import type { ts, Type } from 'ts-morph'
import type { NamedType } from './types/Type.js'
import { createNamedType } from './createType.js'
import type { Language } from '../getPlatformSpecs.js'

export function getInterfaceProperties(
  language: Language,
  interfaceType: Type<ts.ObjectType>
): NamedType[] {
  const symbol = interfaceType.getAliasSymbol() ?? interfaceType.getSymbol()
  if (symbol == null)
    throw new Error(
      `Interface "${interfaceType.getText()}" does not have a Symbol!`
    )
  return interfaceType.getProperties().map((prop) => {
    let propType = prop.getDeclaredType()
    if (propType.isAny() || propType.isUnknown()) {
      // the interface is aliased/merged - we need to look into the actual declaration
      for (const declaration of symbol.getDeclarations()) {
        const declared = prop.getTypeAtLocation(declaration)
        if (!declared.isAny() && !declared.isUnknown()) {
          propType = declared
          break
        }
      }
    }

    const refType = createNamedType(
      language,
      prop.getName(),
      propType,
      prop.isOptional() || propType.isNullable()
    )
    return refType
  })
}