Fix collection data source read

Signed-off-by: KeisukeYamashita <19yamashita15@gmail.com>

typesense/data_source_collection.go

@@ -1,12 +1,16 @@
 package typesense
 
 import (
+	"context"
+	"log"
+
+	"github.com/hashicorp/terraform-plugin-sdk/v2/diag"
 	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
+	"github.com/typesense/typesense-go/typesense"
 )
 
 func dataSourceTypesenseCollection() *schema.Resource {
 	return &schema.Resource{
-		ReadContext: resourceTypesenseCollectionRead,
 		Description: "Group of related documents which are roughly equivalent to a table in a relational database.",
 		Schema: map[string]*schema.Schema{
 			"name": {
@@ -55,5 +59,38 @@ func dataSourceTypesenseCollection() *schema.Resource {
 				Computed: true,
 			},
 		},
+		ReadContext: dataSourceTypesenseCollectionRead,
+	}
+}
+
+func dataSourceTypesenseCollectionRead(ctx context.Context, d *schema.ResourceData, meta interface{}) diag.Diagnostics {
+	client := meta.(*typesense.Client)
+
+	var diags diag.Diagnostics
+
+	collection, err := client.Collection(d.Get("name").(string)).Retrieve()
+	if err != nil {
+		d.SetId("")
+		return diag.FromErr(err)
+	}
+
+	log.Printf("[DEBUG] Got collection name:%s\n", collection.Name)
+
+	if err := d.Set("name", collection.Name); err != nil {
+		return diag.FromErr(err)
+	}
+
+	if err := d.Set("fields", flattenCollectionFields(collection.Fields)); err != nil {
+		return diag.FromErr(err)
+	}
+
+	if err := d.Set("default_sorting_field", collection.DefaultSortingField); err != nil {
+		return diag.FromErr(err)
+	}
+
+	if err := d.Set("num_documents", collection.NumDocuments); err != nil {
+		return diag.FromErr(err)
 	}
+
+	return diags
 }