feat(core): flesh out TotpCore + TotpConfig + TotpAlgorithm + TotpKind

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/idfoto-core/src/item_types/totp.rs

@@ -1,10 +1,38 @@
+//! TOTP: standalone 2FA item type. Also reused as TotpConfig field on Login.
+
 use serde::{Deserialize, Serialize};
+use zeroize::Zeroizing;
 
 #[derive(Debug, Clone, Serialize, Deserialize, Default)]
-pub struct TotpCore {}
+pub struct TotpCore {
+    pub config: TotpConfig,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub issuer: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub label: Option<String>,
+}
 
-#[derive(Debug, Clone, Serialize, Deserialize, Default)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
-pub struct TotpConfig {}
+pub struct TotpConfig {
+    /// Raw bytes of the TOTP secret (decoded from base32 when imported).
+    pub secret: Zeroizing<Vec<u8>>,
+    pub algorithm: TotpAlgorithm,
+    pub digits: u8,
+    pub period_seconds: u32,
+    pub kind: TotpKind,
+}
+
+impl Default for TotpConfig {
+    fn default() -> Self {
+        Self {
+            secret: Zeroizing::new(Vec::new()),
+            algorithm: TotpAlgorithm::Sha1,
+            digits: 6,
+            period_seconds: 30,
+            kind: TotpKind::Totp,
+        }
+    }
+}
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, Default)]
 #[serde(rename_all = "snake_case")]
@@ -15,7 +43,7 @@ pub enum TotpAlgorithm {
     Sha512,
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
 #[serde(rename_all = "snake_case")]
 pub enum TotpKind {
     Totp,
@@ -26,3 +54,55 @@ pub enum TotpKind {
 impl Default for TotpKind {
     fn default() -> Self { TotpKind::Totp }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn totp_default_is_sha1_6_30_totp() {
+        let cfg = TotpConfig::default();
+        assert_eq!(cfg.algorithm, TotpAlgorithm::Sha1);
+        assert_eq!(cfg.digits, 6);
+        assert_eq!(cfg.period_seconds, 30);
+        assert_eq!(cfg.kind, TotpKind::Totp);
+    }
+
+    #[test]
+    fn totp_round_trip() {
+        let core = TotpCore {
+            config: TotpConfig {
+                secret: Zeroizing::new(vec![0x12, 0x34, 0x56]),
+                algorithm: TotpAlgorithm::Sha256,
+                digits: 8,
+                period_seconds: 60,
+                kind: TotpKind::Totp,
+            },
+            issuer: Some("github".into()),
+            label: Some("alice@github".into()),
+        };
+        let json = serde_json::to_string(&core).unwrap();
+        let parsed: TotpCore = serde_json::from_str(&json).unwrap();
+        assert_eq!(parsed.config.digits, 8);
+        assert_eq!(parsed.config.algorithm, TotpAlgorithm::Sha256);
+        assert_eq!(parsed.issuer.as_deref(), Some("github"));
+    }
+
+    #[test]
+    fn hotp_carries_counter() {
+        let cfg = TotpConfig { kind: TotpKind::Hotp { counter: 42 }, ..TotpConfig::default() };
+        let json = serde_json::to_string(&cfg).unwrap();
+        let parsed: TotpConfig = serde_json::from_str(&json).unwrap();
+        match parsed.kind {
+            TotpKind::Hotp { counter } => assert_eq!(counter, 42),
+            other => panic!("expected Hotp, got {:?}", other),
+        }
+    }
+
+    #[test]
+    fn steam_kind_serializes() {
+        let cfg = TotpConfig { kind: TotpKind::Steam, ..TotpConfig::default() };
+        let json = serde_json::to_string(&cfg).unwrap();
+        assert!(json.contains("steam"));
+    }
+}