import type { AnyRecord } from "../type/index.ts"

import { isDate } from "./is.ts"

/**
 * @description Return a new object that includes only the specified keys from the source object.
 *
 * @example
 *   ```
 *   // Expect: { a: 1, c: 3 }
 *   const example1 = includeFields({ a: 1, b: 2, c: 3 }, ["a", "c"])
 *   // Expect: {}
 *   const example2 = includeFields(null, ["a"])
 *   ```
 */
export const includeFields = <T extends AnyRecord, K extends keyof T>(
  object: T | null | undefined,
  keys: K[],
): Pick<T, K> => {
  if (object === null || object === undefined) {
    return {} as Pick<T, K>
  }
  const newObject: Partial<Pick<T, K>> = {} // 初始化一个部分类型的对象
  keys.forEach((key) => {
    if (key in object) {
      newObject[key] = object[key]
    }
  })
  return newObject as Pick<T, K> // 使用正确的变量名并断言返回类型
}

/**
 * @description Return a new object that excludes the specified keys from the source object.
 *
 * @example
 *   ```
 *   // Expect: { a: 1 }
 *   const example1 = excludeFields({ a: 1, b: 2 }, ["b"])
 *   // Expect: {}
 *   const example2 = excludeFields(undefined, ["a"])
 *   ```
 */
export const excludeFields = <T extends AnyRecord, K extends keyof T>(
  object: T | null | undefined,
  keys: K[],
): Omit<T, K> => {
  if (object === null || object === undefined) {
    return {} as Omit<T, K>
  }
  const newObject: Partial<T> = { ...object } // 创建原对象的浅拷贝
  keys.forEach((key) => {
    delete newObject[key] // 删除指定的键
  })
  return newObject as Omit<T, K> // 使用Omit类型确保返回的类型反映了被排除的键
}

/**
 * @description Convert all Date fields in an object to number.
 *
 * @example
 *   ```before
 *   type Obj = {
 *     createdAt: Date,
 *   }
 *   ```
 *   ```after
 *   type Obj = {
 *     createdAt: number,
 *   }
 *   ```
 *
 * @example
 *   ```before
 *   type Obj = {
 *     createdAt: Date | undefined,
 *   }
 *   ```
 *   ```after
 *   type Obj = {
 *     createdAt: number | undefined,
 *   }
 *   ```
 *
 * @example
 *   ```before
 *   type Obj = {
 *     createdAt: Date | null,
 *   }
 *   ```
 *   ```after
 *   type Obj = {
 *     createdAt: number | null,
 *   }
 *   ```
 */
export type ObjectDateFieldsToNumber<O extends object> = {
  [K in keyof O]: O[K] extends Date
    ? number
    : O[K] extends Date | undefined
      ? number | undefined
      : O[K] extends Date | null
        ? number | null
        : O[K] extends object
          ? ObjectDateFieldsToNumber<O[K]>
          : O[K]
}
/**
 * @description Convert all Date fields in an object to number.
 *
 * @example
 *   ```
 *   const obj = { createdAt: new Date() };
 *   const result = objectDateFieldsToNumber(obj);
 *   // Expect: { createdAt: 1712345678901 }
 *   ```
 */
export const objectDateFieldsToNumber = <O extends Record<string | number | symbol, unknown>>(
  obj: O,
): ObjectDateFieldsToNumber<O> => {
  // oxlint-disable-next-line guard-for-in
  for (const key in obj) {
    const value = obj[key]
    if (isDate(value)) {
      obj[key] = value.getTime() as O[Extract<keyof O, string>]
    }
  }
  return obj as ObjectDateFieldsToNumber<O>
}