import type { Language } from '../../getPlatformSpecs.js'
import { type SourceFile, type SourceImport } from '../SourceFile.js'
import type { Type, TypeKind } from './Type.js'

export class OptionalType implements Type {
  readonly wrappingType: Type

  constructor(wrappingType: Type) {
    this.wrappingType = wrappingType
  }

  get canBePassedByReference(): boolean {
    // depends whether the wrapping type is heavy to copy or not.
    return this.wrappingType.canBePassedByReference
  }
  get kind(): TypeKind {
    return 'optional'
  }
  get needsBraces(): boolean {
    switch (this.wrappingType.kind) {
      case 'function':
        return true
      default:
        return false
    }
  }

  getCode(language: Language): string {
    const wrapping = this.wrappingType.getCode(language)
    switch (language) {
      case 'c++':
        return `std::optional<${wrapping}>`
      case 'swift':
        if (this.needsBraces) {
          return `(${wrapping})?`
        } else {
          return `${wrapping}?`
        }
      case 'kotlin':
        if (this.needsBraces) {
          return `(${wrapping})?`
        } else {
          return `${wrapping}?`
        }
      default:
        throw new Error(
          `Language ${language} is not yet supported for OptionalType!`
        )
    }
  }
  getExtraFiles(): SourceFile[] {
    return this.wrappingType.getExtraFiles()
  }
  getRequiredImports(): SourceImport[] {
    return [
      {
        language: 'c++',
        name: 'optional',
        space: 'system',
      },
      ...this.wrappingType.getRequiredImports(),
    ]
  }
}