Scaffold Go plugin skeleton with Ollama client, conversation store, rate limiter

server/ollama.go

@@ -0,0 +1,118 @@
+package main
+
+import (
+    "encoding/json"
+    "fmt"
+    "io"
+    "net/http"
+    "strings"
+    "time"
+)
+
+// OllamaClient communicates with the Ollama API.
+type OllamaClient struct {
+    baseURL    string
+    httpClient *http.Client
+}
+
+// NewOllamaClient creates a new client for the given Ollama server URL.
+func NewOllamaClient(baseURL string) *OllamaClient {
+    return &OllamaClient{
+        baseURL: strings.TrimRight(baseURL, "/"),
+        httpClient: &http.Client{
+            Timeout: 30 * time.Second,
+        },
+    }
+}
+
+// ChatMessage represents a message in the chat conversation.
+type ChatMessage struct {
+    Role    string `json:"role"`
+    Content string `json:"content"`
+}
+
+// ChatRequest is sent to Ollama's /api/chat endpoint.
+type ChatRequest struct {
+    Model    string         `json:"model"`
+    Messages []ChatMessage  `json:"messages"`
+    Stream   bool           `json:"stream"`
+    Options  map[string]any `json:"options,omitempty"`
+}
+
+// ChatResponse is the non-streaming response from Ollama.
+type ChatResponse struct {
+    Message         ChatMessage `json:"message"`
+    Done            bool        `json:"done"`
+    EvalCount       int         `json:"eval_count"`
+    PromptEvalCount int         `json:"prompt_eval_count"`
+}
+
+// ListModelsResponse is the response from /api/tags.
+type ListModelsResponse struct {
+    Models []struct {
+        Name string `json:"name"`
+    } `json:"models"`
+}
+
+// ChatCompletion sends a chat request and returns the full response.
+func (c *OllamaClient) ChatCompletion(req *ChatRequest) (*ChatResponse, error) {
+    req.Stream = false
+    body, err := json.Marshal(req)
+    if err != nil {
+        return nil, fmt.Errorf("marshal request: %w", err)
+    }
+
+    httpReq, err := http.NewRequest("POST", c.baseURL+"/api/chat", strings.NewReader(string(body)))
+    if err != nil {
+        return nil, fmt.Errorf("create request: %w", err)
+    }
+    httpReq.Header.Set("Content-Type", "application/json")
+
+    resp, err := c.httpClient.Do(httpReq)
+    if err != nil {
+        return nil, fmt.Errorf("http request: %w", err)
+    }
+    defer resp.Body.Close()
+
+    if resp.StatusCode != http.StatusOK {
+        respBody, _ := io.ReadAll(resp.Body)
+        return nil, fmt.Errorf("ollama returned status %d: %s", resp.StatusCode, strings.TrimSpace(string(respBody)))
+    }
+
+    var chatResp ChatResponse
+    if err := json.NewDecoder(resp.Body).Decode(&chatResp); err != nil {
+        return nil, fmt.Errorf("decode response: %w", err)
+    }
+
+    return &chatResp, nil
+}
+
+// ListModels fetches the list of available models from Ollama.
+func (c *OllamaClient) ListModels() ([]string, error) {
+    httpReq, err := http.NewRequest("GET", c.baseURL+"/api/tags", nil)
+    if err != nil {
+        return nil, fmt.Errorf("create request: %w", err)
+    }
+
+    resp, err := c.httpClient.Do(httpReq)
+    if err != nil {
+        return nil, fmt.Errorf("http request: %w", err)
+    }
+    defer resp.Body.Close()
+
+    if resp.StatusCode != http.StatusOK {
+        respBody, _ := io.ReadAll(resp.Body)
+        return nil, fmt.Errorf("ollama returned status %d: %s", resp.StatusCode, strings.TrimSpace(string(respBody)))
+    }
+
+    var listResp ListModelsResponse
+    if err := json.NewDecoder(resp.Body).Decode(&listResp); err != nil {
+        return nil, fmt.Errorf("decode response: %w", err)
+    }
+
+    models := make([]string, len(listResp.Models))
+    for i, m := range listResp.Models {
+        models[i] = m.Name
+    }
+    return models, nil
+}