package google

import (
	"fmt"
	"log"

	"github.com/hashicorp/terraform/helper/schema"
	"google.golang.org/api/compute/v1"
)

const computeImageCreateTimeoutDefault = 4

func resourceComputeImage() *schema.Resource {
	return &schema.Resource{
		Create: resourceComputeImageCreate,
		Read:   resourceComputeImageRead,
		Update: resourceComputeImageUpdate,
		Delete: resourceComputeImageDelete,
		Importer: &schema.ResourceImporter{
			State: resourceComputeImageImportState,
		},

		Schema: map[string]*schema.Schema{
			// TODO(cblecker): one of source_disk or raw_disk is required

			"name": &schema.Schema{
				Type:     schema.TypeString,
				Required: true,
				ForceNew: true,
			},

			"description": &schema.Schema{
				Type:     schema.TypeString,
				Optional: true,
				ForceNew: true,
			},

			"family": &schema.Schema{
				Type:     schema.TypeString,
				Optional: true,
				ForceNew: true,
			},

			"project": &schema.Schema{
				Type:     schema.TypeString,
				Optional: true,
				ForceNew: true,
			},

			"source_disk": &schema.Schema{
				Type:     schema.TypeString,
				Optional: true,
				ForceNew: true,
			},

			"raw_disk": &schema.Schema{
				Type:     schema.TypeList,
				Optional: true,
				ForceNew: true,
				MaxItems: 1,
				Elem: &schema.Resource{
					Schema: map[string]*schema.Schema{
						"source": &schema.Schema{
							Type:     schema.TypeString,
							Required: true,
							ForceNew: true,
						},
						"sha1": &schema.Schema{
							Type:     schema.TypeString,
							Optional: true,
							ForceNew: true,
						},
						"container_type": &schema.Schema{
							Type:     schema.TypeString,
							Optional: true,
							Default:  "TAR",
							ForceNew: true,
						},
					},
				},
			},

			"self_link": &schema.Schema{
				Type:     schema.TypeString,
				Computed: true,
			},

			"create_timeout": &schema.Schema{
				Type:     schema.TypeInt,
				Optional: true,
				Default:  computeImageCreateTimeoutDefault,
			},
		},
	}
}

func resourceComputeImageCreate(d *schema.ResourceData, meta interface{}) error {
	config := meta.(*Config)

	project, err := getProject(d, config)
	if err != nil {
		return err
	}

	// Build the image
	image := &compute.Image{
		Name: d.Get("name").(string),
	}

	if v, ok := d.GetOk("description"); ok {
		image.Description = v.(string)
	}

	if v, ok := d.GetOk("family"); ok {
		image.Family = v.(string)
	}

	// Load up the source_disk for this image if specified
	if v, ok := d.GetOk("source_disk"); ok {
		image.SourceDisk = v.(string)
	}

	// Load up the raw_disk for this image if specified
	if v, ok := d.GetOk("raw_disk"); ok {
		rawDiskEle := v.([]interface{})[0].(map[string]interface{})
		imageRawDisk := &compute.ImageRawDisk{
			Source:        rawDiskEle["source"].(string),
			ContainerType: rawDiskEle["container_type"].(string),
		}
		if val, ok := rawDiskEle["sha1"]; ok {
			imageRawDisk.Sha1Checksum = val.(string)
		}

		image.RawDisk = imageRawDisk
	}

	// Read create timeout
	var createTimeout int
	if v, ok := d.GetOk("create_timeout"); ok {
		createTimeout = v.(int)
	}

	// Insert the image
	op, err := config.clientCompute.Images.Insert(
		project, image).Do()
	if err != nil {
		return fmt.Errorf("Error creating image: %s", err)
	}

	// Store the ID
	d.SetId(image.Name)

	err = computeOperationWaitGlobalTime(config, op, project, "Creating Image", createTimeout)
	if err != nil {
		return err
	}

	return resourceComputeImageRead(d, meta)
}

func resourceComputeImageRead(d *schema.ResourceData, meta interface{}) error {
	config := meta.(*Config)

	project, err := getProject(d, config)
	if err != nil {
		return err
	}

	image, err := config.clientCompute.Images.Get(
		project, d.Id()).Do()
	if err != nil {
		return handleNotFoundError(err, d, fmt.Sprintf("Image %q", d.Get("name").(string)))
	}

	if image.SourceDisk != "" {
		d.Set("source_disk", image.SourceDisk)
	} else if image.RawDisk != nil {
		// `raw_disk.*.source` is only used at image creation but is not returned when calling Get.
		// `raw_disk.*.sha1` is not supported, the value is simply discarded by the server.
		// Leaving `raw_disk` to current state value.
	} else {
		return fmt.Errorf("Either raw_disk or source_disk configuration is required.")
	}

	d.Set("name", image.Name)
	d.Set("description", image.Description)
	d.Set("family", image.Family)
	d.Set("self_link", image.SelfLink)

	return nil
}

func resourceComputeImageUpdate(d *schema.ResourceData, meta interface{}) error {
	// Pass-through for updates to Terraform-specific `create_timeout` field.
	// The Google Cloud Image resource doesn't support update.
	return nil
}

func resourceComputeImageDelete(d *schema.ResourceData, meta interface{}) error {
	config := meta.(*Config)

	project, err := getProject(d, config)
	if err != nil {
		return err
	}

	// Delete the image
	log.Printf("[DEBUG] image delete request")
	op, err := config.clientCompute.Images.Delete(
		project, d.Id()).Do()
	if err != nil {
		return fmt.Errorf("Error deleting image: %s", err)
	}

	err = computeOperationWaitGlobal(config, op, project, "Deleting image")
	if err != nil {
		return err
	}

	d.SetId("")
	return nil
}

func resourceComputeImageImportState(d *schema.ResourceData, meta interface{}) ([]*schema.ResourceData, error) {
	// `create_timeout` field is specific to this Terraform resource implementation. Thus, this value cannot be
	// imported from the Google Cloud REST API.
	// Setting to default value otherwise Terraform requires a ForceNew to change the resource to match the
	// default `create_timeout`.
	d.Set("create_timeout", computeImageCreateTimeoutDefault)

	return []*schema.ResourceData{d}, nil
}