import { inspect } from 'node:util';
import { symbolDict, symbolFunction, symbolList, symbolProduct, symbolSum } from '../structures/type_constructors.js';
import { symbolSet } from "../structures/type_constructors.js";
import { getHumanReadableName } from '../primitives/symbol.js';
import { getSymbol } from '../primitives/type.js';

export function pretty(obj) {
  return inspect(obj, { colors: true, depth: null, breakLength: 120 });
}

// Pretty print Type
export const _prettyT = (depth, tags) => type => {
  if (typeof type === 'number' && type < depth) {
    // we've already seen this type, so we'll tag it
    // we mutate tags in-place so our parent type can see it
    const hashTag = `#${tags.size}`;
    // upper level will be tagged:
    tags.set(type, hashTag);
    // and this level is entirely replaced by tag:
    return hashTag;
  }
  const params = type.params.map(p => _prettyT(depth+1, tags)(p(depth)));
  const annot = tags.get(depth) || '';
  return renderType(getSymbol(type), annot, params);
}

export const prettyT = type => _prettyT(0, new Map())(type);

const renderType = (symbol, annot, params) => {
  return {
    [symbolList]    : `${annot}[${params[0]}]`,
    [symbolSet]     : `${annot}{${params[0]}}`,
    [symbolFunction]: `${annot}(${params[0]} -> ${params[1]})`,
    [symbolSum]     : `${annot}(${params[0]} + ${params[1]})`,
    [symbolProduct] : `${annot}(${params[0]} ⨯ ${params[1]})`,
    [symbolDict]    : `${annot}(${params[0]} => ${params[1]})`,
  }[symbol] || getHumanReadableName(symbol);
};