import type { HTTPClientPlugin, PluginHookResult, RequestMethod, RequestConfig } from '../types'

/**
 * 方法重写插件配置
 */
export interface HTTPMethodOverridePluginOptions {
  /**
   * 需要被重写的请求方法
   * - 默认为 ['DELETE', 'PUT', 'PATCH']
   */
  methods?: RequestMethod[]
  /**
   * 重写后的请求方法
   * - 默认为 'POST'
   */
  overrideMethod?: RequestMethod

  /**
   * 方法覆盖请求头名称
   * - 默认为 'X-HTTP-Method-Override'
   */
  headerName?: string
}

export type MethodOverridePluginOptions = HTTPMethodOverridePluginOptions

/**
 * 方法重写插件
 *
 * 用于绕过某些环境对特定 HTTP 方法的限制
 *
 * @example
 * ```ts
 * import { MethodOverridePlugin, HTTPClient } from '@cat-kit/http'
 * const http = new HTTPClient('', {
 *   plugins: [
 *     MethodOverridePlugin()
 *   ]
 * })
 * ```
 */
export function HTTPMethodOverridePlugin(
  options: HTTPMethodOverridePluginOptions = {}
): HTTPClientPlugin {
  const {
    methods = ['DELETE', 'PUT', 'PATCH'],
    overrideMethod = 'POST',
    headerName = 'X-HTTP-Method-Override'
  } = options

  return {
    name: 'method-override',
    beforeRequest({ config }): PluginHookResult {
      const { method } = config

      // 如果没有指定方法或者方法不需要被重写，不做任何处理
      if (!method || !methods.includes(method as RequestMethod)) {
        return {}
      }

      // 创建新的请求头对象
      const headers = { ...config.headers }

      // 添加原始方法到请求头
      headers[headerName] = method

      // 返回修改后的请求选项
      return { config: { ...config, method: overrideMethod, headers } }
    }
  }
}

export const MethodOverridePlugin = HTTPMethodOverridePlugin