3 files changed, 72 insertions, 0 deletions
diff --git a/src/actions/mixins/api/auth/helpers.cr b/src/actions/mixins/api/auth/helpers.cr
new file mode 100644
index 0000000..6b51cb5
--- /dev/null
+++ b/src/actions/mixins/api/auth/helpers.cr
@@ -0,0 +1,28 @@
+module Api::Auth::Helpers
+  # The 'memoize' macro makes sure only one query is issued to find the user
+  memoize def current_user? : User?
+    auth_token.try do |value|
+      user_from_auth_token(value)
+    end
+  end
+
+  private def auth_token : String?
+    bearer_token || token_param
+  end
+
+  private def bearer_token : String?
+    context.request.headers["Authorization"]?
+      .try(&.gsub("Bearer", ""))
+      .try(&.strip)
+  end
+
+  private def token_param : String?
+    params.get?(:auth_token)
+  end
+
+  private def user_from_auth_token(token : String) : User?
+    UserToken.decode_user_id(token).try do |user_id|
+      UserQuery.new.id(user_id).first?
+    end
+  end
+end
diff --git a/src/actions/mixins/api/auth/require_auth_token.cr b/src/actions/mixins/api/auth/require_auth_token.cr
new file mode 100644
index 0000000..e018638
--- /dev/null
+++ b/src/actions/mixins/api/auth/require_auth_token.cr
@@ -0,0 +1,34 @@
+module Api::Auth::RequireAuthToken
+  macro included
+    before require_auth_token
+  end
+
+  private def require_auth_token
+    if current_user?
+      continue
+    else
+      json auth_error_json, 401
+    end
+  end
+
+  private def auth_error_json
+    ErrorSerializer.new(
+      message: "Not authenticated.",
+      details: auth_error_details
+    )
+  end
+
+  private def auth_error_details : String
+    if auth_token
+      "The provided authentication token was incorrect."
+    else
+      "An authentication token is required. Please include a token in an 'auth_token' param or 'Authorization' header."
+    end
+  end
+
+  # Tells the compiler that the current_user is not nil since we have checked
+  # that the user is signed in
+  private def current_user : User
+    current_user?.as(User)
+  end
+end
diff --git a/src/actions/mixins/api/auth/skip_require_auth_token.cr b/src/actions/mixins/api/auth/skip_require_auth_token.cr
new file mode 100644
index 0000000..68098cf
--- /dev/null
+++ b/src/actions/mixins/api/auth/skip_require_auth_token.cr
@@ -0,0 +1,10 @@
+module Api::Auth::SkipRequireAuthToken
+  macro included
+    skip require_auth_token
+  end
+
+  # Since sign in is not required, current_user might be nil
+  def current_user : User?
+    current_user?
+  end
+end