import React, { ReactNode, useEffect, useRef, useState } from 'react';
import { Box, Chip, Icon, IconButton, Icons, Text, color, config, toRem } from 'folds';
import { UploadCard, UploadCardError, UploadCardProgress } from './UploadCard';
import { UploadStatus, UploadSuccess, useBindUploadAtom } from '../../state/upload';
import { useMatrixClient } from '../../hooks/useMatrixClient';
import { TUploadContent } from '../../utils/matrix';
import { bytesToSize, getFileTypeIcon } from '../../utils/common';
import {
  roomUploadAtomFamily,
  TUploadItem,
  TUploadMetadata,
} from '../../state/room/roomInputDrafts';
import { useObjectURL } from '../../hooks/useObjectURL';
import { useMediaConfig } from '../../hooks/useMediaConfig';
import { compressImage, formatFileSize, isCompressible } from '../../utils/imageCompression';
import { tryDeleteMxcContent } from '../../utils/matrix';

type PreviewImageProps = {
  fileItem: TUploadItem;
};
function PreviewImage({ fileItem }: PreviewImageProps) {
  const { originalFile, metadata } = fileItem;
  const fileUrl = useObjectURL(originalFile);

  return (
    <img
      style={{
        objectFit: 'contain',
        width: '100%',
        height: toRem(152),
        filter: metadata.markedAsSpoiler ? 'blur(44px)' : undefined,
      }}
      alt={(originalFile as File).name}
      src={fileUrl}
    />
  );
}

type PreviewVideoProps = {
  fileItem: TUploadItem;
};
function PreviewVideo({ fileItem }: PreviewVideoProps) {
  const { originalFile, metadata } = fileItem;
  const fileUrl = useObjectURL(originalFile);

  return (
    <video
      style={{
        objectFit: 'contain',
        width: '100%',
        height: toRem(152),
        filter: metadata.markedAsSpoiler ? 'blur(44px)' : undefined,
      }}
      src={fileUrl}
    />
  );
}

type MediaPreviewProps = {
  fileItem: TUploadItem;
  onSpoiler: (marked: boolean) => void;
  children: ReactNode;
};
function MediaPreview({ fileItem, onSpoiler, children }: MediaPreviewProps) {
  const { originalFile, metadata } = fileItem;
  const fileUrl = useObjectURL(originalFile);

  return fileUrl ? (
    <Box
      style={{
        borderRadius: config.radii.R300,
        overflow: 'hidden',
        backgroundColor: 'black',
        position: 'relative',
      }}
    >
      {children}
      <Box
        justifyContent="End"
        style={{
          position: 'absolute',
          bottom: config.space.S100,
          left: config.space.S100,
          right: config.space.S100,
        }}
      >
        <Chip
          variant={metadata.markedAsSpoiler ? 'Warning' : 'Secondary'}
          fill="Soft"
          radii="Pill"
          aria-pressed={metadata.markedAsSpoiler}
          before={<Icon src={Icons.EyeBlind} size="50" />}
          onClick={() => onSpoiler(!metadata.markedAsSpoiler)}
        >
          <Text size="B300">Spoiler</Text>
        </Chip>
      </Box>
    </Box>
  ) : null;
}

type CompressionCheckboxProps = {
  fileItem: TUploadItem;
  metadata: TUploadMetadata;
  setMetadata: (fileItem: TUploadItem, metadata: TUploadMetadata) => void;
};
function CompressionCheckbox({ fileItem, metadata, setMetadata }: CompressionCheckboxProps) {
  const originalFile = fileItem.originalFile as File;
  const [compressing, setCompressing] = useState(false);
  const compressPromiseRef = useRef<Promise<void> | null>(null);

  if (!isCompressible(originalFile)) return null;

  const handleChange = async (e: React.ChangeEvent<HTMLInputElement>) => {
    const checked = e.target.checked;
    if (!checked) {
      setMetadata(fileItem, { ...metadata, compressImage: false, compressionResult: undefined });
      return;
    }

    setMetadata(fileItem, { ...metadata, compressImage: true, compressionResult: undefined });
    setCompressing(true);

    const p = compressImage(originalFile).then((result) => {
      setCompressing(false);
      setMetadata(fileItem, { ...metadata, compressImage: true, compressionResult: result });
    });
    compressPromiseRef.current = p;
  };

  const checked = !!metadata.compressImage;
  const result = metadata.compressionResult;

  const savingPct =
    result && result.originalSize > 0
      ? Math.round(((result.originalSize - result.compressedSize) / result.originalSize) * 100)
      : null;

  const originalSize = formatFileSize(originalFile.size);

  return (
    <Box
      direction="Column"
      gap="200"
      style={{
        marginTop: config.space.S100,
        padding: `${config.space.S200} ${config.space.S300}`,
        background: color.SurfaceVariant.Container,
        borderRadius: config.radii.R300,
        border: `1px solid ${color.SurfaceVariant.ContainerLine}`,
      }}
    >
      {/* Checkbox row */}
      <Box alignItems="Center" gap="200">
        <input
          id={`compress-${originalFile.name}-${originalFile.size}`}
          type="checkbox"
          checked={checked}
          onChange={handleChange}
          style={{ cursor: 'pointer', flexShrink: 0 }}
        />
        <label
          htmlFor={`compress-${originalFile.name}-${originalFile.size}`}
          style={{
            cursor: 'pointer',
            color: color.SurfaceVariant.OnContainer,
            userSelect: 'none',
            fontSize: '0.8rem',
          }}
        >
          Compress before uploading
        </label>
        {compressing && (
          <Text size="T200" style={{ opacity: 0.6, marginLeft: 'auto' }}>
            compressing…
          </Text>
        )}
      </Box>

      {/* Before / after row — always show original; show compressed when ready */}
      <Box gap="200" alignItems="Center" wrap="Wrap">
        <Box
          gap="100"
          alignItems="Center"
          style={{
            padding: `2px ${config.space.S200}`,
            borderRadius: config.radii.R300,
            background: color.Surface.Container,
            border: `1px solid ${color.Surface.ContainerLine}`,
          }}
        >
          <Text size="T200" style={{ opacity: 0.6 }}>
            Original
          </Text>
          <Text size="T200" style={{ fontWeight: 600 }}>
            {originalSize}
          </Text>
        </Box>

        {checked && !compressing && result !== undefined && (
          <>
            <Text size="T200" style={{ opacity: 0.5 }}>
              →
            </Text>
            <Box
              gap="100"
              alignItems="Center"
              style={{
                padding: `2px ${config.space.S200}`,
                borderRadius: config.radii.R300,
                background:
                  savingPct !== null && savingPct > 5
                    ? (color.Success?.Container ?? color.Primary.Container)
                    : color.Surface.Container,
                border: `1px solid ${
                  savingPct !== null && savingPct > 5
                    ? (color.Success?.ContainerLine ?? color.Primary.ContainerLine)
                    : color.Surface.ContainerLine
                }`,
              }}
            >
              <Text size="T200" style={{ opacity: 0.6 }}>
                Compressed
              </Text>
              {result ? (
                <Text size="T200" style={{ fontWeight: 600 }}>
                  {formatFileSize(result.compressedSize)}
                  {savingPct !== null && savingPct > 0 && (
                    <span style={{ opacity: 0.7, marginLeft: 4 }}>({savingPct}% smaller)</span>
                  )}
                </Text>
              ) : (
                <Text size="T200" style={{ opacity: 0.6 }}>
                  unavailable
                </Text>
              )}
            </Box>
          </>
        )}
      </Box>
    </Box>
  );
}

type UploadCardRendererProps = {
  isEncrypted?: boolean;
  fileItem: TUploadItem;
  setMetadata: (fileItem: TUploadItem, metadata: TUploadMetadata) => void;
  onRemove: (file: TUploadContent) => void;
  onComplete?: (upload: UploadSuccess) => void;
};
export function UploadCardRenderer({
  isEncrypted,
  fileItem,
  setMetadata,
  onRemove,
  onComplete,
}: UploadCardRendererProps) {
  const mx = useMatrixClient();
  const mediaConfig = useMediaConfig();
  const allowSize = mediaConfig['m.upload.size'] || Infinity;

  const uploadAtom = roomUploadAtomFamily(fileItem.file);
  const { metadata } = fileItem;
  const { upload, startUpload, cancelUpload } = useBindUploadAtom(mx, uploadAtom, isEncrypted);
  const { file } = upload;
  const fileSizeExceeded = file.size >= allowSize;

  if (upload.status === UploadStatus.Idle && !fileSizeExceeded) {
    startUpload();
  }

  const handleSpoiler = (marked: boolean) => {
    setMetadata(fileItem, { ...metadata, markedAsSpoiler: marked });
  };

  const removeUpload = () => {
    if (upload.status === UploadStatus.Success) {
      // Upload already completed — delete the orphaned MXC from the server.
      tryDeleteMxcContent(mx, upload.mxc);
    }
    cancelUpload();
    onRemove(file);
  };

  useEffect(() => {
    if (upload.status === UploadStatus.Success) {
      onComplete?.(upload);
    }
  }, [upload, onComplete]);

  return (
    <UploadCard
      radii="300"
      before={<Icon src={getFileTypeIcon(Icons, file.type)} />}
      after={
        <>
          {upload.status === UploadStatus.Error && (
            <Chip
              as="button"
              onClick={startUpload}
              aria-label="Retry Upload"
              variant="Critical"
              radii="Pill"
              outlined
            >
              <Text size="B300">Retry</Text>
            </Chip>
          )}
          <IconButton
            onClick={removeUpload}
            aria-label="Cancel Upload"
            variant="SurfaceVariant"
            radii="Pill"
            size="300"
          >
            <Icon src={Icons.Cross} size="200" />
          </IconButton>
        </>
      }
      bottom={
        <>
          {fileItem.originalFile.type.startsWith('image') && (
            <MediaPreview fileItem={fileItem} onSpoiler={handleSpoiler}>
              <PreviewImage fileItem={fileItem} />
            </MediaPreview>
          )}
          {fileItem.originalFile.type.startsWith('video') && (
            <MediaPreview fileItem={fileItem} onSpoiler={handleSpoiler}>
              <PreviewVideo fileItem={fileItem} />
            </MediaPreview>
          )}
          {(fileItem.originalFile.type.startsWith('image') ||
            fileItem.originalFile.type.startsWith('video')) && (
            <input
              type="text"
              placeholder="Add a caption… (optional)"
              value={metadata.caption ?? ''}
              onChange={(e) => setMetadata(fileItem, { ...metadata, caption: e.target.value })}
              data-caption-input
              style={{
                marginTop: '6px',
                width: '100%',
                background: 'var(--bg-surface-low)',
                border: '1px solid var(--bg-surface-border)',
                borderRadius: '6px',
                padding: '5px 8px',
                fontSize: '0.85rem',
                color: 'var(--text-primary)',
                outline: 'none',
                boxSizing: 'border-box',
                transition: 'border-color 0.15s, box-shadow 0.15s',
              }}
            />
          )}
          <CompressionCheckbox fileItem={fileItem} metadata={metadata} setMetadata={setMetadata} />
          {upload.status === UploadStatus.Idle && !fileSizeExceeded && (
            <UploadCardProgress sentBytes={0} totalBytes={file.size} />
          )}
          {upload.status === UploadStatus.Loading && (
            <UploadCardProgress sentBytes={upload.progress.loaded} totalBytes={file.size} />
          )}
          {upload.status === UploadStatus.Error && (
            <UploadCardError>
              <Text size="T200">{upload.error.message}</Text>
            </UploadCardError>
          )}
          {upload.status === UploadStatus.Idle && fileSizeExceeded && (
            <UploadCardError>
              <Text size="T200">
                The file size exceeds the limit. Maximum allowed size is{' '}
                <b>{bytesToSize(allowSize)}</b>, but the uploaded file is{' '}
                <b>{bytesToSize(file.size)}</b>.
              </Text>
            </UploadCardError>
          )}
        </>
      }
    >
      <Text size="H6" truncate>
        {(file as File).name}
      </Text>
      {upload.status === UploadStatus.Success && (
        <Icon style={{ color: color.Success.Main }} src={Icons.Check} size="100" />
      )}
    </UploadCard>
  );
}