import {parse as acornParse} from 'acorn';
import {expect, test} from 'vitest';

import Sandbox from '@/astride/sandbox.js';

function parse(code, options = {}) {
  return acornParse(code, {
    ecmaVersion: 'latest',
    sourceType: 'module',
    ...options,
  })
}

async function finish(sandbox) {
  let result;
  let i = 0;
  do {
    result = sandbox.step();
    if (result.async) {
      await result.value;
    }
  } while (!result.done && ++i < 1000);
  return result;
}

test('declares variables', async () => {
  const sandbox = new Sandbox(
    await parse(`
      const scalar = true ? +1 : 32;
      const asyncScalar = await 2;
      const array = [3, 4, 5];
      const asyncArray = await [6, 7, 8];
      const object = {9: '10'};
      const asyncObject = await {11: '12'};
    `),
  );
  await finish(sandbox);
  expect(sandbox.context)
    .to.deep.equal({
      scalar: 1,
      asyncScalar: 2,
      array: [3, 4, 5],
      asyncArray: [6, 7, 8],
      object: {9: '10'},
      asyncObject: {11: '12'},
    });
});

test('scopes variables', async () => {
  const sandbox = new Sandbox(
    await parse(`
      const result = [];
      const scalar = 1;
      result.push(scalar);
      {
        const scalar = 2;
        result.push(scalar);
      }
      result.push(scalar);
    `),
  );
  await finish(sandbox);
  expect(sandbox.context.result)
    .to.deep.equal([1, 2, 1]);
});

test('returns last', async () => {
  const sandbox = new Sandbox(
    await parse(`
      foo = 32;
      {
        bar = 64;
      }
    `),
  );
  ;
  expect(await finish(sandbox))
    .to.deep.include({done: true, value: 64});
});

test('destructures variables', async () => {
  const sandbox = new Sandbox(
    await parse(`
      const [a, , c] = [1, 2, 3];
      const {x: x1, y, z: {zz}} = {x: 4, y: 5, z: {zz: 6}};
      const [d, e] = await [7, 8];
      const {t, u: {uu}} = {t: 9, u: {uu: await 10}};
    `),
  );
  await finish(sandbox);
  expect(sandbox.context)
    .to.deep.equal({
      a: 1,
      c: 3,
      x1: 4,
      y: 5,
      zz: 6,
      d: 7,
      e: 8,
      t: 9,
      uu: 10,
    });
});

test('runs arbitrary number of ops', async () => {
  const sandbox = new Sandbox(
    await parse(`
      const foo = [];
      for (let i = 0; i < 150; ++i) {
        foo.push(i);
      }
    `),
  );
  sandbox.run(100);
  expect(sandbox.context.foo.length)
    .to.equal(100);
  sandbox.run(100);
  expect(sandbox.context.foo.length)
    .to.equal(150);
});

test('evaluates conditional branches', async () => {
  const sandbox = new Sandbox(
    await parse(`
      let foo, bar;
      if (true) {
        foo = 1;
      }
      else {
        foo = 2;
      }
      if (await false) {
        bar = 1;
      }
      else {
        bar = 2;
      }
      if (await false) {
        bar = 1;
      }
    `),
  );
  await finish(sandbox);
  expect(sandbox.context)
    .to.deep.equal({
      foo: 1,
      bar: 2,
    });
});

test('evaluates loops', async () => {
  const sandbox = new Sandbox(
    await parse(`
      x = 0
      y = 0
      a = 0
      b = 0
      c = 0
      for (let i = 0; i < 3; ++i) {
        x += 1;
      }
      for (let i = await 0; i < await 3; i = 1 + await i) {
        y += 1;
      }
      do {
        a += 1;
      } while (a < 3);
      do {
        b += 1;
      } while (await b < 3);
      while (c < 3) {
        c += 1;
      }
    `),
  );
  await finish(sandbox);
  expect(sandbox.context)
    .to.deep.equal({
      a: 3,
      b: 3,
      c: 3,
      x: 3,
      y: 3,
    });
});

test('evaluates undefined for nonexistent variables in scope', async () => {
  const sandbox = new Sandbox(
    await parse(`
      const x = y
    `),
  );
  sandbox.run();
  expect(sandbox.context)
    .to.deep.equal({
      x: undefined,
    });
});

test('returns values at the top level', async () => {
  let sandbox;
  sandbox = new Sandbox(
    await parse(`
      x = 16
      y = 4
      return [x * 3, y * 3]
      x = 32
      y = 8
    `, {allowReturnOutsideFunction: true}),
  );
  const {value} = sandbox.run();
  expect(value)
    .to.deep.equal([48, 12]);
  expect(sandbox.context)
    .to.deep.equal({x: 16, y: 4});
  sandbox = new Sandbox(
    await parse(`
      x = 16
      y = 4
      return
      x = 32
      y = 8
    `, {allowReturnOutsideFunction: true}),
  );
  sandbox.run();
  expect(sandbox.context)
    .to.deep.equal({x: 16, y: 4});
});

test('sets variables in global scope', async () => {
  const sandbox = new Sandbox(
    await parse(`
      x = y
    `),
  );
  sandbox.run();
  expect(sandbox.context)
    .to.deep.equal({
      x: undefined,
    });
});

test('runs arbitrary number of ops', async () => {
  const sandbox = new Sandbox(
    await parse(`
      const foo = [];
      for (let i = 0; i < 1500; ++i) {
        foo.push(i);
      }
    `),
  );
  sandbox.run(1000);
  expect(sandbox.context.foo.length)
    .to.equal(1000);
  sandbox.run(1000);
  expect(sandbox.context.foo.length)
      .to.equal(1500);
  expect(true)
    .to.be.true;
});

test('clears for loop deferred context', async () => {
  const context = {x: 10};
  const sandbox = new Sandbox(
    await parse(`
      let l = 0
      for (let i = 0; i < x; ++i) {
        l += 1
      }
    `),
    context,
  );
  expect(sandbox.run())
    .to.deep.include({
      value: 10,
    });
  context.x = 0
  expect(sandbox.run())
    .to.deep.include({
      value: undefined,
    });
});

test('clears while loop deferred context', async () => {
  const context = {x: 10};
  const sandbox = new Sandbox(
    await parse(`
      let l = 0
      while (l < x) {
        l += 1
      }
    `),
    context,
  );
  expect(sandbox.run())
    .to.deep.include({
      value: 10,
    });
  context.x = 0
  expect(sandbox.run())
    .to.deep.include({
      value: undefined,
    });
});