"use strict";
/*global Promise*/
var crypto = require("crypto");

module.exports.create = function() {
	throw new Error(
		"acme-challenge-test is a test fixture for acme-challenge-* plugins, not a plugin itself"
	);
};

// ignore all of this, it's just to normalize Promise vs node-style callback thunk vs synchronous
function promiseCheckAndCatch(obj, name) {
	var promisify = require("util").promisify;
	// don't loose this-ness, just in case that's important
	var fn = obj[name].bind(obj);
	var promiser;

	// function signature must match, or an error will be thrown
	if (1 === fn.length) {
		// wrap so that synchronous errors are caught (alsa handles synchronous results)
		promiser = function(opts) {
			return Promise.resolve().then(function() {
				return fn(opts);
			});
		};
	} else if (2 === fn.length) {
		// wrap as a promise
		promiser = promisify(fn);
	} else {
		return Promise.reject(
			new Error(
				"'challenge." +
					name +
					"' should accept either one argument, the options," +
					" and return a Promise or accept two arguments, the options and a node-style callback thunk"
			)
		);
	}

	function shouldntBeNull(result) {
		if ("undefined" === typeof result) {
			throw new Error(
				"'challenge.'" +
					name +
					"' should never return `undefined`. Please explicitly return null" +
					" (or fix the place where a value should have been returned but wasn't)."
			);
		}
		return result;
	}

	return function(opts) {
		return promiser(opts).then(shouldntBeNull);
	};
}

// Here's the meat, where the tests are happening:
function run(challenger, opts) {
	var ch = opts.challenge;
	if ("http-01" === ch.type && ch.wildname) {
		throw new Error("http-01 cannot be used for wildcard domains");
	}

	var set = promiseCheckAndCatch(challenger, "set");
	if ("function" !== typeof challenger.get) {
		throw new Error(
			"'challenge.get' should be implemented for the sake of testing." +
				" It should be implemented as the internal method for fetching the challenge" +
				" (i.e. reading from a database, file system or API, not return internal)," +
				" not the external check (the http call, dns query, etc), which will already be done as part of this test."
		);
	}
	var get = promiseCheckAndCatch(challenger, "get");
	var remove = promiseCheckAndCatch(challenger, "remove");

	// The first time we just check it against itself
	// this will cause the prompt to appear
	return set(opts)
		.then(function() {
			// this will cause the final completion message to appear
			// _test is used by the manual cli reference implementations
			var query = { type: ch.type, /*debug*/ status: ch.status, _test: true };
			if ("http-01" === ch.type) {
				query.identifier = ch.identifier;
				query.token = ch.token;
				// For testing only
				query.url = ch.challengeUrl;
			} else if ("dns-01" === ch.type) {
				query.identifier = { type: "dns", value: ch.dnsHost };
				// For testing only
				query.altname = ch.altname;
				// there should only be two possible TXT records per challenge domain:
				// one for the bare domain, and the other if and only if there's a wildcard
				query.wildcard = ch.wildcard;
			} else {
				query = JSON.parse(JSON.stringify(ch));
				query.comment = "unknown challenge type, supplying everything";
			}
			return get({ challenge: query })
				.then(function(secret) {
					if ("string" === typeof secret) {
						console.info(
							"secret was passed as a string, which works historically, but should be an object instead:"
						);
						console.info('{ "keyAuthorization": "' + secret + '" }');
						console.info("or");
						// TODO this should be "keyAuthorizationDigest"
						console.info('{ "dnsAuthorization": "' + secret + '" }');
						console.info(
							"This is to help keep acme / greenlock (and associated plugins) future-proof for new challenge types"
						);
					}
					// historically 'secret' has been a string, but I'd like it to transition to be an object.
					// to make it backwards compatible in v2.7 to change it,
					// so I'm not sure that we really need to.
					if ("http-01" === ch.type) {
						secret = secret.keyAuthorization || secret;
						if (ch.keyAuthorization !== secret) {
							throw new Error(
								"http-01 challenge.get() returned '" +
									secret +
									"', which does not match the keyAuthorization" +
									" saved with challenge.set(), which was '" +
									ch.keyAuthorization +
									"'"
							);
						}
					} else if ("dns-01" === ch.type) {
						secret = secret.dnsAuthorization || secret;
						if (ch.dnsAuthorization !== secret) {
							throw new Error(
								"dns-01 challenge.get() returned '" +
									secret +
									"', which does not match the dnsAuthorization" +
									" (keyAuthDigest) saved with challenge.set(), which was '" +
									ch.dnsAuthorization +
									"'"
							);
						}
					} else {
						if ("tls-alpn-01" === ch.type) {
							console.warn(
								"'tls-alpn-01' support is in development" +
									" (or developed and we haven't update this yet). Please contact us."
							);
						} else {
							console.warn(
								"We don't know how to test '" +
									ch.type +
									"'... are you sure that's a thing?"
							);
						}
						secret = secret.keyAuthorization || secret;
						if (ch.keyAuthorization !== secret) {
							console.warn(
								"The returned value doesn't match keyAuthorization",
								ch.keyAuthorization,
								secret
							);
						}
					}
				})
				.then(function() {
					return remove(opts).then(function() {
						return get(opts).then(function(result) {
							if (result) {
								throw new Error(
									"challenge.remove() should have made it not possible for challenge.get() to return a value"
								);
							}
							if (null !== result) {
								throw new Error(
									"challenge.get() should return null when the value is not set"
								);
							}
						});
					});
				});
		})
		.then(function() {
			console.info("All soft tests: PASS");
			console.warn(
				"Hard tests (actually checking http URLs and dns records) is implemented in acme-v2."
			);
			console.warn(
				"We'll copy them over here as well, but that's a TODO for next week."
			);
		});
}

module.exports.test = function(type, altname, challenger) {
	var expires = new Date(Date.now() + 10 * 60 * 1000).toISOString();
	var token = crypto.randomBytes(8).toString("hex");
	var thumb = crypto.randomBytes(16).toString("hex");
	var keyAuth = token + "." + crypto.randomBytes(16).toString("hex");
	var dnsAuth = crypto
		.createHash("sha256")
		.update(keyAuth)
		.digest("base64")
		.replace(/\+/g, "-")
		.replace(/\//g, "_")
		.replace(/=/g, "");

	var challenge = {
		type: type,
		identifier: { type: "dns", value: null }, // completed below
		wildcard: false, // completed below
		status: "pending",
		expires: expires,
		token: token,
		thumbprint: thumb,
		keyAuthorization: keyAuth,
		url: null, // completed below
		dnsHost: "_acme-challenge.", // completed below
		dnsAuthorization: dnsAuth,
		altname: altname,
		_test: true // used by CLI referenced implementations
	};
	if ("*." === altname.slice(0, 2)) {
		challenge.wildcard = true;
		altname = altname.slice(2);
	}
	challenge.identifier.value = altname;
	challenge.url =
		"http://" + altname + "/.well-known/acme-challenge/" + challenge.token;
	challenge.dnsHost += altname;

	return run(challenger, { challenge: challenge });
};