feat: Add Support for Proxy with Interceptor (#77)

proxy/context.go

@@ -0,0 +1,86 @@
+package proxy
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"fmt"
+	"net"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+)
+
+func newRequestContext(req *http.Request) (*RequestContext, error) {
+	var hostname string
+	// Extract hostname - for MITM'd requests, URL might be relative
+	// so we need to check the Host header
+	if req.URL != nil {
+		hostname = req.URL.Hostname()
+	}
+
+	if hostname == "" && req.Host != "" {
+		// For MITM requests, the URL is relative but Host header contains the hostname
+		hostname = req.Host
+		if host, _, err := net.SplitHostPort(req.Host); err == nil {
+			hostname = host
+		}
+	}
+
+	requestID, err := generateRequestID()
+	if err != nil {
+		return nil, fmt.Errorf("failed to generate request ID: %w", err)
+	}
+
+	return &RequestContext{
+		URL:       req.URL,
+		Method:    req.Method,
+		Headers:   req.Header,
+		Hostname:  hostname,
+		RequestID: requestID,
+		StartTime: time.Now(),
+		Data:      make(map[string]interface{}),
+	}, nil
+}
+
+func newRequestContextFromURL(urlStr string, method string) (*RequestContext, error) {
+	// For CONNECT requests, we receive "hostname:port" (e.g., "registry.npmjs.org:443")
+	// url.Parse treats this as "scheme:path", so we need to add "//" to parse correctly
+	if !strings.Contains(urlStr, "://") {
+		urlStr = "//" + urlStr
+	}
+
+	parsedURL, err := url.Parse(urlStr)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse URL: %w", err)
+	}
+
+	// If URL doesn't have a scheme, add https (typical for CONNECT)
+	if parsedURL.Scheme == "" {
+		parsedURL.Scheme = "https"
+	}
+
+	requestID, err := generateRequestID()
+	if err != nil {
+		return nil, fmt.Errorf("failed to generate request ID: %w", err)
+	}
+
+	return &RequestContext{
+		URL:       parsedURL,
+		Method:    method,
+		Headers:   make(http.Header),
+		Hostname:  parsedURL.Hostname(),
+		RequestID: requestID,
+		StartTime: time.Now(),
+		Data:      make(map[string]interface{}),
+	}, nil
+}
+
+func generateRequestID() (string, error) {
+	bytes := make([]byte, 8)
+	if _, err := rand.Read(bytes); err != nil {
+		return "", err
+	}
+
+	return hex.EncodeToString(bytes), nil
+}