import { Lexer, Parser } from "antlr4ts";

export const keywordRgx: any = /[a-zA-Z][\w]*/;

export class VocabularyPack<L extends Lexer, P extends Parser> {
    private readonly ruleNames: Array<string>;
    private readonly symbolicNames: Array<string | undefined>;
    private readonly literalNames: Array<string | undefined>;
    private readonly operatorNames: Array<string | undefined>;
    private readonly keywordNames: Array<string | undefined>;

    constructor(lexer: L, parser: P) {
        this.ruleNames = Array.from(parser.ruleNames);
        const count = lexer.vocabulary.maxTokenType;
        this.symbolicNames = new Array<string | undefined>(count);
        this.literalNames = new Array<string | undefined>(count);
        this.operatorNames = new Array<string | undefined>(count);
        this.keywordNames = new Array<string | undefined>(count);

        const vocabulary = lexer.vocabulary;
        lexer.ruleNames.forEach(ruleName => {
            if (ruleName in lexer) {
                const index = lexer[ruleName as keyof typeof lexer];
                if (
                    typeof index === "number" &&
                    Number.isInteger(index) &&
                    index > 0 &&
                    index <= count
                ) {
                    this.symbolicNames[index] = ruleName;
                    this.literalNames[index] = vocabulary.getLiteralName(index);
                    this.operatorNames[index] = this.literalNames[index]?.replace(/^'+|'+$/g, "");
                    this.keywordNames[index] = keywordRgx.test(this.operatorNames[index] ?? "")
                        ? this.operatorNames[index]
                        : undefined;
                }
            }
        });
    }

    ruleName(index: number): string | undefined {
        return this.ruleNames[index];
    }

    symbolicName(index: number): string | undefined {
        return this.symbolicNames[index];
    }

    operator(index: number): string | undefined {
        return this.operatorNames[index];
    }

    keyword(index: number): string | undefined {
        return this.keywordNames[index];
    }

    getLiteralNames() {
        return this.literalNames;
    }

    getSymbolicNames() {
        return this.symbolicNames;
    }

    isSymbolicName(name: string) {
        return this.symbolicNames.includes(name);
    }

    isRuleName(name: string) {
        return this.ruleNames.includes(name);
    }

    symbolicIndex(name: string) {
        return this.symbolicNames.indexOf(name);
    }

    hasKeyword(index: number) {
        return !!this.keywordNames[index];
    }

    hasOperator(index: number) {
        return !!this.operatorNames[index];
    }

    getRuleNames() {
        return this.ruleNames;
    }
}