/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package config

import (
	"context"
	"net/url"
	"reflect"
	"time"
)

import (
	"github.com/creasty/defaults"
)

import (
	"github.com/apache/dubbo-go/common"
	"github.com/apache/dubbo-go/common/config"
	"github.com/apache/dubbo-go/common/constant"
	"github.com/apache/dubbo-go/common/extension"
	"github.com/apache/dubbo-go/common/logger"
	"github.com/apache/dubbo-go/config_center"
	perrors "github.com/pkg/errors"
)

// ConfigCenterConfig is configuration for config center
//
// ConfigCenter also introduced concepts of namespace and group to better manage Key-Value pairs by group,
// those configs are already built-in in many professional third-party configuration centers.
// In most cases, namespace is used to isolate different tenants, while group is used to divide the key set from one tenant into groups.
//
// ConfigCenter has currently supported Zookeeper, Nacos, Etcd, Consul, Apollo
type ConfigCenterConfig struct {
	context       context.Context
	Protocol      string `required:"true"  yaml:"protocol"  json:"protocol,omitempty"`
	Address       string `yaml:"address" json:"address,omitempty"`
	Cluster       string `yaml:"cluster" json:"cluster,omitempty"`
	Group         string `default:"dubbo" yaml:"group" json:"group,omitempty"`
	Username      string `yaml:"username" json:"username,omitempty"`
	Password      string `yaml:"password" json:"password,omitempty"`
	LogDir        string `yaml:"log_dir" json:"log_dir,omitempty"`
	ConfigFile    string `default:"dubbo.properties" yaml:"config_file"  json:"config_file,omitempty"`
	Namespace     string `default:"dubbo" yaml:"namespace"  json:"namespace,omitempty"`
	AppConfigFile string `default:"dubbo.properties" yaml:"app_config_file"  json:"app_config_file,omitempty"`
	AppId         string `default:"dubbo" yaml:"app_id"  json:"app_id,omitempty"`
	TimeoutStr    string `yaml:"timeout"  json:"timeout,omitempty"`
	RemoteRef     string `required:"false"  yaml:"remote_ref"  json:"remote_ref,omitempty"`
	timeout       time.Duration
}

// UnmarshalYAML unmarshals the ConfigCenterConfig by @unmarshal function
func (c *ConfigCenterConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
	if err := defaults.Set(c); err != nil {
		return err
	}
	type plain ConfigCenterConfig
	if err := unmarshal((*plain)(c)); err != nil {
		return err
	}
	return nil
}

// GetUrlMap gets url map from ConfigCenterConfig
func (c *ConfigCenterConfig) GetUrlMap() url.Values {
	urlMap := url.Values{}
	urlMap.Set(constant.CONFIG_NAMESPACE_KEY, c.Namespace)
	urlMap.Set(constant.CONFIG_GROUP_KEY, c.Group)
	urlMap.Set(constant.CONFIG_CLUSTER_KEY, c.Cluster)
	urlMap.Set(constant.CONFIG_APP_ID_KEY, c.AppId)
	urlMap.Set(constant.CONFIG_LOG_DIR_KEY, c.LogDir)
	return urlMap
}

type configCenter struct {
}

// toURL will compatible with baseConfig.ConfigCenterConfig.Address and baseConfig.ConfigCenterConfig.RemoteRef before 1.6.0
// After 1.6.0 will not compatible, only baseConfig.ConfigCenterConfig.RemoteRef
func (b *configCenter) toURL(baseConfig BaseConfig) (common.URL, error) {
	if len(baseConfig.ConfigCenterConfig.Address) > 0 {
		return common.NewURL(baseConfig.ConfigCenterConfig.Address,
			common.WithProtocol(baseConfig.ConfigCenterConfig.Protocol), common.WithParams(baseConfig.ConfigCenterConfig.GetUrlMap()))
	}

	remoteRef := baseConfig.ConfigCenterConfig.RemoteRef
	rc, ok := baseConfig.GetRemoteConfig(remoteRef)

	if !ok {
		return common.URL{}, perrors.New("Could not find out the remote ref config, name: " + remoteRef)
	}

	newURL, err := rc.toURL()
	if err == nil {
		newURL.SetParams(baseConfig.ConfigCenterConfig.GetUrlMap())
	}
	return newURL, err
}

// startConfigCenter will start the config center.
// it will prepare the environment
func (b *configCenter) startConfigCenter(baseConfig BaseConfig) error {
	url, err := b.toURL(baseConfig)
	if err != nil {
		return err
	}
	if err = b.prepareEnvironment(baseConfig, &url); err != nil {
		return perrors.WithMessagef(err, "start config center error!")
	}
	// c.fresh()
	return nil
}

func (b *configCenter) prepareEnvironment(baseConfig BaseConfig, configCenterUrl *common.URL) error {
	factory := extension.GetConfigCenterFactory(configCenterUrl.Protocol)
	dynamicConfig, err := factory.GetDynamicConfiguration(configCenterUrl)
	if err != nil {
		logger.Errorf("Get dynamic configuration error , error message is %v", err)
		return perrors.WithStack(err)
	}
	config.GetEnvInstance().SetDynamicConfiguration(dynamicConfig)
	content, err := dynamicConfig.GetProperties(baseConfig.ConfigCenterConfig.ConfigFile, config_center.WithGroup(baseConfig.ConfigCenterConfig.Group))
	if err != nil {
		logger.Errorf("Get config content in dynamic configuration error , error message is %v", err)
		return perrors.WithStack(err)
	}
	var appGroup string
	var appContent string
	if providerConfig != nil && providerConfig.ApplicationConfig != nil &&
		reflect.ValueOf(baseConfig.fatherConfig).Elem().Type().Name() == "ProviderConfig" {
		appGroup = providerConfig.ApplicationConfig.Name
	} else if consumerConfig != nil && consumerConfig.ApplicationConfig != nil &&
		reflect.ValueOf(baseConfig.fatherConfig).Elem().Type().Name() == "ConsumerConfig" {
		appGroup = consumerConfig.ApplicationConfig.Name
	}

	if len(appGroup) != 0 {
		configFile := baseConfig.ConfigCenterConfig.AppConfigFile
		if len(configFile) == 0 {
			configFile = baseConfig.ConfigCenterConfig.ConfigFile
		}
		appContent, err = dynamicConfig.GetProperties(configFile, config_center.WithGroup(appGroup))
		if err != nil {
			return perrors.WithStack(err)
		}
	}
	// global config file
	mapContent, err := dynamicConfig.Parser().Parse(content)
	if err != nil {
		return perrors.WithStack(err)
	}
	config.GetEnvInstance().UpdateExternalConfigMap(mapContent)

	// appGroup config file
	if len(appContent) != 0 {
		appMapConent, err := dynamicConfig.Parser().Parse(appContent)
		if err != nil {
			return perrors.WithStack(err)
		}
		config.GetEnvInstance().UpdateAppExternalConfigMap(appMapConent)
	}

	return nil
}