import { expect, test } from 'bun:test';
import {
  type DenotableFunctionSignature,
  denotableTypesEquivalent,
  matchSignature,
} from '@/interpreter';

test('simple denotable types are equivalent', () => {
  expect(denotableTypesEquivalent('int', 'int')).toBe(true);
  expect(denotableTypesEquivalent('int', 'real')).toBe(false);
  expect(denotableTypesEquivalent('int', 'null')).toBe(false);
  expect(denotableTypesEquivalent('null', 'null')).toBe(true);
});

test('union data types are equivalent', () => {
  expect(denotableTypesEquivalent(['int', 'real'], ['int', 'real'])).toBe(true);
  expect(denotableTypesEquivalent('int', ['int', 'real'])).toBe(false);
});

test('function data types are equivalent', () => {
  expect(
    denotableTypesEquivalent(
      [
        {
          arguments: ['int', 'real'],
          return: 'int',
        },
      ],
      [
        {
          arguments: ['int', 'real'],
          return: 'int',
        },
      ],
    ),
  ).toBe(true);

  expect(
    denotableTypesEquivalent(
      [
        {
          arguments: ['int', 'real'],
          return: 'real',
        },
      ],
      [
        {
          arguments: ['int', 'real'],
          return: 'int',
        },
      ],
    ),
  ).toBe(false);
});

test('matches simple signatures', async () => {
  const simpleSignature: DenotableFunctionSignature[] = [
    {
      arguments: ['int'],
      return: 'int',
    },
  ];

  expect(matchSignature(['int'], simpleSignature)).toEqual(simpleSignature[0]);
});

test('finds first match', async () => {
  const simpleSignature: DenotableFunctionSignature[] = [
    {
      arguments: ['int', 'int'],
      return: 'int',
    },
    {
      arguments: [['int', 'real'], 'int'],
      return: 'real',
    },
  ];

  expect(matchSignature(['int', 'int'], simpleSignature)).toEqual(
    simpleSignature[0],
  );

  expect(matchSignature(['real', 'int'], simpleSignature)).toEqual(
    simpleSignature[1],
  );
});

test('finds first match with a function signature', async () => {
  const testSignature: DenotableFunctionSignature = {
    arguments: ['int', 'real'],
    return: 'int',
  };

  const simpleSignature: DenotableFunctionSignature[] = [
    {
      arguments: ['int', 'int'],
      return: 'int',
    },
    {
      arguments: [[testSignature, 'real'], 'int'],
      return: 'function',
    },
  ];

  expect(matchSignature(['int', 'int'], simpleSignature)).toEqual(
    simpleSignature[0],
  );

  expect(matchSignature(['real', 'int'], simpleSignature)).toEqual(
    simpleSignature[1],
  );

  expect(matchSignature([testSignature, 'int'], simpleSignature)).toEqual(
    simpleSignature[1],
  );
});

test('finds first match with a function with many signatures', async () => {
  const testSignature: DenotableFunctionSignature[] = [
    {
      arguments: ['int', 'real'],
      return: 'int',
    },
    {
      arguments: ['int', 'int'],
      return: 'int',
    },
  ];

  const simpleSignature: DenotableFunctionSignature[] = [
    {
      arguments: ['int', 'int'],
      return: 'int',
    },
    {
      arguments: [[testSignature, 'real'], 'int'],
      return: 'function',
    },
  ];

  expect(matchSignature(['int', 'int'], simpleSignature)).toEqual(
    simpleSignature[0],
  );

  expect(matchSignature(['real', 'int'], simpleSignature)).toEqual(
    simpleSignature[1],
  );

  expect(matchSignature([testSignature, 'int'], simpleSignature)).toEqual(
    simpleSignature[1],
  );

  expect(
    matchSignature([[testSignature[0]], 'int'], simpleSignature),
  ).toBeUndefined();
});