/**
 * @ai-summary Camera viewfinder with live preview and capture controls
 * @ai-context Displays video stream with guidance overlay and capture/cancel buttons
 */

import React, { useRef, useEffect } from 'react';
import { Box, IconButton, Typography } from '@mui/material';
import CameraAltIcon from '@mui/icons-material/CameraAlt';
import CloseIcon from '@mui/icons-material/Close';
import CameraswitchIcon from '@mui/icons-material/Cameraswitch';
import type { CameraViewfinderProps } from './types';
import { GuidanceOverlay } from './GuidanceOverlay';

export const CameraViewfinder: React.FC<CameraViewfinderProps> = ({
  stream,
  guidanceType,
  onCapture,
  onCancel,
  onSwitchCamera,
  canSwitchCamera,
  facingMode,
}) => {
  const videoRef = useRef<HTMLVideoElement>(null);

  // Attach stream to video element
  useEffect(() => {
    if (videoRef.current && stream) {
      videoRef.current.srcObject = stream;
    }

    return () => {
      if (videoRef.current) {
        videoRef.current.srcObject = null;
      }
    };
  }, [stream]);

  return (
    <Box
      sx={{
        position: 'relative',
        width: '100%',
        height: '100%',
        backgroundColor: 'black',
        display: 'flex',
        flexDirection: 'column',
        overflow: 'hidden',
      }}
    >
      {/* Video preview */}
      <Box
        sx={{
          flex: 1,
          position: 'relative',
          display: 'flex',
          alignItems: 'center',
          justifyContent: 'center',
          overflow: 'hidden',
        }}
      >
        <video
          ref={videoRef}
          autoPlay
          playsInline
          muted
          style={{
            width: '100%',
            height: '100%',
            objectFit: 'cover',
            // Mirror front camera for natural preview
            transform: facingMode === 'user' ? 'scaleX(-1)' : 'none',
          }}
        />

        {/* Guidance overlay */}
        <GuidanceOverlay type={guidanceType} />

        {/* Top bar with close and switch camera */}
        <Box
          sx={{
            position: 'absolute',
            top: 0,
            left: 0,
            right: 0,
            display: 'flex',
            justifyContent: 'space-between',
            alignItems: 'center',
            p: 2,
            background: 'linear-gradient(to bottom, rgba(0,0,0,0.5) 0%, transparent 100%)',
          }}
        >
          <IconButton
            onClick={onCancel}
            aria-label="Cancel capture"
            sx={{
              color: 'white',
              backgroundColor: 'rgba(0, 0, 0, 0.3)',
              '&:hover': {
                backgroundColor: 'rgba(0, 0, 0, 0.5)',
              },
            }}
          >
            <CloseIcon />
          </IconButton>

          {canSwitchCamera && (
            <IconButton
              onClick={onSwitchCamera}
              aria-label="Switch camera"
              sx={{
                color: 'white',
                backgroundColor: 'rgba(0, 0, 0, 0.3)',
                '&:hover': {
                  backgroundColor: 'rgba(0, 0, 0, 0.5)',
                },
              }}
            >
              <CameraswitchIcon />
            </IconButton>
          )}
        </Box>
      </Box>

      {/* Bottom controls */}
      <Box
        sx={{
          flexShrink: 0,
          display: 'flex',
          flexDirection: 'column',
          alignItems: 'center',
          gap: 1,
          py: 3,
          px: 2,
          background: 'linear-gradient(to top, rgba(0,0,0,0.8) 0%, rgba(0,0,0,0.5) 100%)',
        }}
      >
        {/* Capture button */}
        <IconButton
          onClick={onCapture}
          aria-label="Take photo"
          sx={{
            width: 72,
            height: 72,
            backgroundColor: 'white',
            border: '4px solid rgba(255, 255, 255, 0.5)',
            '&:hover': {
              backgroundColor: 'rgba(255, 255, 255, 0.9)',
            },
            '&:active': {
              transform: 'scale(0.95)',
              backgroundColor: 'rgba(255, 255, 255, 0.8)',
            },
            transition: 'transform 0.1s ease',
          }}
        >
          <CameraAltIcon
            sx={{
              fontSize: 32,
              color: 'black',
            }}
          />
        </IconButton>

        <Typography
          variant="caption"
          sx={{
            color: 'rgba(255, 255, 255, 0.7)',
            textAlign: 'center',
          }}
        >
          Tap to capture
        </Typography>
      </Box>
    </Box>
  );
};

export default CameraViewfinder;