import React, { PureComponent } from 'react';
import Box from '@mui/material/Box';
import Fab from '@mui/material/Fab';
import Badge from '@mui/material/Badge';
import Tooltip from '@mui/material/Tooltip';
import CircularProgress from '@mui/material/CircularProgress';
import ChatRoundedIcon from '@mui/icons-material/ChatRounded';
import CloseRoundedIcon from '@mui/icons-material/CloseRounded';
import AutoAwesomeRoundedIcon from '@mui/icons-material/AutoAwesomeRounded';
import HelpOutlineRoundedIcon from '@mui/icons-material/HelpOutlineRounded';

import chatAutomat, { selectPendingAskUser, selectHasPendingAsk } from '../../automats/chatAutomat';
import {
  CHAT_BUSY,
  CHAT_FAB_BUSY,
  CHAT_FAB_PENDING,  CHAT_FAB_SHADOW_BUSY,
  CHAT_FAB_SHADOW_IDLE,
  CHAT_FAB_SHADOW_PENDING,  RED,
  RED_GLOW,
  WHITE,
} from '../../colors';

export default class ChatFab extends PureComponent {
  constructor(props) {
    super(props);
    const s = chatAutomat.state;
    this.state = {
      isOpen: s.isOpen,
      conversationState: s.conversationState,
      streamPhase: s.streamPhase,
      isSending: s.isSending,
      hasPendingAsk: selectHasPendingAsk(s),
      pendingAsk: selectPendingAskUser(s),
      sseStatus: s.sseStatus,
    };
  }

  componentDidMount() {
    this.unsub = chatAutomat.subscribe(this, (state) => ({
      isOpen: state.isOpen,
      conversationState: state.conversationState,
      streamPhase: state.streamPhase,
      isSending: state.isSending,
      hasPendingAsk: selectHasPendingAsk(state),
      pendingAsk: selectPendingAskUser(state),
      sseStatus: state.sseStatus,
    }));
  }

  componentWillUnmount() {
    this.unsub?.();
  }

  handleClick = () => {
    chatAutomat.actions.toggleChat();
  };

  render() {
    const { isOpen, conversationState, streamPhase, isSending, hasPendingAsk, pendingAsk } = this.state;
    const isBusy = conversationState === 'busy' || streamPhase === 'thinking' || streamPhase === 'working' || isSending;

    let tooltipTitle = 'KI-Chat öffnen';
    let ariaLabel = 'KI-Chat';
    if (isOpen) {
      tooltipTitle = 'KI-Chat schließen';
      ariaLabel = 'KI-Chat schließen';
    } else if (hasPendingAsk) {
      tooltipTitle = pendingAsk?.question
        ? `Antwort erforderlich: „${pendingAsk.question}“`
        : 'Antwort erforderlich: Das Modell wartet auf Ihre Eingabe';
      ariaLabel = 'KI-Chat: Antwort erforderlich';
    } else if (isBusy) {
      tooltipTitle = 'Modell antwortet gerade…';
      ariaLabel = 'KI-Chat: Modell antwortet';
    }

    return (
      <Box
        sx={(theme) => ({
          position: 'fixed',
          bottom: { xs: 20, sm: 28 },
          left: { xs: 20, sm: 164 },
          zIndex: theme.zIndex.speedDial || 1050,
        })}
      >
        <Box sx={{ position: 'relative' }}>
          {/* Animated pulsing halo when awaiting user answer */}
          {hasPendingAsk && !isOpen && (
            <Box
              sx={{
                position: 'absolute',
                top: -8,
                left: -8,
                right: -8,
                bottom: -8,
                borderRadius: '50%',
                bgcolor: CHAT_BUSY,
                opacity: 0.5,
                animation: 'fabAskPulse 1.5s cubic-bezier(0.4, 0, 0.6, 1) infinite',
                '@keyframes fabAskPulse': {
                  '0%': { transform: 'scale(0.95)', opacity: 0.8 },
                  '50%': { transform: 'scale(1.35)', opacity: 0.12 },
                  '100%': { transform: 'scale(0.95)', opacity: 0.8 },
                },
              }}
            />
          )}

          {/* Animated pulsating halo when model is busy thinking/working */}
          {!hasPendingAsk && isBusy && !isOpen && (
            <Box
              sx={{
                position: 'absolute',
                top: -6,
                left: -6,
                right: -6,
                bottom: -6,
                borderRadius: '50%',
                bgcolor: 'warning.main',
                opacity: 0.4,
                animation: 'fabPulse 1.6s cubic-bezier(0.4, 0, 0.6, 1) infinite',
                '@keyframes fabPulse': {
                  '0%': { transform: 'scale(0.95)', opacity: 0.7 },
                  '50%': { transform: 'scale(1.25)', opacity: 0.15 },
                  '100%': { transform: 'scale(0.95)', opacity: 0.7 },
                },
              }}
            />
          )}

          {/* Circular spinner ring when model is busy */}
          {!hasPendingAsk && isBusy && !isOpen && (
            <CircularProgress
              size={66}
              thickness={2.5}
              sx={{
                position: 'absolute',
                top: -6,
                left: -6,
                color: CHAT_BUSY,
                pointerEvents: 'none',
              }}
            />
          )}

          <Tooltip title={tooltipTitle} placement="right" arrow>
            <Badge
              badgeContent={hasPendingAsk ? '?' : undefined}
              color={hasPendingAsk ? 'error' : isBusy ? 'warning' : 'default'}
              variant={hasPendingAsk ? 'standard' : 'dot'}
              invisible={!hasPendingAsk && !isBusy}
              overlap="circular"
              anchorOrigin={{ vertical: 'top', horizontal: 'right' }}
              sx={{
                '& .MuiBadge-badge': hasPendingAsk
                  ? {
                      bgcolor: RED,
                      color: WHITE,
                      fontWeight: 900,
                      fontSize: '0.85rem',
                      minWidth: 22,
                      height: 22,
                      borderRadius: '50%',
                      boxShadow: `0 2px 10px ${RED_GLOW}`,
                      animation: 'badgePop 1.5s ease infinite',
                      '@keyframes badgePop': {
                        '0%, 100%': { transform: 'scale(1)' },
                        '50%': { transform: 'scale(1.2)' },
                      },
                    }
                  : undefined,
              }}
            >
              <Fab
                color="primary"
                aria-label={ariaLabel}
                onClick={this.handleClick}
                sx={(theme) => ({
                  width: 54,
                  height: 54,
                  boxShadow: hasPendingAsk
                    ? CHAT_FAB_SHADOW_PENDING
                    : isBusy
                    ? CHAT_FAB_SHADOW_BUSY
                    : CHAT_FAB_SHADOW_IDLE,
                  background: hasPendingAsk
                    ? CHAT_FAB_PENDING
                    : isBusy
                    ? CHAT_FAB_BUSY
                    : `linear-gradient(135deg, ${theme.palette.primary.main} 0%, ${theme.palette.primary.dark} 100%)`,
                })}
              >
                {isOpen ? (
                  <CloseRoundedIcon sx={{ fontSize: 24 }} />
                ) : hasPendingAsk ? (
                  <HelpOutlineRoundedIcon
                    sx={{
                      fontSize: 26,
                      animation: 'fabWiggle 2s ease infinite',
                      '@keyframes fabWiggle': {
                        '0%, 100%': { transform: 'rotate(0deg)' },
                        '15%': { transform: 'rotate(-12deg)' },
                        '30%': { transform: 'rotate(12deg)' },
                        '45%': { transform: 'rotate(-8deg)' },
                        '60%': { transform: 'rotate(0deg)' },
                      },
                    }}
                  />
                ) : isBusy ? (
                  <AutoAwesomeRoundedIcon sx={{ fontSize: 24 }} />
                ) : (
                  <ChatRoundedIcon sx={{ fontSize: 24 }} />
                )}
              </Fab>
            </Badge>
          </Tooltip>
        </Box>
      </Box>
    );
  }
}