Add conversation and message model selection

internal/service/static/js/storage.js

@@ -11,7 +11,9 @@
  * - odidere_system_message: the system message used when the next
  *   conversation is created. It does not change a conversation that
  *   already exists.
- * - odidere_provider, odidere_model, odidere_voice: selections.
+ * - odidere_provider, odidere_model, odidere_voice: default selections.
+ * - odidere_conversation_models: per-conversation provider and model
+ *   selections, keyed by conversation ID.
  * - odidere_max_turns, odidere_reasoning_budget: compose settings.
  * - odidere_mute: whether speech playback is muted.
  *
@@ -20,6 +22,7 @@
  */
 
 const CONVERSATION_KEY = 'odidere_conversation';
+const CONVERSATION_MODELS_KEY = 'odidere_conversation_models';
 const SYSTEM_MESSAGE_KEY = 'odidere_system_message';
 const PROVIDER_KEY = 'odidere_provider';
 const MODEL_KEY = 'odidere_model';
@@ -100,7 +103,7 @@ export class Storage {
   }
 
   /**
-   * setModelSelection stores the selected provider and model.
+   * setModelSelection stores the default provider and model.
    * @param {{provider: string, model: string}} selection
    */
   setModelSelection({ provider, model }) {
@@ -108,6 +111,92 @@ export class Storage {
     localStorage.setItem(MODEL_KEY, model);
   }
 
+  /**
+   * _loadConversationModels reads the per-conversation model map.
+   * @returns {Object<string, {provider: string, model: string}>}
+   * @private
+   */
+  _loadConversationModels() {
+    try {
+      const parsed = JSON.parse(localStorage.getItem(CONVERSATION_MODELS_KEY));
+      return parsed && typeof parsed === 'object' && !Array.isArray(parsed)
+        ? parsed
+        : {};
+    } catch (error) {
+      console.error('failed to load conversation models:', error);
+      return {};
+    }
+  }
+
+  /**
+   * getConversationModel returns the provider and model stored for
+   * one conversation, or null fields when none is stored.
+   * @param {string} id - conversation ID.
+   * @returns {{provider: string | null, model: string | null}}
+   */
+  getConversationModel(id) {
+    const entry = this._loadConversationModels()[id];
+    return {
+      provider: entry?.provider || null,
+      model: entry?.model || null,
+    };
+  }
+
+  /**
+   * setConversationModel stores the provider and model for one
+   * conversation.
+   * @param {string} id - conversation ID.
+   * @param {{provider: string, model: string}} selection
+   */
+  setConversationModel(id, { provider, model }) {
+    if (!id || !provider || !model) return;
+    try {
+      const map = this._loadConversationModels();
+      map[id] = { provider, model };
+      localStorage.setItem(CONVERSATION_MODELS_KEY, JSON.stringify(map));
+    } catch (error) {
+      console.error('failed to save conversation model:', error);
+    }
+  }
+
+  /**
+   * deleteConversationModel removes the stored model entry for one
+   * conversation.
+   * @param {string} id - conversation ID.
+   */
+  deleteConversationModel(id) {
+    if (!id) return;
+    try {
+      const map = this._loadConversationModels();
+      if (!(id in map)) return;
+      delete map[id];
+      localStorage.setItem(CONVERSATION_MODELS_KEY, JSON.stringify(map));
+    } catch (error) {
+      console.error('failed to delete conversation model:', error);
+    }
+  }
+
+  /**
+   * pruneConversationModels removes stored model entries for
+   * conversations that no longer exist on the server (for example,
+   * conversations deleted from another device or browser tab), so
+   * the localStorage map does not grow without bound.
+   * @param {Iterable<string>} validIds - conversation IDs currently
+   *   on the server.
+   */
+  pruneConversationModels(validIds) {
+    try {
+      const keep = new Set(validIds);
+      const map = this._loadConversationModels();
+      for (const id of Object.keys(map)) {
+        if (!keep.has(id)) delete map[id];
+      }
+      localStorage.setItem(CONVERSATION_MODELS_KEY, JSON.stringify(map));
+    } catch (error) {
+      console.error('failed to prune conversation models:', error);
+    }
+  }
+
   /** @returns {string} the selected voice, or '' for automatic */
   getVoice() {
     return localStorage.getItem(VOICE_KEY) || '';