// https://microsoft.github.io/monaco-editor/monarch.html
import { languages } from "monaco-editor/esm/vs/editor/editor.api.js";

export const conf: languages.LanguageConfiguration = {
  brackets: [
    ["{", "}"],
    ["(", ")"],
  ],
  autoClosingPairs: [
    { open: "{", close: "}" },
    { open: "(", close: ")" },
    { open: "[", close: "]" },
    { open: '"', close: '"' },
  ],
  surroundingPairs: [
    { open: "(", close: ")" },
    { open: "{", close: "}" },
    { open: "[", close: "]" },
    { open: '"', close: '"' },
  ],
};

export const language = <languages.IMonarchLanguage>{
  // Set defaultToken to invalid to see what you do not tokenize yet
  // defaultToken: 'invalid',

  keywords: ["return", "else", "if", "let", "true", "false", "fn"],

  operators: ["=", ">", "<", "!", "==", "!=", "+", "-", "*", "/"],

  // we include these common regular expressions
  symbols: /[=><!~?:&|+\-*\/\^%]+/,

  typeKeywords: [],

  // C# style strings
  escapes:
    /\\(?:[abfnrtv\\"']|x[0-9A-Fa-f]{1,4}|u[0-9A-Fa-f]{4}|U[0-9A-Fa-f]{8})/,

  // The main tokenizer for our languages
  tokenizer: {
    root: [
      // identifiers and keywords
      [
        /[a-z_$][\w$]*/,
        {
          cases: {
            "@typeKeywords": "keyword",
            "@keywords": "keyword",
            "@default": "identifier",
          },
        },
      ],
      [/[A-Z][\w\$]*/, "type.identifier"], // to show class names nicely

      // whitespace
      { include: "@whitespace" },

      // delimiters and operators
      [/[{}()\[\]]/, "@brackets"],
      [/[<>](?!@symbols)/, "@brackets"],
      [/@symbols/, { cases: { "@operators": "operator", "@default": "" } }],

      // @ annotations.
      // As an example, we emit a debugging log message on these tokens.
      // Note: message are supressed during the first load -- change some lines to see them.
      [
        /@\s*[a-zA-Z_\$][\w\$]*/,
        { token: "annotation", log: "annotation token: $0" },
      ],

      // numbers
      // [/\d*\.\d+([eE][\-+]?\d+)?/, "number.float"],
      // [/0[xX][0-9a-fA-F]+/, "number.hex"],
      [/\d+/, "number"],

      // delimiter: after number because of .\d floats
      [/[;,.]/, "delimiter"],

      // strings
      [/"([^"\\]|\\.)*$/, "string.invalid"], // non-teminated string
      [/"/, { token: "string.quote", bracket: "@open", next: "@string" }],

      // characters
      [/'[^\\']'/, "string"],
      [/(')(@escapes)(')/, ["string", "string.escape", "string"]],
      [/'/, "string.invalid"],
    ],

    string: [
      [/[^\\"]+/, "string"],
      [/@escapes/, "string.escape"],
      [/\\./, "string.escape.invalid"],
      [/"/, { token: "string.quote", bracket: "@close", next: "@pop" }],
    ],

    whitespace: [[/[ \t\r\n]+/, "white"]],
  },
};