feat: oidc (#605)

* chore: add oidc base config

* wip: authorize page

* feat: implement basic oidc functionality

* refactor: implement oidc following tinyauth patterns

* feat: adapt frontend to oidc flow

* fix: review comments

* fix: oidc review comments

* feat: refresh token grant type support

* feat: cleanup expired oidc sessions

* feat: frontend i18n

* fix: fix typo in error screen

* tests: add basic testing

* fix: more review comments

* refactor: rework oidc error messages

* feat: openid discovery endpoint

* feat: jwk endpoint

* i18n: fix typo

* fix: more rabbit nitpicks

* fix: final review comments

* i18n: authorize page error messages

frontend/src/lib/hooks/oidc.ts

@@ -0,0 +1,53 @@
+export type OIDCValues = {
+  scope: string;
+  response_type: string;
+  client_id: string;
+  redirect_uri: string;
+  state: string;
+};
+
+interface IuseOIDCParams {
+  values: OIDCValues;
+  compiled: string;
+  isOidc: boolean;
+  missingParams: string[];
+}
+
+const optionalParams: string[] = ["state"];
+
+export function useOIDCParams(params: URLSearchParams): IuseOIDCParams {
+  let compiled: string = "";
+  let isOidc = false;
+  const missingParams: string[] = [];
+
+  const values: OIDCValues = {
+    scope: params.get("scope") ?? "",
+    response_type: params.get("response_type") ?? "",
+    client_id: params.get("client_id") ?? "",
+    redirect_uri: params.get("redirect_uri") ?? "",
+    state: params.get("state") ?? "",
+  };
+
+  for (const key of Object.keys(values)) {
+    if (!values[key as keyof OIDCValues]) {
+      if (!optionalParams.includes(key)) {
+        missingParams.push(key);
+      }
+    }
+  }
+
+  if (missingParams.length === 0) {
+    isOidc = true;
+  }
+
+  if (isOidc) {
+    compiled = new URLSearchParams(values).toString();
+  }
+
+  return {
+    values,
+    compiled,
+    isOidc,
+    missingParams,
+  };
+}