/*
 This file is part of GNU Taler
 (C) 2022 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/>
 */

/* eslint-disable react-hooks/rules-of-hooks */
import {
  Amounts,
  TalerErrorDetail,
  TalerProtocolTimestamp,
} from "@gnu-taler/taler-util";
import { TalerError, WalletApiOperation } from "@gnu-taler/taler-wallet-core";
import { isFuture, parse } from "date-fns";
import { useState } from "preact/hooks";
import { useAsyncAsHook } from "../../hooks/useAsyncAsHook.js";
import { useSelectedExchange } from "../../hooks/useSelectedExchange.js";
import { wxApi } from "../../wxApi.js";
import { Props, State } from "./index.js";

type RecursiveState<S extends object> = S | (() => RecursiveState<S>);

export function useComponentState(
  { amount: amountStr, onClose, onSuccess }: Props,
  api: typeof wxApi,
): RecursiveState<State> {
  const amount = Amounts.parseOrThrow(amountStr);

  const hook = useAsyncAsHook(() =>
    api.wallet.call(WalletApiOperation.ListExchanges, {}),
  );

  if (!hook) {
    return {
      status: "loading",
      error: undefined,
    };
  }
  if (hook.hasError) {
    return {
      status: "loading-uri",
      error: hook,
    };
  }

  const exchangeList = hook.response.exchanges;

  return () => {
    const [subject, setSubject] = useState<string | undefined>();
    const [timestamp, setTimestamp] = useState<string | undefined>();

    const [operationError, setOperationError] = useState<
      TalerErrorDetail | undefined
    >(undefined);

    const selectedExchange = useSelectedExchange({
      currency: amount.currency,
      defaultExchange: undefined,
      list: exchangeList,
    });

    if (selectedExchange.status !== "ready") {
      return selectedExchange;
    }

    const exchange = selectedExchange.selected;

    const hook = useAsyncAsHook(async () => {
      const resp = await api.wallet.call(
        WalletApiOperation.PreparePeerPullPayment,
        {
          amount: amountStr,
          exchangeBaseUrl: exchange.exchangeBaseUrl,
        },
      );
      return resp;
    });

    if (!hook) {
      return {
        status: "loading",
        error: undefined,
      };
    }
    if (hook.hasError) {
      return {
        status: "loading-uri",
        error: hook,
      };
    }

    const { amountEffective, amountRaw } = hook.response;
    const requestAmount = Amounts.parseOrThrow(amountRaw);
    const toBeReceived = Amounts.parseOrThrow(amountEffective);

    let purse_expiration: TalerProtocolTimestamp | undefined = undefined;
    let timestampError: string | undefined = undefined;

    const t =
      timestamp === undefined
        ? undefined
        : parse(timestamp, "dd/MM/yyyy", new Date());

    if (t !== undefined) {
      if (Number.isNaN(t.getTime())) {
        timestampError = 'Should have the format "dd/MM/yyyy"';
      } else {
        if (!isFuture(t)) {
          timestampError = "Should be in the future";
        } else {
          purse_expiration = {
            t_s: t.getTime() / 1000,
          };
        }
      }
    }

    async function accept(): Promise<void> {
      if (!subject || !purse_expiration) return;
      try {
        const resp = await api.wallet.call(
          WalletApiOperation.InitiatePeerPullPayment,
          {
            exchangeBaseUrl: exchange.exchangeBaseUrl,
            partialContractTerms: {
              amount: Amounts.stringify(amount),
              summary: subject,
              purse_expiration,
            },
          },
        );

        onSuccess(resp.transactionId);
      } catch (e) {
        if (e instanceof TalerError) {
          setOperationError(e.errorDetail);
        }
        console.error(e);
        throw Error("error trying to accept");
      }
    }
    const unableToCreate =
      !subject || Amounts.isZero(amount) || !purse_expiration;

    return {
      status: "ready",
      subject: {
        error:
          subject === undefined
            ? undefined
            : !subject
            ? "Can't be empty"
            : undefined,
        value: subject ?? "",
        onInput: async (e) => setSubject(e),
      },
      expiration: {
        error: timestampError,
        value: timestamp === undefined ? "" : timestamp,
        onInput: async (e) => {
          setTimestamp(e);
        },
      },
      doSelectExchange: selectedExchange.doSelect,
      exchangeUrl: exchange.exchangeBaseUrl,
      create: {
        onClick: unableToCreate ? undefined : accept,
      },
      cancel: {
        onClick: onClose,
      },
      requestAmount,
      toBeReceived,
      error: undefined,
      operationError,
    };
  };
}