/*
 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 { i18n, Timestamp } from "@gnu-taler/taler-util";
import {
  ProviderInfo,
  ProviderPaymentStatus,
} from "@gnu-taler/taler-wallet-core";
import {
  differenceInMonths,
  formatDuration,
  intervalToDuration,
} from "date-fns";
import { Fragment, h, VNode } from "preact";
import {
  BoldLight,
  ButtonPrimary,
  ButtonSuccess,
  Centered,
  CenteredBoldText,
  CenteredText,
  RowBorderGray,
  SmallLightText,
  SmallText,
} from "../components/styled";
import { useBackupStatus } from "../hooks/useBackupStatus";
import { Pages } from "../NavigationBar";

interface Props {
  onAddProvider: () => void;
}

export function BackupPage({ onAddProvider }: Props): VNode {
  const status = useBackupStatus();
  if (!status) {
    return <div>Loading...</div>;
  }
  return (
    <BackupView
      providers={status.providers}
      onAddProvider={onAddProvider}
      onSyncAll={status.sync}
    />
  );
}

export interface ViewProps {
  providers: ProviderInfo[];
  onAddProvider: () => void;
  onSyncAll: () => Promise<void>;
}

export function BackupView({
  providers,
  onAddProvider,
  onSyncAll,
}: ViewProps): VNode {
  return (
    <Fragment>
      <section>
        {providers.map((provider, idx) => (
          <BackupLayout
            key={idx}
            status={provider.paymentStatus}
            timestamp={provider.lastSuccessfulBackupTimestamp}
            id={provider.syncProviderBaseUrl}
            active={provider.active}
            title={provider.name}
          />
        ))}
        {!providers.length && (
          <Centered style={{ marginTop: 100 }}>
            <BoldLight>No backup providers configured</BoldLight>
            <ButtonSuccess onClick={onAddProvider}>
              <i18n.Translate>Add provider</i18n.Translate>
            </ButtonSuccess>
          </Centered>
        )}
      </section>
      {!!providers.length && (
        <footer>
          <div />
          <div>
            <ButtonPrimary onClick={onSyncAll}>
              {providers.length > 1 ? (
                <i18n.Translate>Sync all backups</i18n.Translate>
              ) : (
                <i18n.Translate>Sync now</i18n.Translate>
              )}
            </ButtonPrimary>
            <ButtonSuccess onClick={onAddProvider}>Add provider</ButtonSuccess>
          </div>
        </footer>
      )}
    </Fragment>
  );
}

interface TransactionLayoutProps {
  status: ProviderPaymentStatus;
  timestamp?: Timestamp;
  title: string;
  id: string;
  active: boolean;
}

function BackupLayout(props: TransactionLayoutProps): VNode {
  const date = !props.timestamp ? undefined : new Date(props.timestamp.t_ms);
  const dateStr = date?.toLocaleString([], {
    dateStyle: "medium",
    timeStyle: "short",
  } as any);

  return (
    <RowBorderGray>
      <div style={{ color: !props.active ? "grey" : undefined }}>
        <a
          href={Pages.provider_detail.replace(
            ":pid",
            encodeURIComponent(props.id),
          )}
        >
          <span>{props.title}</span>
        </a>

        {dateStr && (
          <SmallText style={{ marginTop: 5 }}>Last synced: {dateStr}</SmallText>
        )}
        {!dateStr && (
          <SmallLightText style={{ marginTop: 5 }}>Not synced</SmallLightText>
        )}
      </div>
      <div>
        {props.status?.type === "paid" ? (
          <ExpirationText until={props.status.paidUntil} />
        ) : (
          <div>{props.status.type}</div>
        )}
      </div>
    </RowBorderGray>
  );
}

function ExpirationText({ until }: { until: Timestamp }): VNode {
  return (
    <Fragment>
      <CenteredText> Expires in </CenteredText>
      <CenteredBoldText {...{ color: colorByTimeToExpire(until) }}>
        {" "}
        {daysUntil(until)}{" "}
      </CenteredBoldText>
    </Fragment>
  );
}

function colorByTimeToExpire(d: Timestamp): string {
  if (d.t_ms === "never") return "rgb(28, 184, 65)";
  const months = differenceInMonths(d.t_ms, new Date());
  return months > 1 ? "rgb(28, 184, 65)" : "rgb(223, 117, 20)";
}

function daysUntil(d: Timestamp): string {
  if (d.t_ms === "never") return "";
  const duration = intervalToDuration({
    start: d.t_ms,
    end: new Date(),
  });
  const str = formatDuration(duration, {
    delimiter: ", ",
    format: [
      duration?.years
        ? "years"
        : duration?.months
        ? "months"
        : duration?.days
        ? "days"
        : duration.hours
        ? "hours"
        : "minutes",
    ],
  });
  return `${str}`;
}