import { useCallback, useMemo } from 'react';
import { sprintf } from 'sprintf-js';
import styled from 'styled-components';

import { strings } from '../../config.json';
import {
  IpVersion,
  liftConstraint,
  LiftedConstraint,
  ObfuscationType,
  wrapConstraint,
} from '../../shared/daemon-rpc-types';
import { messages } from '../../shared/gettext';
import log from '../../shared/logging';
import { removeNonNumericCharacters } from '../../shared/string-helpers';
import { useAppContext } from '../context';
import { useRelaySettingsUpdater } from '../lib/constraint-updater';
import { useHistory } from '../lib/history';
import { useBoolean } from '../lib/utilityHooks';
import { useSelector } from '../redux/store';
import * as AppButton from './AppButton';
import { AriaDescription, AriaInput, AriaInputGroup, AriaLabel } from './AriaGroup';
import * as Cell from './cell';
import Selector, { SelectorItem, SelectorWithCustomItem } from './cell/Selector';
import InfoButton from './InfoButton';
import { BackAction } from './KeyboardNavigation';
import { Layout, SettingsContainer } from './Layout';
import { ModalAlert, ModalAlertType, ModalMessage } from './Modal';
import {
  NavigationBar,
  NavigationContainer,
  NavigationItems,
  NavigationScrollbars,
  TitleBarItem,
} from './NavigationBar';
import SettingsHeader, { HeaderTitle } from './SettingsHeader';

const MIN_WIREGUARD_MTU_VALUE = 1280;
const MAX_WIREGUARD_MTU_VALUE = 1420;
const WIREUGARD_UDP_PORTS = [51820, 53];
const UDP2TCP_PORTS = [80, 5001];

function mapPortToSelectorItem(value: number): SelectorItem<number> {
  return { label: value.toString(), value };
}

const StyledContent = styled.div({
  display: 'flex',
  flexDirection: 'column',
  flex: 1,
  marginBottom: '2px',
});

const StyledSelectorContainer = styled.div({
  flex: 0,
});

export default function WireguardSettings() {
  const { pop } = useHistory();

  return (
    <BackAction action={pop}>
      <Layout>
        <SettingsContainer>
          <NavigationContainer>
            <NavigationBar>
              <NavigationItems>
                <TitleBarItem>
                  {sprintf(
                    // TRANSLATORS: Title label in navigation bar
                    // TRANSLATORS: Available placeholders:
                    // TRANSLATORS: %(wireguard)s - Will be replaced with the string "WireGuard"
                    messages.pgettext('wireguard-settings-nav', '%(wireguard)s settings'),
                    { wireguard: strings.wireguard },
                  )}
                </TitleBarItem>
              </NavigationItems>
            </NavigationBar>

            <NavigationScrollbars>
              <SettingsHeader>
                <HeaderTitle>
                  {sprintf(
                    // TRANSLATORS: Available placeholders:
                    // TRANSLATORS: %(wireguard)s - Will be replaced with the string "WireGuard"
                    messages.pgettext('wireguard-settings-view', '%(wireguard)s settings'),
                    { wireguard: strings.wireguard },
                  )}
                </HeaderTitle>
              </SettingsHeader>

              <StyledContent>
                <Cell.Group>
                  <PortSelector />
                </Cell.Group>

                <Cell.Group>
                  <ObfuscationSettings />
                  <Udp2tcpPortSetting />
                </Cell.Group>

                {window.env.platform === 'win32' && (
                  <Cell.Group>
                    <DaitaSettings />
                  </Cell.Group>
                )}

                <Cell.Group>
                  <QuantumResistantSetting />
                </Cell.Group>

                <Cell.Group>
                  <MultihopSetting />
                </Cell.Group>

                <Cell.Group>
                  <IpVersionSetting />
                </Cell.Group>

                <Cell.Group>
                  <MtuSetting />
                </Cell.Group>
              </StyledContent>
            </NavigationScrollbars>
          </NavigationContainer>
        </SettingsContainer>
      </Layout>
    </BackAction>
  );
}

function PortSelector() {
  const relaySettings = useSelector((state) => state.settings.relaySettings);
  const relaySettingsUpdater = useRelaySettingsUpdater();
  const allowedPortRanges = useSelector((state) => state.settings.wireguardEndpointData.portRanges);

  const wireguardPortItems = useMemo<Array<SelectorItem<number>>>(
    () => WIREUGARD_UDP_PORTS.map(mapPortToSelectorItem),
    [],
  );

  const port = useMemo(() => {
    const port = 'normal' in relaySettings ? relaySettings.normal.wireguard.port : 'any';
    return port === 'any' ? null : port;
  }, [relaySettings]);

  const setWireguardPort = useCallback(
    async (port: number | null) => {
      try {
        await relaySettingsUpdater((settings) => {
          settings.wireguardConstraints.port = wrapConstraint(port);
          return settings;
        });
      } catch (e) {
        const error = e as Error;
        log.error('Failed to update relay settings', error.message);
      }
    },
    [relaySettingsUpdater],
  );

  const parseValue = useCallback((port: string) => parseInt(port), []);

  const validateValue = useCallback(
    (value: number) => allowedPortRanges.some(([start, end]) => value >= start && value <= end),
    [allowedPortRanges],
  );

  const portRangesText = allowedPortRanges
    .map(([start, end]) => (start === end ? start : `${start}-${end}`))
    .join(', ');

  return (
    <AriaInputGroup>
      <StyledSelectorContainer>
        <SelectorWithCustomItem
          // TRANSLATORS: The title for the WireGuard port selector.
          title={messages.pgettext('wireguard-settings-view', 'Port')}
          items={wireguardPortItems}
          value={port}
          onSelect={setWireguardPort}
          inputPlaceholder={messages.pgettext('wireguard-settings-view', 'Port')}
          automaticValue={null}
          parseValue={parseValue}
          modifyValue={removeNonNumericCharacters}
          validateValue={validateValue}
          maxLength={5}
          details={
            <>
              <ModalMessage>
                {messages.pgettext(
                  'wireguard-settings-view',
                  'The automatic setting will randomly choose from the valid port ranges shown below.',
                )}
              </ModalMessage>
              <ModalMessage>
                {sprintf(
                  messages.pgettext(
                    'wireguard-settings-view',
                    'The custom port can be any value inside the valid ranges: %(portRanges)s.',
                  ),
                  { portRanges: portRangesText },
                )}
              </ModalMessage>
            </>
          }
        />
      </StyledSelectorContainer>
    </AriaInputGroup>
  );
}

function ObfuscationSettings() {
  const { setObfuscationSettings } = useAppContext();
  const obfuscationSettings = useSelector((state) => state.settings.obfuscationSettings);

  const obfuscationType = obfuscationSettings.selectedObfuscation;
  const obfuscationTypeItems: SelectorItem<ObfuscationType>[] = useMemo(
    () => [
      {
        label: messages.pgettext('wireguard-settings-view', 'On (UDP-over-TCP)'),
        value: ObfuscationType.udp2tcp,
      },
      {
        label: messages.gettext('Off'),
        value: ObfuscationType.off,
      },
    ],
    [],
  );

  const selectObfuscationType = useCallback(
    async (value: ObfuscationType) => {
      await setObfuscationSettings({
        ...obfuscationSettings,
        selectedObfuscation: value,
      });
    },
    [setObfuscationSettings, obfuscationSettings],
  );

  return (
    <AriaInputGroup>
      <StyledSelectorContainer>
        <Selector
          // TRANSLATORS: The title for the WireGuard obfuscation selector.
          title={messages.pgettext('wireguard-settings-view', 'Obfuscation')}
          details={
            <ModalMessage>
              {messages.pgettext(
                'wireguard-settings-view',
                'Obfuscation hides the WireGuard traffic inside another protocol. It can be used to help circumvent censorship and other types of filtering, where a plain WireGuard connect would be blocked.',
              )}
            </ModalMessage>
          }
          items={obfuscationTypeItems}
          value={obfuscationType}
          onSelect={selectObfuscationType}
          automaticValue={ObfuscationType.auto}
        />
      </StyledSelectorContainer>
    </AriaInputGroup>
  );
}

function Udp2tcpPortSetting() {
  const { setObfuscationSettings } = useAppContext();
  const obfuscationSettings = useSelector((state) => state.settings.obfuscationSettings);

  const port = liftConstraint(obfuscationSettings.udp2tcpSettings.port);
  const portItems: SelectorItem<number>[] = useMemo(
    () => UDP2TCP_PORTS.map(mapPortToSelectorItem),
    [],
  );

  const expandableProps = useMemo(() => ({ expandable: true, id: 'udp2tcp-port' }), []);

  const selectPort = useCallback(
    async (port: LiftedConstraint<number>) => {
      await setObfuscationSettings({
        ...obfuscationSettings,
        udp2tcpSettings: {
          ...obfuscationSettings.udp2tcpSettings,
          port: wrapConstraint(port),
        },
      });
    },
    [setObfuscationSettings, obfuscationSettings],
  );

  return (
    <AriaInputGroup>
      <StyledSelectorContainer>
        <Selector
          // TRANSLATORS: The title for the UDP-over-TCP port selector.
          title={messages.pgettext('wireguard-settings-view', 'UDP-over-TCP port')}
          details={
            <ModalMessage>
              {messages.pgettext(
                'wireguard-settings-view',
                'Which TCP port the UDP-over-TCP obfuscation protocol should connect to on the VPN server.',
              )}
            </ModalMessage>
          }
          items={portItems}
          value={port}
          onSelect={selectPort}
          disabled={obfuscationSettings.selectedObfuscation === ObfuscationType.off}
          expandable={expandableProps}
          thinTitle
          automaticValue={'any' as const}
        />
      </StyledSelectorContainer>
    </AriaInputGroup>
  );
}

function MultihopSetting() {
  const relaySettings = useSelector((state) => state.settings.relaySettings);
  const relaySettingsUpdater = useRelaySettingsUpdater();

  const multihop = 'normal' in relaySettings ? relaySettings.normal.wireguard.useMultihop : false;

  const [confirmationDialogVisible, showConfirmationDialog, hideConfirmationDialog] = useBoolean();

  const setMultihopImpl = useCallback(
    async (enabled: boolean) => {
      try {
        await relaySettingsUpdater((settings) => {
          settings.wireguardConstraints.useMultihop = enabled;
          return settings;
        });
      } catch (e) {
        const error = e as Error;
        log.error('Failed to update WireGuard multihop settings', error.message);
      }
    },
    [relaySettingsUpdater],
  );

  const setMultihop = useCallback(
    async (newValue: boolean) => {
      if (newValue) {
        showConfirmationDialog();
      } else {
        await setMultihopImpl(false);
      }
    },
    [setMultihopImpl],
  );

  const confirmMultihop = useCallback(async () => {
    await setMultihopImpl(true);
    hideConfirmationDialog();
  }, [setMultihopImpl]);

  return (
    <>
      <AriaInputGroup>
        <Cell.Container>
          <AriaLabel>
            <Cell.InputLabel>
              {
                // TRANSLATORS: The label next to the multihop settings toggle.
                messages.pgettext('vpn-settings-view', 'Enable multihop')
              }
            </Cell.InputLabel>
          </AriaLabel>
          <AriaInput>
            <Cell.Switch isOn={multihop} onChange={setMultihop} />
          </AriaInput>
        </Cell.Container>
        <Cell.CellFooter>
          <AriaDescription>
            <Cell.CellFooterText>
              {sprintf(
                // TRANSLATORS: Description for multihop settings toggle.
                // TRANSLATORS: Available placeholders:
                // TRANSLATORS: %(wireguard)s - Will be replaced with the string "WireGuard"
                messages.pgettext(
                  'vpn-settings-view',
                  'Increases anonymity by routing your traffic into one %(wireguard)s server and out another, making it harder to trace.',
                ),
                { wireguard: strings.wireguard },
              )}
            </Cell.CellFooterText>
          </AriaDescription>
        </Cell.CellFooter>
      </AriaInputGroup>
      <ModalAlert
        isOpen={confirmationDialogVisible}
        type={ModalAlertType.caution}
        message={
          // TRANSLATORS: Warning text in a dialog that is displayed after a setting is toggled.
          messages.gettext('This setting increases latency. Use only if needed.')
        }
        buttons={[
          <AppButton.RedButton key="confirm" onClick={confirmMultihop}>
            {messages.gettext('Enable anyway')}
          </AppButton.RedButton>,
          <AppButton.BlueButton key="back" onClick={hideConfirmationDialog}>
            {messages.gettext('Back')}
          </AppButton.BlueButton>,
        ]}
        close={hideConfirmationDialog}
      />
    </>
  );
}

function IpVersionSetting() {
  const relaySettingsUpdater = useRelaySettingsUpdater();
  const relaySettings = useSelector((state) => state.settings.relaySettings);
  const ipVersion = useMemo(() => {
    const ipVersion = 'normal' in relaySettings ? relaySettings.normal.wireguard.ipVersion : 'any';
    return ipVersion === 'any' ? null : ipVersion;
  }, [relaySettings]);

  const ipVersionItems: SelectorItem<IpVersion>[] = useMemo(
    () => [
      {
        label: messages.gettext('IPv4'),
        value: 'ipv4',
      },
      {
        label: messages.gettext('IPv6'),
        value: 'ipv6',
      },
    ],
    [],
  );

  const setIpVersion = useCallback(
    async (ipVersion: IpVersion | null) => {
      try {
        await relaySettingsUpdater((settings) => {
          settings.wireguardConstraints.ipVersion = wrapConstraint(ipVersion);
          return settings;
        });
      } catch (e) {
        const error = e as Error;
        log.error('Failed to update relay settings', error.message);
      }
    },
    [relaySettingsUpdater],
  );

  return (
    <AriaInputGroup>
      <StyledSelectorContainer>
        <Selector
          // TRANSLATORS: The title for the WireGuard IP version selector.
          title={messages.pgettext('wireguard-settings-view', 'IP version')}
          items={ipVersionItems}
          value={ipVersion}
          onSelect={setIpVersion}
          automaticValue={null}
        />
      </StyledSelectorContainer>
      <Cell.CellFooter>
        <AriaDescription>
          <Cell.CellFooterText>
            {sprintf(
              // TRANSLATORS: The hint displayed below the WireGuard IP version selector.
              // TRANSLATORS: Available placeholders:
              // TRANSLATORS: %(wireguard)s - Will be replaced with the string "WireGuard"
              messages.pgettext(
                'wireguard-settings-view',
                'This allows access to %(wireguard)s for devices that only support IPv6.',
              ),
              { wireguard: strings.wireguard },
            )}
          </Cell.CellFooterText>
        </AriaDescription>
      </Cell.CellFooter>
    </AriaInputGroup>
  );
}

function mtuIsValid(mtu: string): boolean {
  const parsedMtu = mtu ? parseInt(mtu) : undefined;
  return (
    parsedMtu === undefined ||
    (parsedMtu >= MIN_WIREGUARD_MTU_VALUE && parsedMtu <= MAX_WIREGUARD_MTU_VALUE)
  );
}

function MtuSetting() {
  const { setWireguardMtu: setWireguardMtuImpl } = useAppContext();
  const mtu = useSelector((state) => state.settings.wireguard.mtu);

  const setMtu = useCallback(
    async (mtu?: number) => {
      try {
        await setWireguardMtuImpl(mtu);
      } catch (e) {
        const error = e as Error;
        log.error('Failed to update mtu value', error.message);
      }
    },
    [setWireguardMtuImpl],
  );

  const onSubmit = useCallback(
    async (value: string) => {
      const parsedValue = value === '' ? undefined : parseInt(value, 10);
      if (mtuIsValid(value)) {
        await setMtu(parsedValue);
      }
    },
    [setMtu],
  );

  return (
    <AriaInputGroup>
      <Cell.Container>
        <AriaLabel>
          <Cell.InputLabel>{messages.pgettext('wireguard-settings-view', 'MTU')}</Cell.InputLabel>
        </AriaLabel>
        <AriaInput>
          <Cell.AutoSizingTextInput
            initialValue={mtu ? mtu.toString() : ''}
            inputMode={'numeric'}
            maxLength={4}
            placeholder={messages.gettext('Default')}
            onSubmitValue={onSubmit}
            validateValue={mtuIsValid}
            submitOnBlur={true}
            modifyValue={removeNonNumericCharacters}
          />
        </AriaInput>
      </Cell.Container>
      <Cell.CellFooter>
        <AriaDescription>
          <Cell.CellFooterText>
            {sprintf(
              // TRANSLATORS: The hint displayed below the WireGuard MTU input field.
              // TRANSLATORS: Available placeholders:
              // TRANSLATORS: %(wireguard)s - Will be replaced with the string "WireGuard"
              // TRANSLATORS: %(max)d - the maximum possible wireguard mtu value
              // TRANSLATORS: %(min)d - the minimum possible wireguard mtu value
              messages.pgettext(
                'wireguard-settings-view',
                'Set %(wireguard)s MTU value. Valid range: %(min)d - %(max)d.',
              ),
              {
                wireguard: strings.wireguard,
                min: MIN_WIREGUARD_MTU_VALUE,
                max: MAX_WIREGUARD_MTU_VALUE,
              },
            )}
          </Cell.CellFooterText>
        </AriaDescription>
      </Cell.CellFooter>
    </AriaInputGroup>
  );
}

function DaitaSettings() {
  const { setDaitaSettings } = useAppContext();
  const daita = useSelector((state) => state.settings.wireguard.daita?.enabled ?? false);

  const [confirmationDialogVisible, showConfirmationDialog, hideConfirmationDialog] = useBoolean();

  const setDaita = useCallback((value: boolean) => {
    if (value) {
      showConfirmationDialog();
    } else {
      void setDaitaSettings({ enabled: value });
    }
  }, []);

  const confirmDaita = useCallback(() => {
    void setDaitaSettings({ enabled: true });
    hideConfirmationDialog();
  }, []);

  return (
    <>
      <AriaInputGroup>
        <Cell.Container>
          <AriaLabel>
            <Cell.InputLabel>{strings.daita}</Cell.InputLabel>
          </AriaLabel>
          <InfoButton>
            <ModalMessage>
              {sprintf(
                messages.pgettext(
                  'wireguard-settings-view',
                  '%(daita)s (%(daitaFull)s) hides patterns in your encrypted VPN traffic. If anyone is monitoring your connection, this makes it significantly harder for them to identify what websites you are visiting. It does this by carefully adding network noise and making all network packets the same size.',
                ),
                { daita: strings.daita, daitaFull: strings.daitaFull },
              )}
            </ModalMessage>
            <ModalMessage>
              {sprintf(
                messages.pgettext(
                  'wireguard-settings-view',
                  'Attention: Since this increases your total network traffic, be cautious if you have a limited data plan. It can also negatively impact your network speed. Please consider this if you want to enable %(daita)s.',
                ),
                { daita: strings.daita },
              )}
            </ModalMessage>
          </InfoButton>
          <AriaInput>
            <Cell.Switch isOn={daita} onChange={setDaita} />
          </AriaInput>
        </Cell.Container>
      </AriaInputGroup>
      <ModalAlert
        isOpen={confirmationDialogVisible}
        type={ModalAlertType.caution}
        buttons={[
          <AppButton.BlueButton key="confirm" onClick={confirmDaita}>
            {messages.gettext('Enable anyway')}
          </AppButton.BlueButton>,
          <AppButton.BlueButton key="back" onClick={hideConfirmationDialog}>
            {messages.gettext('Back')}
          </AppButton.BlueButton>,
        ]}
        close={hideConfirmationDialog}>
        <ModalMessage>
          {
            // TRANSLATORS: Warning text in a dialog that is displayed after a setting is toggled.
            messages.pgettext(
              'wireguard-settings-view',
              "This feature isn't available on all servers. You might need to change location after enabling.",
            )
          }
        </ModalMessage>
        <ModalMessage>
          {sprintf(
            messages.pgettext(
              'wireguard-settings-view',
              'Attention: Since this increases your total network traffic, be cautious if you have a limited data plan. It can also negatively impact your network speed. Please consider this if you want to enable %(daita)s.',
            ),
            { daita: strings.daita },
          )}
        </ModalMessage>
      </ModalAlert>
    </>
  );
}

function QuantumResistantSetting() {
  const { setWireguardQuantumResistant } = useAppContext();
  const quantumResistant = useSelector((state) => state.settings.wireguard.quantumResistant);

  const items: SelectorItem<boolean>[] = useMemo(
    () => [
      {
        label: messages.gettext('On'),
        value: true,
      },
      {
        label: messages.gettext('Off'),
        value: false,
      },
    ],
    [],
  );

  const selectQuantumResistant = useCallback(
    async (quantumResistant: boolean | null) => {
      await setWireguardQuantumResistant(quantumResistant ?? undefined);
    },
    [setWireguardQuantumResistant],
  );

  return (
    <AriaInputGroup>
      <StyledSelectorContainer>
        <Selector
          title={
            // TRANSLATORS: The title for the WireGuard quantum resistance selector. This setting
            // TRANSLATORS: makes the cryptography resistant to the future abilities of quantum
            // TRANSLATORS: computers.
            messages.pgettext('wireguard-settings-view', 'Quantum-resistant tunnel')
          }
          details={
            <>
              <ModalMessage>
                {messages.pgettext(
                  'wireguard-settings-view',
                  'This feature makes the WireGuard tunnel resistant to potential attacks from quantum computers.',
                )}
              </ModalMessage>
              <ModalMessage>
                {messages.pgettext(
                  'wireguard-settings-view',
                  'It does this by performing an extra key exchange using a quantum safe algorithm and mixing the result into WireGuard’s regular encryption. This extra step uses approximately 500 kiB of traffic every time a new tunnel is established.',
                )}
              </ModalMessage>
            </>
          }
          items={items}
          value={quantumResistant ?? null}
          onSelect={selectQuantumResistant}
          automaticValue={null}
        />
      </StyledSelectorContainer>
    </AriaInputGroup>
  );
}