From 9ac7786c14d18b5b7cfe623ec59da8978159b492 Mon Sep 17 00:00:00 2001
From: Ben F <benj-fletch@users.noreply.github.com>
Date: Thu, 13 Feb 2020 14:00:33 +0000
Subject: [PATCH] GH-144 - Added handling for retrieving releases by various
 methods

---
 github/data_source_github_release.go | 43 +++++++++++++++++++++++++---
 1 file changed, 39 insertions(+), 4 deletions(-)

diff --git a/github/data_source_github_release.go b/github/data_source_github_release.go
index 91f4606d86..ad71bd9750 100644
--- a/github/data_source_github_release.go
+++ b/github/data_source_github_release.go
@@ -2,9 +2,12 @@ package github
 
 import (
 	"context"
+	"errors"
 	"log"
 	"strconv"
+	"strings"
 
+	"github.com/google/go-github/v28/github"
 	"github.com/hashicorp/terraform/helper/schema"
 )
 
@@ -21,9 +24,17 @@ func dataSourceGithubRelease() *schema.Resource {
 				Type:     schema.TypeString,
 				Required: true,
 			},
+			"retrieve_by": {
+				Type:     schema.TypeString,
+				Required: true,
+			},
+			"release_tag": {
+				Type:     schema.TypeString,
+				Optional: true,
+			},
 			"release_id": {
 				Type:     schema.TypeInt,
-				Required: true,
+				Optional: true,
 			},
 			"url": {
 				Type:     schema.TypeString,
@@ -36,13 +47,37 @@ func dataSourceGithubRelease() *schema.Resource {
 func dataSourceGithubReleaseRead(d *schema.ResourceData, meta interface{}) error {
 	repository := d.Get("repository").(string)
 	owner := d.Get("owner").(string)
-	releaseID := int64(d.Get("release_id").(int))
-	log.Printf("[INFO] Refreshing GitHub release %s from repository %s", releaseID, repository)
 
 	client := meta.(*Organization).client
 	ctx := context.Background()
 
-	release, _, err := client.Repositories.GetRelease(ctx, owner, repository, releaseID)
+	var err error
+	var release *github.RepositoryRelease
+
+	switch retrieveBy := strings.ToLower(d.Get("retrieve_by").(string)); retrieveBy {
+	case "latest":
+		log.Printf("[INFO] Refreshing GitHub latest release from repository %s", repository)
+		release, _, err = client.Repositories.GetLatestRelease(ctx, owner, repository)
+	case "id":
+		releaseID := int64(d.Get("release_id").(int))
+		if releaseID == 0 {
+			return errors.New("'release_id' must be set when 'retrieve_by' = 'id'")
+		}
+
+		log.Printf("[INFO] Refreshing GitHub release by id %s from repository %s", releaseID, repository)
+		release, _, err = client.Repositories.GetRelease(ctx, owner, repository, releaseID)
+	case "tag":
+		tag := d.Get("release_tag").(string)
+		if tag == "" {
+			return errors.New("'release_tag' must be set when 'retrieve_by' = 'tag'")
+		}
+
+		log.Printf("[INFO] Refreshing GitHub release by tag %s from repository %s", tag, repository)
+		release, _, err = client.Repositories.GetReleaseByTag(ctx, owner, repository, tag)
+	default:
+		return errors.New("One of: 'latest', 'id', 'tag' must be set for 'retrieve_by'")
+	}
+
 	if err != nil {
 		return err
 	}