package aws

import (
	"fmt"
	"testing"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/service/cloudwatch"
	"github.com/hashicorp/terraform/helper/resource"
	"github.com/hashicorp/terraform/terraform"
)

func TestAccAWSCloudWatchMetricAlarm_basic(t *testing.T) {
	var alarm cloudwatch.MetricAlarm

	resource.Test(t, resource.TestCase{
		PreCheck:     func() { testAccPreCheck(t) },
		Providers:    testAccProviders,
		CheckDestroy: testAccCheckAWSCloudWatchMetricAlarmDestroy,
		Steps: []resource.TestStep{
			resource.TestStep{
				Config: testAccAWSCloudWatchMetricAlarmConfig,
				Check: resource.ComposeTestCheckFunc(
					testAccCheckCloudWatchMetricAlarmExists("aws_cloudwatch_metric_alarm.foobar", &alarm),
					resource.TestCheckResourceAttr("aws_cloudwatch_metric_alarm.foobar", "metric_name", "CPUUtilization"),
					resource.TestCheckResourceAttr("aws_cloudwatch_metric_alarm.foobar", "statistic", "Average"),
				),
			},
		},
	})
}

func testAccCheckCloudWatchMetricAlarmExists(n string, alarm *cloudwatch.MetricAlarm) resource.TestCheckFunc {
	return func(s *terraform.State) error {
		rs, ok := s.RootModule().Resources[n]
		if !ok {
			return fmt.Errorf("Not found: %s", n)
		}

		conn := testAccProvider.Meta().(*AWSClient).cloudwatchconn
		params := cloudwatch.DescribeAlarmsInput{
			AlarmNames: []*string{aws.String(rs.Primary.ID)},
		}
		resp, err := conn.DescribeAlarms(&params)
		if err != nil {
			return err
		}
		if len(resp.MetricAlarms) == 0 {
			return fmt.Errorf("Alarm not found")
		}
		*alarm = *resp.MetricAlarms[0]

		return nil
	}
}

func testAccCheckAWSCloudWatchMetricAlarmDestroy(s *terraform.State) error {
	conn := testAccProvider.Meta().(*AWSClient).cloudwatchconn

	for _, rs := range s.RootModule().Resources {
		if rs.Type != "aws_cloudwatch_metric_alarm" {
			continue
		}

		params := cloudwatch.DescribeAlarmsInput{
			AlarmNames: []*string{aws.String(rs.Primary.ID)},
		}

		resp, err := conn.DescribeAlarms(&params)

		if err == nil {
			if len(resp.MetricAlarms) != 0 &&
				*resp.MetricAlarms[0].AlarmName == rs.Primary.ID {
				return fmt.Errorf("Alarm Still Exists: %s", rs.Primary.ID)
			}
		}
	}

	return nil
}

var testAccAWSCloudWatchMetricAlarmConfig = fmt.Sprintf(`
resource "aws_cloudwatch_metric_alarm" "foobar" {
    alarm_name = "terraform-test-foobar5"
    comparison_operator = "GreaterThanOrEqualToThreshold"
    evaluation_periods = "2"
    metric_name = "CPUUtilization"
    namespace = "AWS/EC2"
    period = "120"
    statistic = "Average"
    threshold = "80"
    alarm_description = "This metric monitor ec2 cpu utilization"
    insufficient_data_actions = []
}
`)