import type { Type } from './schema'
import { assert } from '../assert'
import { isPrimitive } from '../data'
import { objectMap } from '../data/object'
import { isSchemaObjectFlat } from './utils'

declare module './schema' {
  interface TypeMeta {
    swiftName?: string
    swiftProtocol?: string
    swiftDesc?: string
    swiftDefault?: string
  }
}

const mapSwiftType = {
  string: 'String',
  number: 'Double',
  int: 'Int',
  boolean: 'Bool',
} as any

export function schemaExportSwiftStruct<T>(schema: Type<T>, name: string = 'Example'): string {
  assert(isSchemaObjectFlat(schema), 'schema should be a flat object')

  let protocol = ''
  if (schema._meta?.swiftProtocol) {
    protocol = `: ${schema._meta.swiftProtocol}`
  }

  const lines: string[] = [
    `struct ${schema._meta?.swiftName ?? name}${protocol} {`,
  ]

  objectMap(schema._object!, (key, schema: Type<any>) => {
    let s = `  var ${key}: ${mapSwiftType[schema.type] ?? schema.type}`
    if (schema._optional === true)
      s += '?'
    if (schema._meta?.swiftDefault || (schema._default != null && isPrimitive(schema._default)))
      s += ` = ${schema._meta?.swiftDefault ?? JSON.stringify(schema._default)}`
    lines.push(s)
  })

  lines.push('}')

  return lines.join('\n')
}