'use strict';

var cstScalar = require('./cst-scalar.js');
var cstStringify = require('./cst-stringify.js');
var cstVisit = require('./cst-visit.js');

/** The byte order mark */
const BOM = '\u{FEFF}';
/** Start of doc-mode */
const DOCUMENT = '\x02'; // C0: Start of Text
/** Unexpected end of flow-mode */
const FLOW_END = '\x18'; // C0: Cancel
/** Next token is a scalar value */
const SCALAR = '\x1f'; // C0: Unit Separator
/** @returns `true` if `token` is a flow or block collection */
const isCollection = (token) => !!token && 'items' in token;
/** @returns `true` if `token` is a flow or block scalar; not an alias */
const isScalar = (token) => !!token &&
    (token.type === 'scalar' ||
        token.type === 'single-quoted-scalar' ||
        token.type === 'double-quoted-scalar' ||
        token.type === 'block-scalar');
/* istanbul ignore next */
/** Get a printable representation of a lexer token */
function prettyToken(token) {
    switch (token) {
        case BOM:
            return '<BOM>';
        case DOCUMENT:
            return '<DOC>';
        case FLOW_END:
            return '<FLOW_END>';
        case SCALAR:
            return '<SCALAR>';
        default:
            return JSON.stringify(token);
    }
}
/** Identify the type of a lexer token. May return `null` for unknown tokens. */
function tokenType(source) {
    switch (source) {
        case BOM:
            return 'byte-order-mark';
        case DOCUMENT:
            return 'doc-mode';
        case FLOW_END:
            return 'flow-error-end';
        case SCALAR:
            return 'scalar';
        case '---':
            return 'doc-start';
        case '...':
            return 'doc-end';
        case '':
        case '\n':
        case '\r\n':
            return 'newline';
        case '-':
            return 'seq-item-ind';
        case '?':
            return 'explicit-key-ind';
        case ':':
            return 'map-value-ind';
        case '{':
            return 'flow-map-start';
        case '}':
            return 'flow-map-end';
        case '[':
            return 'flow-seq-start';
        case ']':
            return 'flow-seq-end';
        case ',':
            return 'comma';
    }
    switch (source[0]) {
        case ' ':
        case '\t':
            return 'space';
        case '#':
            return 'comment';
        case '%':
            return 'directive-line';
        case '*':
            return 'alias';
        case '&':
            return 'anchor';
        case '!':
            return 'tag';
        case "'":
            return 'single-quoted-scalar';
        case '"':
            return 'double-quoted-scalar';
        case '|':
        case '>':
            return 'block-scalar-header';
    }
    return null;
}

exports.createScalarToken = cstScalar.createScalarToken;
exports.resolveAsScalar = cstScalar.resolveAsScalar;
exports.setScalarValue = cstScalar.setScalarValue;
exports.stringify = cstStringify.stringify;
exports.visit = cstVisit.visit;
exports.BOM = BOM;
exports.DOCUMENT = DOCUMENT;
exports.FLOW_END = FLOW_END;
exports.SCALAR = SCALAR;
exports.isCollection = isCollection;
exports.isScalar = isScalar;
exports.prettyToken = prettyToken;
exports.tokenType = tokenType;