/*
 This file is part of TALER
 (C) 2016 GNUnet e.V.

 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.

 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
 TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
 */

import {
  AmountString,
  Balance,
  Transaction,
  TransactionsResponse,
} from "@gnu-taler/taler-util";
import { format } from "date-fns";
import { Fragment, h, JSX } from "preact";
import { useEffect, useState } from "preact/hooks";
import { DateSeparator, WalletBox } from "../components/styled";
import { TransactionItem } from "../components/TransactionItem";
import { useBalances } from "../hooks/useBalances";
import * as wxApi from "../wxApi";

export function HistoryPage(props: any): JSX.Element {
  const [transactions, setTransactions] = useState<
    TransactionsResponse | undefined
  >(undefined);
  const balance = useBalances();
  const balanceWithoutError = balance?.hasError
    ? []
    : balance?.response.balances || [];

  useEffect(() => {
    const fetchData = async (): Promise<void> => {
      const res = await wxApi.getTransactions();
      setTransactions(res);
    };
    fetchData();
  }, []);

  if (!transactions) {
    return <div>Loading ...</div>;
  }

  return (
    <HistoryView
      balances={balanceWithoutError}
      list={[...transactions.transactions].reverse()}
    />
  );
}

function amountToString(c: AmountString) {
  const idx = c.indexOf(":");
  return `${c.substring(idx + 1)} ${c.substring(0, idx)}`;
}

export function HistoryView({
  list,
  balances,
}: {
  list: Transaction[];
  balances: Balance[];
}) {
  const byDate = list.reduce(function (rv, x) {
    const theDate =
      x.timestamp.t_ms === "never"
        ? "never"
        : format(x.timestamp.t_ms, "dd MMMM yyyy");
    (rv[theDate] = rv[theDate] || []).push(x);
    return rv;
  }, {} as { [x: string]: Transaction[] });

  const multiCurrency = balances.length > 1;

  return (
    <WalletBox noPadding>
      {balances.length > 0 && (
        <header>
          {balances.length === 1 && (
            <div class="title">
              Balance: <span>{amountToString(balances[0].available)}</span>
            </div>
          )}
          {balances.length > 1 && (
            <div class="title">
              Balance:{" "}
              <ul style={{ margin: 0 }}>
                {balances.map((b) => (
                  <li>{b.available}</li>
                ))}
              </ul>
            </div>
          )}
        </header>
      )}
      <section>
        {Object.keys(byDate).map((d, i) => {
          return (
            <Fragment key={i}>
              <DateSeparator>{d}</DateSeparator>
              {byDate[d].map((tx, i) => (
                <TransactionItem
                  key={i}
                  tx={tx}
                  multiCurrency={multiCurrency}
                />
              ))}
            </Fragment>
          );
        })}
      </section>
    </WalletBox>
  );
}