var _ = require('lodash');

function formatParse(format) {
    format = format.split('-');
    var keyType = 'private';
    var keyOpt = {type: 'default'};

    for (var i = 1; i < format.length; i++) {
        if (format[i]) {
            switch (format[i]) {
                case 'public':
                    keyType = format[i];
                    break;
                case 'private':
                    keyType = format[i];
                    break;
                case 'pem':
                    keyOpt.type = format[i];
                    break;
                case 'der':
                    keyOpt.type = format[i];
                    break;
            }
        }
    }

    return {scheme: format[0], keyType: keyType, keyOpt: keyOpt};
}

module.exports = {
    pkcs1: require('./pkcs1'),
    pkcs8: require('./pkcs8'),

    isPrivateExport: function (format) {
        return module.exports[format] && typeof module.exports[format].privateExport === 'function';
    },

    isPrivateImport: function (format) {
        return module.exports[format] && typeof module.exports[format].privateImport === 'function';
    },

    isPublicExport: function (format) {
        return module.exports[format] && typeof module.exports[format].publicExport === 'function';
    },

    isPublicImport: function (format) {
        return module.exports[format] && typeof module.exports[format].publicImport === 'function';
    },

    detectAndImport: function (key, data, format) {
        if (format === undefined) {
            for (var scheme in module.exports) {
                if (typeof module.exports[scheme].autoImport === 'function' && module.exports[scheme].autoImport(key, data)) {
                    return true;
                }
            }
        } else if (format) {
            var fmt = formatParse(format);

            if (module.exports[fmt.scheme]) {
                if (fmt.keyType === 'private') {
                    module.exports[fmt.scheme].privateImport(key, data, fmt.keyOpt);
                } else {
                    module.exports[fmt.scheme].publicImport(key, data, fmt.keyOpt);
                }
            } else {
                throw Error('Unsupported key format');
            }
        }

        return false;
    },

    detectAndExport: function (key, format) {
        if (format) {
            var fmt = formatParse(format);

            if (module.exports[fmt.scheme]) {
                if (fmt.keyType === 'private') {
                    if (!key.isPrivate()) {
                        throw Error("It is not private key");
                    }
                    return module.exports[fmt.scheme].privateExport(key, fmt.keyOpt);
                } else {
                    if (!key.isPublic()) {
                        throw Error("It is not public key");
                    }
                    return module.exports[fmt.scheme].publicExport(key, fmt.keyOpt);
                }
            } else {
                throw Error('Unsupported key format');
            }
        }
    }
};