/*
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 Affero 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 Affero General Public License for more details.

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

package services

import (
	"sync"

	"github.com/cgrates/cgrates/agents"
	"github.com/cgrates/cgrates/config"
	"github.com/cgrates/cgrates/servmanager"
	"github.com/cgrates/cgrates/utils"
)

// NewHTTPAgent returns the HTTP Agent
func NewHTTPAgent(cfg *config.CGRConfig) *HTTPAgent {
	return &HTTPAgent{
		cfg:       cfg,
		stateDeps: NewStateDependencies([]string{utils.StateServiceUP, utils.StateServiceDOWN}),
	}
}

// HTTPAgent implements Agent interface
type HTTPAgent struct {
	mu  sync.RWMutex
	cfg *config.CGRConfig

	// we can realy stop the HTTPAgent so keep a flag
	// if we registerd the handlers
	started bool

	stateDeps *StateDependencies // channel subscriptions for state changes
}

// Start should handle the sercive start
func (ha *HTTPAgent) Start(_ *utils.SyncedChan, registry *servmanager.ServiceRegistry) (err error) {
	srvDeps, err := WaitForServicesToReachState(utils.StateServiceUP,
		[]string{
			utils.CommonListenerS,
			utils.ConnManager,
			utils.FilterS,
		},
		registry, ha.cfg.GeneralCfg().ConnectTimeout)
	if err != nil {
		return err
	}
	cl := srvDeps[utils.CommonListenerS].(*CommonListenerService).CLS()
	cm := srvDeps[utils.ConnManager].(*ConnManagerService).ConnManager()
	fs := srvDeps[utils.FilterS].(*FilterService).FilterS()

	ha.mu.Lock()
	defer ha.mu.Unlock()

	ha.started = true
	for _, agntCfg := range ha.cfg.HTTPAgentCfg() {
		cl.RegisterHttpHandler(agntCfg.URL,
			agents.NewHTTPAgent(cm, agntCfg.SessionSConns, agntCfg.StatSConns, agntCfg.ThresholdSConns,
				fs, ha.cfg.GeneralCfg().DefaultTenant, agntCfg.RequestPayload, agntCfg.ReplyPayload,
				agntCfg.RequestProcessors))
	}
	return
}

// Reload handles the change of config
func (ha *HTTPAgent) Reload(_ *utils.SyncedChan, _ *servmanager.ServiceRegistry) (err error) {
	return // no reload
}

// Shutdown stops the service
func (ha *HTTPAgent) Shutdown(_ *servmanager.ServiceRegistry) (err error) {
	ha.mu.Lock()
	ha.started = false
	ha.mu.Unlock()
	return // no shutdown for the momment
}

// ServiceName returns the service name
func (ha *HTTPAgent) ServiceName() string {
	return utils.HTTPAgent
}

// ShouldRun returns if the service should be running
func (ha *HTTPAgent) ShouldRun() bool {
	return len(ha.cfg.HTTPAgentCfg()) != 0
}

// StateChan returns signaling channel of specific state
func (ha *HTTPAgent) StateChan(stateID string) chan struct{} {
	return ha.stateDeps.StateChan(stateID)
}