initial commit

internal/stdlib/fetch.go

@@ -0,0 +1,102 @@
+package stdlib
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"maps"
+	"net/http"
+	"strings"
+
+	"reichard.io/poiesis/internal/functions"
+)
+
+func init() {
+	functions.RegisterAsyncFunction("fetch", Fetch)
+}
+
+type FetchArgs struct {
+	Input string       `json:"input"`
+	Init  *RequestInit `json:"init,omitempty"`
+}
+
+func (f FetchArgs) Validate() error {
+	return nil
+}
+
+type RequestInit struct {
+	Method  string            `json:"method,omitempty"`
+	Headers map[string]string `json:"headers,omitempty"`
+	Body    *string           `json:"body,omitempty"`
+}
+
+func (o *RequestInit) Validate() error {
+	return nil
+}
+
+type Response struct {
+	OK      bool              `json:"ok"`
+	Status  int               `json:"status"`
+	Body    string            `json:"body"`
+	Headers map[string]string `json:"headers"`
+}
+
+func Fetch(ctx context.Context, args FetchArgs) (Response, error) {
+	// Set Default Method and Headers
+	method := "GET"
+	headers := make(map[string]string)
+
+	// Apply Init Options
+	if args.Init != nil {
+		if args.Init.Method != "" {
+			method = args.Init.Method
+		}
+		if args.Init.Headers != nil {
+			maps.Copy(headers, args.Init.Headers)
+		}
+	}
+
+	// Create Request
+	req, err := http.NewRequestWithContext(ctx, method, args.Input, nil)
+	if err != nil {
+		return Response{}, fmt.Errorf("failed to create request: %w", err)
+	}
+
+	// Set Request Headers
+	for k, v := range headers {
+		req.Header.Set(k, v)
+	}
+
+	// Execute Request
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return Response{}, fmt.Errorf("failed to fetch: %w", err)
+	}
+	defer func() {
+		_ = resp.Body.Close()
+	}()
+
+	// Read Response Body
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return Response{}, fmt.Errorf("failed to read body: %w", err)
+	}
+
+	// Collect Response Headers
+	resultHeaders := make(map[string]string)
+	for key, values := range resp.Header {
+		if len(values) > 0 {
+			val := values[0]
+			resultHeaders[key] = val
+			resultHeaders[strings.ToLower(key)] = val
+		}
+	}
+
+	// Return Response
+	return Response{
+		OK:      resp.StatusCode >= 200 && resp.StatusCode < 300,
+		Status:  resp.StatusCode,
+		Body:    string(body),
+		Headers: resultHeaders,
+	}, nil
+}