import React, { useMemo } from 'react';
import { StyleSheet, Text, View } from 'react-native';

import { ChannelPreviewProps } from './ChannelPreview';

import { LastMessageType } from './hooks/useChannelPreviewData';

import { useChannelPreviewDraftMessage } from './hooks/useChannelPreviewDraftMessage';
import { useChannelPreviewPollLabel } from './hooks/useChannelPreviewPollLabel';

import { useChannelTypingState } from './hooks/useChannelTypingState';

import { useChatContext } from '../../contexts/chatContext/ChatContext';
import { useComponentsContext } from '../../contexts/componentsContext/ComponentsContext';
import { useTheme } from '../../contexts/themeContext/ThemeContext';
import { useTranslationContext } from '../../contexts/translationContext/TranslationContext';

import { PollIcon } from '../../icons/poll';
import { primitives } from '../../theme';
import { MessageStatusTypes } from '../../utils/utils';
import { ErrorBadge } from '../ui';

export type ChannelPreviewMessageProps = Pick<ChannelPreviewProps, 'channel'> & {
  lastMessage?: LastMessageType;
};

export const ChannelPreviewMessage = (props: ChannelPreviewMessageProps) => {
  const { channel, lastMessage } = props;
  const {
    ChannelPreviewTypingIndicator,
    ChannelPreviewMessageDeliveryStatus,
    ChannelPreviewLastMessage,
  } = useComponentsContext();
  const {
    theme: { semantics },
  } = useTheme();
  const isMessageDeleted = lastMessage?.type === 'deleted';
  const styles = useStyles({ isMessageDeleted });
  const { client } = useChatContext();
  const { t } = useTranslationContext();

  const { usersTyping } = useChannelTypingState({ channel });

  const draftMessage = useChannelPreviewDraftMessage({ channel });

  const pollLabel = useChannelPreviewPollLabel({ pollId: lastMessage?.poll_id ?? '' });

  const membersWithoutSelf = useMemo(() => {
    return Object.values(channel.state.members).filter(
      (member) => member.user?.id !== client.user?.id,
    );
  }, [channel.state.members, client.user?.id]);

  const isFailedMessage =
    lastMessage?.status === MessageStatusTypes.FAILED || lastMessage?.type === 'error';
  const showMessageDeliveryStatus = !isMessageDeleted;

  if (usersTyping.length > 0) {
    return <ChannelPreviewTypingIndicator channel={channel} usersTyping={usersTyping} />;
  }

  if (draftMessage) {
    return (
      <View style={styles.container}>
        <Text style={styles.draftText}>{t('Draft')}:</Text>
        <ChannelPreviewLastMessage message={draftMessage} />
      </View>
    );
  }

  // If there are no messages yet, show a message saying "No messages yet"
  if (!lastMessage) {
    return (
      <Text style={[styles.subtitle, { color: semantics.textTertiary }]}>
        {t('No messages yet')}
      </Text>
    );
  }

  if (pollLabel) {
    return (
      <View style={styles.container}>
        <PollIcon height={16} width={16} stroke={semantics.textSecondary} />
        <Text ellipsizeMode='tail' numberOfLines={1} style={styles.subtitle}>
          {pollLabel}
        </Text>
      </View>
    );
  }

  if (isFailedMessage) {
    return (
      <View style={styles.container}>
        <ErrorBadge size='xs' />
        <Text style={styles.errorText}>{t('Message failed to send')}</Text>
      </View>
    );
  }

  if (channel.data?.name || membersWithoutSelf.length > 1) {
    return (
      <View style={styles.container}>
        {showMessageDeliveryStatus ? (
          <ChannelPreviewMessageDeliveryStatus channel={channel} message={lastMessage} />
        ) : null}
        <ChannelPreviewLastMessage message={lastMessage} />
      </View>
    );
  } else {
    return (
      <View style={styles.container}>
        {showMessageDeliveryStatus ? (
          <ChannelPreviewMessageDeliveryStatus channel={channel} message={lastMessage} />
        ) : null}
        <ChannelPreviewLastMessage message={lastMessage} />
      </View>
    );
  }
};

const useStyles = ({ isMessageDeleted = false }: { isMessageDeleted?: boolean }) => {
  const {
    theme: {
      semantics,
      channelPreview: { message },
    },
  } = useTheme();

  return useMemo(() => {
    return StyleSheet.create({
      container: {
        flexDirection: 'row',
        alignItems: 'center',
        gap: primitives.spacingXxs,
        flexShrink: 1,
        ...message.container,
      },
      subtitle: {
        color: isMessageDeleted ? semantics.textTertiary : semantics.textSecondary,
        fontSize: primitives.typographyFontSizeSm,
        fontWeight: primitives.typographyFontWeightRegular,
        includeFontPadding: false,
        lineHeight: primitives.typographyLineHeightNormal,
        flexShrink: 1,
        ...message.subtitle,
      },
      draftText: {
        color: semantics.accentPrimary,
        fontSize: primitives.typographyFontSizeSm,
        fontWeight: primitives.typographyFontWeightSemiBold,
        lineHeight: primitives.typographyLineHeightNormal,
        includeFontPadding: false,
        ...message.draftText,
      },
      errorText: {
        color: semantics.accentError,
        fontSize: primitives.typographyFontSizeSm,
        fontWeight: primitives.typographyFontWeightRegular,
        includeFontPadding: false,
        lineHeight: primitives.typographyLineHeightNormal,
        ...message.errorText,
      },
    });
  }, [semantics, isMessageDeleted, message]);
};