Fix chat completions response handling

AGENTS.md

@@ -10,7 +10,7 @@ This file provides guidelines for codex agents contributing to the Sortana proje
 - `options/`: The options page HTML, JavaScript and bundled Bulma CSS (v1.0.3).
 - `details.html` and `details.js`: View AI reasoning and clear cache for a message.
 - `resources/`: Images and other static files.
-- `prompt_templates/`: Provider-specific templated message formats for non-OpenAI flows (qwen, mistral, harmony, plus legacy openai template material kept in-repo).
+- `prompt_templates/`: Custom/legacy templated message material kept in-repo for non-native prompt flows.
 - `build-xpi.ps1`: PowerShell script to package the extension.
 - `build-xpi.sh`: Bash script to package the extension.
 
@@ -36,7 +36,7 @@ There are currently no automated tests for this project. If you add tests in the
 Sortana targets `POST /v1/chat/completions`. The endpoint value stored in settings is a base URL; the full request URL is constructed by appending `/v1/chat/completions` (adding a slash when needed) and defaulting to `https://` if no scheme is provided. Endpoint normalization strips a trailing `/v1`, `/v1/chat/completions`, `/v1/completions`, or `/v1/models`.
 The options page can query `/v1/models` from the same base URL to populate the Model dropdown; selecting **None** omits the `model` field from the request payload.
 Advanced options allow an optional API key plus `OpenAI-Organization` and `OpenAI-Project` headers; these headers are only sent when values are provided.
-Requests use a Chat Completions `messages` array and ask for strict JSON schema output via `response_format`. Responses are parsed from `choices[0].message`, with `match` as a boolean and `reason` as a short string. Unsupported OpenAI sampling fields are filtered out, and the saved `max_tokens` setting is translated to `max_completion_tokens`.
+Requests use a Chat Completions `messages` array and ask for strict JSON schema output via `response_format`. Built-in request formats send native `system` and `user` chat messages; only the custom format sends a single templated user message. Responses are parsed from `choices[0].message`, with `match` as a boolean and `reason` as a short string, and parsing falls back to the last JSON object if a backend prepends extra reasoning text. Unsupported OpenAI sampling fields are filtered out, and the saved `max_tokens` setting is translated to `max_completion_tokens`.
 
 ## Documentation
 

README.md

@@ -15,7 +15,7 @@ Classification requests ask the model for structured JSON output with a required
 - **Configurable endpoint** – set the classification service base URL on the options page.
 - **Model selection** – load available models from the endpoint and choose one (or omit the model field).
 - **Optional OpenAI auth headers** – provide an API key plus optional organization/project headers when needed.
-- **Request formats** – use native OpenAI chat messages or choose Qwen, Mistral, Harmony (gpt-oss), or a custom templated message format.
+- **Request formats** – built-in formats use native chat messages; a custom format can still send one templated user message when needed.
 - **Custom system prompts** – tailor the instructions sent to the model for more precise results.
 - **Persistent result caching** – classification results and reasoning are saved to disk so messages aren't re-evaluated across restarts.
 - **Advanced parameters** – tune generation settings like temperature and top‑p from the options page. Unsupported OpenAI sampling fields are filtered out automatically.

modules/AiClassifier.js

@@ -268,7 +268,7 @@ Classification criterion: ${criterion}`;
 }
 
 function buildMessages(body, criterion) {
-  if (gTemplateName === "openai") {
+  if (gTemplateName !== "custom") {
     return [
       {
         role: "system",
@@ -391,6 +391,56 @@ function extractMessageContent(content) {
   };
 }
 
+function extractLastJsonObject(text) {
+  if (typeof text !== "string" || !text) {
+    return null;
+  }
+
+  let last = null;
+  let start = -1;
+  let depth = 0;
+  let inString = false;
+  let escape = false;
+
+  for (let i = 0; i < text.length; i += 1) {
+    const ch = text[i];
+    if (inString) {
+      if (escape) {
+        escape = false;
+        continue;
+      }
+      if (ch === "\\") {
+        escape = true;
+        continue;
+      }
+      if (ch === "\"") {
+        inString = false;
+      }
+      continue;
+    }
+    if (ch === "\"") {
+      inString = true;
+      continue;
+    }
+    if (ch === "{") {
+      if (depth === 0) {
+        start = i;
+      }
+      depth += 1;
+      continue;
+    }
+    if (ch === "}" && depth > 0) {
+      depth -= 1;
+      if (depth === 0 && start !== -1) {
+        last = text.slice(start, i + 1);
+        start = -1;
+      }
+    }
+  }
+
+  return last;
+}
+
 function parseMatch(result) {
   const message = result?.choices?.[0]?.message;
   if (!message || typeof message !== "object") {
@@ -424,9 +474,18 @@ function parseMatch(result) {
   try {
     obj = JSON.parse(extracted.text);
   } catch (e) {
+    const candidate = extractLastJsonObject(extracted.text);
+    if (!candidate) {
       reportParseError("Failed to parse JSON from AI response.", extracted.text.slice(0, 800));
       return { matched: false, reason: "" };
     }
+    try {
+      obj = JSON.parse(candidate);
+    } catch (inner) {
+      reportParseError("Failed to parse JSON from AI response.", extracted.text.slice(0, 800));
+      return { matched: false, reason: "" };
+    }
+  }
 
   if (typeof obj?.match !== "boolean") {
     reportParseError("AI response missing valid match boolean.", extracted.text.slice(0, 800));

options/options.html

@@ -99,7 +99,7 @@
                             <select id="template"></select>
                         </div>
                     </div>
-                    <p class="help">OpenAI Chat uses native chat messages. Other formats send one templated user message over Chat Completions.</p>
+                    <p class="help">Built-in formats use native chat messages over Chat Completions. Custom format sends one templated user message.</p>
                 </div>
 
                 <div id="custom-template-container" class="field is-hidden">