Use Ollama rewrite path for CV generation

2026-04-11 22:26:03 +02:00
parent 591c9b8a64
commit 54abc9f546
4 changed files with 223 additions and 5 deletions
@@ -11,7 +11,7 @@ namespace JobTrackerApi.Tests;
 public sealed class SummarizerServiceTests
 {
    [Fact]
-    public async Task Summarize_section_clamps_lengths_to_ai_service_limits()
+    public async Task Summarize_section_uses_cv_rewrite_endpoint()
    {
        var handler = new CapturingHandler();
        var httpClient = new HttpClient(handler)
@@ -27,7 +27,31 @@ public sealed class SummarizerServiceTests

        var result = await service.SummarizeSectionAsync("Rewrite this CV", "Professional Summary\nBuilt backend systems.", 1800, 400);

-        Assert.Equal("ok", result);
+        Assert.Equal("rewritten cv", result);
+        Assert.Equal("/cv/rewrite", handler.LastPath);
+        Assert.NotNull(handler.LastBody);
+        Assert.Contains("\"instruction\":\"Rewrite this CV\"", handler.LastBody);
+        Assert.Contains("\"max_length\":256", handler.LastBody);
+        Assert.Contains("\"min_length\":180", handler.LastBody);
+    }
+
+    [Fact]
+    public async Task Summarize_section_clamps_lengths_to_ai_service_limits()
+    {
+        var handler = new CapturingHandler();
+        var httpClient = new HttpClient(handler)
+        {
+            BaseAddress = new Uri("http://localhost:8001")
+        };
+
+        var httpFactory = new Mock<IHttpClientFactory>();
+        httpFactory.Setup(x => x.CreateClient("ai-service")).Returns(httpClient);
+
+        using var memoryCache = new MemoryCache(new MemoryCacheOptions());
+        var service = new SummarizerService(httpFactory.Object, memoryCache);
+
+        await service.SummarizeSectionAsync("Rewrite this CV", "Professional Summary\nBuilt backend systems.", 1800, 400);
+
        Assert.NotNull(handler.LastBody);
        Assert.Contains("\"max_length\":256", handler.LastBody);
        Assert.Contains("\"min_length\":180", handler.LastBody);
@@ -36,13 +60,18 @@ public sealed class SummarizerServiceTests
    private sealed class CapturingHandler : HttpMessageHandler
    {
        public string? LastBody { get; private set; }
+        public string? LastPath { get; private set; }

        protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
        {
+            LastPath = request.RequestUri?.AbsolutePath;
            LastBody = request.Content is null ? null : await request.Content.ReadAsStringAsync(cancellationToken);
+            var responseBody = LastPath == "/cv/rewrite"
+                ? "{\"rewritten_text\":\"rewritten cv\"}"
+                : "{\"summary\":\"ok\"}";
            return new HttpResponseMessage(HttpStatusCode.OK)
            {
-                Content = new StringContent("{\"summary\":\"ok\"}", Encoding.UTF8, "application/json")
+                Content = new StringContent(responseBody, Encoding.UTF8, "application/json")
            };
        }
    }
@@ -153,8 +153,7 @@ namespace JobTrackerApi.Services
        public Task<string?> SummarizeSectionAsync(string instruction, string text, int maxLength = 180, int minLength = 40)
        {
            if (string.IsNullOrWhiteSpace(instruction) || string.IsNullOrWhiteSpace(text)) return Task.FromResult<string?>(null);
-            var composed = ComposeBoundedPrompt(instruction.Trim(), text.Trim());
-            return SummarizeCoreAsync(composed, maxLength, minLength);
+            return RewriteCoreAsync(instruction.Trim(), text.Trim(), maxLength, minLength);
        }

        private static string ComposeBoundedPrompt(string instruction, string text)
@@ -174,6 +173,95 @@ namespace JobTrackerApi.Services
            return prefix + text[..remaining];
        }

+        private async Task<string?> RewriteCoreAsync(string instruction, string text, int maxLength, int minLength)
+        {
+            var normalizedMaxLength = Math.Clamp(maxLength, AiServiceMinSummaryLength, AiServiceMaxSummaryLength);
+            var normalizedMinLength = Math.Clamp(minLength, AiServiceMinMinLength, AiServiceMaxMinLength);
+            if (normalizedMinLength >= normalizedMaxLength)
+            {
+                normalizedMinLength = Math.Max(AiServiceMinMinLength, normalizedMaxLength - 1);
+            }
+
+            var composed = ComposeBoundedPrompt(instruction, text);
+            var key = BuildCacheKey($"rewrite::{composed}", normalizedMaxLength, normalizedMinLength);
+            Interlocked.Increment(ref _requests);
+
+            if (_cache.TryGetValue<string>(key, out var cached))
+            {
+                Interlocked.Increment(ref _cacheHits);
+                lock (_metricsLock)
+                {
+                    _lastSuccessAt = DateTimeOffset.UtcNow;
+                    _lastError = null;
+                }
+                return cached;
+            }
+
+            Interlocked.Increment(ref _cacheMisses);
+
+            var client = _httpFactory.CreateClient("ai-service");
+            var payload = JsonSerializer.Serialize(new
+            {
+                instruction,
+                text,
+                max_length = normalizedMaxLength,
+                min_length = normalizedMinLength,
+            });
+            using var content = new StringContent(payload, Encoding.UTF8, "application/json");
+            var sw = Stopwatch.StartNew();
+
+            try
+            {
+                var res = await client.PostAsync("/cv/rewrite", content);
+                sw.Stop();
+                Interlocked.Add(ref _totalLatencyTicks, sw.ElapsedTicks);
+                if (!res.IsSuccessStatusCode)
+                {
+                    var errorBody = await ReadErrorBodyAsync(res);
+                    Interlocked.Increment(ref _failures);
+                    lock (_metricsLock)
+                    {
+                        _lastFailureAt = DateTimeOffset.UtcNow;
+                        _lastError = $"AI rewrite failed: {errorBody}";
+                    }
+                    return null;
+                }
+
+                using var stream = await res.Content.ReadAsStreamAsync();
+                using var doc = await JsonDocument.ParseAsync(stream);
+                if (doc.RootElement.TryGetProperty("rewritten_text", out var el))
+                {
+                    var s = el.GetString();
+                    if (!string.IsNullOrWhiteSpace(s)) _cache.Set(key, s, TimeSpan.FromHours(6));
+                    lock (_metricsLock)
+                    {
+                        _lastSuccessAt = DateTimeOffset.UtcNow;
+                        _lastError = null;
+                    }
+                    return s;
+                }
+
+                lock (_metricsLock)
+                {
+                    _lastFailureAt = DateTimeOffset.UtcNow;
+                    _lastError = "AI rewrite failed: response did not contain rewritten_text.";
+                }
+                return null;
+            }
+            catch (Exception ex)
+            {
+                sw.Stop();
+                Interlocked.Add(ref _totalLatencyTicks, sw.ElapsedTicks);
+                Interlocked.Increment(ref _failures);
+                lock (_metricsLock)
+                {
+                    _lastFailureAt = DateTimeOffset.UtcNow;
+                    _lastError = ex.Message;
+                }
+                return null;
+            }
+        }
+
        private async Task<string?> SummarizeCoreAsync(string text, int maxLength, int minLength)
        {
            var normalizedMaxLength = Math.Clamp(maxLength, AiServiceMinSummaryLength, AiServiceMaxSummaryLength);
@@ -86,6 +86,13 @@ class SummarizeRequest(BaseModel):
    top_skills: int = Field(default=8, ge=3, le=12)


+class RewriteRequest(BaseModel):
+    instruction: str = Field(min_length=1, max_length=6000)
+    text: str = Field(min_length=1, max_length=MAX_INPUT_CHARS)
+    max_length: int = Field(default=220, ge=24, le=256)
+    min_length: int = Field(default=80, ge=8, le=180)
+
+
 class CvNormalizeRequest(BaseModel):
    text: str = Field(min_length=1, max_length=50000)

@@ -424,6 +431,39 @@ def _ollama_generate_json(prompt: str):
        raise HTTPException(status_code=502, detail="Ollama did not return valid JSON.")


+def _ollama_generate_text(prompt: str) -> str:
+    if not OLLAMA_MODEL:
+        raise HTTPException(status_code=503, detail="OLLAMA_MODEL is not configured.")
+
+    payload = json.dumps({
+        "model": OLLAMA_MODEL,
+        "prompt": prompt,
+        "stream": False,
+        "options": {"temperature": 0.2}
+    }).encode("utf-8")
+
+    req = urllib_request.Request(
+        f"{OLLAMA_BASE_URL}/api/generate",
+        data=payload,
+        headers={"Content-Type": "application/json"},
+        method="POST",
+    )
+
+    try:
+        with urllib_request.urlopen(req, timeout=180) as response:
+            body = json.loads(response.read().decode("utf-8"))
+    except HTTPError as ex:
+        raise HTTPException(status_code=502, detail=f"Ollama request failed with {ex.code}.")
+    except URLError as ex:
+        raise HTTPException(status_code=503, detail=f"Ollama is unreachable: {ex.reason}.")
+
+    raw = (body.get("response") or "").strip()
+    if not raw:
+        raise HTTPException(status_code=502, detail="Ollama returned an empty rewrite.")
+
+    return raw
+
+
@app.post("/cv/normalize")
 async def normalize_cv(req: CvNormalizeRequest):
    prompt = f"""
@@ -536,6 +576,49 @@ Block:
    }


+@app.post("/cv/rewrite")
+async def rewrite_cv(req: RewriteRequest):
+    prompt = f"""
+You are an expert CV and resume writer.
+Rewrite the candidate CV into a polished, factual CV tailored to the target role.
+Return ONLY the final CV text. No analysis. No commentary. No JSON. No markdown code fences. No recruiter notes.
+
+Non-negotiable rules:
+- Preserve facts only. Never invent employers, dates, locations, salaries, education, qualifications, technologies, metrics, or achievements.
+- Never output sections like 'Role summary', 'What the company wants most', 'Keywords to mirror', 'Interview focus', 'Top hard skills', or similar analysis headings.
+- Do not describe the job ad. Rewrite the candidate CV.
+- Use crisp CV language, not prose about what the company wants.
+- Keep the output directly usable as a CV.
+- If rewriting the whole CV, output a complete CV with sensible headings and bullets.
+- If rewriting only one section, return only that rewritten section.
+- Keep bullets concrete and concise.
+- If a fact is not present in the source CV, omit it.
+
+Preferred whole-CV structure when the source supports it:
+# Contact
+# Professional Summary
+# Work Experience
+# Education
+# Skills
+# Certifications
+# Projects
+# Languages
+# Interests
+
+Instruction:
+{req.instruction.strip()}
+
+Candidate source CV:
+{req.text.strip()}
+""".strip()
+
+    rewritten = _ollama_generate_text(prompt).strip()
+    if not rewritten:
+        raise HTTPException(status_code=502, detail="Ollama returned an empty rewrite.")
+
+    return {"rewritten_text": rewritten}
+
+
@app.post("/summarize")
 async def summarize(req: SummarizeRequest):
    if req.min_length >= req.max_length:
@@ -76,6 +76,24 @@ def test_health_reports_ollama_unreachable_when_configured_but_not_available(mon
    assert payload["ollama_model_available"] is False


+def test_rewrite_cv_returns_plain_rewritten_text(monkeypatch):
+    module = load_app_module(monkeypatch, ollama_model="qwen2.5:7b")
+    monkeypatch.setattr(module, "_ollama_generate_text", lambda prompt: "# Professional Summary\nBuilt resilient backend systems.\n\n# Skills\n- C#\n- .NET")
+    client = TestClient(module.app)
+
+    response = client.post("/cv/rewrite", json={
+        "instruction": "Rewrite this CV into a cleaner master CV.",
+        "text": "Professional Summary\nBuilt backend systems.",
+        "max_length": 220,
+        "min_length": 80,
+    })
+
+    assert response.status_code == 200
+    payload = response.json()
+    assert payload["rewritten_text"].startswith("# Professional Summary")
+    assert "Role summary:" not in payload["rewritten_text"]
+
+
 def test_classify_block_returns_structured_json(monkeypatch):
    module = load_app_module(monkeypatch)