ai-servers/llm-gateway/internal/provider/openai.go

130 lines
3.1 KiB
Go

package provider
import (
"bytes"
"context"
"encoding/json"
"fmt"
"io"
"net/http"
"time"
)
// OpenAIProvider is a generic OpenAI-compatible HTTP client.
type OpenAIProvider struct {
name string
baseURL string
apiKey string
client *http.Client
}
func NewOpenAIProvider(name, baseURL, apiKey string, timeout time.Duration) *OpenAIProvider {
return &OpenAIProvider{
name: name,
baseURL: baseURL,
apiKey: apiKey,
client: &http.Client{
Timeout: timeout,
},
}
}
func (p *OpenAIProvider) Name() string { return p.name }
func (p *OpenAIProvider) ChatCompletion(ctx context.Context, model string, req *ChatRequest) (*ChatResponse, error) {
reqCopy := *req
reqCopy.Model = model
reqCopy.Stream = false
body, err := json.Marshal(reqCopy)
if err != nil {
return nil, fmt.Errorf("marshaling request: %w", err)
}
httpReq, err := http.NewRequestWithContext(ctx, http.MethodPost, p.baseURL+"/chat/completions", bytes.NewReader(body))
if err != nil {
return nil, fmt.Errorf("creating request: %w", err)
}
p.setHeaders(httpReq)
resp, err := p.client.Do(httpReq)
if err != nil {
return nil, fmt.Errorf("sending request: %w", err)
}
defer resp.Body.Close()
respBody, err := io.ReadAll(resp.Body)
if err != nil {
return nil, fmt.Errorf("reading response: %w", err)
}
if resp.StatusCode != http.StatusOK {
return nil, &ProviderError{
StatusCode: resp.StatusCode,
Body: string(respBody),
Provider: p.name,
}
}
var chatResp ChatResponse
if err := json.Unmarshal(respBody, &chatResp); err != nil {
return nil, fmt.Errorf("unmarshaling response: %w", err)
}
return &chatResp, nil
}
func (p *OpenAIProvider) ChatCompletionStream(ctx context.Context, model string, req *ChatRequest) (io.ReadCloser, error) {
reqCopy := *req
reqCopy.Model = model
reqCopy.Stream = true
body, err := json.Marshal(reqCopy)
if err != nil {
return nil, fmt.Errorf("marshaling request: %w", err)
}
httpReq, err := http.NewRequestWithContext(ctx, http.MethodPost, p.baseURL+"/chat/completions", bytes.NewReader(body))
if err != nil {
return nil, fmt.Errorf("creating request: %w", err)
}
p.setHeaders(httpReq)
resp, err := p.client.Do(httpReq)
if err != nil {
return nil, fmt.Errorf("sending request: %w", err)
}
if resp.StatusCode != http.StatusOK {
defer resp.Body.Close()
respBody, _ := io.ReadAll(resp.Body)
return nil, &ProviderError{
StatusCode: resp.StatusCode,
Body: string(respBody),
Provider: p.name,
}
}
return resp.Body, nil
}
func (p *OpenAIProvider) setHeaders(req *http.Request) {
req.Header.Set("Content-Type", "application/json")
req.Header.Set("Authorization", "Bearer "+p.apiKey)
}
// ProviderError represents a non-200 response from a provider.
type ProviderError struct {
StatusCode int
Body string
Provider string
}
func (e *ProviderError) Error() string {
return fmt.Sprintf("provider %s returned %d: %s", e.Provider, e.StatusCode, e.Body)
}
// IsRetryable returns true if the error is a server-side error worth retrying with another provider.
func (e *ProviderError) IsRetryable() bool {
return e.StatusCode >= 500 || e.StatusCode == 429
}