'use strict';

const NO_WRAP_RE = /^(?:\(.*\)|\\?.)$/;
function wrap(s) {
  const v = s.toString();
  return NO_WRAP_RE.test(v) ? v : `(?:${v})`;
}

const GROUPED_AS_REPLACE_RE = /^(?:\(\?:(.+)\)|(.+))$/;
const GROUPED_REPLACE_RE = /^(?:\(\?:(.+)\)([?+*]|\{[\d,]+\})?|(.+))$/;
function createInput(s) {
  const groupedAsFn = (key) => createInput(`(?<${key}>${`${s}`.replace(GROUPED_AS_REPLACE_RE, "$1$2")})`);
  return {
    toString: () => s.toString(),
    and: Object.assign((...inputs) => createInput(`${s}${exactly(...inputs)}`), {
      referenceTo: (groupName) => createInput(`${s}\\k<${groupName}>`)
    }),
    or: (...inputs) => createInput(`(?:${s}|${inputs.map((v) => exactly(v)).join("|")})`),
    after: (...input) => createInput(`(?<=${exactly(...input)})${s}`),
    before: (...input) => createInput(`${s}(?=${exactly(...input)})`),
    notAfter: (...input) => createInput(`(?<!${exactly(...input)})${s}`),
    notBefore: (...input) => createInput(`${s}(?!${exactly(...input)})`),
    times: Object.assign((number) => createInput(`${wrap(s)}{${number}}`), {
      any: () => createInput(`${wrap(s)}*`),
      atLeast: (min) => createInput(`${wrap(s)}{${min},}`),
      atMost: (max) => createInput(`${wrap(s)}{0,${max}}`),
      between: (min, max) => createInput(`${wrap(s)}{${min},${max}}`)
    }),
    optionally: () => createInput(`${wrap(s)}?`),
    as: groupedAsFn,
    groupedAs: groupedAsFn,
    grouped: () => createInput(`${s}`.replace(GROUPED_REPLACE_RE, "($1$3)$2")),
    at: {
      lineStart: () => createInput(`^${s}`),
      lineEnd: () => createInput(`${s}$`)
    }
  };
}

const ESCAPE_REPLACE_RE = /[.*+?^${}()|[\]\\/]/g;
function createCharInput(raw) {
  const input = createInput(`[${raw}]`);
  const from = (charFrom, charTo) => createCharInput(`${raw}${escapeCharInput(charFrom)}-${escapeCharInput(charTo)}`);
  const orChar = Object.assign((chars) => createCharInput(`${raw}${escapeCharInput(chars)}`), { from });
  return Object.assign(input, { orChar, from });
}
function escapeCharInput(raw) {
  return raw.replace(/[-\\^\]]/g, "\\$&");
}
const charIn = Object.assign((chars) => {
  return createCharInput(escapeCharInput(chars));
}, createCharInput(""));
const charNotIn = Object.assign((chars) => {
  return createCharInput(`^${escapeCharInput(chars)}`);
}, createCharInput("^"));
function anyOf(...inputs) {
  return createInput(`(?:${inputs.map((a) => exactly(a)).join("|")})`);
}
const char = createInput(".");
const word = createInput("\\b\\w+\\b");
const wordChar = createInput("\\w");
const wordBoundary = createInput("\\b");
const digit = createInput("\\d");
const whitespace = createInput("\\s");
const letter = Object.assign(createInput("[a-zA-Z]"), {
  lowercase: createInput("[a-z]"),
  uppercase: createInput("[A-Z]")
});
const tab = createInput("\\t");
const linefeed = createInput("\\n");
const carriageReturn = createInput("\\r");
const not = {
  word: createInput("\\W+"),
  wordChar: createInput("\\W"),
  wordBoundary: createInput("\\B"),
  digit: createInput("\\D"),
  whitespace: createInput("\\S"),
  letter: Object.assign(createInput("[^a-zA-Z]"), {
    lowercase: createInput("[^a-z]"),
    uppercase: createInput("[^A-Z]")
  }),
  tab: createInput("[^\\t]"),
  linefeed: createInput("[^\\n]"),
  carriageReturn: createInput("[^\\r]")
};
function maybe(...inputs) {
  return createInput(`${wrap(exactly(...inputs))}?`);
}
function exactly(...inputs) {
  return createInput(
    inputs.map((input) => typeof input === "string" ? input.replace(ESCAPE_REPLACE_RE, "\\$&") : input).join("")
  );
}
function oneOrMore(...inputs) {
  return createInput(`${wrap(exactly(...inputs))}+`);
}

const withIndices = "d";
const caseInsensitive = "i";
const global = "g";
const multiline = "m";
const dotAll = "s";
const unicode = "u";
const sticky = "y";

exports.anyOf = anyOf;
exports.carriageReturn = carriageReturn;
exports.caseInsensitive = caseInsensitive;
exports.char = char;
exports.charIn = charIn;
exports.charNotIn = charNotIn;
exports.digit = digit;
exports.dotAll = dotAll;
exports.exactly = exactly;
exports.global = global;
exports.letter = letter;
exports.linefeed = linefeed;
exports.maybe = maybe;
exports.multiline = multiline;
exports.not = not;
exports.oneOrMore = oneOrMore;
exports.sticky = sticky;
exports.tab = tab;
exports.unicode = unicode;
exports.whitespace = whitespace;
exports.withIndices = withIndices;
exports.word = word;
exports.wordBoundary = wordBoundary;
exports.wordChar = wordChar;