package aws

import (
	"fmt"

	"github.com/aws/aws-sdk-go/service/ec2"
	"github.com/hashicorp/errwrap"
	"github.com/hashicorp/terraform/helper/schema"
)

// Security group import fans out to multiple resources due to the
// security group rules. Instead of creating one resource with nested
// rules, we use the best practices approach of one resource per rule.
func resourceAwsSecurityGroupImportState(
	d *schema.ResourceData,
	meta interface{}) ([]*schema.ResourceData, error) {
	conn := meta.(*AWSClient).ec2conn

	// First query the security group
	sgRaw, _, err := SGStateRefreshFunc(conn, d.Id())()
	if err != nil {
		return nil, err
	}
	if sgRaw == nil {
		return nil, fmt.Errorf("security group not found")
	}
	sg := sgRaw.(*ec2.SecurityGroup)
	sgId := d.Id()

	// Start building our results
	results := make([]*schema.ResourceData, 1,
		1+len(sg.IpPermissions)+len(sg.IpPermissionsEgress))
	results[0] = d

	// Construct the rules
	ruleResource := resourceAwsSecurityGroupRule()
	permMap := map[string][]*ec2.IpPermission{
		"ingress": sg.IpPermissions,
		"egress":  sg.IpPermissionsEgress,
	}
	for ruleType, perms := range permMap {
		for _, perm := range perms {
			// Construct the rule. We do this by populating the absolute
			// minimum necessary for Refresh on the rule to work. This
			// happens to be a lot of fields since they're almost all needed
			// for de-dupping.
			id := ipPermissionIDHash(sgId, ruleType, perm)
			d := ruleResource.Data(nil)
			d.SetId(id)
			d.SetType("aws_security_group_rule")
			d.Set("security_group_id", sgId)
			d.Set("type", ruleType)

			// 'self' is false by default. Below, we range over the group ids and set true
			// if the parent sg id is found
			d.Set("self", false)

			if len(perm.UserIdGroupPairs) > 0 {
				s := perm.UserIdGroupPairs[0]

				// Check for Pair that is the same as the Security Group, to denote self.
				// Otherwise, mark the group id in source_security_group_id
				isVPC := sg.VpcId != nil && *sg.VpcId != ""
				if isVPC {
					if *s.GroupId == *sg.GroupId {
						d.Set("self", true)
						// prune the self reference from the UserIdGroupPairs, so we don't
						// have duplicate sg ids (both self and in source_security_group_id)
						perm.UserIdGroupPairs = append(perm.UserIdGroupPairs[:0], perm.UserIdGroupPairs[0+1:]...)
					}
				} else {
					if *s.GroupName == *sg.GroupName {
						d.Set("self", true)
						// prune the self reference from the UserIdGroupPairs, so we don't
						// have duplicate sg ids (both self and in source_security_group_id)
						perm.UserIdGroupPairs = append(perm.UserIdGroupPairs[:0], perm.UserIdGroupPairs[0+1:]...)
					}
				}
			}

			// XXX If the rule contained more than one source security group, this
			// will choose one of them. We actually need to create one rule for each
			// source security group.
			if err := setFromIPPerm(d, sg, perm); err != nil {
				return nil, errwrap.Wrapf("Error importing AWS Security Group: {{err}}", err)
			}
			results = append(results, d)
		}
	}

	return results, nil
}