/*
 This file is part of GNU Taler
 (C) 2021 Taler Systems S.A.

 GNU Taler is free software; you can redistribute it and/or modify it under the
 terms of the GNU General Public License as published by the Free Software
 Foundation; either version 3, or (at your option) any later version.

 GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

 You should have received a copy of the GNU General Public License along with
 GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
 */
import { useEffect, useState } from 'preact/hooks';
import useSWR from 'swr';
import { useBackendContext } from '../context/backend';
import { useInstanceContext } from '../context/instance';
import { MerchantBackend } from '../declaration';
import { MAX_RESULT_SIZE, PAGE_SIZE } from '../utils/constants';
import { fetcher, HttpError, HttpResponse, HttpResponseOk, HttpResponsePaginated, mutateAll, request } from './backend';

export interface OrderAPI {
  //FIXME: add OutOfStockResponse on 410
  createOrder: (data: MerchantBackend.Orders.PostOrderRequest) => Promise<HttpResponseOk<MerchantBackend.Orders.PostOrderResponse>>;
  forgetOrder: (id: string, data: MerchantBackend.Orders.ForgetRequest) => Promise<HttpResponseOk<void>>;
  refundOrder: (id: string, data: MerchantBackend.Orders.RefundRequest) => Promise<HttpResponseOk<MerchantBackend.Orders.MerchantRefundResponse>>;
  deleteOrder: (id: string) => Promise<HttpResponseOk<void>>;
  getPaymentURL: (id: string) => Promise<HttpResponseOk<string>>;
}

type YesOrNo = 'yes' | 'no';


export function orderFetcher<T>(url: string, token: string, backend: string, paid?: YesOrNo, refunded?: YesOrNo, wired?: YesOrNo, searchDate?: Date, delta?: number): Promise<HttpResponseOk<T>> {
  const date_ms = delta && delta < 0 && searchDate ? searchDate.getTime() + 1 : searchDate?.getTime()
  const params: any = {}
  if (paid !== undefined) params.paid = paid
  if (delta !== undefined) params.delta = delta
  if (refunded !== undefined) params.refunded = refunded
  if (wired !== undefined) params.wired = wired
  if (date_ms !== undefined) params.date_ms = date_ms
  return request<T>(`${backend}${url}`, { token, params })
}


export function useOrderAPI(): OrderAPI {
  const { url: baseUrl, token: adminToken } = useBackendContext()
  const { token: instanceToken, id, admin } = useInstanceContext()

  const { url, token } = !admin ? {
    url: baseUrl, token: adminToken
  } : {
    url: `${baseUrl}/instances/${id}`, token: instanceToken
  }

  const createOrder = async (data: MerchantBackend.Orders.PostOrderRequest): Promise<HttpResponseOk<MerchantBackend.Orders.PostOrderResponse>> => {
    const res = await request<MerchantBackend.Orders.PostOrderResponse>(`${url}/private/orders`, {
      method: 'post',
      token,
      data
    })
    await mutateAll(/@"\/private\/orders"@/)
    return res
  }
  const refundOrder = async (orderId: string, data: MerchantBackend.Orders.RefundRequest): Promise<HttpResponseOk<MerchantBackend.Orders.MerchantRefundResponse>> => {
    mutateAll(/@"\/private\/orders"@/)
    return request<MerchantBackend.Orders.MerchantRefundResponse>(`${url}/private/orders/${orderId}/refund`, {
      method: 'post',
      token,
      data
    })

    // return res
  }

  const forgetOrder = async (orderId: string, data: MerchantBackend.Orders.ForgetRequest): Promise<HttpResponseOk<void>> => {
    mutateAll(/@"\/private\/orders"@/)
    return request(`${url}/private/orders/${orderId}/forget`, {
      method: 'patch',
      token,
      data
    })

  }
  const deleteOrder = async (orderId: string): Promise<HttpResponseOk<void>> => {
    mutateAll(/@"\/private\/orders"@/)
    return request(`${url}/private/orders/${orderId}`, {
      method: 'delete',
      token
    })
  }

  const getPaymentURL = async (orderId: string): Promise<HttpResponseOk<string>> => {
    return request<MerchantBackend.Orders.MerchantOrderStatusResponse>(`${url}/private/orders/${orderId}`, {
      method: 'get',
      token
    }).then((res) => {
      const url = res.data.order_status === "unpaid" ? res.data.taler_pay_uri : res.data.contract_terms.fulfillment_url
      const response: HttpResponseOk<string> = res as any
      response.data = url || ''
      return response
    })
  }

  return { createOrder, forgetOrder, deleteOrder, refundOrder, getPaymentURL }
}

export function useOrderDetails(oderId: string): HttpResponse<MerchantBackend.Orders.MerchantOrderStatusResponse> {
  const { url: baseUrl, token: baseToken } = useBackendContext();
  const { token: instanceToken, id, admin } = useInstanceContext();

  const { url, token } = !admin ? {
    url: baseUrl, token: baseToken
  } : {
    url: `${baseUrl}/instances/${id}`, token: instanceToken
  };

  const { data, error, isValidating } = useSWR<HttpResponseOk<MerchantBackend.Orders.MerchantOrderStatusResponse>, HttpError>([`/private/orders/${oderId}`, token, url], fetcher, {
    refreshInterval: 0,
    refreshWhenHidden: false,
    revalidateOnFocus: false,
    revalidateOnReconnect: false,
    refreshWhenOffline: false,
  })

  if (isValidating) return { loading: true, data: data?.data }
  if (data) return data
  if (error) return error
  return { loading: true }
}

export interface InstanceOrderFilter {
  paid?: YesOrNo;
  refunded?: YesOrNo;
  wired?: YesOrNo;
  date?: Date;
}

export function useInstanceOrders(args?: InstanceOrderFilter, updateFilter?: (d: Date) => void): HttpResponsePaginated<MerchantBackend.Orders.OrderHistory> {
  const { url: baseUrl, token: baseToken } = useBackendContext();
  const { token: instanceToken, id, admin } = useInstanceContext();

  const { url, token } = !admin ? {
    url: baseUrl, token: baseToken
  } : {
    url: `${baseUrl}/instances/${id}`, token: instanceToken
  }

  const [pageBefore, setPageBefore] = useState(1)
  const [pageAfter, setPageAfter] = useState(1)

  const totalAfter = pageAfter * PAGE_SIZE;
  const totalBefore = args?.date ? pageBefore * PAGE_SIZE : 0;

  /**
   * FIXME: this can be cleaned up a little
   * 
   * the logic of double query should be inside the orderFetch so from the hook perspective and cache
   * is just one query and one error status
   */
  const { data: beforeData, error: beforeError, isValidating: loadingBefore } = useSWR<HttpResponseOk<MerchantBackend.Orders.OrderHistory>, HttpError>(
    [`/private/orders`, token, url, args?.paid, args?.refunded, args?.wired, args?.date, totalBefore],
    orderFetcher,
  )
  const { data: afterData, error: afterError, isValidating: loadingAfter } = useSWR<HttpResponseOk<MerchantBackend.Orders.OrderHistory>, HttpError>(
    [`/private/orders`, token, url, args?.paid, args?.refunded, args?.wired, args?.date, -totalAfter],
    orderFetcher,
  )

  //this will save last result
  const [lastBefore, setLastBefore] = useState<HttpResponse<MerchantBackend.Orders.OrderHistory>>({ loading: true })
  const [lastAfter, setLastAfter] = useState<HttpResponse<MerchantBackend.Orders.OrderHistory>>({ loading: true })
  useEffect(() => {
    if (afterData) setLastAfter(afterData)
    if (beforeData) setLastBefore(beforeData)
  }, [afterData, beforeData])

  // this has problems when there are some ids missing

  if (beforeError) return beforeError
  if (afterError) return afterError


  const pagination = {
    isReachingEnd: afterData && afterData.data.orders.length < totalAfter,
    isReachingStart: (!args?.date) || (beforeData && beforeData.data.orders.length < totalBefore),
    loadMore: () => {
      if (!afterData) return
      if (afterData.data.orders.length < MAX_RESULT_SIZE) {
        setPageAfter(pageAfter + 1)
      } else {
        const from = afterData.data.orders[afterData.data.orders.length - 1].timestamp.t_s
        if (from && updateFilter) updateFilter(new Date(from))
      }
    },
    loadMorePrev: () => {
      if (!beforeData) return
      if (beforeData.data.orders.length < MAX_RESULT_SIZE) {
        setPageBefore(pageBefore + 1)
      } else if (beforeData) {
        const from = beforeData.data.orders[beforeData.data.orders.length - 1].timestamp.t_s
        if (from && updateFilter) updateFilter(new Date(from))
      }
    },
  }

  const orders = !beforeData || !afterData ? [] : (beforeData || lastBefore).data.orders.slice().reverse().concat((afterData || lastAfter).data.orders)
  if (loadingAfter || loadingBefore) return { loading: true, data: { orders } }
  if (beforeData && afterData) {
    return { ok: true, data: { orders }, ...pagination }
  }
  return { loading: true }

}