var multiaddr = require('multiaddr')

var IP = or(base('ip4'), base('ip6'))
var TCP = and(IP, base('tcp'))
var UDP = and(IP, base('udp'))
var UTP = and(UDP, base('utp'))
var Reliable = or(TCP, UTP)
var IPFS = and(Reliable, base('ipfs'))

exports.IP = IP
exports.TCP = TCP
exports.UDP = UDP
exports.UTP = UTP
exports.Reliable = Reliable
exports.IPFS = IPFS

function and() {
	var args = Array.from(arguments)

	function matches(a) {
		if (typeof a === 'string') {
			a = multiaddr(a)
		}
		out = partialMatch(a.protoNames())
		if (out === null) {
			return false
		}
		return out.length === 0
	}

	function partialMatch(a) {
		if (a.length < args.length) {
			return null
		}

		args.some(function(arg) {
			a = arg.partialMatch(a)
			if (a === null) {
				return true
			}
		})

		return a
	}

	return {
		input: args,
		matches: matches,
		partialMatch: partialMatch,
	}
}

function or() {
	var args = Array.from(arguments)

	function matches(a) {
		if (typeof a === 'string') {
			a = multiaddr(a)
		}
		var out = partialMatch(a.protoNames())
		if (out === null) {
			return false
		}
		return out.length === 0
	}

	function partialMatch(a) {
		var out = null
		args.some(function(arg) {
			res = arg.partialMatch(a)
			if (res) {
				out = res
				return true
			}
		})

		return out
	}

	return {
		toString: function() { return "{ " + args.join(" ") + " }" },
		input: args,
		matches: matches,
		partialMatch: partialMatch,
	}
}

function base(n) {
	var name = n
	function matches(a) {
		if (typeof a === 'string') {
			a = multiaddr(a)
		}

		pnames = a.protoNames()
		if (pnames.length === 1 && pnames[0] === name) {
			return true
		}
		return false
	}

	function partialMatch(protos) {
		if (protos.length === 0) {
			return null
		}

		if (protos[0] === name) {
			return protos.slice(1)
		}
		return null
	}

	return {
		toString: function() {return name} ,
		matches: matches,
		partialMatch: partialMatch,
	}
}