feat: initial goget release — modern IPv6-first download utility

internal/protocol/http/handler.go

@@ -0,0 +1,179 @@
+//go:build linux || freebsd
+// +build linux freebsd
+
+package http
+
+import (
+	"fmt"
+	"mime"
+	"net/http"
+	"net/url"
+	"path/filepath"
+	"strings"
+)
+
+// URLInfo contains extracted information from an HTTP URL
+type URLInfo struct {
+	Scheme   string
+	Host     string
+	Port     string
+	Path     string
+	Query    string
+	Fragment string
+	User     *url.Userinfo
+}
+
+// Handler contains HTTP-specific logic
+type Handler struct {
+	client *Client
+}
+
+// NewHandler creates new handler
+func NewHandler(client *Client) *Handler {
+	return &Handler{client: client}
+}
+
+// ParseHTTPURL parses an HTTP URL and extracts information
+func ParseHTTPURL(u *url.URL) (*URLInfo, error) {
+	if u.Scheme != "http" && u.Scheme != "https" {
+		return nil, fmt.Errorf("invalid http url scheme: %s", u.Scheme)
+	}
+
+	host := u.Hostname()
+	port := u.Port()
+	if port == "" {
+		if u.Scheme == "https" {
+			port = "443"
+		} else {
+			port = "80"
+		}
+	}
+
+	return &URLInfo{
+		Scheme:   u.Scheme,
+		Host:     host,
+		Port:     port,
+		Path:     u.Path,
+		Query:    u.RawQuery,
+		Fragment: u.Fragment,
+		User:     u.User,
+	}, nil
+}
+
+// GetContentType extracts Content-Type from the response
+func GetContentType(resp *http.Response) string {
+	return resp.Header.Get("Content-Type")
+}
+
+// GetContentLength extracts Content-Length from the response
+func GetContentLength(resp *http.Response) int64 {
+	return resp.ContentLength
+}
+
+// GetContentEncoding extracts Content-Encoding from the response
+func GetContentEncoding(resp *http.Response) string {
+	return resp.Header.Get("Content-Encoding")
+}
+
+// GetETag extracts ETag from the response
+func GetETag(resp *http.Response) string {
+	return resp.Header.Get("ETag")
+}
+
+// GetLastModified extracts Last-Modified from the response
+func GetLastModified(resp *http.Response) string {
+	return resp.Header.Get("Last-Modified")
+}
+
+// SupportsRangeCheck checks whether the server supports range requests
+func SupportsRangeCheck(resp *http.Response) bool {
+	acceptRanges := resp.Header.Get("Accept-Ranges")
+	return strings.ToLower(acceptRanges) == "bytes"
+}
+
+// IsRedirect checks whether the response is a redirect
+func IsRedirect(statusCode int) bool {
+	return statusCode >= 300 && statusCode < 400
+}
+
+// GetRedirectLocation gets the Location header from a redirect response
+func GetRedirectLocation(resp *http.Response) string {
+	return resp.Header.Get("Location")
+}
+
+// BuildURLWithQuery creates a URL with query parameters
+func BuildURLWithQuery(base *url.URL, params map[string]string) (*url.URL, error) {
+	if base == nil {
+		return nil, fmt.Errorf("base url cannot be nil")
+	}
+
+	result := *base
+	query := result.Query()
+
+	for key, value := range params {
+		query.Set(key, value)
+	}
+
+	result.RawQuery = query.Encode()
+	return &result, nil
+}
+
+// GetUserinfo extracts authentication credentials from the URL
+func GetUserinfo(u *url.URL) (username, password string, ok bool) {
+	if u.User == nil {
+		return "", "", false
+	}
+	username = u.User.Username()
+	password, ok = u.User.Password()
+	return username, password, true
+}
+
+// IsSecure checks whether the URL uses HTTPS
+func IsSecure(u *url.URL) bool {
+	return u.Scheme == "https"
+}
+
+// GetDefaultPortForScheme returns the default port for the scheme
+func GetDefaultPortForScheme(scheme string) string {
+	switch scheme {
+	case "https":
+		return "443"
+	case "http":
+		return "80"
+	default:
+		return ""
+	}
+}
+
+// ParseContentDisposition extracts filename from Content-Disposition header
+func ParseContentDisposition(headerValue string) string {
+	if headerValue == "" {
+		return ""
+	}
+
+	_, params, err := mime.ParseMediaType(headerValue)
+	if err != nil {
+		return ""
+	}
+
+	// Try filename* first (RFC 5987, extended filename)
+	if filename, ok := params["filename*"]; ok {
+		return filename
+	}
+
+	// Fall back to filename
+	if filename, ok := params["filename"]; ok {
+		return filename
+	}
+
+	return ""
+}
+
+// SanitizeFilename removes path components from a filename for security
+func SanitizeFilename(name string) string {
+	name = filepath.Base(name)
+	if name == "" || name == "." || name == ".." {
+		return ""
+	}
+	return name
+}