factory.ts

/* eslint-disable @typescript-eslint/no-explicit-any */
import { Hono } from '../../hono'
import type { Env, H, HandlerResponse, Input, MiddlewareHandler } from '../../types'

type InitApp<E extends Env = Env> = (app: Hono<E>) => void

interface CreateHandlersInterface<E extends Env, P extends string> {
  <I extends Input = {}, R extends HandlerResponse<any> = any>(handler1: H<E, P, I, R>): [
    H<E, P, I, R>
  ]
  // handler x2
  <I extends Input = {}, I2 extends Input = I, R extends HandlerResponse<any> = any>(
    handler1: H<E, P, I, R>,
    handler2: H<E, P, I2, R>
  ): [H<E, P, I, R>, H<E, P, I2, R>]

  // handler x3
  <
    I extends Input = {},
    I2 extends Input = I,
    I3 extends Input = I & I2,
    R extends HandlerResponse<any> = any
  >(
    handler1: H<E, P, I, R>,
    handler2: H<E, P, I2, R>,
    handler3: H<E, P, I3, R>
  ): [H<E, P, I, R>, H<E, P, I2, R>, H<E, P, I3, R>]

  // handler x4
  <
    I extends Input = {},
    I2 extends Input = I,
    I3 extends Input = I & I2,
    I4 extends Input = I & I2 & I3,
    R extends HandlerResponse<any> = any
  >(
    handler1: H<E, P, I, R>,
    handler2: H<E, P, I2, R>,
    handler3: H<E, P, I3, R>,
    handler4: H<E, P, I4, R>
  ): [H<E, P, I, R>, H<E, P, I2, R>, H<E, P, I3, R>, H<E, P, I4, R>]

  // handler x5
  <
    I extends Input = {},
    I2 extends Input = I,
    I3 extends Input = I & I2,
    I4 extends Input = I & I2 & I3,
    I5 extends Input = I & I2 & I3 & I4,
    R extends HandlerResponse<any> = any
  >(
    handler1: H<E, P, I, R>,
    handler2: H<E, P, I2, R>,
    handler3: H<E, P, I3, R>,
    handler4: H<E, P, I4, R>,
    handler5: H<E, P, I5, R>
  ): [H<E, P, I, R>, H<E, P, I2, R>, H<E, P, I3, R>, H<E, P, I4, R>, H<E, P, I5, R>]

  // handler x6
  <
    I extends Input = {},
    I2 extends Input = I,
    I3 extends Input = I & I2,
    I4 extends Input = I & I2 & I3,
    I5 extends Input = I & I2 & I3 & I4,
    I6 extends Input = I & I2 & I3 & I4 & I5,
    R extends HandlerResponse<any> = any
  >(
    handler1: H<E, P, I, R>,
    handler2: H<E, P, I2, R>,
    handler3: H<E, P, I3, R>,
    handler4: H<E, P, I4, R>,
    handler5: H<E, P, I5, R>,
    handler6: H<E, P, I6, R>
  ): [H<E, P, I, R>, H<E, P, I2, R>, H<E, P, I3, R>, H<E, P, I4, R>, H<E, P, I5, R>, H<E, P, I6, R>]

  // handler x7
  <
    I extends Input = {},
    I2 extends Input = I,
    I3 extends Input = I & I2,
    I4 extends Input = I & I2 & I3,
    I5 extends Input = I & I2 & I3 & I4,
    I6 extends Input = I & I2 & I3 & I4 & I5,
    I7 extends Input = I & I2 & I3 & I4 & I5 & I6,
    R extends HandlerResponse<any> = any
  >(
    handler1: H<E, P, I, R>,
    handler2: H<E, P, I2, R>,
    handler3: H<E, P, I3, R>,
    handler4: H<E, P, I4, R>,
    handler5: H<E, P, I5, R>,
    handler6: H<E, P, I6, R>,
    handler7: H<E, P, I7, R>
  ): [
    H<E, P, I, R>,
    H<E, P, I2, R>,
    H<E, P, I3, R>,
    H<E, P, I4, R>,
    H<E, P, I5, R>,
    H<E, P, I6, R>,
    H<E, P, I7, R>
  ]

  // handler x8
  <
    I extends Input = {},
    I2 extends Input = I,
    I3 extends Input = I & I2,
    I4 extends Input = I & I2 & I3,
    I5 extends Input = I & I2 & I3 & I4,
    I6 extends Input = I & I2 & I3 & I4 & I5,
    I7 extends Input = I & I2 & I3 & I4 & I5 & I6,
    I8 extends Input = I & I2 & I3 & I4 & I5 & I6 & I7,
    R extends HandlerResponse<any> = any
  >(
    handler1: H<E, P, I, R>,
    handler2: H<E, P, I2, R>,
    handler3: H<E, P, I3, R>,
    handler4: H<E, P, I4, R>,
    handler5: H<E, P, I5, R>,
    handler6: H<E, P, I6, R>,
    handler7: H<E, P, I7, R>,
    handler8: H<E, P, I8, R>
  ): [
    H<E, P, I, R>,
    H<E, P, I2, R>,
    H<E, P, I3, R>,
    H<E, P, I4, R>,
    H<E, P, I5, R>,
    H<E, P, I6, R>,
    H<E, P, I7, R>,
    H<E, P, I8, R>
  ]

  // handler x9
  <
    I extends Input = {},
    I2 extends Input = I,
    I3 extends Input = I & I2,
    I4 extends Input = I & I2 & I3,
    I5 extends Input = I & I2 & I3 & I4,
    I6 extends Input = I & I2 & I3 & I4 & I5,
    I7 extends Input = I & I2 & I3 & I4 & I5 & I6,
    I8 extends Input = I & I2 & I3 & I4 & I5 & I6 & I7,
    I9 extends Input = I & I2 & I3 & I4 & I5 & I6 & I7 & I8,
    R extends HandlerResponse<any> = any
  >(
    handler1: H<E, P, I, R>,
    handler2: H<E, P, I2, R>,
    handler3: H<E, P, I3, R>,
    handler4: H<E, P, I4, R>,
    handler5: H<E, P, I5, R>,
    handler6: H<E, P, I6, R>,
    handler7: H<E, P, I7, R>,
    handler8: H<E, P, I8, R>,
    handler9: H<E, P, I9, R>
  ): [
    H<E, P, I, R>,
    H<E, P, I2, R>,
    H<E, P, I3, R>,
    H<E, P, I4, R>,
    H<E, P, I5, R>,
    H<E, P, I6, R>,
    H<E, P, I7, R>,
    H<E, P, I8, R>,
    H<E, P, I9, R>
  ]

  // handler x10
  <
    I extends Input = {},
    I2 extends Input = I,
    I3 extends Input = I & I2,
    I4 extends Input = I & I2 & I3,
    I5 extends Input = I & I2 & I3 & I4,
    I6 extends Input = I & I2 & I3 & I4 & I5,
    I7 extends Input = I & I2 & I3 & I4 & I5 & I6,
    I8 extends Input = I & I2 & I3 & I4 & I5 & I6 & I7,
    I9 extends Input = I & I2 & I3 & I4 & I5 & I6 & I7 & I8,
    I10 extends Input = I & I2 & I3 & I4 & I5 & I6 & I7 & I8 & I9,
    R extends HandlerResponse<any> = any
  >(
    handler1: H<E, P, I, R>,
    handler2: H<E, P, I2, R>,
    handler3: H<E, P, I3, R>,
    handler4: H<E, P, I4, R>,
    handler5: H<E, P, I5, R>,
    handler6: H<E, P, I6, R>,
    handler7: H<E, P, I7, R>,
    handler8: H<E, P, I8, R>,
    handler9: H<E, P, I9, R>,
    handler10: H<E, P, I10, R>
  ): [
    H<E, P, I, R>,
    H<E, P, I2, R>,
    H<E, P, I3, R>,
    H<E, P, I4, R>,
    H<E, P, I5, R>,
    H<E, P, I6, R>,
    H<E, P, I7, R>,
    H<E, P, I8, R>,
    H<E, P, I9, R>,
    H<E, P, I10, R>
  ]
}

export class Factory<E extends Env = any, P extends string = any> {
  private initApp?: InitApp<E>

  constructor(init?: { initApp?: InitApp<E> }) {
    this.initApp = init?.initApp
  }

  /**
   * @experimental
   * `createApp` is an experimental feature.
   */
  createApp = () => {
    const app = new Hono<E>()
    if (this.initApp) {
      this.initApp(app)
    }
    return app
  }

  createMiddleware = <I extends Input = {}>(middleware: MiddlewareHandler<E, P, I>) => middleware

  createHandlers: CreateHandlersInterface<E, P> = (handlers: any) => {
    // @ts-expect-error this is not typed
    return handlers.filter((handler) => handler !== undefined)
  }
}

export const createFactory = <E extends Env = any, P extends string = any>(init?: {
  initApp?: InitApp<E>
}) => new Factory<E, P>(init)

export const createMiddleware = <E extends Env = any, P extends string = any, I extends Input = {}>(
  middleware: MiddlewareHandler<E, P, I>
) => createFactory<E, P>().createMiddleware<I>(middleware)