import ChevronLeftIcon from '@mui/icons-material/ChevronLeft';
import ChevronRightIcon from '@mui/icons-material/ChevronRight';
import ErrorOutlineIcon from '@mui/icons-material/ErrorOutlineOutlined';
import { Button, IconButton, ListSubheader, Menu, MenuItem, Stack } from '@mui/material';
import { memo, useEffect, useMemo, useState } from 'react';
import { groupValidationErrors } from '../utils/validationUtils';

// AURORA-1893: «более выделенный формат контроля за ошибками» — красная плашка
// вместо прежней бледно-оранжевой.
const errorColors = {
	bg: '#FDEDED',
	text: '#D32F2F',
	border: '#D32F2F',
	hover: '#FBD5D5',
};

const stepButtonSx = {
	color: errorColors.text,
	border: `1px solid ${errorColors.border}`,
	borderRadius: '0.5rem',
	'&:hover': { bgcolor: errorColors.hover },
	'&.Mui-disabled': { color: errorColors.border, border: `1px solid ${errorColors.border}`, opacity: 0.5 },
};

// Внутри одной группы (правило + колонка) показываем не больше 20 строк,
// остальные — свёрнутой строкой «и ещё N».
const MAX_VISIBLE_CELLS_PER_GROUP = 20;

const getColumnTitle = (headerPaths, columnId) => headerPaths?.[columnId]?.filter(Boolean).join(' / ') || columnId;

const ValidationErrorsAlert = ({ errors = [], onNavigateToError, headerPaths }) => {
	const [anchorEl, setAnchorEl] = useState(null);
	const [activeIndex, setActiveIndex] = useState(0);
	const isOpen = Boolean(anchorEl);

	const groups = useMemo(() => groupValidationErrors(errors), [errors]);

	useEffect(() => {
		if (errors.length === 0) {
			setAnchorEl(null);
			setActiveIndex(0);
			return;
		}
		if (activeIndex >= errors.length) {
			setActiveIndex(0);
		}
	}, [errors, activeIndex]);

	if (errors.length === 0) return null;

	const navigateToIndex = (index) => {
		const error = errors[index];
		if (!error) return;
		setActiveIndex(index);
		onNavigateToError?.({ rowKey: error.rowKey, columnId: error.columnId });
	};

	const handleStep = (direction) => {
		const nextIndex = (activeIndex + direction + errors.length) % errors.length;
		navigateToIndex(nextIndex);
	};

	const handleSelectCell = (cell) => {
		const index = errors.findIndex((candidate) => candidate.id === cell.id);
		navigateToIndex(index < 0 ? 0 : index);
		setAnchorEl(null);
	};

	return (
		<>
			<Stack direction='row' sx={{ alignItems: 'center', gap: 0.5 }}>
				<IconButton size='small' onClick={() => handleStep(-1)} aria-label='Предыдущая ошибка' sx={stepButtonSx}>
					<ChevronLeftIcon fontSize='small' />
				</IconButton>

				<Button
					variant='outlined'
					onClick={(e) => setAnchorEl(e.currentTarget)}
					sx={{
						maxWidth: 360,
						height: '2.5rem',
						borderRadius: '0.5rem',
						bgcolor: errorColors.bg,
						color: errorColors.text,
						borderColor: errorColors.border,
						textTransform: 'none',
						fontWeight: 600,
						justifyContent: 'flex-start',
						px: 1.5,
						gap: 1,
						'&:hover': {
							bgcolor: errorColors.hover,
							borderColor: errorColors.border,
						},
					}}>
					<ErrorOutlineIcon sx={{ fontSize: '1.1rem', flexShrink: 0 }} />
					<span
						style={{
							overflow: 'hidden',
							textOverflow: 'ellipsis',
							whiteSpace: 'nowrap',
							textAlign: 'left',
						}}>
						Ошибок: {errors.length}
					</span>
				</Button>

				<IconButton size='small' onClick={() => handleStep(1)} aria-label='Следующая ошибка' sx={stepButtonSx}>
					<ChevronRightIcon fontSize='small' />
				</IconButton>
			</Stack>

			<Menu
				anchorEl={anchorEl}
				open={isOpen}
				onClose={() => setAnchorEl(null)}
				anchorOrigin={{ vertical: 'bottom', horizontal: 'left' }}
				transformOrigin={{ vertical: 'top', horizontal: 'left' }}
				slotProps={{
					paper: {
						'data-validation-errors-menu': true,
						sx: {
							mt: 0.5,
							bgcolor: errorColors.bg,
							color: errorColors.text,
							border: `1px solid ${errorColors.border}`,
							borderRadius: '0.5rem',
							boxShadow: 'none',
							minWidth: anchorEl?.offsetWidth,
							maxWidth: 420,
							maxHeight: 420,
						},
					},
				}}>
				{groups.flatMap((group) => {
					const columnTitle = getColumnTitle(headerPaths, group.columnId);
					const visibleCells = group.cells.slice(0, MAX_VISIBLE_CELLS_PER_GROUP);
					const hiddenCount = group.count - visibleCells.length;

					return [
						<ListSubheader
							key={`${group.id}-header`}
							sx={{
								bgcolor: 'inherit',
								color: errorColors.text,
								fontWeight: 600,
								lineHeight: 1.3,
								whiteSpace: 'normal',
								py: 0.5,
							}}>
							{group.message} · {columnTitle} ({group.count})
						</ListSubheader>,
						...visibleCells.map((cell) => (
							<MenuItem
								key={cell.id}
								selected={errors[activeIndex]?.id === cell.id}
								onClick={() => handleSelectCell(cell)}
								sx={{
									whiteSpace: 'normal',
									color: errorColors.text,
									cursor: 'pointer',
									pl: 3,
									'&:hover': {
										bgcolor: errorColors.hover,
									},
								}}>
								{cell.rowLabel}
							</MenuItem>
						)),
						...(hiddenCount > 0
							? [
									<MenuItem key={`${group.id}-more`} disabled sx={{ pl: 3, color: errorColors.text, opacity: 0.7 }}>
										и ещё {hiddenCount}
									</MenuItem>,
								]
							: []),
					];
				})}
			</Menu>
		</>
	);
};

export default memo(ValidationErrorsAlert);