var ewpass = {};

(function(ns) {
    const SEED_PREFIX = 'E. W. Password Generator Seed/';
    const DERIVE_PREFIX = 'Domain Password/';
    const Storage = window.localStorage;

    const BASIC_MAP = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
    const EXTENDED_MAP = BASIC_MAP + '`~!@#$%^&*()-_=+[{]}\\|;:\'",<.>/?';

    var settings = {
        'checksum': undefined,
        'DEFAULT': [ 16, 1, true ],
        'domains': {}
    };
    var currentDomain = undefined;
    var seedValid = false;

    var checkSeedChecksum = () => {
        const valid = $('#checksum').text() === settings.checksum;

        $('#chkok').html(valid ? '✓' : '✗');
        $('#chkset').prop('disabled', valid ? 'disabled' : '');

        seedValid = valid;
    };

    var setDomains = () => {
        $domainlist = $("#domainlist")

        $domainlist.html('');

        Object.keys(settings.domains).sort().forEach(domain =>
            $domainlist.append($('<option>').attr('value', domain).text(domain))
        );
    };

    var storeDomains = () => {
        Storage.setItem('domains', JSON.stringify(settings.domains));
    };

    var calcRounds = (l, allowBias) => {
        var m = 0xffffffff;
        var n = 0;

        while (m > 0) {
            m = Math.floor(m / l);
            n++;
        }

        return n;
    };

    ns.resetSeed = () => {
        $('#seed').val('');
        $('#seed').prop('disabled', '');
        $('#checksum').text('-');
        $('#chkok').text('');
        $('#chkset').prop('disabled', 'disabled');

        seedValid = false;

        $('#seed').focus();
    };

    ns.calculateSeed = () => {
        sha256(SEED_PREFIX + $('#seed').val()).then(hash => {
            $('#seed').val(hash);
            $('#seed').prop('disabled', 'disabled');
            $('#checksum').text(hash.substring(0, 2));
            checkSeedChecksum();
        });
    };

    ns.storeSeedChecksum = () => {
        settings.checksum = $('#checksum').text();
        Storage.setItem('checksum', settings.checksum);
        checkSeedChecksum();
    };

    ns.checkDomainInputMatchesToOption = () => {
        var domain = $('#domain').val();
        if (domain in settings.domains) {
            ns.loadSettingsForDomain(domain);
        } else {
            ns.loadSettingsForDomain('');
        }
    };

    ns.loadSettingsForDomain = (domain) => {
        if (domain === undefined) {
            ns.loadSettingsForDomain($('#domain').val());
            return;
        }

        var _settings;

        if (domain === '') {
            $('#length').prop('disabled', 'disabled');
            $('#iteration').prop('disabled', 'disabled');
            $('#nextiter').prop('disabled', 'disabled');
            $('#extended').prop('disabled', 'disabled');
            $('#storedomain').prop('disabled', 'disabled');
            $('#docopy').prop('disabled', 'disabled');

            _settings = settings.DEFAULT;
        } else if (domain in settings.domains) {
            _settings = settings.domains[domain];
        } else if (!confirm('Add new domain "' + domain + '" ?')) {
            $('#domain').val('');
            ns.loadSettingsForDomain('');
            return;
        } else {
            settings.domains[domain] = settings.DEFAULT.slice();
            setDomains();

            _settings = settings.domains[domain];
            Storage.setItem('domains', JSON.stringify(settings.domains));
        }

        $('#length').val(_settings[0]);
        $('#iteration').val(_settings[1]);
        $('#extended').prop('checked', _settings[2] ? 'checked' : '');

        if (_settings !== settings.DEFAULT) {
            $('#length').prop('disabled', '');
            $('#iteration').prop('disabled', '');
            $('#nextiter').prop('disabled', '');
            $('#extended').prop('disabled', '');
            $('#storedomain').prop('disabled', '');
            $('#docopy').prop('disabled', '');

            currentDomain = domain;
        }
    };

    ns.storeSettingsForDomain = () => {
        _settings = [
            parseInt($('#length').val()),
            parseInt($('#iteration').val()),
            $('#extended').prop('checked')
        ];

        settings.domains[currentDomain] = _settings;
        storeDomains();
    };

    ns.nextIteration = () => {
        $('#iteration').val(parseInt($('#iteration').val()) + 1);
        ns.storeSettingsForDomain();
    };

    ns.deriveAndCopyToClipboard = () => {
        if (!seedValid) {
            alert('Enter master password first!');
            ns.resetSeed();
            return;
        }

        $docopy = $('#docopy');
        $docopy.prop('disabled', 'disabled');

        const ENTROPY_SIZE = 8;
        const map = settings.domains[currentDomain][2] ? EXTENDED_MAP : BASIC_MAP;
        const rounds = calcRounds(map.length);

        if (settings.domains[currentDomain][0] > ENTROPY_SIZE * rounds) {
            settings.domains[currentDomain][0] = ENTROPY_SIZE * rounds;
            ns.loadSettingsForDomain();
        }

        sha256(DERIVE_PREFIX + $('#seed').val() + '/' + settings.domains[currentDomain][1] + '/' + currentDomain).then(hash => {
            var pw = '';

            for (var i = 0; i < ENTROPY_SIZE; i++) {
                var x = parseInt(hash.substring(i * ENTROPY_SIZE, (i+1) * ENTROPY_SIZE), 16);
                for (var j = 0; j < rounds; j++) {
                    pw += map.substring(x % map.length, x % map.length + 1);
                    x = Math.floor(x / map.length);
                }
            }

            pw = pw.substring(0, settings.domains[currentDomain][0]);

            navigator.clipboard.writeText(pw).then(() => {
                $docopy.val('[ COPIED ]');
                setTimeout(() => {
                    $docopy.val('Copy password');
                    $docopy.prop('disabled', '');
                }, 1500);
            });
        });
    };

    ns.deleteDomain = () => {
        if (Object.keys(settings.domains).indexOf($('#domain').val()) >= 0) {
            delete settings.domains[$('#domain').val()];
            storeDomains();

            $('#domain').val('');
            ns.loadSettingsForDomain();
        }
    };

    ns.setup = () => {
        if (Storage.getItem('checksum') != null) {
            settings.checksum = Storage.getItem('checksum');
        }
        if (Storage.getItem('domains') != null) {
            settings.domains = JSON.parse(Storage.getItem('domains'));
            console.debug('Loaded domains:', settings.domains);
            setDomains();
        }

        var setupReturnEvent = (o, handler) => {
            o.keypress((event, value) => {
                if (event.which === 13) {
                    handler(o.val());
                }
            });
        };

        setupReturnEvent($('#seed'), ns.calculateSeed);
        setupReturnEvent($('#domain'), ns.loadSettingsForDomain);

        ns.resetSeed();
        ns.loadSettingsForDomain();
    };

    ns.configuration = {};
    ns.configuration.dump = () =>
        console.log(JSON.stringify(settings.domains));

    ns.configuration.load = domainSettings => {
        for (let k in domainSettings)
            settings.domains[k] = domainSettings[k];

        Storage.setItem('domains', JSON.stringify(settings.domains));
        setDomains();
        ns.loadSettingsForDomain();
    };

})(ewpass);