/*
Copyright 2024. projectsveltos.io. All rights reserved.

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 v1beta1

import (
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
)

const (
	// ClusterHealthCheckFinalizer allows ClusterHealthCheckReconciler to clean up resources associated with
	// ClusterHealthCheck before removing it from the apiserver.
	ClusterHealthCheckFinalizer = "clusterhcfinalizer.projectsveltos.io"

	ClusterHealthCheckKind = "ClusterHealthCheck"

	FeatureClusterHealthCheck = "ClusterHealthCheck"
)

// Slack constant
// To have Sveltos sends a slack notification, create a Secret of type "addons.projectsveltos.io/cluster-profile"
// In the data section set both slack token and slack channel id
const (
	SlackToken     = "SLACK_TOKEN"
	SlackChannelID = "SLACK_CHANNEL_ID"
)

// Webex constant
// To have Sveltos sends a webex notification, create a Secret of type "addons.projectsveltos.io/cluster-profile"
// In the data section set both webex token and webex room ID
const (
	WebexToken  = "WEBEX_TOKEN"
	WebexRoomID = "WEBEX_ROOM_ID"
)

// Discord constant
// To have Sveltos sends a Discord notification, create a Secret of type "addons.projectsveltos.io/cluster-profile"
// In the data section set both discord token and discord server ID
const (
	DiscordToken     = "DISCORD_TOKEN"
	DiscordChannelID = "DISCORD_CHANNEL_ID"
)

// Teams constant
// To have Sveltos sends a Microsoft Teams notification, create a Secret of type "addons.projectsveltos.io/cluster-profile"
// In the data section set the Webhook URL
const (
	TeamsWebhookURL = "TEAMS_WEBHOOK_URL"
)

// Telegram constant
// To have Sveltos sends a Telegram notification, create a Secret of type "addons.projectsveltos.io/cluster-profile"
// In the data section set both discord token and discord server ID
const (
	TelegramToken  = "TELEGRAM_TOKEN"
	TelegramChatID = "TELEGRAM_CHAT_ID"
)

// SMTP constant
// To have Sveltos sends an SMTP notification, create a Secret of type "addons.projectsveltos.io/cluster-profile"
// In the data section set the SMTP information
const (
	SmtpRecipients = "SMTP_RECIPIENTS"
	SmtpCc         = "SMTP_CC"
	SmtpBcc        = "SMTP_BCC"
	SmtpSender     = "SMTP_SENDER"
	SmtpPassword   = "SMTP_PASSWORD"
	SmtpHost       = "SMTP_HOST"
	SmtpPort       = "SMTP_PORT"
)

// ConditionSeverity expresses the severity of a Condition Type failing.
type ConditionSeverity string

const (
	// ConditionSeverityError specifies that a condition with `Status=False` is an error.
	ConditionSeverityError ConditionSeverity = "Error"

	// ConditionSeverityWarning specifies that a condition with `Status=False` is a warning.
	ConditionSeverityWarning ConditionSeverity = "Warning"

	// ConditionSeverityInfo specifies that a condition with `Status=False` is informative.
	ConditionSeverityInfo ConditionSeverity = "Info"

	// ConditionSeverityNone should apply only to conditions with `Status=True`.
	ConditionSeverityNone ConditionSeverity = ""
)

// ConditionType is a valid value for Condition.Type.
type ConditionType string

// Condition defines an observation of a Cluster API resource operational state.
type Condition struct {
	// Condition name
	Name string `json:"name"`

	// Type of condition in CamelCase or in foo.example.com/CamelCase.
	Type ConditionType `json:"type"`

	// Status of the condition, one of True, False, Unknown.
	Status corev1.ConditionStatus `json:"status"`

	// Severity provides an explicit classification of Reason code, so the users or machines can immediately
	// understand the current situation and act accordingly.
	// The Severity field MUST be set only when Status=False.
	// +optional
	Severity ConditionSeverity `json:"severity,omitempty"`

	// Last time the condition transitioned from one status to another.
	// This should be when the underlying condition changed. If that is not known, then using the time when
	// the API field changed is acceptable.
	LastTransitionTime metav1.Time `json:"lastTransitionTime"`

	// The reason for the condition's last transition in CamelCase.
	// The specific API may choose whether or not this field is considered a guaranteed API.
	// This field may not be empty.
	// +optional
	Reason string `json:"reason,omitempty"`

	// A human readable message indicating details about the transition.
	// This field may be empty.
	// +optional
	Message string `json:"message,omitempty"`
}

type ClusterCondition struct {
	ClusterInfo ClusterInfo `json:"clusterInfo"`

	// Cluster conditions.
	// +optional
	Conditions []Condition `json:"conditions,omitempty"`

	// NotificationSummaries contains status information on notifications
	// +optional
	NotificationSummaries []NotificationSummary `json:"notificationSummaries,omitempty"`
}

// Event specifies different type of liveness checks
// +kubebuilder:validation:Enum:=Addons;HealthCheck
type LivenessType string

const (
	// LivenessTypeAddons refers to add-ons deployment state.
	LivenessTypeAddons = LivenessType("Addons")

	// LivenessTypeHealthCheck refers to HealthCheck state.
	LivenessTypeHealthCheck = LivenessType("HealthCheck")
)

type LivenessCheck struct {
	// Name of the liveness check.
	// Must be a DNS_LABEL and unique within the ClusterHealthCheck.
	Name string `json:"name" protobuf:"bytes,1,opt,name=name"`

	// Type specifies the type of liveness
	Type LivenessType `json:"type"`

	// LivenessSourceRef is a reference to a liveness-specific resource that holds
	// the details for the liveness check.
	// +optional
	LivenessSourceRef *corev1.ObjectReference `json:"livenessSourceRef,omitempty"`
}

// NotificationType specifies different type of notifications
// +kubebuilder:validation:Enum:=KubernetesEvent;Slack;Webex;Discord;Teams;Telegram;SMTP
type NotificationType string

const (
	// NotificationTypeKubernetesEvent refers to generating a Kubernetes event
	NotificationTypeKubernetesEvent = NotificationType("KubernetesEvent")

	// NotificationTypeSlack refers to generating a Slack message
	NotificationTypeSlack = NotificationType("Slack")

	// NotificationTypeWebex refers to generating a Webex message
	NotificationTypeWebex = NotificationType("Webex")

	// NotificationTypeDiscord refers to generating a Discord message
	NotificationTypeDiscord = NotificationType("Discord")

	// NotificationTypeTeams refers to generating a Teams message
	NotificationTypeTeams = NotificationType("Teams")

	// NotificationTypeSMTP refers to generating an email message
	NotificationTypeSMTP = NotificationType("SMTP")

	// NotificationTypeTelegram refers to generating a telegram message
	NotificationTypeTelegram = NotificationType("Telegram")
)

type Notification struct {
	// Name of the notification check.
	// Must be a DNS_LABEL and unique within the ClusterHealthCheck.
	Name string `json:"name" protobuf:"bytes,1,opt,name=name"`

	// NotificationType specifies the type of notification
	Type NotificationType `json:"type"`

	// NotificationRef is a reference to a notification-specific resource that holds
	// the details for the notification.
	// +optional
	NotificationRef *corev1.ObjectReference `json:"notificationRef,omitempty"`
}

// NotificationStatus specifies status of notifications
// +kubebuilder:validation:Enum:=Delivered;FailedToDeliver
type NotificationStatus string

const (
	// NotificationStatusDelivered indicates notification has been delivered
	NotificationStatusDelivered = NotificationStatus("Delivered")

	// NotificationStatusFailedToDeliver indicates notification was not delivered
	// due to an error
	NotificationStatusFailedToDeliver = NotificationStatus("FailedToDeliver")
)

type NotificationSummary struct {
	// Name of the notification check.
	Name string `json:"name" protobuf:"bytes,1,opt,name=name"`

	// NotificationStatus specifies the notification status
	Status NotificationStatus `json:"status"`

	// FailureMessage is a human consumable message explaining the
	// misconfiguration
	// +optional
	FailureMessage *string `json:"failureMessage,omitempty"`
}

// ClusterHealthCheckSpec defines the desired state of ClusterHealthCheck
type ClusterHealthCheckSpec struct {
	// Selector identifies clusters to associate to.
	// +optional
	ClusterSelector Selector `json:"clusterSelector,omitempty"`

	// LivenessChecks is a list of source of liveness checks to evaluate.
	// Anytime one of those changes, notifications will be sent
	// +patchMergeKey=name
	// +patchStrategy=merge,retainKeys
	LivenessChecks []LivenessCheck `json:"livenessChecks"`

	// Notification is a list of notification mechanisms.
	// +patchMergeKey=name
	// +patchStrategy=merge,retainKeys
	Notifications []Notification `json:"notifications"`
}

type ClusterHealthCheckStatus struct {
	// MatchingClusterRefs reference all the clusters currently matching
	// ClusterHealthCheck ClusterSelector
	MatchingClusterRefs []corev1.ObjectReference `json:"matchingClusters,omitempty"`

	// ClusterConditions contains conditions and notification status for all clusters
	// matching ClusterHealthCheck instance
	// +optional
	ClusterConditions []ClusterCondition `json:"clusterCondition,omitempty"`
}

//+kubebuilder:object:root=true
//+kubebuilder:resource:path=clusterhealthchecks,scope=Cluster
//+kubebuilder:subresource:status
//+kubebuilder:storageversion

// ClusterHealthCheck is the Schema for the clusterhealthchecks API
type ClusterHealthCheck struct {
	metav1.TypeMeta   `json:",inline"`
	metav1.ObjectMeta `json:"metadata,omitempty"`

	Spec   ClusterHealthCheckSpec   `json:"spec,omitempty"`
	Status ClusterHealthCheckStatus `json:"status,omitempty"`
}

//+kubebuilder:object:root=true

// ClusterHealthCheckList contains a list of ClusterHealthChecks
type ClusterHealthCheckList struct {
	metav1.TypeMeta `json:",inline"`
	metav1.ListMeta `json:"metadata,omitempty"`
	Items           []ClusterHealthCheck `json:"items"`
}

func init() {
	SchemeBuilder.Register(&ClusterHealthCheck{}, &ClusterHealthCheckList{})
}