initial commit

internal/infrastructure/llm/openrouter.go

@@ -0,0 +1,113 @@
+package llm
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/paramah/ai_devs4/s01e01/internal/domain"
+)
+
+// OpenRouterProvider implements domain.LLMProvider for OpenRouter API
+type OpenRouterProvider struct {
+	apiKey  string
+	model   string
+	baseURL string
+	client  *http.Client
+}
+
+// NewOpenRouterProvider creates a new OpenRouter provider
+func NewOpenRouterProvider(apiKey, model string) *OpenRouterProvider {
+	return &OpenRouterProvider{
+		apiKey:  apiKey,
+		model:   model,
+		baseURL: "https://openrouter.ai/api/v1/chat/completions",
+		client:  &http.Client{},
+	}
+}
+
+type openRouterRequest struct {
+	Model          string                   `json:"model"`
+	Messages       []map[string]interface{} `json:"messages"`
+	ResponseFormat *responseFormat          `json:"response_format,omitempty"`
+}
+
+type responseFormat struct {
+	Type       string      `json:"type"`
+	JSONSchema interface{} `json:"json_schema,omitempty"`
+}
+
+type openRouterResponse struct {
+	Choices []struct {
+		Message struct {
+			Content string `json:"content"`
+		} `json:"message"`
+	} `json:"choices"`
+	Error *struct {
+		Message string `json:"message"`
+	} `json:"error,omitempty"`
+}
+
+// Complete sends a request to OpenRouter API
+func (p *OpenRouterProvider) Complete(ctx context.Context, request domain.LLMRequest) (*domain.LLMResponse, error) {
+	reqBody := openRouterRequest{
+		Model: p.model,
+		Messages: []map[string]interface{}{
+			{
+				"role":    "user",
+				"content": request.Prompt,
+			},
+		},
+	}
+
+	if request.Schema != nil {
+		reqBody.ResponseFormat = &responseFormat{
+			Type:       "json_schema",
+			JSONSchema: request.Schema,
+		}
+	}
+
+	jsonData, err := json.Marshal(reqBody)
+	if err != nil {
+		return nil, fmt.Errorf("marshaling request: %w", err)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, p.baseURL, bytes.NewBuffer(jsonData))
+	if err != nil {
+		return nil, fmt.Errorf("creating request: %w", err)
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", "Bearer "+p.apiKey)
+
+	resp, err := p.client.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("sending request: %w", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("reading response: %w", err)
+	}
+
+	var apiResp openRouterResponse
+	if err := json.Unmarshal(body, &apiResp); err != nil {
+		return nil, fmt.Errorf("unmarshaling response: %w", err)
+	}
+
+	if apiResp.Error != nil {
+		return nil, fmt.Errorf("API error: %s", apiResp.Error.Message)
+	}
+
+	if len(apiResp.Choices) == 0 {
+		return nil, fmt.Errorf("no choices in response")
+	}
+
+	return &domain.LLMResponse{
+		Content: apiResp.Choices[0].Message.Content,
+	}, nil
+}