func RenderToPng(c *middleware.Context) {
	queryReader := util.NewUrlQueryReader(c.Req.URL)
	queryParams := fmt.Sprintf("?%s", c.Req.URL.RawQuery)
	sessionId := c.Session.ID()

	// Handle api calls authenticated without session
	if sessionId == "" && c.ApiKeyId != 0 {
		c.Session.Start(c)
		c.Session.Set(middleware.SESS_KEY_APIKEY, c.ApiKeyId)
		// release will make sure the new session is persisted before
		// we spin up phantomjs
		c.Session.Release()
		// cleanup session after render is complete
		defer func() { c.Session.Destory(c) }()
	}

	renderOpts := &renderer.RenderOpts{
		Url:       c.Params("*") + queryParams,
		Width:     queryReader.Get("width", "800"),
		Height:    queryReader.Get("height", "400"),
		SessionId: c.Session.ID(),
	}

	renderOpts.Url = setting.ToAbsUrl(renderOpts.Url)
	pngPath, err := renderer.RenderToPng(renderOpts)

	if err != nil {
		c.Handle(500, "Failed to render to png", err)
		return
	}

	c.Resp.Header().Set("Content-Type", "image/png")
	http.ServeFile(c.Resp, c.Req.Request, pngPath)
}

func AdminUpdateUserPassword(c *middleware.Context, form dtos.AdminUpdateUserPasswordForm) {
	userId := c.ParamsInt64(":id")

	if len(form.Password) < 4 {
		c.JsonApiErr(400, "New password too short", nil)
		return
	}

	userQuery := m.GetUserByIdQuery{Id: userId}

	if err := bus.Dispatch(&userQuery); err != nil {
		c.JsonApiErr(500, "Could not read user from database", err)
		return
	}

	passwordHashed := util.EncodePassword(form.Password, userQuery.Result.Salt)

	cmd := m.ChangeUserPasswordCommand{
		UserId:      userId,
		NewPassword: passwordHashed,
	}

	if err := bus.Dispatch(&cmd); err != nil {
		c.JsonApiErr(500, "Failed to update user password", err)
		return
	}

	c.JsonOK("User password updated")
}

func GetDataSources(c *middleware.Context) {
	query := m.GetDataSourcesQuery{OrgId: c.OrgId}

	if err := bus.Dispatch(&query); err != nil {
		c.JsonApiErr(500, "Failed to query datasources", err)
		return
	}

	result := make([]*dtos.DataSource, len(query.Result))
	for i, ds := range query.Result {
		result[i] = &dtos.DataSource{
			Id:        ds.Id,
			OrgId:     ds.OrgId,
			Name:      ds.Name,
			Url:       ds.Url,
			Type:      ds.Type,
			Access:    ds.Access,
			Password:  ds.Password,
			Database:  ds.Database,
			User:      ds.User,
			BasicAuth: ds.BasicAuth,
			IsDefault: ds.IsDefault,
		}
	}

	c.JSON(200, result)
}

func handleDescribeInstances(req *cwRequest, c *middleware.Context) {
	svc := ec2.New(&aws.Config{Region: aws.String(req.Region)})

	reqParam := &struct {
		Parameters struct {
			Filters     []*ec2.Filter `json:"filters"`
			InstanceIds []*string     `json:"instanceIds"`
		} `json:"parameters"`
	}{}
	json.Unmarshal(req.Body, reqParam)

	params := &ec2.DescribeInstancesInput{}
	if len(reqParam.Parameters.Filters) > 0 {
		params.Filters = reqParam.Parameters.Filters
	}
	if len(reqParam.Parameters.InstanceIds) > 0 {
		params.InstanceIds = reqParam.Parameters.InstanceIds
	}

	resp, err := svc.DescribeInstances(params)
	if err != nil {
		c.JsonApiErr(500, "Unable to call AWS API", err)
		return
	}

	c.JSON(200, resp)
}

func RevokeInvite(c *middleware.Context) Response {
	if ok, rsp := updateTempUserStatus(c.Params(":code"), m.TmpUserRevoked); !ok {
		return rsp
	}

	return ApiSuccess("Invite revoked")
}

func LoginPost(c *middleware.Context, cmd dtos.LoginCommand) Response {
	authQuery := login.LoginUserQuery{
		Username: cmd.User,
		Password: cmd.Password,
	}

	if err := bus.Dispatch(&authQuery); err != nil {
		if err == login.ErrInvalidCredentials {
			return ApiError(401, "Invalid username or password", err)
		}

		return ApiError(500, "Error while trying to authenticate user", err)
	}

	user := authQuery.User

	loginUserWithUser(user, c)

	result := map[string]interface{}{
		"message": "Logged in",
	}

	if redirectTo, _ := url.QueryUnescape(c.GetCookie("redirect_to")); len(redirectTo) > 0 {
		result["redirectUrl"] = redirectTo
		c.SetCookie("redirect_to", "", -1, setting.AppSubUrl+"/")
	}

	metrics.M_Api_Login_Post.Inc(1)

	return Json(200, result)
}

func handleListMetrics(req *cwRequest, c *middleware.Context) {
	creds := credentials.NewChainCredentials(
		[]credentials.Provider{
			&credentials.EnvProvider{},
			&credentials.SharedCredentialsProvider{Filename: "", Profile: req.DataSource.Database},
			&ec2rolecreds.EC2RoleProvider{ExpiryWindow: 5 * time.Minute},
		})
	svc := cloudwatch.New(&aws.Config{
		Region:      aws.String(req.Region),
		Credentials: creds,
	})

	reqParam := &struct {
		Parameters struct {
			Namespace  string                        `json:"namespace"`
			MetricName string                        `json:"metricName"`
			Dimensions []*cloudwatch.DimensionFilter `json:"dimensions"`
		} `json:"parameters"`
	}{}
	json.Unmarshal(req.Body, reqParam)

	params := &cloudwatch.ListMetricsInput{
		Namespace:  aws.String(reqParam.Parameters.Namespace),
		MetricName: aws.String(reqParam.Parameters.MetricName),
		Dimensions: reqParam.Parameters.Dimensions,
	}

	resp, err := svc.ListMetrics(params)
	if err != nil {
		c.JsonApiErr(500, "Unable to call AWS API", err)
		return
	}

	c.JSON(200, resp)
}

/**
 * @function name:   func GetHomepageUrl(w http.ResponseWriter, c *middleware.Context)
 * @description:     This function returns URL of login page.
 * @related issues:  OWL-201
 * @param:           w http.ResponseWriter
 * @param:           c *middleware.Context
 * @return:          void
 * @author:          Don Hsieh
 * @since:           12/10/2015
 * @last modified:   12/10/2015
 * @called by:       func Register(r *macaron.Macaron)
 *                    in grafana/pkg/api/api.go
 */
func GetLoginUrl(w http.ResponseWriter, c *middleware.Context) {
	url := ""
	sig := c.GetCookie("sig")
	if len(sig) == 0 {
		url = setting.ConfigOpenFalcon.Login
	}
	RenderJson(w, url)
}

func handleGetNamespaces(req *cwRequest, c *middleware.Context) {
	result := []interface{}{}
	for key := range metricsMap {
		result = append(result, util.DynMap{"text": key, "value": key})
	}

	c.JSON(200, result)
}

func LoginApiPing(c *middleware.Context) {
	if !tryLoginUsingRememberCookie(c) {
		c.JsonApiErr(401, "Unauthorized", nil)
		return
	}

	c.JsonOK("Logged in")
}

func GetFrontendSettings(c *middleware.Context) {
	settings, err := getFrontendSettingsMap(c)
	if err != nil {
		c.JsonApiErr(400, "Failed to get frontend settings", err)
		return
	}

	c.JSON(200, settings)
}

func AddDataSource(c *middleware.Context, cmd m.AddDataSourceCommand) {
	cmd.OrgId = c.OrgId

	if err := bus.Dispatch(&cmd); err != nil {
		c.JsonApiErr(500, "Failed to add datasource", err)
		return
	}

	c.JSON(200, util.DynMap{"message": "Datasource added", "id": cmd.Result.Id})
}

func GetDashboardTags(c *middleware.Context) {
	query := m.GetDashboardTagsQuery{OrgId: c.OrgId}
	err := bus.Dispatch(&query)
	if err != nil {
		c.JsonApiErr(500, "Failed to get tags from database", err)
		return
	}

	c.JSON(200, query.Result)
}

func GetDataSourcePlugins(c *middleware.Context) {
	dsList := make(map[string]interface{})

	for key, value := range plugins.DataSources {
		if value.(map[string]interface{})["builtIn"] == nil {
			dsList[key] = value
		}
	}

	c.JSON(200, dsList)
}

func loginUserWithUser(user *m.User, c *middleware.Context) {
	if user == nil {
		log.Error(3, "User login with nil user")
	}

	days := 86400 * setting.LogInRememberDays
	c.SetCookie(setting.CookieUserName, user.Login, days, setting.AppSubUrl+"/")
	c.SetSuperSecureCookie(util.EncodeMd5(user.Rands+user.Password), setting.CookieRememberName, user.Login, days, setting.AppSubUrl+"/")

	c.Session.Set(middleware.SESS_KEY_USERID, user.Id)
}

func DeleteApiKey(c *middleware.Context) Response {
	id := c.ParamsInt64(":id")

	cmd := &m.DeleteApiKeyCommand{Id: id, OrgId: c.OrgId}

	err := bus.Dispatch(cmd)
	if err != nil {
		return ApiError(500, "Failed to delete API key", err)
	}

	return ApiSuccess("API key deleted")
}

func handleGetRegions(req *cwRequest, c *middleware.Context) {
	regions := []string{
		"us-west-2", "us-west-1", "eu-west-1", "eu-central-1", "ap-southeast-1",
		"ap-southeast-2", "ap-northeast-1", "sa-east-1",
	}

	result := []interface{}{}
	for _, region := range regions {
		result = append(result, util.DynMap{"text": region, "value": region})
	}

	c.JSON(200, result)
}

func HandleRequest(c *middleware.Context, ds *m.DataSource) {
	var req cwRequest
	req.Body, _ = ioutil.ReadAll(c.Req.Request.Body)
	req.DataSource = ds
	json.Unmarshal(req.Body, &req)

	if handler, found := actionHandlers[req.Action]; !found {
		c.JsonApiErr(500, "Unexpected AWS Action", errors.New(req.Action))
		return
	} else {
		handler(&req, c)
	}
}

func Logout(c *middleware.Context) {
	c.SetCookie(setting.CookieUserName, "", -1, setting.AppSubUrl+"/")
	c.SetCookie(setting.CookieRememberName, "", -1, setting.AppSubUrl+"/")
	c.SetCookie("sig", "", -1, setting.AppSubUrl+"/")
	c.Session.Destory(c)
	c.Redirect(setting.ConfigOpenFalcon.Login)
}

func UnstarDashboard(c *middleware.Context) Response {

	cmd := m.UnstarDashboardCommand{UserId: c.UserId, DashboardId: c.ParamsInt64(":id")}

	if cmd.DashboardId <= 0 {
		return ApiError(400, "Missing dashboard id", nil)
	}

	if err := bus.Dispatch(&cmd); err != nil {
		return ApiError(500, "Failed to unstar dashboard", err)
	}

	return ApiSuccess("Dashboard unstarred")
}