package aws

import (
	"fmt"
	"strings"
	"testing"

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

func TestAWSPolicy_namePrefix(t *testing.T) {
	var out iam.GetPolicyOutput

	resource.Test(t, resource.TestCase{
		PreCheck:     func() { testAccPreCheck(t) },
		Providers:    testAccProviders,
		CheckDestroy: testAccCheckAWSPolicyDestroy,
		Steps: []resource.TestStep{
			resource.TestStep{
				Config: testAccAWSPolicyPrefixNameConfig,
				Check: resource.ComposeTestCheckFunc(
					testAccCheckAWSPolicyExists("aws_iam_policy.policy", &out),
					testAccCheckAWSPolicyGeneratedNamePrefix(
						"aws_iam_policy.policy", "test-policy-"),
				),
			},
		},
	})
}

func testAccCheckAWSPolicyDestroy(s *terraform.State) error {
	iamconn := testAccProvider.Meta().(*AWSClient).iamconn

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

		// Try to get policy
		_, err := iamconn.GetPolicy(&iam.GetPolicyInput{
			PolicyArn: aws.String(rs.Primary.Attributes["arn"]),
		})
		if err == nil {
			return fmt.Errorf("still exist.")
		}

		// Verify the error is what we want
		ec2err, ok := err.(awserr.Error)
		if !ok {
			return err
		}
		if ec2err.Code() != "NoSuchEntity" {
			return err
		}
	}

	return nil
}

func testAccCheckAWSPolicyExists(resource string, res *iam.GetPolicyOutput) resource.TestCheckFunc {
	return func(s *terraform.State) error {
		rs, ok := s.RootModule().Resources[resource]
		if !ok {
			return fmt.Errorf("Not found: %s", resource)
		}

		if rs.Primary.ID == "" {
			return fmt.Errorf("No Policy name is set")
		}

		iamconn := testAccProvider.Meta().(*AWSClient).iamconn

		resp, err := iamconn.GetPolicy(&iam.GetPolicyInput{
			PolicyArn: aws.String(rs.Primary.Attributes["arn"]),
		})
		if err != nil {
			return err
		}

		*res = *resp

		return nil
	}
}

func testAccCheckAWSPolicyGeneratedNamePrefix(resource, prefix string) resource.TestCheckFunc {
	return func(s *terraform.State) error {
		r, ok := s.RootModule().Resources[resource]
		if !ok {
			return fmt.Errorf("Resource not found")
		}
		name, ok := r.Primary.Attributes["name"]
		if !ok {
			return fmt.Errorf("Name attr not found: %#v", r.Primary.Attributes)
		}
		if !strings.HasPrefix(name, prefix) {
			return fmt.Errorf("Name: %q, does not have prefix: %q", name, prefix)
		}
		return nil
	}
}

const testAccAWSPolicyPrefixNameConfig = `
resource "aws_iam_policy" "policy" {
	name_prefix = "test-policy-"
	path = "/"
  policy = <<EOF
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Action": [
        "ec2:Describe*"
      ],
      "Effect": "Allow",
      "Resource": "*"
    }
  ]
}
EOF
}
`