err == utils.ErrNotFound {
				continue
			}
			return nil, err
		}
		evTime := time.Now()
		if ev.Time != nil {
			evTime = *ev.Time
		}
		if aPrfl.ActivationInterval != nil &&
			!aPrfl.ActivationInterval.IsActiveAtTime(evTime) { // not active
			continue
		}
		if pass, err := alS.filterS.PassFiltersForEvent(ev.Tenant,
			ev.Event, aPrfl.FilterIDs); err != nil {
			return nil, err
		} else if !pass {
			continue
		}
		matchingAPs[apID] = aPrfl
	}
	// All good, convert from Map to Slice so we can sort
	aPrfls = make(AliasProfiles, len(matchingAPs))
	i := 0
	for _, aPrfl := range matchingAPs {
		aPrfls[i] = aPrfl
		i++
	}
	aPrfls.Sort()
	return
}

func (alS *AliasService) V1ProcessEvent(ev *utils.CGREvent,
	reply *string) (err error) {
	return
}

type ExternalAliasProfile struct {
	Tenant             string
	ID                 string
	FilterIDs          []string
	ActivationInterval *utils.ActivationInterval // Activation interval
	Aliases            []*AliasEntry
	Weight             float64
}

func (eap *ExternalAliasProfile) AsAliasProfile() *AliasProfile {
	alsPrf := &AliasProfile{
		Tenant:             eap.Tenant,
		ID:                 eap.ID,
		Weight:             eap.Weight,
		FilterIDs:          eap.FilterIDs,
		ActivationInterval: eap.ActivationInterval,
	}
	alsMap := make(map[string]map[string]string)
	for _, als := range eap.Aliases {
		alsMap[als.FieldName] = make(map[string]string)
		alsMap[als.FieldName][als.Initial] = als.Alias
	}
	alsPrf.Aliases = alsMap
	return alsPrf
}

func NewExternalAliasProfileFromAliasProfile(alsPrf *AliasProfile) *ExternalAliasProfile {
	extals := &ExternalAliasProfile{
		Tenant:             alsPrf.Tenant,
		ID:                 alsPrf.ID,
		Weight:             alsPrf.Weight,
		ActivationInterval: alsPrf.ActivationInterval,
		FilterIDs:          alsPrf.FilterIDs,
	}
	for key, val := range alsPrf.Aliases {
		for key2, val2 := range val {
			extals.Aliases = append(extals.Aliases, &AliasEntry{
				FieldName: key,
				Initial:   key2,
				Alias:     val2,
			})
		}
	}
	return extals

}