import { Type } from "@nestjs/common";
import {
  EnumAllowedTypes,
  SchemaObjectMetadata,
} from "@nestjs/swagger/dist/interfaces/schema-object-metadata.interface";
import { EnumSchemaAttributes } from "@nestjs/swagger/dist/interfaces/enum-schema-attributes.interface";
import { getTypeIsArrayTuple } from "@nestjs/swagger/dist/decorators/helpers";
import {
  getEnumType,
  getEnumValues,
} from "@nestjs/swagger/dist/utils/enum.utils";
import { DECORATORS } from "@nestjs/swagger/dist/constants";
import { createPropertyDecorator } from "./helpers";

export type ApiPropertyCommonOptions = SchemaObjectMetadata & {
  "x-enumNames"?: string[];
  /**
   * Lazy function returning the type for which the decorated property
   * can be used as an id
   *
   * Use together with @ApiDefaultGetter on the getter route of the type
   * to generate OpenAPI link objects
   *
   * @see [Swagger link objects](https://swagger.io/docs/specification/links/)
   */
  // eslint-disable-next-line @typescript-eslint/no-unsafe-function-type
  link?: () => Type<unknown> | Function;
};

export type ApiPropertyOptions =
  | ApiPropertyCommonOptions
  | (ApiPropertyCommonOptions & {
      enumName: string;
      enumSchema?: EnumSchemaAttributes;
    });

const isEnumArray = (
  opts: ApiPropertyOptions
): opts is {
  isArray: true;
  enum: EnumAllowedTypes;
  type: any;
  items: any;
} => (opts.isArray && "enum" in opts && opts.enum !== undefined) as boolean;

/**
 * @publicApi
 */
export function ApiProperty(
  options: ApiPropertyOptions = {}
): PropertyDecorator {
  return createApiPropertyDecorator(options);
}

export function createApiPropertyDecorator(
  options: ApiPropertyOptions = {},
  overrideExisting = true
): PropertyDecorator {
  const [type, isArray] = getTypeIsArrayTuple(
    options.type,
    options.isArray as boolean
  );
  options = {
    ...options,
    type,
    isArray,
  } as ApiPropertyOptions;

  if (isEnumArray(options)) {
    options.type = "array";

    const enumValues = getEnumValues(options.enum);
    options.items = {
      type: getEnumType(enumValues),
      enum: enumValues,
    };
    // @ts-expect-error nest swagger override
    delete options.enum;
  } else if ("enum" in options && options.enum !== undefined) {
    const enumValues = getEnumValues(options.enum);

    options.enum = enumValues;
    options.type = getEnumType(enumValues);
  }

  if (Array.isArray(options.type)) {
    options.type = "array";
    options.items = {
      type: "array",
      items: {
        type: options.type[0],
      },
    };
  }

  return createPropertyDecorator(
    DECORATORS.API_MODEL_PROPERTIES,
    options,
    overrideExisting
  );
}

export function ApiPropertyOptional(
  options: ApiPropertyOptions = {}
): PropertyDecorator {
  return ApiProperty({
    ...options,
    required: false,
  } as ApiPropertyOptions);
}

export function ApiResponseProperty(
  options: Pick<
    ApiPropertyOptions,
    "type" | "example" | "format" | "deprecated" | "enum"
  > = {}
): PropertyDecorator {
  return ApiProperty({
    readOnly: true,
    ...options,
  } as ApiPropertyOptions);
}