const R = require("ramda");
const { VALID_RECORD_TYPES } = require("./constants");
const {
    or,
    and,
    validate,
    between,
    testRegex,
    withLengthEq,
    withLengthGte,
} = require("./helpers");
const INVALID_NAMES = require("./invalid-domains.json");
const ipRegex_ = require("ip-regex");
const ipRegex = ipRegex_.default ?? ipRegex_;

const isValidURL = and([R.is(String), testRegex(/^https?:\/\//gi)]);

const isValidDomain = and([
    R.is(String),
    testRegex(/^(([a-z0-9-]+)\.)+[a-z]+$/gi),
]);

const validateCnameRecord = (type) =>
    and([
        R.propIs(String, type),
        R.compose(withLengthEq(1), R.keys), // CNAME cannot be used with any other record
        R.propSatisfies(withLengthGte(4), type),
        R.propSatisfies(isValidDomain, type),
    ]);

const validateARecord = (type) =>
    and([
        R.propIs(Array, type),
        R.propSatisfies(withLengthGte(1), type),
        R.all(testRegex(ipRegex.v4({ exact: true }))),
    ]);

const validateMXRecord = (type) =>
    and([
        R.propIs(Array, type),
        R.propSatisfies(withLengthGte(1), type),
        R.propSatisfies(R.all(isValidDomain), type),
    ]);

const validateAAAARecord = R.propSatisfies(
    and([
        R.is(Array),
        withLengthGte(1),
        R.all(testRegex(ipRegex.v6({ exact: true }))),
    ]),
);

const checkRestrictedNames = R.complement(R.includes(R.__, INVALID_NAMES));

const extraSupportedNames = [
    testRegex(/^_github(-pages)?-challenge-[a-z0-9-_]+$/i),
    R.equals("_discord"),
    R.equals("_gitlab-pages-verification-code"),
    R.equals("_acme-challenge"),
    R.equals("_dmarc"),
    R.equals("_domainkey"),
    testRegex(/^_gh-[a-z0-9-_]+$/i),
];

const validateDomainData = validate({
    name: {
        reason: "The name of the file is invalid. It must be lowercased, alphanumeric and each component must be between 1-100 characters long.",
        fn: or([
            R.equals("@"),
            and([
                R.is(String),
                checkRestrictedNames,
                R.compose(
                    R.all(
                        or([
                            and([
                                R.compose(between(1, 100), R.length),
                                testRegex(/^[a-z0-9-]+$/g),
                                checkRestrictedNames,
                            ]),
                            ...extraSupportedNames,
                        ]),
                    ),
                    R.split("."),
                ),
            ]),
        ]),
    },
    description: { reason: "", fn: R.T },
    repo: { reason: "", fn: R.T },
    owner: {
        reason: "`owner` key needs valid username and email properties.",
        fn: and([
            R.is(Object),
            R.complement(R.isEmpty),
            R.where({
                username: and([R.is(String), withLengthGte(1)]),
                email: R.is(String),
            }),
        ]),
    },
    record: {
        reason: "Invalid record(s) found. Please check the record types and values.",
        fn: and([
            R.is(Object),
            R.compose(
                R.isEmpty,
                R.difference(R.__, VALID_RECORD_TYPES),
                R.keys,
            ),
            R.cond([
                [R.has("CNAME"), validateCnameRecord("CNAME")],
                [R.has("A"), validateARecord("A")],
                [R.has("URL"), R.propSatisfies(isValidURL, "URL")],
                [R.has("MX"), validateMXRecord("MX")],
                [
                    R.has("TXT"),
                    R.propSatisfies(or([R.is(String), R.is(Array)]), "TXT"),
                ],
                [R.has("AAAA"), validateAAAARecord("AAAA")],
                [R.T, R.T],
            ]),
        ]),
    },
});

module.exports = { validateDomainData, isValidDomain };