feat: add group resource (#6)

* feat: add group resource

* docs: add docs for group resource

internal/provider/resource_group.go

@@ -0,0 +1,172 @@
+package provider
+
+import (
+	"fmt"
+
+	"github.com/hashicorp/terraform-plugin-sdk/helper/schema"
+	"github.com/hashicorp/watchtower/api/groups"
+	"github.com/hashicorp/watchtower/api/scopes"
+)
+
+const (
+	groupNameKey        = "name"
+	groupDescriptionKey = "description"
+)
+
+func resourceGroup() *schema.Resource {
+	return &schema.Resource{
+		Create: resourceGroupCreate,
+		Read:   resourceGroupRead,
+		Update: resourceGroupUpdate,
+		Delete: resourceGroupDelete,
+		Schema: map[string]*schema.Schema{
+			groupNameKey: {
+				Type:     schema.TypeString,
+				Optional: true,
+			},
+			groupDescriptionKey: {
+				Type:     schema.TypeString,
+				Optional: true,
+			},
+		},
+	}
+
+}
+
+// convertGroupToResourceData creates a ResourceData type from a Group
+func convertGroupToResourceData(u *groups.Group, d *schema.ResourceData) error {
+	if u.Name != nil {
+		if err := d.Set(groupNameKey, u.Name); err != nil {
+			return err
+		}
+	}
+
+	if u.Description != nil {
+		if err := d.Set(groupDescriptionKey, u.Description); err != nil {
+			return err
+		}
+	}
+
+	d.SetId(u.Id)
+
+	return nil
+}
+
+// convertResourceDataToGroup returns a localy built Group using the values provided in the ResourceData.
+func convertResourceDataToGroup(d *schema.ResourceData) *groups.Group {
+	u := &groups.Group{}
+	if descVal, ok := d.GetOk(groupDescriptionKey); ok {
+		desc := descVal.(string)
+		u.Description = &desc
+	}
+	if nameVal, ok := d.GetOk(groupNameKey); ok {
+		name := nameVal.(string)
+		u.Name = &name
+	}
+
+	if d.Id() != "" {
+		u.Id = d.Id()
+	}
+
+	return u
+}
+
+func resourceGroupCreate(d *schema.ResourceData, meta interface{}) error {
+	md := meta.(*metaData)
+	client := md.client
+	ctx := md.ctx
+
+	o := &scopes.Organization{
+		Client: client,
+	}
+
+	u := convertResourceDataToGroup(d)
+
+	u, apiErr, err := o.CreateGroup(ctx, u)
+	if err != nil {
+		return fmt.Errorf("error calling new group: %s", err.Error())
+	}
+	if apiErr != nil {
+		return fmt.Errorf("error creating group: %s", *apiErr.Message)
+	}
+
+	d.SetId(u.Id)
+
+	return nil
+}
+
+func resourceGroupRead(d *schema.ResourceData, meta interface{}) error {
+	md := meta.(*metaData)
+	client := md.client
+	ctx := md.ctx
+
+	o := &scopes.Organization{
+		Client: client,
+	}
+
+	u := convertResourceDataToGroup(d)
+
+	u, apiErr, err := o.ReadGroup(ctx, u)
+	if err != nil {
+		return fmt.Errorf("error reading group: %s", err.Error())
+	}
+	if apiErr != nil {
+		return fmt.Errorf("error reading group: %s", *apiErr.Message)
+	}
+
+	return convertGroupToResourceData(u, d)
+}
+
+func resourceGroupUpdate(d *schema.ResourceData, meta interface{}) error {
+	md := meta.(*metaData)
+	client := md.client
+	ctx := md.ctx
+
+	o := &scopes.Organization{
+		Client: client,
+	}
+
+	u := convertResourceDataToGroup(d)
+
+	if d.HasChange(groupNameKey) {
+		n := d.Get(groupNameKey).(string)
+		u.Name = &n
+	}
+
+	if d.HasChange(groupDescriptionKey) {
+		d := d.Get(groupDescriptionKey).(string)
+		u.Description = &d
+	}
+
+	u, apiErr, err := o.UpdateGroup(ctx, u)
+	if err != nil {
+		return err
+	}
+	if apiErr != nil {
+		return fmt.Errorf("error updating group: %s\n   Invalid request fields: %v\n", *apiErr.Message, apiErr.Details.RequestFields)
+	}
+
+	return convertGroupToResourceData(u, d)
+}
+
+func resourceGroupDelete(d *schema.ResourceData, meta interface{}) error {
+	md := meta.(*metaData)
+	client := md.client
+	ctx := md.ctx
+
+	o := &scopes.Organization{
+		Client: client,
+	}
+
+	u := convertResourceDataToGroup(d)
+
+	_, apiErr, err := o.DeleteGroup(ctx, u)
+	if err != nil {
+		return fmt.Errorf("error deleting group: %s", err.Error())
+	}
+	if apiErr != nil {
+		return fmt.Errorf("error deleting group: %s", *apiErr.Message)
+	}
+
+	return nil
+}