/*
 * Please refer to the LICENSE file in the root directory of the project.
 * https://github.com/kubesphere/kubesphere/blob/master/LICENSE
 */

package config

import (
	"fmt"
	"strings"
	"sync"

	"github.com/spf13/viper"
	"gopkg.in/yaml.v3"
	corev1 "k8s.io/api/core/v1"
	"kubesphere.io/utils/s3"

	"kubesphere.io/kubesphere/pkg/apiserver/auditing"
	"kubesphere.io/kubesphere/pkg/apiserver/authentication"
	"kubesphere.io/kubesphere/pkg/apiserver/authorization"
	"kubesphere.io/kubesphere/pkg/constants"
	"kubesphere.io/kubesphere/pkg/controller/options"
	"kubesphere.io/kubesphere/pkg/models/composedapp"
	"kubesphere.io/kubesphere/pkg/models/terminal"
	"kubesphere.io/kubesphere/pkg/multicluster"
	"kubesphere.io/kubesphere/pkg/simple/client/cache"
	"kubesphere.io/kubesphere/pkg/simple/client/k8s"
)

// Package config saves configuration for running KubeSphere components
//
// Config can be configured from command line flags and configuration file.
// Command line flags hold higher priority than configuration file. But if
// component Endpoint/Host/APIServer was left empty, all of that component
// command line flags will be ignored, use configuration file instead.
// For example, we have configuration file
//
// mysql:
//   host: mysql.kubesphere-system.svc
//   username: root
//   password: password
//
// At the same time, have command line flags like following:
//
// --mysql-host mysql.openpitrix-system.svc --mysql-username king --mysql-password 1234
//
// We will use `king:1234@mysql.openpitrix-system.svc` from command line flags rather
// than `root:password@mysql.kubesphere-system.svc` from configuration file,
// cause command line has higher priority. But if command line flags like following:
//
// --mysql-username root --mysql-password password
//
// we will `root:password@mysql.kubesphere-system.svc` as input, cause
// mysql-host is missing in command line flags, all other mysql command line flags
// will be ignored.

var (
	// singleton instance of config package
	_config = defaultConfig()
)

const (
	// DefaultConfigurationName is the default name of configuration
	defaultConfigurationName = "kubesphere"

	// DefaultConfigurationPath the default location of the configuration file
	defaultConfigurationPath = "/etc/kubesphere"

	envPrefix = defaultConfigurationName
)

type config struct {
	cfg      *Config
	loadOnce sync.Once
}

func (c *config) loadFromDisk() (*Config, error) {
	var err error
	c.loadOnce.Do(func() {
		if err = viper.ReadInConfig(); err != nil {
			return
		}
		err = viper.Unmarshal(c.cfg)
	})
	return c.cfg, err
}

func defaultConfig() *config {
	viper.SetConfigName(defaultConfigurationName)
	viper.AddConfigPath(defaultConfigurationPath)

	// Load from current working directory, only used for debugging
	viper.AddConfigPath(".")

	// Load from Environment variables
	viper.SetEnvPrefix(envPrefix)
	viper.AutomaticEnv()
	viper.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))

	return &config{
		cfg:      New(),
		loadOnce: sync.Once{},
	}
}

// Config defines everything needed for apiserver to deal with external services
type Config struct {
	KubernetesOptions     *k8s.Options                 `json:"kubernetes,omitempty" yaml:"kubernetes,omitempty" mapstructure:"kubernetes"`
	CacheOptions          *cache.Options               `json:"cache,omitempty" yaml:"cache,omitempty" mapstructure:"cache"`
	AuthenticationOptions *authentication.Options      `json:"authentication,omitempty" yaml:"authentication,omitempty" mapstructure:"authentication"`
	AuthorizationOptions  *authorization.Options       `json:"authorization,omitempty" yaml:"authorization,omitempty" mapstructure:"authorization"`
	MultiClusterOptions   *multicluster.Options        `json:"multicluster,omitempty" yaml:"multicluster,omitempty" mapstructure:"multicluster"`
	AuditingOptions       *auditing.Options            `json:"auditing,omitempty" yaml:"auditing,omitempty" mapstructure:"auditing"`
	TerminalOptions       *terminal.Options            `json:"terminal,omitempty" yaml:"terminal,omitempty" mapstructure:"terminal"`
	HelmExecutorOptions   *options.HelmExecutorOptions `json:"helmExecutor,omitempty" yaml:"helmExecutor,omitempty" mapstructure:"helmExecutor"`
	TelemetryOptions      *options.TelemetryOptions    `json:"telemetry,omitempty" yaml:"telemetry,omitempty" mapstructure:"telemetry"`
	ExtensionOptions      *options.ExtensionOptions    `json:"extension,omitempty" yaml:"extension,omitempty" mapstructure:"extension"`
	S3Options             *s3.Options                  `json:"s3,omitempty" yaml:"s3,omitempty" mapstructure:"s3"`
	KubeSphereOptions     *options.KubeSphereOptions   `json:"kubesphere,omitempty" yaml:"kubesphere,omitempty" mapstructure:"kubesphere"`
	ComposedAppOptions    *composedapp.Options         `json:"composedApp,omitempty" yaml:"composedApp,omitempty" mapstructure:"composedApp"`
	ExperimentalOptions   *ExperimentalOptions         `json:"experimental,omitempty" yaml:"experimental,omitempty" mapstructure:"experimental"`
}

// New config creates a default non-empty Config
func New() *Config {
	return &Config{
		KubernetesOptions:     k8s.NewKubernetesOptions(),
		CacheOptions:          cache.NewCacheOptions(),
		AuthenticationOptions: authentication.NewOptions(),
		AuthorizationOptions:  authorization.NewOptions(),
		MultiClusterOptions:   multicluster.NewOptions(),
		TerminalOptions:       terminal.NewOptions(),
		AuditingOptions:       auditing.NewAuditingOptions(),
		TelemetryOptions:      options.NewTelemetryOptions(),
		HelmExecutorOptions:   options.NewHelmExecutorOptions(),
		ExtensionOptions:      options.NewExtensionOptions(),
		S3Options:             s3.NewS3Options(),
		KubeSphereOptions:     options.NewKubeSphereOptions(),
		ComposedAppOptions:    composedapp.NewOptions(),
		ExperimentalOptions:   NewExperimentalOptions(),
	}
}

// TryLoadFromDisk loads configuration from default location after server startup
// return nil error if configuration file not exists
func TryLoadFromDisk() (*Config, error) {
	return _config.loadFromDisk()
}

// FromConfigMap returns KubeSphere running config by the given ConfigMap.
func FromConfigMap(cm *corev1.ConfigMap) (*Config, error) {
	c := &Config{}
	value, ok := cm.Data[constants.KubeSphereConfigMapDataKey]
	if !ok {
		return nil, fmt.Errorf("failed to get configmap kubesphere.yaml value")
	}

	if err := yaml.Unmarshal([]byte(value), c); err != nil {
		return nil, fmt.Errorf("failed to unmarshal value from configmap. err: %s", err)
	}
	return c, nil
}