import { Box, type UnionValue } from 'treb-base-types';
import { ValueType } from 'treb-base-types';
import { AddExtendedFunction } from 'treb-calculator';
import { ValueError } from 'treb-calculator';

AddExtendedFunction('ISEVEN', {
  description: 'Returns TRUE if a number is even',
  arguments: [
    { name: 'number', description: 'The value to test', unroll: true },
  ],
  fn: (num?: number): UnionValue => {
    if (num === undefined) return ValueError();
    return Box(Math.trunc(num) % 2 === 0);
  },
});

AddExtendedFunction('ISODD', {
  description: 'Returns TRUE if a number is odd',
  arguments: [
    { name: 'number', description: 'The value to test', unroll: true },
  ],
  fn: (num?: number): UnionValue => {
    if (num === undefined) return ValueError();
    return Box(Math.trunc(num) % 2 !== 0);
  },
});

AddExtendedFunction('ISNONTEXT', {
  description: 'Returns TRUE if a value is not text',
  arguments: [
    { name: 'value', description: 'The value to test', boxed: true },
  ],
  fn: (value?: UnionValue): UnionValue => {
    if (!value) return Box(true);
    return Box(value.type !== ValueType.string);
  },
});

AddExtendedFunction('N', {
  description: 'Converts a value to a number',
  arguments: [
    { name: 'value', description: 'The value to convert', boxed: true },
  ],
  fn: (value?: UnionValue): UnionValue => {
    if (!value) return Box(0);
    switch (value.type) {
      case ValueType.number:
        return value;
      case ValueType.boolean:
        return Box(value.value ? 1 : 0);
      case ValueType.error:
        return value;
      default:
        return Box(0);
    }
  },
});

AddExtendedFunction('TYPE', {
  description: 'Returns the type of a value',
  arguments: [
    { name: 'value', description: 'The value to test', boxed: true, allow_error: true },
  ],
  fn: (value?: UnionValue): UnionValue => {
    if (!value || value.type === ValueType.undefined) return Box(1);
    switch (value.type) {
      case ValueType.number: return Box(1);
      case ValueType.string: return Box(2);
      case ValueType.boolean: return Box(4);
      case ValueType.error: return Box(16);
      case ValueType.array: return Box(64);
      default: return Box(1);
    }
  },
});

AddExtendedFunction('ERROR.TYPE', {
  description: 'Returns the number corresponding to an error type',
  arguments: [
    { name: 'error_val', description: 'The error value', boxed: true, allow_error: true },
  ],
  fn: (value?: UnionValue): UnionValue => {
    if (!value || value.type !== ValueType.error) {
      return { type: ValueType.error, value: 'N/A' };
    }
    switch (value.value) {
      case 'VALUE': return Box(3);
      case 'REF': return Box(4);
      case 'NAME': return Box(5);
      case 'DIV/0': return Box(2);
      case 'N/A': return Box(7);
      case 'DATA': return Box(3);
      default: return { type: ValueType.error, value: 'N/A' };
    }
  },
});