/*
Copyright 2014 The Kubernetes Authors.
Copyright 2020 Authors of Arktos - file modified.

Licensed 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 api

import (
	"fmt"

	"k8s.io/apimachinery/pkg/runtime"
)

// Where possible, json tags match the cli argument names.
// Top level config objects and all values required for proper functioning are not "omitempty".  Any truly optional piece of config is allowed to be omitted.

// Config holds the information needed to build connect to remote kubernetes clusters as a given user
// IMPORTANT if you add fields to this struct, please update IsConfigEmpty()
// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
type Config struct {
	// Legacy field from pkg/api/types.go TypeMeta.
	// TODO(jlowdermilk): remove this after eliminating downstream dependencies.
	// +optional
	Kind string `json:"kind,omitempty"`
	// Legacy field from pkg/api/types.go TypeMeta.
	// TODO(jlowdermilk): remove this after eliminating downstream dependencies.
	// +optional
	APIVersion string `json:"apiVersion,omitempty"`
	// Preferences holds general information to be use for cli interactions
	Preferences Preferences `json:"preferences"`
	// Clusters is a map of referencable names to cluster configs
	Clusters map[string]*Cluster `json:"clusters"`
	// AuthInfos is a map of referencable names to user configs
	AuthInfos map[string]*AuthInfo `json:"users"`
	// Contexts is a map of referencable names to context configs
	Contexts map[string]*Context `json:"contexts"`
	// CurrentContext is the name of the context that you would like to use by default
	CurrentContext string `json:"current-context"`
	// Extensions holds additional information. This is useful for extenders so that reads and writes don't clobber unknown fields
	// +optional
	Extensions map[string]runtime.Object `json:"extensions,omitempty"`
}

// IMPORTANT if you add fields to this struct, please update IsConfigEmpty()
type Preferences struct {
	// +optional
	Colors bool `json:"colors,omitempty"`
	// Extensions holds additional information. This is useful for extenders so that reads and writes don't clobber unknown fields
	// +optional
	Extensions map[string]runtime.Object `json:"extensions,omitempty"`
}

// Cluster contains information about how to communicate with a kubernetes cluster
type Cluster struct {
	// LocationOfOrigin indicates where this object came from.  It is used for round tripping config post-merge, but never serialized.
	LocationOfOrigin string
	// Server is the address of the kubernetes cluster (https://hostname:port).
	Server string `json:"server"`
	// InsecureSkipTLSVerify skips the validity check for the server's certificate. This will make your HTTPS connections insecure.
	// +optional
	InsecureSkipTLSVerify bool `json:"insecure-skip-tls-verify,omitempty"`
	// CertificateAuthority is the path to a cert file for the certificate authority.
	// +optional
	CertificateAuthority string `json:"certificate-authority,omitempty"`
	// CertificateAuthorityData contains PEM-encoded certificate authority certificates. Overrides CertificateAuthority
	// +optional
	CertificateAuthorityData []byte `json:"certificate-authority-data,omitempty"`
	// Extensions holds additional information. This is useful for extenders so that reads and writes don't clobber unknown fields
	// +optional
	Extensions map[string]runtime.Object `json:"extensions,omitempty"`
}

// AuthInfo contains information that describes identity information.  This is use to tell the kubernetes cluster who you are.
type AuthInfo struct {
	// LocationOfOrigin indicates where this object came from.  It is used for round tripping config post-merge, but never serialized.
	LocationOfOrigin string
	// ClientCertificate is the path to a client cert file for TLS.
	// +optional
	ClientCertificate string `json:"client-certificate,omitempty"`
	// ClientCertificateData contains PEM-encoded data from a client cert file for TLS. Overrides ClientCertificate
	// +optional
	ClientCertificateData []byte `json:"client-certificate-data,omitempty"`
	// ClientKey is the path to a client key file for TLS.
	// +optional
	ClientKey string `json:"client-key,omitempty"`
	// ClientKeyData contains PEM-encoded data from a client key file for TLS. Overrides ClientKey
	// +optional
	ClientKeyData []byte `json:"client-key-data,omitempty"`
	// Token is the bearer token for authentication to the kubernetes cluster.
	// +optional
	Token string `json:"token,omitempty"`
	// TokenFile is a pointer to a file that contains a bearer token (as described above).  If both Token and TokenFile are present, Token takes precedence.
	// +optional
	TokenFile string `json:"tokenFile,omitempty"`
	// Impersonate is the username to act-as.
	// +optional
	Impersonate string `json:"act-as,omitempty"`
	// ImpersonateGroups is the groups to imperonate.
	// +optional
	ImpersonateGroups []string `json:"act-as-groups,omitempty"`
	// ImpersonateUserExtra contains additional information for impersonated user.
	// +optional
	ImpersonateUserExtra map[string][]string `json:"act-as-user-extra,omitempty"`
	// Username is the username for basic authentication to the kubernetes cluster.
	// +optional
	Username string `json:"username,omitempty"`
	// Password is the password for basic authentication to the kubernetes cluster.
	// +optional
	Password string `json:"password,omitempty"`
	// AuthProvider specifies a custom authentication plugin for the kubernetes cluster.
	// +optional
	AuthProvider *AuthProviderConfig `json:"auth-provider,omitempty"`
	// Exec specifies a custom exec-based authentication plugin for the kubernetes cluster.
	// +optional
	Exec *ExecConfig `json:"exec,omitempty"`
	// Extensions holds additional information. This is useful for extenders so that reads and writes don't clobber unknown fields
	// +optional
	Extensions map[string]runtime.Object `json:"extensions,omitempty"`
}

// Context is a tuple of references to a cluster (how do I communicate with a kubernetes cluster), a user (how do I identify myself), and a namespace (what subset of resources do I want to work with)
type Context struct {
	// LocationOfOrigin indicates where this object came from.  It is used for round tripping config post-merge, but never serialized.
	LocationOfOrigin string
	// Cluster is the name of the cluster for this context
	Cluster string `json:"cluster"`
	// AuthInfo is the name of the authInfo for this context
	AuthInfo string `json:"user"`
	// Namespace is the default namespace to use on unspecified requests
	// +optional
	Namespace string `json:"namespace,omitempty"`
	// Extensions holds additional information. This is useful for extenders so that reads and writes don't clobber unknown fields
	// +optional
	Extensions map[string]runtime.Object `json:"extensions,omitempty"`
	// Tenant is the default tenant to use on unspecified requests
	// +optional
	Tenant string `json:"tenant,omitempty"`
}

// AuthProviderConfig holds the configuration for a specified auth provider.
type AuthProviderConfig struct {
	Name string `json:"name"`
	// +optional
	Config map[string]string `json:"config,omitempty"`
}

var _ fmt.Stringer = new(AuthProviderConfig)
var _ fmt.GoStringer = new(AuthProviderConfig)

// GoString implements fmt.GoStringer and sanitizes sensitive fields of
// AuthProviderConfig to prevent accidental leaking via logs.
func (c AuthProviderConfig) GoString() string {
	return c.String()
}

// String implements fmt.Stringer and sanitizes sensitive fields of
// AuthProviderConfig to prevent accidental leaking via logs.
func (c AuthProviderConfig) String() string {
	cfg := "<nil>"
	if c.Config != nil {
		cfg = "--- REDACTED ---"
	}
	return fmt.Sprintf("api.AuthProviderConfig{Name: %q, Config: map[string]string{%s}}", c.Name, cfg)
}

// ExecConfig specifies a command to provide client credentials. The command is exec'd
// and outputs structured stdout holding credentials.
//
// See the client.authentiction.k8s.io API group for specifications of the exact input
// and output format
type ExecConfig struct {
	// Command to execute.
	Command string `json:"command"`
	// Arguments to pass to the command when executing it.
	// +optional
	Args []string `json:"args"`
	// Env defines additional environment variables to expose to the process. These
	// are unioned with the host's environment, as well as variables client-go uses
	// to pass argument to the plugin.
	// +optional
	Env []ExecEnvVar `json:"env"`

	// Preferred input version of the ExecInfo. The returned ExecCredentials MUST use
	// the same encoding version as the input.
	APIVersion string `json:"apiVersion,omitempty"`
}

var _ fmt.Stringer = new(ExecConfig)
var _ fmt.GoStringer = new(ExecConfig)

// GoString implements fmt.GoStringer and sanitizes sensitive fields of
// ExecConfig to prevent accidental leaking via logs.
func (c ExecConfig) GoString() string {
	return c.String()
}

// String implements fmt.Stringer and sanitizes sensitive fields of ExecConfig
// to prevent accidental leaking via logs.
func (c ExecConfig) String() string {
	var args []string
	if len(c.Args) > 0 {
		args = []string{"--- REDACTED ---"}
	}
	env := "[]ExecEnvVar(nil)"
	if len(c.Env) > 0 {
		env = "[]ExecEnvVar{--- REDACTED ---}"
	}
	return fmt.Sprintf("api.AuthProviderConfig{Command: %q, Args: %#v, Env: %s, APIVersion: %q}", c.Command, args, env, c.APIVersion)
}

// ExecEnvVar is used for setting environment variables when executing an exec-based
// credential plugin.
type ExecEnvVar struct {
	Name  string `json:"name"`
	Value string `json:"value"`
}

// NewConfig is a convenience function that returns a new Config object with non-nil maps
func NewConfig() *Config {
	return &Config{
		Preferences: *NewPreferences(),
		Clusters:    make(map[string]*Cluster),
		AuthInfos:   make(map[string]*AuthInfo),
		Contexts:    make(map[string]*Context),
		Extensions:  make(map[string]runtime.Object),
	}
}

// NewContext is a convenience function that returns a new Context
// object with non-nil maps
func NewContext() *Context {
	return &Context{Extensions: make(map[string]runtime.Object)}
}

// NewCluster is a convenience function that returns a new Cluster
// object with non-nil maps
func NewCluster() *Cluster {
	return &Cluster{Extensions: make(map[string]runtime.Object)}
}

// NewAuthInfo is a convenience function that returns a new AuthInfo
// object with non-nil maps
func NewAuthInfo() *AuthInfo {
	return &AuthInfo{
		Extensions:           make(map[string]runtime.Object),
		ImpersonateUserExtra: make(map[string][]string),
	}
}

// NewPreferences is a convenience function that returns a new
// Preferences object with non-nil maps
func NewPreferences() *Preferences {
	return &Preferences{Extensions: make(map[string]runtime.Object)}
}
