//@flow
class A {
  #p: number;
  constructor() {
    this.#p = 3;
  }
}

class C {
  #p: number;
  #q: number;
  constructor() {
    this.#p = 0; // in scope
    this.#q; // in scope
  }
  test(other: C) {
    other.#q; // in lexical scope, object has the property.
  }
}

class D {
  #p: number; // Note that C also has a #p with number, and #p is in
  // lexical scope
  constructor() {
    this.#p = 3;
  }
  test(other: C) {
    other.#p; // Error: other does not have access to private variables in here.
  }
}

class Outer {
  #outer: number;
  constructor() {
    var Inner = class A {
      #inner: Outer;
      constructor() {
        this.#inner = new Outer();
        var x = new Outer();
        x.#outer = 0; // Both inner and outer should be visible here!
        x.#inner = new Outer(); // Error, #inner is not a private field of Outer
      }
    };
  }
}

class Clash {
  #p: number;
  constructor() {
    var Inner = class A {
      #p: string;
      constructor() {
        this.#p as number; // Error, #p is a string not a number
        this.#p = 'test';
        this.#p = 3; // Error, #p is a string not a number
        var x = new Clash();
        x.#p as string; // Error, here #p is a number not a string
      }
    };
  }
}

class Refinements {
  #p: ?number;
  constructor() {
    if (this.#p) {
      this.#p as number; // Refinements work properly
    } else {
      this.#p as number; // Error #p is null or undefined
    }
  }
}

class IncompatibleGetAndSet {
  #p: number;
  static #q: number;
  constructor() {
    const a: number = 3;
    a.#p = 3; // Error, #p not on number
    const b: {p: number} = {p: 3};
    b.#p; // Error, #p not on b.
  }
}

class Static {
  static #p: number;
  static #q: number;
  #r: number;
  m(): number {
    Static.#p = 2 as number;
    if (Static.#p === 3) {
      // Refinements still work
      Static.#p as 3;
    }
    return Static.#p;
  }
  bad() {
    IncompatibleGetAndSet.#q; // Error, not visible here
    Static.#q = Static.#p;
    this.#p = 3; // Error, no #p on instance
    this.#q; // Error, no #q on instance
    Static.#r; // Error, no #r on class
    Static.#r = Static.#q; // Error, no #r on class
  }
}

class Annotations {
  // Private class fields must either be annotated or have an initializer
  #p: number;
  #q = 0;
  #r: number;
  #s: string = 0; // Error, number ~> string
  #t: string = 'yay!';
  static #sp: number;
  static #sq = 0;
  static #sr: number;
  static #ss: string = 0; // Error, number ~> string
  static #st: string = 'yay!';
  test1(): number {
    return this.#p;
  }
  test2(): number {
    return this.#t; // Error, string ~> number
  }
  test3(): number {
    return Annotations.#sp;
  }
  test4(): number {
    return Annotations.#st; // Error, string ~> number
  }
  test5(): number {
    return this.#r;
  }
  test6(): string {
    return this.#r; // Error, number ~> string
  }
  test5And6Helper() {
    this.#r = 3;
  }
  test7(): number {
    return Annotations.#sr;
  }
  test8(): string {
    return Annotations.#sr; // Error, number ~> string
  }
  test7And9Helper() {
    Annotations.#sr = 3;
  }
}

class RefinementClashes {
  // Refinements on private fields can be considered separately from the
  // rest of heap refinements
  #p: number;
  p: number;
  static q: number;
  static #q: number;
  test1() {
    if (this.#p === 3) {
      this.p as 3; // Error, this.#p doesn't refine this.p
      this.#p as 3;
      this.p = 4;
      this.p as 4;
      this.#p as 4; // Error, this.p doesnt refine this.#p
      this.#p as 3; // this.p doesnt havoc this.#p
      this.#p = 3;
      this.p as 3; // Error, this.#p doesnt refine this.p
      this.p as 4; // this.#p doesnt havoc this.p
    }
    this.#p as 3; // Error, Havoc happens as normal
  }
  test2() {
    if (RefinementClashes.#q === 3) {
      RefinementClashes.q as 3; // Error, RefinementClashes.#q doesn't refine RefinementClashes.q
      RefinementClashes.#q as 3;
      RefinementClashes.q = 4;
      RefinementClashes.q as 4;
      RefinementClashes.#q as 4; // Error, RefinementClashes.q doesnt refine RefinementClashes.#q
      RefinementClashes.#q as 3; // RefinementClashes.q doesnt havoc RefinementClashes.#q
      RefinementClashes.#q = 3;
      RefinementClashes.q as 3; // Error, RefinementClashes.#q doesnt refine RefinementClashes.q
      RefinementClashes.q as 4; // RefinementClashes.#q doesnt havoc RefinementClashes.q
    }
    RefinementClashes.#q as 3; // Error, Havoc happens as normal
  }
  test3(other: RefinementClashes) {
    if (this.#p === 3) {
      this.#p as 3;
      other.#p = 3;
      this.#p as 3; // Error, other.#p does havoc this.#p
    }
  }
}

class Calls {
  #foo = (): number => 3;

  static #bar = (): string => 'baz';

  #optionalFoo: ?(string) => number;

  static #optionalBar: ?(number) => string;

  test(): void {
    const fooValid: number = this.#foo();
    const fooInvalid: string = this.#foo();
    const barValid: string = Calls.#bar();
    const barInvalid: number = Calls.#bar();

    const optionalFooValid: ?number = this.#optionalFoo?.('');
    const optionalFooInvalid1: number = this.#optionalFoo?.('');
    const optionalFooInvalid2: ?string = this.#optionalFoo?.('');
    const optionalFooInvalid3: ?number = this.#optionalFoo?.(42);

    const optionalBarValid: ?string = Calls.#optionalBar?.(0);
    const optionalBarInvalid1: string = Calls.#optionalBar?.(0);
    const optionalBarInvalid2: ?number = Calls.#optionalBar?.(0);
    const optionalBarInvalid3: ?string = Calls.#optionalBar?.('');
  }
}

class PrivateReadOnly {
  +#p: number;
  constructor(other: PrivateReadOnly) {
    this.#p = 42; // ok
    other.#p = 42; // error;
  }
  f() {
    this.#p = 42; // error
  }
}
