import type { GrammarRule, KeywordBlock } from "#types/grammar.types";
import { LINE_BREAK } from "#configuration/constants/code.constants";
import { ONTOLOGY } from "#core/assets/ontology.generated";

const HEADING = "# ";
const GAP = "\n\n";
const PRODUCES = " ::= ";
const OPEN = "<";
const CLOSE = ">";

export const joinRules = function joinRules(rules: readonly GrammarRule[]): string {
    return rules.map((rule) => HEADING + rule.title + LINE_BREAK + rule.grammar).join(GAP);
};

export const keywordsOf = function keywordsOf(category: string): KeywordBlock {
    const group = ONTOLOGY.grammar.categories.find((entry) => entry.category === category);
    return {
        keywords: (group?.keywords ?? []).map((keyword) => ({
            description: keyword.meaning,
            example: keyword.example,
            name: keyword.name,
        })),
        kind: "keyword",
    };
};

export const productionsOf = function productionsOf(group: string, title: string): GrammarRule {
    const found = ONTOLOGY.grammar.groups.find((entry) => entry.group === group);
    return {
        grammar: (found?.productions ?? [])
            .map((production) => OPEN + production.lhs + CLOSE + PRODUCES + production.rhs)
            .join(LINE_BREAK),
        title,
    };
};

export const templateBodyOf = function templateBodyOf(type: string): string {
    return ONTOLOGY.grammar.templates.find((template) => template.type === type)?.body ?? "";
};

export const templateConstraintsOf = function templateConstraintsOf(type: string): readonly string[] {
    return ONTOLOGY.grammar.templates.find((template) => template.type === type)?.constraints ?? [];
};