const {
  concat,
  group,
  hardline,
  indent,
  join,
  literalline,
  softline
} = require("../prettier");
const { concatBody, empty, makeList, prefix, surround } = require("../utils");
const escapePattern = require("../escapePattern");

// If there is some part of this string that matches an escape sequence or that
// contains the interpolation pattern ("#{"), then we are locked into whichever
// quote the user chose. (If they chose single quotes, then double quoting
// would activate the escape sequence, and if they chose double quotes, then
// single quotes would deactivate it.)
const isQuoteLocked = string =>
  string.body.some(
    part =>
      part.type === "@tstring_content" &&
      (escapePattern.test(part.body) || part.body.includes("#{"))
  );

// A string is considered to be able to use single quotes if it contains only
// plain string content and that content does not contain a single quote.
const isSingleQuotable = string =>
  string.body.every(
    part => part.type === "@tstring_content" && !part.body.includes("'")
  );

const getStringQuote = (string, preferSingleQuotes) => {
  if (isQuoteLocked(string)) {
    return string.quote;
  }

  return preferSingleQuotes && isSingleQuotable(string) ? "'" : '"';
};

const quotePattern = new RegExp("\\\\([\\s\\S])|(['\"])", "g");

const makeString = (content, enclosingQuote) => {
  const otherQuote = enclosingQuote === '"' ? "'" : '"';

  // Escape and unescape single and double quotes as needed to be able to
  // enclose `content` with `enclosingQuote`.
  return content.replace(quotePattern, (match, escaped, quote) => {
    if (escaped === otherQuote) {
      return escaped;
    }

    if (quote === enclosingQuote) {
      return `\\${quote}`;
    }

    if (quote) {
      return quote;
    }

    return `\\${escaped}`;
  });
};

module.exports = {
  "@CHAR": (path, { preferSingleQuotes }, _print) => {
    const { body } = path.getValue();

    if (body.length !== 2) {
      return body;
    }

    const quote = preferSingleQuotes ? "'" : '"';
    return body.length === 2 ? concat([quote, body.slice(1), quote]) : body;
  },
  dyna_symbol: (path, opts, print) => {
    const { quote } = path.getValue().body[0];

    return concat([":", quote, concat(path.call(print, "body", 0)), quote]);
  },
  heredoc: (path, opts, print) => {
    const { beging, ending } = path.getValue();

    return concat([
      beging,
      concat([literalline].concat(path.map(print, "body"))),
      ending
    ]);
  },
  string: makeList,
  string_concat: (path, opts, print) =>
    group(
      concat([
        path.call(print, "body", 0),
        " \\",
        indent(concat([hardline, path.call(print, "body", 1)]))
      ])
    ),
  string_dvar: surround("#{", "}"),
  string_embexpr: (path, opts, print) =>
    group(
      concat([
        "#{",
        indent(concat([softline, path.call(print, "body", 0)])),
        concat([softline, "}"])
      ])
    ),
  string_literal: (path, { preferSingleQuotes }, print) => {
    const string = path.getValue().body[0];

    // If this string is actually a heredoc, bail out and return to the print
    // function for heredocs
    if (string.type === "heredoc") {
      return path.call(print, "body", 0);
    }

    // If the string is empty, it will not have any parts, so just print out the
    // quotes corresponding to the config
    if (string.body.length === 0) {
      return preferSingleQuotes ? "''" : '""';
    }

    const quote = getStringQuote(string, preferSingleQuotes);
    const parts = [];

    string.body.forEach((part, index) => {
      if (part.type === "@tstring_content") {
        // In this case, the part of the string is just regular string content
        parts.push(makeString(part.body, quote));
      } else {
        // In this case, the part of the string is an embedded expression
        parts.push(path.call(print, "body", 0, "body", index));
      }
    });

    return concat([quote].concat(parts).concat([quote]));
  },
  symbol: prefix(":"),
  symbol_literal: concatBody,
  word_add: concatBody,
  word_new: empty,
  xstring: makeList,
  xstring_literal: (path, opts, print) => {
    const parts = path.call(print, "body", 0);

    if (typeof parts[0] === "string") {
      parts[0] = parts[0].replace(/^\s+/, "");
    }

    const lastIndex = parts.length - 1;
    if (typeof parts[lastIndex] === "string") {
      parts[lastIndex] = parts[lastIndex].replace(/\s+$/, "");
    }

    return group(
      concat([
        "`",
        indent(concat([softline, join(softline, parts)])),
        concat([softline, "`"])
      ])
    );
  }
};