// SetPathParam takes payload and updates path Query attribute
// If query param not found, it will append new
// Returns modified payload
func SetPathParam(payload, name, value []byte) []byte {
	path := Path(payload)
	_, vs, ve := PathParam(payload, name)

	if vs != -1 { // If param found, replace its value and set new Path
		newPath := make([]byte, len(path))
		copy(newPath, path)
		newPath = byteutils.Replace(newPath, vs, ve, value)

		return SetPath(payload, newPath)
	}

	// if param not found append to end of url
	// Adding 2 because of '?' or '&' at start, and '=' in middle
	newParam := make([]byte, len(name)+len(value)+2)

	if bytes.IndexByte(path, '?') == -1 {
		newParam[0] = '?'
	} else {
		newParam[0] = '&'
	}

	// Copy "param=value" into buffer, after it looks like "?param=value"
	copy(newParam[1:], name)
	newParam[1+len(name)] = '='
	copy(newParam[2+len(name):], value)

	// Append param to the end of path
	newPath := make([]byte, len(path)+len(newParam))
	copy(newPath, path)
	copy(newPath[len(path):], newParam)

	return SetPath(payload, newPath)
}

func SetPathParam(payload, name, value []byte) []byte {
	path := Path(payload)
	_, vs, ve := PathParam(payload, name)

	if vs != -1 {
		newPath := make([]byte, len(path))
		copy(newPath, path)
		newPath = byteutils.Replace(newPath, vs, ve, value)

		return SetPath(payload, newPath)
	} else { // if param not found append to end of url
		// Adding 2 because of '?' or '&' at start, and '=' in middle
		newParam := make([]byte, len(name)+len(value)+2)

		if bytes.IndexByte(path, '?') == -1 {
			newParam[0] = '?'
		} else {
			newParam[0] = '&'
		}

		copy(newParam[1:], name)
		newParam[1+len(name)] = '='
		copy(newParam[2+len(name):], value)

		newPath := make([]byte, len(path)+len(newParam))
		copy(newPath, path)
		copy(newPath[len(path):], newParam)

		return SetPath(payload, newPath)
	}
}

func SetPath(payload, path []byte) []byte {
	start := bytes.IndexByte(payload, ' ')
	start += 1

	end := bytes.IndexByte(payload[start:], ' ')

	return byteutils.Replace(payload, start, start+end, path)
}

// SetHeader sets header value. If header not found it creates new one.
// Returns modified request payload
func SetHeader(payload, name, value []byte) []byte {
	_, hs, vs, he := header(payload, name)

	if hs != -1 {
		// If header found we just repace its value
		return byteutils.Replace(payload, vs, he, value)
	}

	return AddHeader(payload, name, value)
}

func SetHeader(payload, name, value []byte) []byte {
	_, hs, vs, he := Header(payload, name)

	// If header found
	if hs != -1 {
		return byteutils.Replace(payload, vs, he, value)
	} else {
		return AddHeader(payload, name, value)
	}
}

// SetHost updates Host header for HTTP/1.1 or updates host in path for HTTP/1.0 or Proxy requests
// Returns modified payload
func SetHost(payload, url, host []byte) []byte {
	// If this is HTTP 1.0 traffic or proxy traffic it may include host right into path variable, so instead of setting Host header we rewrite Path
	// Fix for https://github.com/buger/gor/issues/156
	if path := Path(payload); bytes.HasPrefix(path, []byte("http")) {
		hostStart := bytes.IndexByte(path, ':') // : position "https?:"
		hostStart += 3                          // Skip 1 ':' and 2 '\'
		hostEnd := hostStart + bytes.IndexByte(path[hostStart:], '/')

		newPath := make([]byte, len(path))
		copy(newPath, path)
		newPath = byteutils.Replace(newPath, 0, hostEnd, url)

		return SetPath(payload, newPath)
	}

	return SetHeader(payload, []byte("Host"), host)
}