add: release show api

app/services/gitea/versions/get_service.rb

@@ -0,0 +1,37 @@
+# Get a list of all commits from a repository
+class Gitea::Versions::GetService < Gitea::ClientService
+  attr_reader :token, :user_name, :repo, :gid, :args
+
+  # sha: SHA or branch to start listing commits from (usually 'master')
+  def initialize(token, user_name, repo, gid, args={})
+    @token = token
+    @user_name = user_name
+    @repo = repo
+    @gid = gid
+    @args = args
+  end
+
+  def call
+    response = get(url, params)
+    render_result(response)
+  end
+
+  private
+  def params
+    args.merge(token: token)
+  end
+
+  def url
+    "/repos/#{@user_name}/#{@repo}/releases/#{@gid}".freeze
+  end
+
+  def render_result(response)
+    body = JSON.parse(response.body)
+    case response.status
+    when 200
+      body
+    else
+      {status: -1, message: "#{body['message']}"}
+    end
+  end
+end