import type { InputToData, InputToTypeData, ValidationTypes } from './types.ts'
import { parseBody } from './utils/body.ts'
import type { BodyData } from './utils/body.ts'
import type { Cookie } from './utils/cookie.ts'
import { parse } from './utils/cookie.ts'
import { mergeObjects } from './utils/object.ts'
import type { UnionToIntersection } from './utils/types.ts'
import { getQueryStringFromURL, getQueryParam, getQueryParams } from './utils/url.ts'

// eslint-disable-next-line @typescript-eslint/no-unused-vars
type ParamKeyName<NameWithPattern> = NameWithPattern extends `${infer Name}{${infer _Pattern}`
  ? Name
  : NameWithPattern

type ParamKey<Component> = Component extends `:${infer NameWithPattern}`
  ? ParamKeyName<NameWithPattern>
  : never

type ParamKeys<Path> = Path extends `${infer Component}/${infer Rest}`
  ? ParamKey<Component> | ParamKeys<Rest>
  : ParamKey<Path>

type RemoveQuestion<T> = T extends `${infer R}?` ? R : T

// eslint-disable-next-line @typescript-eslint/no-unused-vars
type UndefinedIfHavingQuestion<T> = T extends `${infer _}?` ? string | undefined : string

type ParamKeyToRecord<T extends string> = T extends `${infer R}?`
  ? Record<R, string | undefined>
  : Record<T, string>

export class HonoRequest<Path extends string = '/', Input = {}> {
  raw: Request

  private paramData: Record<string, string> | undefined
  private headerData: Record<string, string> | undefined
  private bodyData: BodyData | undefined
  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  private jsonData: Promise<any> | undefined
  private validatedData: { [K in keyof ValidationTypes]?: {} }
  private queryIndex: number

  constructor(
    request: Request,
    paramData?: Record<string, string> | undefined,
    queryIndex: number = -1
  ) {
    this.raw = request
    this.paramData = paramData
    this.queryIndex = queryIndex
    this.validatedData = {}
  }

  param(key: RemoveQuestion<ParamKeys<Path>>): UndefinedIfHavingQuestion<ParamKeys<Path>>
  param(): UnionToIntersection<ParamKeyToRecord<ParamKeys<Path>>>
  param(key?: string): unknown {
    if (this.paramData) {
      if (key) {
        const param = this.paramData[key]
        return param ? (/\%/.test(param) ? decodeURIComponent(param) : param) : undefined
      } else {
        const decoded: Record<string, string> = {}

        for (const [key, value] of Object.entries(this.paramData)) {
          if (value && typeof value === 'string') {
            decoded[key] = /\%/.test(value) ? decodeURIComponent(value) : value
          }
        }

        return decoded
      }
    }
    return null
  }

  query(key: string): string
  query(): Record<string, string>
  query(key?: string) {
    const queryString = getQueryStringFromURL(this.url, this.queryIndex)
    return getQueryParam(queryString, key)
  }

  queries(key: string): string[]
  queries(): Record<string, string[]>
  queries(key?: string) {
    const queryString = getQueryStringFromURL(this.url, this.queryIndex)
    return getQueryParams(queryString, key)
  }

  header(name: string): string
  header(): Record<string, string>
  header(name?: string) {
    if (!this.headerData) {
      this.headerData = {}
      this.raw.headers.forEach((value, key) => {
        // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
        this.headerData![key] = value
      })
    }
    if (name) {
      return this.headerData[name.toLowerCase()]
    } else {
      return this.headerData
    }
  }

  cookie(key: string): string | undefined
  cookie(): Cookie
  cookie(key?: string) {
    const cookie = this.raw.headers.get('Cookie')
    if (!cookie) return
    const obj = parse(cookie)
    if (key) {
      const value = obj[key]
      return value
    } else {
      return obj
    }
  }

  async parseBody(): Promise<BodyData> {
    // Cache the parsed body
    let body: BodyData
    if (!this.bodyData) {
      body = await parseBody(this.raw)
      this.bodyData = body
    } else {
      body = this.bodyData
    }
    return body
  }

  async json<JSONData = unknown>() {
    // Cache the JSON body
    let jsonData: Promise<Partial<JSONData>>
    if (!this.jsonData) {
      jsonData = this.raw.json()
      this.jsonData = jsonData
    } else {
      jsonData = this.jsonData
    }
    return jsonData
  }

  async text() {
    return this.raw.text()
  }

  async arrayBuffer() {
    return this.raw.arrayBuffer()
  }

  async blob() {
    return this.raw.blob()
  }

  async formData() {
    return this.raw.formData()
  }

  addValidatedData(type: keyof ValidationTypes, data: {}) {
    const storedData = this.validatedData[type] || {}
    const merged = mergeObjects(storedData, data)
    this.validatedData[type] = merged
  }

  valid(): InputToData<Input>
  valid<T extends keyof ValidationTypes>(type: T): InputToTypeData<T, Input>
  valid<T extends keyof ValidationTypes>(type?: T) {
    if (type) {
      const data = this.validatedData[type]
      return data
    } else {
      let data: Record<string, unknown> = {}
      for (const v of Object.values(this.validatedData)) {
        data = mergeObjects(data, v)
      }
      return data
    }
  }

  get url() {
    return this.raw.url
  }
  get method() {
    return this.raw.method
  }
  get headers() {
    return this.raw.headers
  }
  get redirect() {
    return this.raw.redirect
  }
  get body() {
    return this.raw.body
  }
  get bodyUsed() {
    return this.raw.bodyUsed
  }
  get cache() {
    return this.raw.cache
  }
  get credentials() {
    return this.raw.credentials
  }
  get integrity() {
    return this.raw.integrity
  }
  get keepalive() {
    return this.raw.keepalive
  }
  get mode() {
    return this.raw.mode
  }
  get referrer() {
    return this.raw.referrer
  }
  get refererPolicy() {
    return this.raw.referrerPolicy
  }
  get signal() {
    return this.raw.signal
  }
}