// Copyright 2019 Yunion
//
// 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 monitor

import (
	"reflect"
	"time"

	"yunion.io/x/jsonutils"
	"yunion.io/x/pkg/errors"
	"yunion.io/x/pkg/gotypes"

	"yunion.io/x/onecloud/pkg/apis"
)

type AlertStateType string
type AlertSeverityType string
type NoDataOption string
type ExecutionErrorOption string

const (
	AlertStateNoData   AlertStateType = "no_data"
	AlertStatePaused   AlertStateType = "paused"
	AlertStateAlerting AlertStateType = "alerting"
	AlertStateOK       AlertStateType = "ok"
	AlertStatePending  AlertStateType = "pending"
	AlertStateUnknown  AlertStateType = "unknown"
)

const (
	NoDataSetOK       NoDataOption = "ok"
	NoDataSetNoData   NoDataOption = "no_data"
	NoDataKeepState   NoDataOption = "keep_state"
	NoDataSetAlerting NoDataOption = "alerting"
)

const (
	ExecutionErrorSetAlerting ExecutionErrorOption = "alerting"
	ExecutionErrorKeepState   ExecutionErrorOption = "keep_state"
)

var (
	ErrCannotChangeStateOnPausedAlert = errors.Error("Cannot change state on pause alert")
	ErrRequiresNewState               = errors.Error("update alert state requires a new state")
)

func (s AlertStateType) IsValid() bool {
	return s == AlertStateOK ||
		s == AlertStateNoData ||
		s == AlertStatePaused ||
		s == AlertStatePending ||
		s == AlertStateAlerting ||
		s == AlertStateUnknown
}

func (s NoDataOption) IsValid() bool {
	return s == NoDataSetNoData || s == NoDataSetAlerting || s == NoDataKeepState || s == NoDataSetOK
}

func (s NoDataOption) ToAlertState() AlertStateType {
	return AlertStateType(s)
}

func (s ExecutionErrorOption) IsValid() bool {
	return s == ExecutionErrorSetAlerting || s == ExecutionErrorKeepState
}

func (s ExecutionErrorOption) ToAlertState() AlertStateType {
	return AlertStateType(s)
}

// AlertSettings contains alert conditions
type AlertSetting struct {
	Conditions []AlertCondition `json:"conditions"`
}

func (s AlertSetting) String() string {
	return jsonutils.Marshal(s).String()
}

func (s AlertSetting) IsZero() bool {
	return len(s.Conditions) == 0
}

type AlertCondition struct {
	Type         string             `json:"type"`
	Query        AlertQuery         `json:"query"`
	Reducer      Condition          `json:"reducer"`
	ReducerOrder ResultReducerOrder `json:"reducer_order"`
	Evaluator    Condition          `json:"evaluator"`
	Operator     string             `json:"operator"`
}

type ResultReducerOrder string

const (
	RESULT_REDUCER_ORDER_ASC  ResultReducerOrder = "asc"
	RESULT_REDUCER_ORDER_DESC ResultReducerOrder = "desc"
)

type AlertQuery struct {
	Model MetricQuery `json:"model"`
	From  string      `json:"from"`
	To    string      `json:"to"`
	// 查询结果 reducer，执行 p95 这些操作
	ResultReducer      *Condition         `json:"result_reducer"`
	ResultReducerOrder ResultReducerOrder `json:"result_reducer_order"`
}

type AlertCreateInput struct {
	apis.Meta

	// 报警名称
	Name string `json:"name"`
	// 报警执行频率
	Frequency int64 `json:"frequency"`
	// 报警持续时间
	For int64 `json:"for"`
	// 报警设置
	Settings AlertSetting `json:"settings"`
	// 启用报警
	Enabled *bool `json:"enabled"`
	// 报警级别
	Level string `json:"level"`
	// 没有收到监控指标时将当前报警状态设置为对应的状态
	NoDataState string `json:"no_data_state"`
	// 报警执行错误将当前报警状态设置为对应的状态
	ExecutionErrorState string `json:"execution_error_state"`
	UsedBy              string `json:"used_by"`
	// customize info
	CustomizeConfig jsonutils.JSONObject `json:"customize_config"`
	Reason          string               `json:"reason"`
}

type MeterCustomizeConfig struct {
	UnitDesc string `json:"unit_desc"`
	Name     string `json:"name"`
	Currency string `json:"currency"`
}

type AlertUpdateInput struct {
	apis.StandaloneResourceBaseUpdateInput

	Message *string `json:"message"`

	// 报警执行频率
	Frequency *int64 `json:"frequency"`
	// 报警持续时间
	For int64 `json:"for"`
	// 报警设置
	Settings *AlertSetting `json:"settings"`
	// 启用报警
	Enabled *bool `json:"enabled"`
	// 报警级别
	Level *string `json:"level"`
	// 没有收到监控指标时将当前报警状态设置为对应的状态
	NoDataState string `json:"no_data_state"`
	// 报警执行错误将当前报警状态设置为对应的状态
	ExecutionErrorState string `json:"execution_error_state"`
	// 报警原因
	Reason string `json:"reason"`
}

type AlertListInput struct {
	apis.ScopedResourceBaseListInput
	apis.EnabledResourceBaseListInput
	apis.StatusStandaloneResourceListInput
	// 以报警是否启用/禁用过滤列表
	// Enabled *bool `json:"enabled"`
	MonitorResourceId []string `json:"monitor_resource_id"`
}

type AlertDetails struct {
	SAlert

	apis.StatusStandaloneResourceDetails
	apis.ScopedResourceBaseInfo
}

type AlertTestRunInput struct {
	apis.Meta

	IsDebug bool `json:"is_debug"`
}

// ResultLogEntry represents log data for the alert evaluation.
type ResultLogEntry struct {
	Message string      `json:"message"`
	Data    interface{} `json:"data"`
}

// EvalMatch represents the series violating the threshold.
type EvalMatch struct {
	Condition    string               `json:"condition"`
	Value        *float64             `json:"value"`
	ValueStr     string               `json:"value_str"`
	Metric       string               `json:"metric"`
	Tags         map[string]string    `json:"tags"`
	Unit         string               `json:"unit"`
	AlertDetails jsonutils.JSONObject `json:"alert_details"`
	IsRecovery   bool                 `json:"is_recovery"`
}

type AlertTestRunOutput struct {
	apis.Meta

	Firing             bool              `json:"firing"`
	IsTestRun          bool              `json:"is_test_run"`
	IsDebug            bool              `json:"is_debug"`
	EvalMatches        []*EvalMatch      `json:"eval_matches"`
	AlertOKEvalMatches []*EvalMatch      `json:"alert_ok_eval_matches"`
	Logs               []*ResultLogEntry `json:"logs"`
	Error              error             `json:"error"`
	ConditionEvals     string            `json:"condition_evals"`
	StartTime          time.Time         `json:"start_time"`
	EndTime            time.Time         `json:"end_time"`
	NoDataFound        bool              `json:"no_data_found"`
	PrevAlertState     string            `json:"prev_alert_state"`
}

type AlertPauseInput struct {
	apis.Meta

	Paused bool `json:"paused"`
}

func init() {
	gotypes.RegisterSerializable(reflect.TypeOf(&AlertSetting{}), func() gotypes.ISerializable {
		return &AlertSetting{}
	})
}

type EvaluatorType string

const (
	EvaluatorTypeGT           EvaluatorType = "gt"
	EvaluatorTypeLT           EvaluatorType = "lt"
	EvaluatorTypeEQ           EvaluatorType = "eq"
	EvaluatorTypeWithinRange  EvaluatorType = "within_range"
	EvaluatorTypeOutsideRange EvaluatorType = "outside_range"
)