/*
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 services

import (
	"fmt"
	"sync"

	v1 "github.com/cgrates/cgrates/apier/v1"
	"github.com/cgrates/cgrates/config"
	"github.com/cgrates/cgrates/engine"
	"github.com/cgrates/cgrates/loaders"
	"github.com/cgrates/cgrates/servmanager"
	"github.com/cgrates/cgrates/utils"
	"github.com/cgrates/rpcclient"
)

// NewLoaderService returns the Loader Service
func NewLoaderService(cfg *config.CGRConfig, dm *DataDBService,
	filterSChan chan *engine.FilterS, server *utils.Server,
	cacheSChan, dispatcherChan chan rpcclient.RpcClientConnection,
	exitChan chan bool) servmanager.Service {
	return &LoaderService{
		connChan:       make(chan rpcclient.RpcClientConnection, 1),
		cfg:            cfg,
		dm:             dm,
		cacheSChan:     cacheSChan,
		dispatcherChan: dispatcherChan,
		filterSChan:    filterSChan,
		server:         server,
		exitChan:       exitChan,
	}
}

// LoaderService implements Service interface
type LoaderService struct {
	sync.RWMutex
	cfg            *config.CGRConfig
	dm             *DataDBService
	filterSChan    chan *engine.FilterS
	server         *utils.Server
	cacheSChan     chan rpcclient.RpcClientConnection
	dispatcherChan chan rpcclient.RpcClientConnection
	exitChan       chan bool

	ldrs     *loaders.LoaderService
	rpc      *v1.LoaderSv1
	connChan chan rpcclient.RpcClientConnection
}

// Start should handle the sercive start
func (ldrs *LoaderService) Start() (err error) {
	if ldrs.IsRunning() {
		return fmt.Errorf("service aleady running")
	}

	filterS := <-ldrs.filterSChan
	ldrs.filterSChan <- filterS
	internalChan := ldrs.cacheSChan
	if ldrs.cfg.DispatcherSCfg().Enabled {
		internalChan = ldrs.dispatcherChan
	}

	ldrs.Lock()
	defer ldrs.Unlock()

	ldrs.ldrs = loaders.NewLoaderService(ldrs.dm.GetDM(), ldrs.cfg.LoaderCfg(),
		ldrs.cfg.GeneralCfg().DefaultTimezone, ldrs.exitChan, filterS, internalChan)
	if !ldrs.ldrs.Enabled() {
		return
	}
	ldrs.rpc = v1.NewLoaderSv1(ldrs.ldrs)
	ldrs.server.RpcRegister(ldrs.rpc)
	ldrs.connChan <- ldrs.rpc
	return
}

// GetIntenternalChan returns the internal connection chanel
func (ldrs *LoaderService) GetIntenternalChan() (conn chan rpcclient.RpcClientConnection) {
	return ldrs.connChan
}

// Reload handles the change of config
func (ldrs *LoaderService) Reload() (err error) {
	filterS := <-ldrs.filterSChan
	ldrs.filterSChan <- filterS
	ldrs.RLock()
	internalChan := ldrs.cacheSChan
	if ldrs.cfg.DispatcherSCfg().Enabled {
		internalChan = ldrs.dispatcherChan
	}
	ldrs.ldrs.Reload(ldrs.dm.GetDM(), ldrs.cfg.LoaderCfg(), ldrs.cfg.GeneralCfg().DefaultTimezone,
		ldrs.exitChan, filterS, internalChan)
	ldrs.RUnlock()
	return
}

// Shutdown stops the service
func (ldrs *LoaderService) Shutdown() (err error) {
	ldrs.Lock()
	ldrs.ldrs = nil
	ldrs.rpc = nil
	<-ldrs.connChan
	ldrs.Unlock()
	return
}

// IsRunning returns if the service is running
func (ldrs *LoaderService) IsRunning() bool {
	ldrs.RLock()
	defer ldrs.RUnlock()
	return ldrs != nil && ldrs.ldrs != nil && ldrs.ldrs.Enabled()
}

// ServiceName returns the service name
func (ldrs *LoaderService) ServiceName() string {
	return utils.LoaderS
}

// ShouldRun returns if the service should be running
func (ldrs *LoaderService) ShouldRun() bool {
	return ldrs.cfg.LoaderCfg().Enabled()
}