package starnet

import "strings"

var isTokenTable = [127]bool{
	'!':  true,
	'#':  true,
	'$':  true,
	'%':  true,
	'&':  true,
	'\'': true,
	'*':  true,
	'+':  true,
	'-':  true,
	'.':  true,
	'0':  true,
	'1':  true,
	'2':  true,
	'3':  true,
	'4':  true,
	'5':  true,
	'6':  true,
	'7':  true,
	'8':  true,
	'9':  true,
	'A':  true,
	'B':  true,
	'C':  true,
	'D':  true,
	'E':  true,
	'F':  true,
	'G':  true,
	'H':  true,
	'I':  true,
	'J':  true,
	'K':  true,
	'L':  true,
	'M':  true,
	'N':  true,
	'O':  true,
	'P':  true,
	'Q':  true,
	'R':  true,
	'S':  true,
	'T':  true,
	'U':  true,
	'W':  true,
	'V':  true,
	'X':  true,
	'Y':  true,
	'Z':  true,
	'^':  true,
	'_':  true,
	'`':  true,
	'a':  true,
	'b':  true,
	'c':  true,
	'd':  true,
	'e':  true,
	'f':  true,
	'g':  true,
	'h':  true,
	'i':  true,
	'j':  true,
	'k':  true,
	'l':  true,
	'm':  true,
	'n':  true,
	'o':  true,
	'p':  true,
	'q':  true,
	'r':  true,
	's':  true,
	't':  true,
	'u':  true,
	'v':  true,
	'w':  true,
	'x':  true,
	'y':  true,
	'z':  true,
	'|':  true,
	'~':  true,
}

func IsTokenRune(r rune) bool {
	i := int(r)
	return i < len(isTokenTable) && isTokenTable[i]
}

func validMethod(method string) bool {
	/*
	     Method         = "OPTIONS"                ; Section 9.2
	                    | "GET"                    ; Section 9.3
	                    | "HEAD"                   ; Section 9.4
	                    | "POST"                   ; Section 9.5
	                    | "PUT"                    ; Section 9.6
	                    | "DELETE"                 ; Section 9.7
	                    | "TRACE"                  ; Section 9.8
	                    | "CONNECT"                ; Section 9.9
	                    | extension-method
	   extension-method = token
	     token          = 1*<any CHAR except CTLs or separators>
	*/
	return len(method) > 0 && strings.IndexFunc(method, isNotToken) == -1
}

func isNotToken(r rune) bool {
	return !IsTokenRune(r)
}

func hasPort(s string) bool { return strings.LastIndex(s, ":") > strings.LastIndex(s, "]") }

// removeEmptyPort strips the empty port in ":port" to ""
// as mandated by RFC 3986 Section 6.2.3.
func removeEmptyPort(host string) string {
	if hasPort(host) {
		return strings.TrimSuffix(host, ":")
	}
	return host
}