Add providers buttons on login page

src/data/provider.rs

@@ -1,4 +1,5 @@
 use crate::data::entity_manager::EntityManager;
+use crate::data::login_redirect::LoginRedirect;
 use crate::utils::string_utils::apply_env_vars;
 
 #[derive(Clone, Debug, serde::Serialize, serde::Deserialize, Eq, PartialEq)]
@@ -28,6 +29,11 @@ pub struct Provider {
 }
 
 impl Provider {
+    /// Get URL-encoded provider id
+    pub fn id_encoded(&self) -> String {
+        urlencoding::encode(&self.id.0).to_string()
+    }
+
     /// Get the URL where the logo can be located
     pub fn logo_url(&self) -> &str {
         match self.logo.as_str() {
@@ -39,6 +45,15 @@ impl Provider {
             s => s,
         }
     }
+
+    /// Get the URL to use to login with the provider
+    pub fn login_url(&self, redirect_url: &LoginRedirect) -> String {
+        format!(
+            "/login_with_prov?id={}&redirect_url={}",
+            self.id_encoded(),
+            redirect_url.get_encoded()
+        )
+    }
 }
 
 impl PartialEq for Provider {