package aws

import (
	"fmt"
	"log"

	"math/rand"
	"testing"
	"time"

	"github.com/hashicorp/terraform/helper/resource"
	"github.com/hashicorp/terraform/terraform"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/awserr"
	"github.com/aws/aws-sdk-go/service/rds"
)

func TestAccAWSDBInstance_basic(t *testing.T) {
	var v rds.DBInstance

	resource.Test(t, resource.TestCase{
		PreCheck:     func() { testAccPreCheck(t) },
		Providers:    testAccProviders,
		CheckDestroy: testAccCheckAWSDBInstanceDestroy,
		Steps: []resource.TestStep{
			resource.TestStep{
				Config: testAccAWSDBInstanceConfig,
				Check: resource.ComposeTestCheckFunc(
					testAccCheckAWSDBInstanceExists("aws_db_instance.bar", &v),
					testAccCheckAWSDBInstanceAttributes(&v),
					resource.TestCheckResourceAttr(
						"aws_db_instance.bar", "allocated_storage", "10"),
					resource.TestCheckResourceAttr(
						"aws_db_instance.bar", "engine", "mysql"),
					resource.TestCheckResourceAttr(
						"aws_db_instance.bar", "license_model", "general-public-license"),
					resource.TestCheckResourceAttr(
						"aws_db_instance.bar", "instance_class", "db.t1.micro"),
					resource.TestCheckResourceAttr(
						"aws_db_instance.bar", "name", "baz"),
					resource.TestCheckResourceAttr(
						"aws_db_instance.bar", "username", "foo"),
					resource.TestCheckResourceAttr(
						"aws_db_instance.bar", "parameter_group_name", "default.mysql5.6"),
				),
			},
		},
	})
}

func TestAccAWSDBInstanceReplica(t *testing.T) {
	var s, r rds.DBInstance

	resource.Test(t, resource.TestCase{
		PreCheck:     func() { testAccPreCheck(t) },
		Providers:    testAccProviders,
		CheckDestroy: testAccCheckAWSDBInstanceDestroy,
		Steps: []resource.TestStep{
			resource.TestStep{
				Config: testAccReplicaInstanceConfig(rand.New(rand.NewSource(time.Now().UnixNano())).Int()),
				Check: resource.ComposeTestCheckFunc(
					testAccCheckAWSDBInstanceExists("aws_db_instance.bar", &s),
					testAccCheckAWSDBInstanceExists("aws_db_instance.replica", &r),
					testAccCheckAWSDBInstanceReplicaAttributes(&s, &r),
				),
			},
		},
	})
}

func TestAccAWSDBInstanceSnapshot(t *testing.T) {
	var snap rds.DBInstance

	resource.Test(t, resource.TestCase{
		PreCheck:     func() { testAccPreCheck(t) },
		Providers:    testAccProviders,
		CheckDestroy: testAccCheckAWSDBInstanceSnapshot,
		Steps: []resource.TestStep{
			resource.TestStep{
				Config: testAccSnapshotInstanceConfig,
				Check: resource.ComposeTestCheckFunc(
					testAccCheckAWSDBInstanceExists("aws_db_instance.snapshot", &snap),
				),
			},
		},
	})
}

func TestAccAWSDBInstanceNoSnapshot(t *testing.T) {
	var nosnap rds.DBInstance

	resource.Test(t, resource.TestCase{
		PreCheck:     func() { testAccPreCheck(t) },
		Providers:    testAccProviders,
		CheckDestroy: testAccCheckAWSDBInstanceNoSnapshot,
		Steps: []resource.TestStep{
			resource.TestStep{
				Config: testAccNoSnapshotInstanceConfig,
				Check: resource.ComposeTestCheckFunc(
					testAccCheckAWSDBInstanceExists("aws_db_instance.no_snapshot", &nosnap),
				),
			},
		},
	})
}

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

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

		// Try to find the Group
		var err error
		resp, err := conn.DescribeDBInstances(
			&rds.DescribeDBInstancesInput{
				DBInstanceIdentifier: aws.String(rs.Primary.ID),
			})

		if err == nil {
			if len(resp.DBInstances) != 0 &&
				*resp.DBInstances[0].DBInstanceIdentifier == rs.Primary.ID {
				return fmt.Errorf("DB Instance still exists")
			}
		}

		// Verify the error
		newerr, ok := err.(awserr.Error)
		if !ok {
			return err
		}
		if newerr.Code() != "InvalidDBInstance.NotFound" {
			return err
		}
	}

	return nil
}

func testAccCheckAWSDBInstanceAttributes(v *rds.DBInstance) resource.TestCheckFunc {
	return func(s *terraform.State) error {

		if *v.Engine != "mysql" {
			return fmt.Errorf("bad engine: %#v", *v.Engine)
		}

		if *v.EngineVersion == "" {
			return fmt.Errorf("bad engine_version: %#v", *v.EngineVersion)
		}

		if *v.BackupRetentionPeriod != 0 {
			return fmt.Errorf("bad backup_retention_period: %#v", *v.BackupRetentionPeriod)
		}

		return nil
	}
}

func testAccCheckAWSDBInstanceReplicaAttributes(source, replica *rds.DBInstance) resource.TestCheckFunc {
	return func(s *terraform.State) error {

		if replica.ReadReplicaSourceDBInstanceIdentifier != nil && *replica.ReadReplicaSourceDBInstanceIdentifier != *source.DBInstanceIdentifier {
			return fmt.Errorf("bad source identifier for replica, expected: '%s', got: '%s'", *source.DBInstanceIdentifier, *replica.ReadReplicaSourceDBInstanceIdentifier)
		}

		return nil
	}
}

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

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

		var err error
		resp, err := conn.DescribeDBInstances(
			&rds.DescribeDBInstancesInput{
				DBInstanceIdentifier: aws.String(rs.Primary.ID),
			})

		if err != nil {
			newerr, _ := err.(awserr.Error)
			if newerr.Code() != "DBInstanceNotFound" {
				return err
			}

		} else {
			if len(resp.DBInstances) != 0 &&
				*resp.DBInstances[0].DBInstanceIdentifier == rs.Primary.ID {
				return fmt.Errorf("DB Instance still exists")
			}
		}

		log.Printf("[INFO] Trying to locate the DBInstance Final Snapshot")
		snapshot_identifier := "foobarbaz-test-terraform-final-snapshot-1"
		_, snapErr := conn.DescribeDBSnapshots(
			&rds.DescribeDBSnapshotsInput{
				DBSnapshotIdentifier: aws.String(snapshot_identifier),
			})

		if snapErr != nil {
			newerr, _ := snapErr.(awserr.Error)
			if newerr.Code() == "DBSnapshotNotFound" {
				return fmt.Errorf("Snapshot %s not found", snapshot_identifier)
			}
		} else {
			log.Printf("[INFO] Deleting the Snapshot %s", snapshot_identifier)
			_, snapDeleteErr := conn.DeleteDBSnapshot(
				&rds.DeleteDBSnapshotInput{
					DBSnapshotIdentifier: aws.String(snapshot_identifier),
				})
			if snapDeleteErr != nil {
				return err
			}
		}
	}

	return nil
}

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

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

		var err error
		resp, err := conn.DescribeDBInstances(
			&rds.DescribeDBInstancesInput{
				DBInstanceIdentifier: aws.String(rs.Primary.ID),
			})

		if err != nil {
			newerr, _ := err.(awserr.Error)
			if newerr.Code() != "DBInstanceNotFound" {
				return err
			}

		} else {
			if len(resp.DBInstances) != 0 &&
				*resp.DBInstances[0].DBInstanceIdentifier == rs.Primary.ID {
				return fmt.Errorf("DB Instance still exists")
			}
		}

		snapshot_identifier := "foobarbaz-test-terraform-final-snapshot-2"
		_, snapErr := conn.DescribeDBSnapshots(
			&rds.DescribeDBSnapshotsInput{
				DBSnapshotIdentifier: aws.String(snapshot_identifier),
			})

		if snapErr != nil {
			newerr, _ := snapErr.(awserr.Error)
			if newerr.Code() != "DBSnapshotNotFound" {
				return fmt.Errorf("Snapshot %s found and it shouldn't have been", snapshot_identifier)
			}
		}
	}

	return nil
}

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

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

		conn := testAccProvider.Meta().(*AWSClient).rdsconn

		opts := rds.DescribeDBInstancesInput{
			DBInstanceIdentifier: aws.String(rs.Primary.ID),
		}

		resp, err := conn.DescribeDBInstances(&opts)

		if err != nil {
			return err
		}

		if len(resp.DBInstances) != 1 ||
			*resp.DBInstances[0].DBInstanceIdentifier != rs.Primary.ID {
			return fmt.Errorf("DB Instance not found")
		}

		*v = *resp.DBInstances[0]

		return nil
	}
}

// Database names cannot collide, and deletion takes so long, that making the
// name a bit random helps so able we can kill a test that's just waiting for a
// delete and not be blocked on kicking off another one.
var testAccAWSDBInstanceConfig = fmt.Sprintf(`
resource "aws_db_instance" "bar" {
	identifier = "foobarbaz-test-terraform-%d"

	allocated_storage = 10
	engine = "MySQL"
	engine_version = "5.6.21"
	instance_class = "db.t1.micro"
	name = "baz"
	password = "barbarbarbar"
	username = "foo"


	# Maintenance Window is stored in lower case in the API, though not strictly 
	# documented. Terraform will downcase this to match (as opposed to throw a 
	# validation error).
	maintenance_window = "Fri:09:00-Fri:09:30"

	backup_retention_period = 0

	parameter_group_name = "default.mysql5.6"
}`, rand.New(rand.NewSource(time.Now().UnixNano())).Int())

func testAccReplicaInstanceConfig(val int) string {
	return fmt.Sprintf(`
	resource "aws_db_instance" "bar" {
		identifier = "foobarbaz-test-terraform-%d"

		allocated_storage = 5
		engine = "mysql"
		engine_version = "5.6.21"
		instance_class = "db.t1.micro"
		name = "baz"
		password = "barbarbarbar"
		username = "foo"

		backup_retention_period = 1

		parameter_group_name = "default.mysql5.6"
	}
	
	resource "aws_db_instance" "replica" {
	  identifier = "tf-replica-db-%d"
		backup_retention_period = 0
		replicate_source_db = "${aws_db_instance.bar.identifier}"
		allocated_storage = "${aws_db_instance.bar.allocated_storage}"
		engine = "${aws_db_instance.bar.engine}"
		engine_version = "${aws_db_instance.bar.engine_version}"
		instance_class = "${aws_db_instance.bar.instance_class}"
		password = "${aws_db_instance.bar.password}"
		username = "${aws_db_instance.bar.username}"
		tags {
			Name = "tf-replica-db"
		}
	}
	`, val, val)
}

var testAccSnapshotInstanceConfig = `
provider "aws" {
  region = "us-east-1"
}
resource "aws_db_instance" "snapshot" {
	identifier = "foobarbaz-test-terraform-snapshot-1"

	allocated_storage = 5
	engine = "mysql"
	engine_version = "5.6.21"
	instance_class = "db.t1.micro"
	name = "baz"
	password = "barbarbarbar"
	username = "foo"
	security_group_names = ["default"]
	backup_retention_period = 1

	parameter_group_name = "default.mysql5.6"

	skip_final_snapshot = false
	final_snapshot_identifier = "foobarbaz-test-terraform-final-snapshot-1"
}
`

var testAccNoSnapshotInstanceConfig = `
provider "aws" {
  region = "us-east-1"
}
resource "aws_db_instance" "no_snapshot" {
	identifier = "foobarbaz-test-terraform-snapshot-2"

	allocated_storage = 5
	engine = "mysql"
	engine_version = "5.6.21"
	instance_class = "db.t1.micro"
	name = "baz"
	password = "barbarbarbar"
	username = "foo"
    security_group_names = ["default"]
	backup_retention_period = 1

	parameter_group_name = "default.mysql5.6"

	skip_final_snapshot = true
	final_snapshot_identifier = "foobarbaz-test-terraform-final-snapshot-2"
}
`