import {expect, test} from 'vitest';

import Component from './component.js';
import Ecs from './ecs.js';
import System from './system.js';
import {wrapComponents} from './test-helper.js';

const Components = wrapComponents([
  ['Empty', {}],
  ['Momentum', {x: {type: 'int32'}, y: {type: 'int32'}, z: {type: 'int32'}}],
  ['Name', {name: {type: 'string'}}],
  ['Position', {x: {type: 'int32', defaultValue: 32}, y: {type: 'int32'}, z: {type: 'int32'}}],
]);

const {
  Empty,
  Momentum,
  Position,
  Name,
} = Components;

function asyncTimesTwo(x) {
  return new Promise((resolve) => {
    setTimeout(() => {
      resolve(x * 2)
    }, 5);
  });
}

class Async extends Component {
  static componentName = 'Async';
  static properties = {
    foo: {type: 'uint8'},
  };
  async load(instance) {
    instance.foo = await asyncTimesTwo(instance.foo);
  }
}

test('activates and deactivates systems at runtime', () => {
  let oneCount = 0;
  let twoCount = 0;
  const ecs = new Ecs({
    Systems: {
      OneSystem: class extends System {
        tick() {
          oneCount += 1;
        }
      },
      TwoSystem: class extends System {
        tick() {
          twoCount += 1;
        }
      },
    },
  });
  ecs.tick();
  expect(oneCount)
    .to.equal(0);
  expect(twoCount)
    .to.equal(0);
  ecs.system('OneSystem').active = true;
  ecs.tick();
  expect(oneCount)
    .to.equal(1);
  ecs.system('TwoSystem').active = true;
  ecs.tick();
  expect(oneCount)
    .to.equal(2);
  expect(twoCount)
    .to.equal(1);
  ecs.system('OneSystem').active = false;
  ecs.tick();
  expect(oneCount)
    .to.equal(2);
  expect(twoCount)
    .to.equal(2);
});

test('creates entities with components', async () => {
  const ecs = new Ecs({Components: {Empty, Position}});
  const entity = await ecs.create({Empty: {}, Position: {y: 128}});
  expect(JSON.stringify(ecs.get(entity)))
    .to.deep.equal(JSON.stringify({Empty: {}, Position: {y: 128}}));
});

test("removes entities' components", async () => {
  const ecs = new Ecs({Components: {Empty, Position}});
  const entity = await ecs.create({Empty: {}, Position: {y: 128}});
  ecs.remove(entity, ['Position']);
  expect(JSON.stringify(ecs.get(entity)))
    .to.deep.equal(JSON.stringify({Empty: {}}));
});

test('gets entities', async () => {
  const ecs = new Ecs({Components: {Empty, Position}});
  const entity = await ecs.create({Empty: {}, Position: {y: 128}});
  expect(JSON.stringify(ecs.get(entity)))
    .to.deep.equal(JSON.stringify({Empty: {}, Position: {y: 128}}));
});

test('destroys entities', async () => {
  const ecs = new Ecs({Components: {Empty, Position}});
  const entity = await ecs.create({Empty: {}, Position: {y: 128}});
  expect(JSON.stringify(ecs.get(entity)))
    .to.deep.equal(JSON.stringify({Empty: {}, Position: {y: 128}}));
  expect(ecs.get(entity))
    .to.not.be.undefined;
  ecs.destroyMany(new Set([entity]));
  expect(ecs.get(entity))
    .to.be.undefined;
  expect(() => {
    ecs.destroyMany(new Set([entity]));
  })
    .to.throw();
});

test('inserts components into entities', async () => {
  const ecs = new Ecs({Components: {Empty, Position}});
  const entity = await ecs.create({Empty: {}});
  await ecs.insert(entity, {Position: {y: 128}});
  expect(JSON.stringify(ecs.get(entity)))
    .to.deep.equal(JSON.stringify({Empty: {}, Position: {y: 128}}));
    await ecs.insert(entity, {Position: {y: 64}});
  expect(JSON.stringify(ecs.get(entity)))
    .to.deep.equal(JSON.stringify({Empty: {}, Position: {y: 64}}));
});

test('ticks systems', async () => {
  const ecs = new Ecs({
    Components: {Momentum, Position},
    Systems: {
      Physics: class Physics extends System {

        static queries() {
          return {
            default: ['Position', 'Momentum'],
          };
        }

        tick(elapsed) {
          for (const {Position, Momentum} of this.select('default')) {
            Position.x += Momentum.x * elapsed;
            Position.y += Momentum.y * elapsed;
            Position.z += Momentum.z * elapsed;
          }
        }

      },
    },
  });
  ecs.system('Physics').active = true;
  const entity = await ecs.create({Momentum: {}, Position: {y: 128}});
  const position = JSON.stringify(ecs.get(entity).Position);
  ecs.tick(1);
  expect(JSON.stringify(ecs.get(entity).Position))
    .to.deep.equal(position);
  ecs.get(1).Momentum.y = 30;
  ecs.tick(1);
  expect(JSON.stringify(ecs.get(entity).Position))
    .to.deep.equal(JSON.stringify({y: 128 + 30}));
});

test('schedules entities to be deleted when ticking systems', async () => {
  const ecs = new Ecs({
    Components: {Empty},
    Systems: {
      Despawn: class extends System {
        static queries() {
          return {
            default: ['Empty'],
          };
        }
        tick() {
          this.ecs.destroy(1);
          expect(ecs.get(1))
            .to.not.be.undefined;
        }
      },
    },
  });
  ecs.system('Despawn').active = true;
  await ecs.create({Empty: {}});
  ecs.tick(1);
  expect(Array.from(ecs.system('Despawn').select('default')))
    .to.have.lengthOf(0);
  expect(ecs.get(1))
    .to.be.undefined;
});

test('skips indexing detached entities', async () => {
  const ecs = new Ecs({
    Components: {Empty},
    Systems: {
      Indexer: class extends System {
        static queries() {
          return {
            default: ['Empty'],
          };
        }
      },
    },
  });
  const {$$map: map} = ecs.system('Indexer').queries.default;
  ecs.system('Indexer').active = true;
  const attached = await ecs.create({Empty: {}});
  ecs.tick(0);
  expect(Array.from(map.keys()))
    .to.deep.equal([attached]);
  ecs.destroyMany(new Set([attached]));
  ecs.tick(0);
  expect(Array.from(map.keys()))
    .to.deep.equal([]);
  const detached = await ecs.createDetached({Empty: {}});
  ecs.tick(0);
  expect(Array.from(map.keys()))
    .to.deep.equal([]);
  ecs.destroyMany(new Set([detached]));
  ecs.tick(0);
  expect(Array.from(map.keys()))
    .to.deep.equal([]);
});

test('generates diffs for entity creation', async () => {
  const ecs = new Ecs();
  let entity;
  entity = await ecs.create();
  expect(ecs.diff)
    .to.deep.equal({[entity]: {}});
});

test('generates diffs for adding and removing components', async () => {
  const ecs = new Ecs({Components: {Position}});
  let entity;
  entity = await ecs.create();
  ecs.setClean();
  await ecs.insert(entity, {Position: {x: 64}});
  expect(ecs.diff)
    .to.deep.equal({[entity]: {Position: {x: 64}}});
  ecs.setClean();
  expect(ecs.diff)
    .to.deep.equal({});
  ecs.remove(entity, ['Position']);
  expect(ecs.diff)
    .to.deep.equal({[entity]: {Position: false}});
});

test('generates diffs for empty components', async () => {
  const ecs = new Ecs({Components: {Empty}});
  let entity;
  entity = await ecs.create({Empty: {}});
  expect(ecs.diff)
    .to.deep.equal({[entity]: {Empty: {}}});
  ecs.setClean();
  ecs.remove(entity, ['Empty']);
  expect(ecs.diff)
    .to.deep.equal({[entity]: {Empty: false}});
});

test('generates diffs for entity mutations', async () => {
  const ecs = new Ecs({Components: {Position}});
  let entity;
  entity = await ecs.create({Position: {}});
  ecs.setClean();
  ecs.get(entity).Position.x = 128;
  expect(ecs.diff)
    .to.deep.equal({[entity]: {Position: {x: 128}}});
  ecs.setClean();
  expect(ecs.diff)
    .to.deep.equal({});
});

test('generates no diffs for detached entities', async () => {
  const ecs = new Ecs({Components: {Position}});
  let entity;
  entity = await ecs.createDetached();
  expect(ecs.diff)
    .to.deep.equal({});
  await ecs.insert(entity, {Position: {x: 64}});
  expect(ecs.diff)
    .to.deep.equal({});
  ecs.get(entity).Position.x = 128;
  expect(ecs.diff)
    .to.deep.equal({});
  ecs.remove(entity, ['Position']);
  expect(ecs.diff)
    .to.deep.equal({});
});

test('generates coalesced diffs for components', async () => {
  const ecs = new Ecs({Components: {Position}});
  let entity;
  entity = await ecs.create({Position});
  ecs.remove(entity, ['Position']);
  expect(ecs.diff)
    .to.deep.equal({[entity]: {Position: false}});
  await ecs.insert(entity, {Position: {}});
  expect(ecs.diff)
    .to.deep.equal({[entity]: {Position: {}}});
});

test('generates coalesced diffs for mutations', async () => {
  const ecs = new Ecs({Components: {Position}});
  let entity;
  entity = await ecs.create({Position});
  ecs.setClean();
  ecs.get(entity).Position.x = 128;
  ecs.get(entity).Position.x = 256;
  ecs.get(entity).Position.x = 512;
  expect(ecs.diff)
    .to.deep.equal({[entity]: {Position: {x: 512}}});
});

test('generates diffs for deletions', async () => {
  const ecs = new Ecs();
  let entity;
  entity = await ecs.create();
  ecs.setClean();
  ecs.destroy(entity);
  ecs.tick(0);
  expect(ecs.diff)
    .to.deep.equal({[entity]: false});
});

test('applies creation patches', async () => {
  const ecs = new Ecs({Components: {Position}});
  await ecs.apply({16: {Position: {x: 64}}});
  expect(Array.from(ecs.entities).length)
    .to.equal(1);
  expect(ecs.get(16).Position.x)
    .to.equal(64);
});

test('applies update patches', async () => {
  const ecs = new Ecs({Components: {Position}});
  await ecs.createSpecific(16, {Position: {x: 64}});
  await ecs.apply({16: {Position: {x: 128}}});
  expect(Object.keys(ecs.$$entities).length)
    .to.equal(1);
  expect(ecs.get(16).Position.x)
    .to.equal(128);
});

test('applies entity deletion patches', () => {
  const ecs = new Ecs({Components: {Position}});
  ecs.createSpecific(16, {Position: {x: 64}});
  ecs.apply({16: false});
  expect(Array.from(ecs.entities).length)
    .to.equal(0);
});

test('applies component deletion patches', async () => {
  const ecs = new Ecs({Components: {Empty, Position}});
  await ecs.createSpecific(16, {Empty: {}, Position: {x: 64}});
  expect(ecs.get(16).constructor.componentNames)
    .to.deep.equal(['Empty', 'Position']);
  await ecs.apply({16: {Empty: false}});
  expect(ecs.get(16).constructor.componentNames)
    .to.deep.equal(['Position']);
});

test('calculates entity size', async () => {
  const ecs = new Ecs({Components: {Empty, Position}});
  await ecs.createSpecific(1, {Empty: {}, Position: {}});
  // ID + # of components + Empty + Position + x + y + z
  // 4  + 2               + 2 + 4 + 2 + 4    + 4 + 4 + 4 = 30
  expect(ecs.get(1).size())
    .to.equal(30);
});

test('serializes and deserializes', async () => {
  const ecs = new Ecs({Components: {Empty, Name, Position}});
  await ecs.createSpecific(1, {Empty: {}, Position: {x: 64}});
  await ecs.createSpecific(16, {Name: {name: 'foobar'}, Position: {x: 128}});
  expect(ecs.toJSON())
    .to.deep.equal({
      entities: {
        1: {Empty: {}, Position: {x: 64}},
        16: {Name: {name: 'foobar'}, Position: {x: 128}},
      },
      systems: [],
    });
  const view = Ecs.serialize(ecs);
  const deserialized = await Ecs.deserialize(
    new Ecs({Components: {Empty, Name, Position}}),
    view,
  );
  expect(Array.from(deserialized.entities).length)
    .to.equal(2);
  expect(deserialized.get(1).constructor.componentNames)
    .to.deep.equal(['Empty', 'Position']);
  expect(deserialized.get(16).constructor.componentNames)
    .to.deep.equal(['Name', 'Position']);
  expect(JSON.stringify(deserialized.get(1)))
    .to.equal(JSON.stringify({Empty: {}, Position: {x: 64}}))
  expect(JSON.stringify(deserialized.get(1).Position))
    .to.equal(JSON.stringify({x: 64}));
  expect(JSON.stringify(deserialized.get(16).Position))
    .to.equal(JSON.stringify({x: 128}));
  expect(deserialized.get(16).Name.name)
    .to.equal('foobar');
});

test('deserializes from compatible ECS', async () => {
  const ecs = new Ecs({Components: {Empty, Name, Position}});
  await ecs.createSpecific(1, {Empty: {}, Position: {x: 64}});
  await ecs.createSpecific(16, {Name: {name: 'foobar'}, Position: {x: 128}});
  const view = Ecs.serialize(ecs);
  const deserialized = await Ecs.deserialize(
    new Ecs({Components: {Empty, Name}}),
    view,
  );
  expect(deserialized.get(1).toJSON())
    .to.deep.equal({Empty: {}});
  expect(deserialized.get(16).toJSON())
    .to.deep.equal({Name: {name: 'foobar'}});
});

test('creates entities asynchronously', async () => {
  const ecs = new Ecs({Components: {Async}});
  const entity = await ecs.create({Async: {foo: 64}});
  expect(ecs.get(entity).toJSON())
    .to.deep.equal({Async: {foo: 128}});
});

test('inserts components asynchronously', async () => {
  const ecs = new Ecs({Components: {Async}});
  const entity = await ecs.create();
  await ecs.insert(entity, {Async: {foo: 64}});
  expect(ecs.get(entity).toJSON())
    .to.deep.equal({Async: {foo: 128}});
});

test('deserializes asynchronously', async () => {
  const ecs = new Ecs({Components: {Async}});
  await ecs.createSpecific(16, {Async: {foo: 16}});
  const view = Ecs.serialize(ecs);
  const deserialized = await Ecs.deserialize(
    new Ecs({Components: {Async}}),
    view,
  );
  expect(deserialized.get(16).toJSON())
    .to.deep.equal({Async: {foo: 64}});
});