package google

import (
	"context"
	"fmt"
	"log"

	"github.com/hashicorp/terraform/helper/schema"
	"github.com/hashicorp/terraform/helper/validation"

	"cloud.google.com/go/bigtable"
)

func resourceBigtableInstance() *schema.Resource {
	return &schema.Resource{
		Create: resourceBigtableInstanceCreate,
		Read:   resourceBigtableInstanceRead,
		Delete: resourceBigtableInstanceDestroy,

		Schema: map[string]*schema.Schema{
			"name": {
				Type:     schema.TypeString,
				Required: true,
				ForceNew: true,
			},

			"cluster": {
				Type:     schema.TypeSet,
				Required: true,
				ForceNew: true,
				MaxItems: 2,
				Elem: &schema.Resource{
					Schema: map[string]*schema.Schema{
						"cluster_id": {
							Type:     schema.TypeString,
							Required: true,
							ForceNew: true,
						},
						"zone": {
							Type:     schema.TypeString,
							Required: true,
							ForceNew: true,
						},
						"num_nodes": {
							Type:         schema.TypeInt,
							Optional:     true,
							ForceNew:     true,
							ValidateFunc: validation.IntAtLeast(3),
						},
						"storage_type": {
							Type:         schema.TypeString,
							Optional:     true,
							Default:      "SSD",
							ForceNew:     true,
							ValidateFunc: validation.StringInSlice([]string{"SSD", "HDD"}, false),
						},
					},
				},
			},

			"display_name": {
				Type:     schema.TypeString,
				Optional: true,
				ForceNew: true,
				Computed: true,
			},

			"instance_type": {
				Type:         schema.TypeString,
				Optional:     true,
				ForceNew:     true,
				Default:      "PRODUCTION",
				ValidateFunc: validation.StringInSlice([]string{"DEVELOPMENT", "PRODUCTION"}, false),
			},

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

			"cluster_id": {
				Type:     schema.TypeString,
				Optional: true,
				Computed: true,
				Removed:  "Use cluster instead.",
			},

			"zone": {
				Type:     schema.TypeString,
				Optional: true,
				Computed: true,
				Removed:  "Use cluster instead.",
			},

			"num_nodes": {
				Type:     schema.TypeInt,
				Optional: true,
				Computed: true,
				Removed:  "Use cluster instead.",
			},

			"storage_type": {
				Type:     schema.TypeString,
				Optional: true,
				Computed: true,
				Removed:  "Use cluster instead.",
			},
		},
	}
}

func resourceBigtableInstanceCreate(d *schema.ResourceData, meta interface{}) error {
	config := meta.(*Config)
	ctx := context.Background()

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

	conf := &bigtable.InstanceWithClustersConfig{
		InstanceID: d.Get("name").(string),
	}

	displayName, ok := d.GetOk("display_name")
	if !ok {
		displayName = conf.InstanceID
	}
	conf.DisplayName = displayName.(string)

	switch d.Get("instance_type").(string) {
	case "DEVELOPMENT":
		conf.InstanceType = bigtable.DEVELOPMENT
	case "PRODUCTION":
		conf.InstanceType = bigtable.PRODUCTION
	}

	conf.Clusters = expandBigtableClusters(d.Get("cluster").(*schema.Set).List(), conf.InstanceID)

	c, err := config.bigtableClientFactory.NewInstanceAdminClient(project)
	if err != nil {
		return fmt.Errorf("Error starting instance admin client. %s", err)
	}

	defer c.Close()

	err = c.CreateInstanceWithClusters(ctx, conf)
	if err != nil {
		return fmt.Errorf("Error creating instance. %s", err)
	}

	d.SetId(conf.InstanceID)

	return resourceBigtableInstanceRead(d, meta)
}

func resourceBigtableInstanceRead(d *schema.ResourceData, meta interface{}) error {
	config := meta.(*Config)
	ctx := context.Background()

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

	c, err := config.bigtableClientFactory.NewInstanceAdminClient(project)
	if err != nil {
		return fmt.Errorf("Error starting instance admin client. %s", err)
	}

	defer c.Close()

	instance, err := c.InstanceInfo(ctx, d.Id())
	if err != nil {
		log.Printf("[WARN] Removing %s because it's gone", d.Id())
		d.SetId("")
		return fmt.Errorf("Error retrieving instance. Could not find %s. %s", d.Id(), err)
	}

	d.Set("project", project)

	clusters := d.Get("cluster").(*schema.Set).List()
	clusterState := []map[string]interface{}{}
	for _, cl := range clusters {
		cluster := cl.(map[string]interface{})
		clus, err := c.GetCluster(ctx, instance.Name, cluster["cluster_id"].(string))
		if err != nil {
			if isGoogleApiErrorWithCode(err, 404) {
				log.Printf("[WARN] Cluster %q not found, not setting it in state", cluster["cluster_id"].(string))
				continue
			}
			return fmt.Errorf("Error retrieving cluster %q: %s", cluster["cluster_id"].(string), err.Error())
		}
		clusterState = append(clusterState, flattenBigtableCluster(clus, cluster["storage_type"].(string)))
	}

	err = d.Set("cluster", clusterState)
	if err != nil {
		return fmt.Errorf("Error setting clusters in state: %s", err.Error())
	}

	d.Set("name", instance.Name)
	d.Set("display_name", instance.DisplayName)

	return nil
}

func resourceBigtableInstanceDestroy(d *schema.ResourceData, meta interface{}) error {
	config := meta.(*Config)
	ctx := context.Background()

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

	c, err := config.bigtableClientFactory.NewInstanceAdminClient(project)
	if err != nil {
		return fmt.Errorf("Error starting instance admin client. %s", err)
	}

	defer c.Close()

	name := d.Id()
	err = c.DeleteInstance(ctx, name)
	if err != nil {
		return fmt.Errorf("Error deleting instance. %s", err)
	}

	d.SetId("")

	return nil
}

func flattenBigtableCluster(c *bigtable.ClusterInfo, storageType string) map[string]interface{} {
	return map[string]interface{}{
		"zone":         c.Zone,
		"num_nodes":    c.ServeNodes,
		"cluster_id":   c.Name,
		"storage_type": storageType,
	}
}

func expandBigtableClusters(clusters []interface{}, instanceID string) []bigtable.ClusterConfig {
	results := make([]bigtable.ClusterConfig, 0, len(clusters))
	for _, c := range clusters {
		cluster := c.(map[string]interface{})
		zone := cluster["zone"].(string)
		var storageType bigtable.StorageType
		switch cluster["storage_type"].(string) {
		case "SSD":
			storageType = bigtable.SSD
		case "HDD":
			storageType = bigtable.HDD
		}
		results = append(results, bigtable.ClusterConfig{
			InstanceID:  instanceID,
			Zone:        zone,
			ClusterID:   cluster["cluster_id"].(string),
			NumNodes:    int32(cluster["num_nodes"].(int)),
			StorageType: storageType,
		})
	}
	return results
}