const fs = require("fs");
const path = require("path");
const glob = require("glob");

const PREFIX = "tw-";
const rootDir = "./src";

function replaceClassNames(classNamesString) {
  const classNames = classNamesString.split(" ");

  return classNames
    .map((className) => {
      const values = className.split(":");
      const modifiers = values.length > 1 ? values.slice(0, values.length - 1) : [];
      const value = values[values.length - 1];
      const isNegative = value.startsWith("-");

      if (value.includes(PREFIX)) {
        return className;
      }

      return [
        modifiers.length ? modifiers.join(":") + ":" : null,
        isNegative ? "-" : "",
        PREFIX,
        isNegative ? value.slice(1) : value,
      ]
        .filter((value) => !!value)
        .join("");
    })
    .join(" ");
}

glob("**/*.{js,jsx,ts,tsx,vue,css}", { cwd: rootDir }, (er, files) => {
  files.forEach((file) => {
    const filePath = path.join(rootDir, file);
    fs.readFile(filePath, "utf-8", (err, data) => {
      if (err) {
        console.error(err);
        return;
      }

      const result = data
        // Classes
        .replace(/class=["']([."'\w\s\/:\[\]-]+)["']/g, (match, p1) => {
          return `class="${replaceClassNames(p1)}"`;
        })
        // @apply directives
        .replace(/@apply ([."'\w\s\/:\[\]-]+)/g, (match, p1) => {
          return `@apply ${replaceClassNames(p1)}`;
        })
        // Conditionals
        // TODO: Handle multi-line conditionals
        .replace(/:class="(.*\?\s)["'](.*)["'](.*:\s)["'](.*)["']"/g, (match, p1, p2, p3, p4) => {
          return `:class="${p1}'${replaceClassNames(p2)}'${p3}'${replaceClassNames(p4)}'"`;
        })
        .replace(/:class="(.*&&\s)["'](.*)["']"/g, (match, p1, p2) => {
          return `:class="${p1}'${replaceClassNames(p2)}'"`;
        });

      fs.writeFile(filePath, result, "utf-8", (err) => {
        if (err) console.error(err);
      });
    });
  });
});