From e375de0f33cd644c0976045d234f7a45d327fe6a Mon Sep 17 00:00:00 2001
From: xdrm-brackets <doowap31@gmail.com>
Date: Wed, 25 Apr 2018 15:00:43 +0200
Subject: [PATCH] [internal.http.request.parser.header] multi-value header
 parser

---
 internal/http/request/parser/header/public.go | 51 +++++++++++++++++++
 internal/http/request/parser/header/types.go  | 22 ++++++++
 2 files changed, 73 insertions(+)
 create mode 100644 internal/http/request/parser/header/public.go
 create mode 100644 internal/http/request/parser/header/types.go

diff --git a/internal/http/request/parser/header/public.go b/internal/http/request/parser/header/public.go
new file mode 100644
index 0000000..36be125
--- /dev/null
+++ b/internal/http/request/parser/header/public.go
@@ -0,0 +1,51 @@
+package header
+
+import (
+	"regexp"
+	"fmt"
+	"strings"
+	"bytes"
+)
+
+// parse tries to return a 'T' (httpHeader) from a byte array
+func Parse(b []byte) (*T, error) {
+
+	/* (1) Split by ':' */
+	parts := bytes.Split(b, []byte(": "))
+
+	if len(parts) != 2 {
+		return nil, fmt.Errorf("Invalid HTTP header format '%s'", b)
+	}
+
+	/* (2) Create instance */
+	inst := new(T)
+
+	/* (3) Check for header name */
+	switch strings.ToLower(string(parts[0])) {
+		case "host":                     inst.Name = HOST
+		case "upgrade":                  inst.Name = UPGRADE
+		case "connection":               inst.Name = CONNECTION
+		case "origin":                   inst.Name = ORIGIN
+		case "sec-websocket-key":        inst.Name = WSKEY
+		case "sec-websocket-protocol":   inst.Name = WSPROTOCOL
+		case "sec-websocket-extensions": inst.Name = WSEXTENSIONS
+		case "sec-websocket-version":    inst.Name = WSVERSION
+		default:                         inst.Name = UNKNOWN
+	}
+
+	/* (4) Check format */
+	checker := regexp.MustCompile(`^(?:[^,]+,\s*)*[^,]+$`)
+	if !checker.Match(parts[1]) {
+		return nil, fmt.Errorf("Invalid HTTP header value format '%s'", parts[1]);
+	}
+
+	/* (5) Normalise format */
+	normaliser := regexp.MustCompile(`,\s+`)
+	values := normaliser.ReplaceAll(parts[1], []byte(","))
+
+	/* (5) Split values */
+	inst.Values = bytes.Split(values, []byte(","))
+
+	return inst, nil
+
+}
\ No newline at end of file
diff --git a/internal/http/request/parser/header/types.go b/internal/http/request/parser/header/types.go
new file mode 100644
index 0000000..e72c27e
--- /dev/null
+++ b/internal/http/request/parser/header/types.go
@@ -0,0 +1,22 @@
+package header
+
+// HeaderType represents all 'valid' HTTP request headers
+type HeaderType byte
+const (
+	UNKNOWN HeaderType = iota
+	HOST
+	UPGRADE
+	CONNECTION
+	ORIGIN
+	WSKEY
+	WSPROTOCOL
+	WSEXTENSIONS
+	WSVERSION
+)
+
+
+// T represents the data of a HTTP request header
+type T struct{
+	Name   HeaderType
+	Values [][]byte
+}
\ No newline at end of file