import { isDefined, isEmpty, isNotEmpty, isPresent, isTrue } from '../types/Is';
import { Optional } from '../types/Types';
import { Construct, ofConstruct, use } from '../types/Constructor';
import { Get, ofGet } from '../types/Get';
import { OneOrMore } from '../types/Array';
import { toList } from '../types/List';
import { isEqual } from '../types/IsEqual';

export function ifTrue<Out, In = unknown>(o: unknown, f: Construct<Out, NonNullable<In>>, alt: Construct<Out>): Out;
export function ifTrue<Out, In = unknown>(o: unknown, f: Construct<Out, NonNullable<In>>, alt?: Construct<Out>): Optional<Out>;
export function ifTrue<Out, In = unknown>(o: unknown, f: Construct<Out, NonNullable<In>>, alt?: Construct<Out>): Optional<Out> {
  return isTrue(o) ? ofConstruct(f, o) : ofConstruct(alt, o);
}

export function ifFalse<Out, In = unknown>(o: unknown, f: Construct<Out, NonNullable<In>>, alt: Construct<Out>): Out;
export function ifFalse<Out, In = unknown>(o: unknown, f: Construct<Out, NonNullable<In>>, alt?: Construct<Out>): Optional<Out>;
export function ifFalse<Out, In = unknown>(o: unknown, f: Construct<Out, NonNullable<In>>, alt?: Construct<Out>): Optional<Out> {
  return !isTrue(o) ? ofConstruct(f, o) : ofConstruct(alt, o);
}

export function ifDefined<Out, In = unknown>(o: Optional<In>, f: Construct<Out, NonNullable<In>>, alt: Construct<Out>): Out;
export function ifDefined<Out, In = unknown>(o: Optional<In>, f: Construct<Out, NonNullable<In>>, alt?: Construct<Out>): Optional<Out>;
export function ifDefined<Out, In = unknown>(o: Optional<In>, f: Construct<Out, NonNullable<In>>, alt?: Construct<Out>): Optional<Out> {
  return isDefined(o) ? ofConstruct(f, o) : ofConstruct(alt);
}

export function ifNotEmpty<Out, In = unknown>(o: In, f: Construct<Out, NonNullable<In>>, alt: Construct<Out>): Out;
export function ifNotEmpty<Out, In = unknown>(o: In, f?: Construct<Out, NonNullable<In>>, alt?: Construct<Out>): Optional<Out>;
export function ifNotEmpty<Out, In = unknown>(o: In, f: Construct<Out, NonNullable<In>>, alt?: Construct<Out>): Optional<Out>;
export function ifNotEmpty<Out, In = unknown>(o: In, f: Construct<Out, NonNullable<In>> = o => o as Out, alt?: Construct<Out>): Optional<Out> {
  return isNotEmpty(o) ? ofConstruct(f, o) : ofConstruct(alt, o);
}

export function ifEmpty<Out, In = unknown>(o: In, f: Construct<Out, NonNullable<In>>, alt: Construct<Out>): Out;
export function ifEmpty<Out, In = unknown>(o: In, f?: Construct<Out, NonNullable<In>>, alt?: Construct<Out>): Optional<Out>;
export function ifEmpty<Out, In = unknown>(o: In, f: Construct<Out, NonNullable<In>>, alt?: Construct<Out>): Optional<Out>;
export function ifEmpty<Out, In = unknown>(o: In, f: Construct<Out, NonNullable<In>> = o => o as Out, alt?: Construct<Out>): Optional<Out> {
  return isEmpty(o) ? ofConstruct(f, o) : ofConstruct(alt, o);
}

export function given<T extends object, K extends keyof T>(o: T, key: K, alt: Get<T[K]>): T[K];
export function given<T extends object, K extends keyof T>(o: T, key: K, alt?: Get<T[K]>): Optional<T[K]>;
export function given<T extends object, K extends keyof T>(o: T, key: K, alt?: Get<T[K]>): Optional<T[K]> {
  return isDefined(o) && key in o ? o[key] : ofGet(alt);
}


export function ifEqual<Out>(one: unknown, another: unknown, f: Construct<Out>, alt: Construct<Out>): Out;
export function ifEqual<Out>(one: unknown, another: unknown, f: Construct<Out>, alt?: Construct<Out>): Optional<Out>;
export function ifEqual<Out>(one: unknown, another: unknown, f: Construct<Out>, alt?: Construct<Out>): Optional<Out> {
  return isEqual(one, another) ? ofConstruct(f) : ofConstruct(alt);
}

export function ifEither<Out, In = unknown>(os: OneOrMore<In>, f: Construct<Out, NonNullable<In>>, alt: Construct<Out>): Out;
export function ifEither<Out, In = unknown>(os: OneOrMore<In>, f?: Construct<Out, NonNullable<In>>, alt?: Construct<Out>): Optional<Out>;
export function ifEither<Out, In = unknown>(os: OneOrMore<In>, f: Construct<Out, NonNullable<In>>, alt?: Construct<Out>): Optional<Out>;
export function ifEither<Out, In = unknown>(os: OneOrMore<In>, f: Construct<Out, NonNullable<In>> = o => o as Out, alt?: Construct<Out>): Optional<Out> {
  return use(
    toList(os).first(o => isPresent(o)),
    o => (isDefined(o) ? ofConstruct(f, o) : ofConstruct(alt, o))
  );
}