rule.go

// Copyright 2015 Eleme Inc. All rights reserved.

package webapp

import (
	"net/http"
	"strconv"
	"time"

	"github.com/eleme/banshee/models"
	"github.com/jinzhu/gorm"
	"github.com/julienschmidt/httprouter"
	"github.com/mattn/go-sqlite3"
)

// createRule request
type createRuleRequest struct {
	Pattern       string  `json:"pattern"`
	TrendUp       bool    `json:"trendUp"`
	TrendDown     bool    `json:"trendDown"`
	ThresholdMax  float64 `json:"thresholdMax"`
	ThresholdMin  float64 `json:"thresholdMin"`
	Comment       string  `json:"comment"`
	Level         int     `json:"level"`
	Disabled      bool    `json:"disabled"`
	DisabledFor   int     `json:"disabledFor"` // in Minute
	TrackIdle     bool    `json:"trackIdle"`
	NeverFillZero bool    `json:"neverFillZero"`
}

// createRule creates a rule.
func createRule(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
	// Params
	projectID, err := strconv.Atoi(ps.ByName("id"))
	if err != nil {
		ResponseError(w, ErrProjectID)
		return
	}
	// Request
	req := &createRuleRequest{
		Level:    models.RuleLevelLow,
		Disabled: false,
	}
	if err := RequestBind(r, req); err != nil {
		ResponseError(w, ErrBadRequest)
		return
	}
	// Validate
	if err := models.ValidateRulePattern(req.Pattern); err != nil {
		ResponseError(w, NewValidationWebError(err))
		return
	}
	if len(req.Comment) <= 0 {
		ResponseError(w, ErrRuleNoComment)
		return
	}
	if projectID <= 0 {
		// ProjectID is invalid.
		ResponseError(w, ErrProjectID)
		return
	}
	if !req.TrendUp && !req.TrendDown && req.ThresholdMax == 0 && req.ThresholdMin == 0 {
		ResponseError(w, ErrRuleNoCondition)
		return
	}
	if err := models.ValidateRuleLevel(req.Level); err != nil {
		ResponseError(w, NewValidationWebError(err))
		return
	}
	if err := db.Admin.DB().Where("project_id = ? AND pattern = ?", projectID, req.Pattern).First(&models.Rule{}).Error; err == nil {
		ResponseError(w, ErrDuplicateRulePattern)
		return
	}
	// Find project.
	proj := &models.Project{}
	if err := db.Admin.DB().First(proj, projectID).Error; err != nil {
		switch err {
		case gorm.RecordNotFound:
			ResponseError(w, ErrProjectNotFound)
			return
		default:
			ResponseError(w, NewUnexceptedWebError(err))
			return
		}
	}
	// Create rule.
	rule := &models.Rule{
		ProjectID:     projectID,
		Pattern:       req.Pattern,
		TrendUp:       req.TrendUp,
		TrendDown:     req.TrendDown,
		ThresholdMax:  req.ThresholdMax,
		ThresholdMin:  req.ThresholdMin,
		Comment:       req.Comment,
		Level:         req.Level,
		Disabled:      req.Disabled,
		DisabledFor:   req.DisabledFor,
		DisabledAt:    time.Now(),
		TrackIdle:     req.TrackIdle,
		NeverFillZero: req.NeverFillZero,
	}
	if err := db.Admin.DB().Create(rule).Error; err != nil {
		// Write errors.
		sqliteErr, ok := err.(sqlite3.Error)
		if ok {
			switch sqliteErr.ExtendedCode {
			case sqlite3.ErrConstraintNotNull:
				ResponseError(w, ErrNotNull)
				return
			case sqlite3.ErrConstraintPrimaryKey:
				ResponseError(w, ErrPrimaryKey)
				return
			}
		}
		// Unexcepted error.
		ResponseError(w, NewUnexceptedWebError(err))
		return
	}
	// Cache
	db.Admin.RulesCache.Put(rule)
	// Response
	rule.SetNumMetrics(db.Index.NumFilter(rule.Pattern))
	ResponseJSONOK(w, rule)
}

// deleteRule deletes a rule from a project.
func deleteRule(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
	// Params
	id, err := strconv.Atoi(ps.ByName("id"))
	if err != nil {
		ResponseError(w, ErrProjectID)
		return
	}
	// Delete
	if err := db.Admin.DB().Delete(&models.Rule{ID: id}).Error; err != nil {
		switch err {
		case gorm.RecordNotFound:
			ResponseError(w, ErrRuleNotFound)
			return
		default:
			ResponseError(w, NewUnexceptedWebError(err))
			return
		}
	}
	// Cache
	db.Admin.RulesCache.Delete(id)
}

// editRule edits a rule
func editRule(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
	// id
	id, err := strconv.Atoi(ps.ByName("id"))
	if err != nil {
		ResponseError(w, ErrProjectID)
		return
	}

	// Request
	req := &createRuleRequest{}
	if err := RequestBind(r, req); err != nil {
		ResponseError(w, ErrBadRequest)
		return
	}
	// Validate
	if err := models.ValidateRulePattern(req.Pattern); err != nil {
		ResponseError(w, NewValidationWebError(err))
		return
	}
	if err := models.ValidateRuleLevel(req.Level); err != nil {
		ResponseError(w, NewValidationWebError(err))
		return
	}
	if len(req.Comment) <= 0 {
		ResponseError(w, ErrRuleNoComment)
		return
	}
	if !req.TrendUp && !req.TrendDown && req.ThresholdMax == 0 && req.ThresholdMin == 0 {
		ResponseError(w, ErrRuleNoCondition)
		return
	}

	rule := &models.Rule{}
	if db.Admin.DB().Where("id = ?", id).First(&rule).Error != nil {
		ResponseError(w, ErrRuleNotFound)
		return
	}

	rule.Comment = req.Comment
	rule.Level = req.Level
	rule.Pattern = req.Pattern
	rule.TrendUp = req.TrendUp
	rule.TrendDown = req.TrendDown
	rule.ThresholdMax = req.ThresholdMax
	rule.ThresholdMin = req.ThresholdMin
	rule.Disabled = req.Disabled
	rule.DisabledFor = req.DisabledFor
	rule.DisabledAt = time.Now()
	rule.TrackIdle = req.TrackIdle
	rule.NeverFillZero = req.NeverFillZero

	if db.Admin.DB().Save(rule).Error != nil {
		ResponseError(w, ErrRuleUpdateFailed)
		return
	}
	// Cache
	db.Admin.RulesCache.Delete(id)
	db.Admin.RulesCache.Put(rule)
	rule.SetNumMetrics(db.Index.NumFilter(rule.Pattern))
	ResponseJSONOK(w, rule)
}