import RefreshRoundedIcon from '@mui/icons-material/RefreshRounded';
import { Alert, Box, Button, Paper, Tab, Tabs, Typography } from '@mui/material';
import { MaterialReactTable, useMaterialReactTable } from 'material-react-table';
import { MRT_Localization_RU } from 'material-react-table/locales/ru';
import { useCallback, useEffect, useMemo, useRef, useState } from 'react';

import { HeaderSwitch } from '../../components/HeaderMenu/HeaderSwitch';
import { PrimaryButton } from '../../components/common/Buttons/Buttons';
import { useSvod } from '../SvodPage/SvodContext';
import { SvodFilters } from '../SvodPage/SvodFilters';

const SHEETS = [
	{ value: 'GO', label: 'ССП' },
	{ value: 'RF', label: 'РФ' },
];
const createInitialTableState = () =>
	Object.fromEntries(SHEETS.map(({ value }) => [value, { rows: [], loading: false, error: '', loadedQueryKey: '' }]));
const QUARTERS = [1, 2, 3, 4];
const tableSize = (rem) => rem * 16;
const numberFormatter = new Intl.NumberFormat('ru-RU', { maximumFractionDigits: 2 });
const ROW_HEIGHT = 37;
const ROW_VIRTUALIZER_OPTIONS = {
	overscan: 8,
	estimateSize: () => ROW_HEIGHT,
	measureElement: (element) => element?.offsetHeight || ROW_HEIGHT,
};
const COLUMN_BAND_COLORS = {
	head: ['#f8f9fa', '#f1f7f3'],
	body: ['#ffffff', '#f8fbf9'],
};

const valueAt = (row, path) => path.reduce((value, key) => value?.[key], row.data);

const formatValue = (value) => {
	if (value === null || value === undefined || value === '') return '—';
	const numericValue = typeof value === 'number' ? value : Number(value);
	return Number.isNaN(numericValue) ? value : numberFormatter.format(numericValue);
};

const textColumn = (id, header, path, size = 10, options = {}) => ({
	id,
	header,
	accessorFn: (row) => valueAt(row, path),
	Cell: ({ cell }) => cell.getValue() || '—',
	size: tableSize(size),
	enableColumnFilter: false,
	...options,
});

const numericColumn = (id, header, path, size = 7.5) => ({
	id,
	header,
	accessorFn: (row) => valueAt(row, path),
	Cell: ({ cell }) => formatValue(cell.getValue()),
	size: tableSize(size),
	enableColumnFilter: false,
	muiTableBodyCellProps: { align: 'right' },
	muiTableHeadCellProps: { align: 'right' },
});

const MONTHS_BY_QUARTER = {
	1: ['Январь', 'Февраль', 'Март'],
	2: ['Апрель', 'Май', 'Июнь'],
	3: ['Июль', 'Август', 'Сентябрь'],
	4: ['Октябрь', 'Ноябрь', 'Декабрь'],
};
const CARRYOVER_HEADERS = {
	1: 'Корректировка из 1 квартала во 2–4 кварталы',
	2: 'Корректировка из 2 квартала в 3–4 кварталы',
	3: 'Корректировка из 3 квартала в 4 квартал',
};
const ESTIMATE_TYPE_STYLES = {
	АХР: { backgroundColor: '#ecf9f0', borderColor: '#a7d9b8', color: '#08783e' },
	Операц: { backgroundColor: '#eff6ff', borderColor: '#93c5fd', color: '#1d4ed8' },
	КВП: { backgroundColor: '#fff7ed', borderColor: '#fdba74', color: '#c2410c' },
};

const createCorrectionColumns = (quarter) => ({
	id: `q${quarter}.correction`,
	header: 'Корректировка внутри квартала',
	columns: [
		numericColumn(`q${quarter}.adj_current`, 'Текущие корректировки (= 0)', [`q${quarter}`, 'adj_current'], 12),
		numericColumn(`q${quarter}.adj_ssp`, 'Корректировки с ССП / сметой развития', [`q${quarter}`, 'adj_ssp'], 15),
		numericColumn(`q${quarter}.adj_rf`, 'Корректировки с РФ', [`q${quarter}`, 'adj_rf'], 11),
		numericColumn(`q${quarter}.adj_reserve`, 'Корректировки из резерва', [`q${quarter}`, 'adj_reserve'], 12),
	],
});

const createPaymentColumns = (quarter) => ({
	id: `q${quarter}.payment`,
	header: 'Платеж и предоставление акта',
	columns: [
		textColumn(`q${quarter}.payment_date`, 'Дата платежа', [`q${quarter}`, 'payment_date'], 9),
		numericColumn(`q${quarter}.payment_amount`, 'Сумма, тыс. руб. (без НДС)', [`q${quarter}`, 'payment_amount'], 12),
		numericColumn(`q${quarter}.payment_amount_ho`, 'в т.ч. сумма (без НДС) ГО', [`q${quarter}`, 'payment_amount_ho'], 12),
		numericColumn(`q${quarter}.payment_amount_rf`, 'в т.ч. сумма (без НДС) РФ', [`q${quarter}`, 'payment_amount_rf'], 12),
		textColumn(`q${quarter}.payment_act`, 'Предоставление акта (др. подтверждения)', [`q${quarter}`, 'payment_act'], 16),
	],
});

const createActualColumns = (quarter) => ({
	id: `q${quarter}.actual`,
	header: 'Фактические расходы за квартал',
	columns: [
		numericColumn(`q${quarter}.booking`, `Бронь ${quarter} кв.`, [`q${quarter}`, 'booking_amount'], 9),
		...MONTHS_BY_QUARTER[quarter].map((month, index) =>
			numericColumn(`q${quarter}.actual_m${index + 1}`, `Факт ${month}`, [`q${quarter}`, `actual_m${index + 1}`], 9),
		),
		...(quarter === 4 ? [numericColumn('q4.actual_spod', 'Факт СПОД', ['q4', 'actual_spod'], 9)] : []),
	],
});

const createCarryoverColumns = (quarter) => {
	const nextQuarter = quarter + 1;
	const transferColumns = QUARTERS.filter((targetQuarter) => targetQuarter > quarter).map((targetQuarter) =>
		numericColumn(
			`q${quarter}.transfer_to_q${targetQuarter}`,
			`Перенос в ${targetQuarter} кв.`,
			[`q${quarter}`, `transfer_to_q${targetQuarter}`],
			9,
		),
	);
	return {
		id: `q${quarter}.carryover`,
		header: CARRYOVER_HEADERS[quarter],
		columns: [
			...transferColumns,
			numericColumn(`q${quarter}.transfer_to_economy`, 'Перенос в фонд экономии', [`q${quarter}`, 'transfer_to_economy'], 12),
			numericColumn(
				`q${nextQuarter}.plan_revision_eco_change`,
				'Изменение целевого назначения перенесенной экономии (= 0)',
				[`q${nextQuarter}`, 'plan_revision_eco_change'],
				16,
			),
			numericColumn(
				`q${nextQuarter}.plan_revision_item_adj`,
				'Корректировка статей базового плана (= 0)',
				[`q${nextQuarter}`, 'plan_revision_item_adj'],
				15,
			),
			numericColumn(
				`q${nextQuarter}.plan_revision_increase`,
				'Увеличение базового плана (> 0)',
				[`q${nextQuarter}`, 'plan_revision_increase'],
				13,
			),
			numericColumn(
				`q${nextQuarter}.plan_revision_sequester`,
				'Секвестр базового плана (< 0)',
				[`q${nextQuarter}`, 'plan_revision_sequester'],
				13,
			),
		],
	};
};

const createColumns = (sheet) => [
	textColumn('smeta_type', 'Вид сметы', ['header', 'smeta_type'], 8, {
		enableColumnFilter: true,
		filterVariant: 'select',
		Cell: ({ cell }) => {
			const value = cell.getValue();
			if (!value) return '—';
			const colors = ESTIMATE_TYPE_STYLES[value] || {
				backgroundColor: '#f3f4f6',
				borderColor: '#d1d5db',
				color: '#4b5563',
			};
			return (
				<Box
					component='span'
					sx={{
						display: 'inline-block',
						px: '0.625rem',
						py: '0.25rem',
						border: '0.0625rem solid',
						borderRadius: '0.5rem',
						fontWeight: 600,
						lineHeight: 1.35,
						whiteSpace: 'nowrap',
						...colors,
					}}>
					{value}
				</Box>
			);
		},
	}),
	textColumn('smeta_direction', 'Направление', ['header', 'smeta_direction'], 10, { enableColumnFilter: true, filterVariant: 'select' }),
	textColumn('org_name', 'ССП', ['header', 'org_name'], 14, {
		enableColumnFilter: true,
		filterVariant: 'select',
		Cell: ({ cell }) => {
			const value = cell.getValue();
			if (!value) return '—';
			return (
				<Box
					component='span'
					sx={{
						display: 'inline-block',
						maxWidth: '100%',
						px: '0.625rem',
						py: '0.25rem',
						border: '0.0625rem solid #a7d9b8',
						borderRadius: '0.5rem',
						backgroundColor: '#ecf9f0',
						color: '#08783e',
						fontWeight: 600,
						lineHeight: 1.35,
						textTransform: 'uppercase',
						overflow: 'hidden',
						textOverflow: 'ellipsis',
						whiteSpace: 'nowrap',
					}}>
					{value}
				</Box>
			);
		},
	}),
	textColumn('name', 'Наименование статьи', ['header', 'name'], 20),

	{
		id: 'estimate',
		header: sheet === 'GO' ? 'Смета расходов ГО в разрезе договоров' : 'Смета расходов РФ в разрезе договоров',
		columns: [
			textColumn('item_id', 'ID статьи', ['header', 'item_id'], 7),
			textColumn('num_group', 'ID группы номенклатуры', ['header', 'num_group'], 10),
			textColumn('justification', 'Конкретный вид расхода', ['header', 'justification'], 18),
			...QUARTERS.map((quarter) => numericColumn(`plan.q${quarter}`, `${quarter} кв.`, ['plan', `plan_q${quarter}`])),
		],
	},
	{
		id: 'allocation',
		header: 'Аллокация расходов',
		columns: [
			textColumn('allocation.internal_order', 'Внутренний заказ', ['allocation', 'internal_order'], 12),
			textColumn('allocation.property_object', 'Объект недвижимости', ['allocation', 'property_object'], 14),
		],
	},
	{
		id: 'sequestration',
		header: 'Секвестирование ДФиП',
		columns: QUARTERS.map((quarter) =>
			numericColumn(`sequestration.q${quarter}`, `${quarter} кв.`, ['sequestration', 'DFIP', `adj_q${quarter}`]),
		),
	},
	{
		id: 'reserve',
		header: 'Отнесение в резерв',
		columns: QUARTERS.map((quarter) => numericColumn(`reserve.q${quarter}`, `${quarter} кв.`, ['reserve', `amount_q${quarter}`])),
	},
	{
		id: 'approved',
		header: 'Итоговая смета расходов',
		columns: QUARTERS.map((quarter) => numericColumn(`approved.q${quarter}`, `${quarter} кв.`, ['approved', `approved_q${quarter}`])),
	},
	{
		id: 'contract',
		header: 'Договор',
		columns: [
			textColumn('contract.counterparty', 'Контрагент', ['contract_detail', 'counterparty'], 14),
			textColumn('contract.reference', 'Договор (реквизиты)', ['contract_detail', 'reference'], 12),
			textColumn('contract.subject', 'Предмет', ['contract_detail', 'subject'], 18),
			textColumn('contract.currency', 'Валюта договора', ['contract_detail', 'currency'], 9),
			numericColumn('contract.ceiling', 'Предельная ст-ть, тыс. руб. (без НДС)', ['contract_detail', 'ceiling_amount'], 14),
			...QUARTERS.map((quarter) =>
				numericColumn(
					`contract.expenses_q${quarter}`,
					`Расходы ${quarter} кв., тыс. руб. (без НДС)`,
					['contract_detail', `expenses_q${quarter}`],
					13,
				),
			),
			textColumn('contract.vat_rate', 'Ставка НДС (%)', ['contract_detail', 'vat_rate'], 9),
			textColumn('contract.deadline', 'Срок', ['contract_detail', 'deadline'], 9),
		],
	},
	createCorrectionColumns(1),
	createPaymentColumns(1),
	createActualColumns(1),
	createCarryoverColumns(1),
	createCorrectionColumns(2),
	createPaymentColumns(2),
	createActualColumns(2),
	createCarryoverColumns(2),
	createCorrectionColumns(3),
	createPaymentColumns(3),
	createActualColumns(3),
	createCarryoverColumns(3),
	createCorrectionColumns(4),
	createPaymentColumns(4),
	createActualColumns(4),
];

const createColumnBandMap = (columns) => {
	const bands = new Map();
	const addColumn = (column, band) => {
		bands.set(column.id, band);
		column.columns?.forEach((childColumn) => addColumn(childColumn, band));
	};
	columns.forEach((column, index) => addColumn(column, index % 2));
	return bands;
};

const createColumnGroupEndSet = (columns) => {
	const groupEnds = new Set();
	const getLastLeafId = (column) => {
		if (!column.columns?.length) return column.id;
		return getLastLeafId(column.columns.at(-1));
	};
	columns.forEach((column) => {
		if (!column.columns?.length) return;
		groupEnds.add(column.id);
		groupEnds.add(getLastLeafId(column));
	});
	return groupEnds;
};

const disableGroupColumnFilters = (columns) =>
	columns.map((column) => {
		if (!column.columns?.length) return column;
		return {
			...column,
			enableColumnFilter: false,
			columns: disableGroupColumnFilters(column.columns),
		};
	});

const COLUMN_CONFIG_CACHE = new Map();

const getColumnConfig = (sheet) => {
	if (!COLUMN_CONFIG_CACHE.has(sheet)) {
		const columns = disableGroupColumnFilters(createColumns(sheet));
		COLUMN_CONFIG_CACHE.set(sheet, {
			columns,
			columnBands: createColumnBandMap(columns),
			columnGroupEnds: createColumnGroupEndSet(columns),
		});
	}

	return COLUMN_CONFIG_CACHE.get(sheet);
};

const matchesSearch = (row, query) => {
	const searchableData = {
		...row.data?.header,
		...row.data?.contract_summary,
		...row.data?.contract_detail,
	};
	return Object.values(searchableData).some((value) =>
		String(value ?? '')
			.toLowerCase()
			.includes(query),
	);
};

export default function Svod2Page() {
	const { getSheetFilters, updateSheetFilters, getSummary, invalidateSummary } = useSvod();
	const [sheet, setSheet] = useState('GO');
	const [tableStateBySheet, setTableStateBySheet] = useState(createInitialTableState);
	const [columnFiltersBySheet, setColumnFiltersBySheet] = useState(() => Object.fromEntries(SHEETS.map(({ value }) => [value, []])));
	const latestSummaryRequestRef = useRef(Object.fromEntries(SHEETS.map(({ value }) => [value, 0])));
	const { year, selectedOrganizations, search } = getSheetFilters(sheet);
	const { rows, loading, error, loadedQueryKey } = tableStateBySheet[sheet];
	const columnFilters = columnFiltersBySheet[sheet];
	const selectedOrganizationIds = useMemo(
		() => (selectedOrganizations.some(({ id }) => id === '__all__') ? [] : selectedOrganizations.map(({ id }) => id)),
		[selectedOrganizations],
	);
	const currentQueryKey = useMemo(
		() => JSON.stringify([sheet, year, selectedOrganizations.map(({ id }) => String(id)).sort()]),
		[sheet, year, selectedOrganizations],
	);
	const hasCurrentData = loadedQueryKey === currentQueryKey;
	const updateCurrentSheetFilters = useCallback((changes) => updateSheetFilters(sheet, changes), [sheet, updateSheetFilters]);
	const updateCurrentColumnFilters = useCallback(
		(updater) => {
			setColumnFiltersBySheet((current) => {
				const currentFilters = current[sheet];
				const nextFilters = typeof updater === 'function' ? updater(currentFilters) : updater;
				return nextFilters === currentFilters ? current : { ...current, [sheet]: nextFilters };
			});
		},
		[sheet],
	);

	const loadSummary = useCallback(async () => {
		const requestId = latestSummaryRequestRef.current[sheet] + 1;
		latestSummaryRequestRef.current[sheet] = requestId;
		setTableStateBySheet((current) => ({
			...current,
			[sheet]: { ...current[sheet], loading: true, error: '' },
		}));
		try {
			const response = await getSummary(sheet, year, selectedOrganizationIds);
			if (latestSummaryRequestRef.current[sheet] !== requestId) return;
			setTableStateBySheet((current) => ({
				...current,
				[sheet]: { ...current[sheet], rows: response.result || [], loadedQueryKey: currentQueryKey },
			}));
		} catch (loadError) {
			if (latestSummaryRequestRef.current[sheet] !== requestId) return;
			setTableStateBySheet((current) => ({
				...current,
				[sheet]: {
					...current[sheet],
					rows: [],
					error: loadError.response?.data?.detail || 'Не удалось загрузить свод. Попробуйте ещё раз.',
				},
			}));
		} finally {
			if (latestSummaryRequestRef.current[sheet] === requestId) {
				setTableStateBySheet((current) => ({
					...current,
					[sheet]: { ...current[sheet], loading: false },
				}));
			}
		}
	}, [currentQueryKey, getSummary, selectedOrganizationIds, sheet, year]);

	useEffect(() => {
		return () => {
			SHEETS.forEach(({ value }) => {
				latestSummaryRequestRef.current[value] += 1;
			});
		};
	}, []);

	const refreshSummary = useCallback(() => {
		invalidateSummary(sheet, year, selectedOrganizationIds);
		loadSummary();
	}, [invalidateSummary, loadSummary, selectedOrganizationIds, sheet, year]);

	const filteredRows = useMemo(() => {
		if (!hasCurrentData) return [];
		const normalizedSearch = search.trim().toLowerCase();
		return normalizedSearch ? rows.filter((row) => matchesSearch(row, normalizedSearch)) : rows;
	}, [hasCurrentData, rows, search]);
	const { columns, columnBands, columnGroupEnds } = useMemo(() => getColumnConfig(sheet), [sheet]);
	const table = useMaterialReactTable({
		columns,
		data: filteredRows,
		getRowId: (row) => `${row.data?.header?.source_form}-${row.data?.header?.source_id}-${row.data?.line_id}`,
		enableColumnActions: false,
		enableColumnFilters: true,
		enableFacetedValues: true,
		onColumnFiltersChange: updateCurrentColumnFilters,
		enableDensityToggle: false,
		enableFullScreenToggle: false,
		enableHiding: false,
		enablePagination: false,
		enableRowVirtualization: true,
		enableTopToolbar: false,
		enableBottomToolbar: false,
		enableSorting: false,
		rowVirtualizerOptions: ROW_VIRTUALIZER_OPTIONS,
		state: { isLoading: loading, columnFilters },
		initialState: {
			columnPinning: { left: ['smeta_type', 'smeta_direction', 'org_name', 'name'] },
			showColumnFilters: true,
		},
		muiTablePaperProps: {
			elevation: 0,
			sx: {
				border: '0.0625rem solid #e5e7eb',
				borderRadius: '0.75rem',
				overflow: 'hidden',
				flex: 1,
				minHeight: 0,
				width: '100%',
				display: 'flex',
				flexDirection: 'column',
			},
		},
		muiTableContainerProps: {
			sx: {
				flex: 1,
				overflow: 'auto',
				minHeight: 0,
				height: '100%',
				'& thead': { position: 'sticky', top: 0, zIndex: 10 },
			},
		},
		muiTableHeadProps: {
			sx: {
				'& tr:not(:last-of-type) > th > .MuiCollapse-root': {
					display: 'none',
				},
			},
		},
		muiTableHeadCellProps: ({ column }) => ({
			sx: {
				position: 'sticky',
				top: 0,
				boxShadow: 'none',
				backgroundColor: COLUMN_BAND_COLORS.head[columnBands.get(column.id) ?? 0],
				borderRight: columnGroupEnds.has(column.id) ? '0.1875rem solid #9eafa3' : '0.0625rem solid #e5e7eb',
				color: '#4a5565',
				fontSize: '0.75rem',
				fontWeight: 700,
				lineHeight: 1.2,
				px: '0.75rem',
				py: '0.5rem',
				whiteSpace: 'nowrap',
				opacity: 1,
				zIndex: column.getIsPinned() ? 5 : undefined,
			},
		}),
		muiTableHeadRowProps: { sx: { boxShadow: 'none' } },
		muiTableBodyCellProps: ({ column }) => ({
			sx: {
				backgroundColor: COLUMN_BAND_COLORS.body[columnBands.get(column.id) ?? 0],
				borderRight: columnGroupEnds.has(column.id) ? '0.1875rem solid #9eafa3' : '0.0625rem solid #edf0f2',
				fontSize: '0.8125rem',
				px: '0.75rem',
				py: '0.5rem',
				whiteSpace: 'nowrap',
				opacity: 1,
				zIndex: column.getIsPinned() ? 2 : undefined,
			},
		}),
		localization: {
			...MRT_Localization_RU,
			noRecordsToDisplay: 'Нет данных для выбранных параметров',
		},
	});
	let content = <MaterialReactTable table={table} />;
	if (!hasCurrentData && !loading && !error) {
		content = (
			<Alert severity='info'>
				{selectedOrganizations.length === 0
					? 'Выберите одно или несколько ССП/РФ либо пункт «Все ССП/РФ», затем нажмите «Загрузить».'
					: 'Нажмите «Загрузить», чтобы получить данные по выбранным параметрам.'}
			</Alert>
		);
	} else if (error) {
		content = (
			<Alert
				severity='error'
				action={
					<Button color='inherit' size='small' onClick={refreshSummary}>
						Повторить
					</Button>
				}>
				{error}
			</Alert>
		);
	}

	return (
		<Box
			sx={{
				px: '2rem',
				pt: '1rem',
				pb: '1.5rem',
				height: '100%',
				minHeight: 0,
				overflow: 'hidden',
				display: 'flex',
				flexDirection: 'column',
				gap: '1rem',
			}}>
			<HeaderSwitch />
			<Paper elevation={0} sx={{ border: '0.0625rem solid #e5e7eb', borderRadius: '0.75rem', overflow: 'hidden', flexShrink: 0 }}>
				<Tabs
					value={sheet}
					onChange={(_event, value) => setSheet(value)}
					sx={{ px: '0.5rem', minHeight: '3rem', borderBottom: '0.0625rem solid #edf0f2' }}>
					{SHEETS.map((item) => (
						<Tab key={item.value} value={item.value} label={item.label} sx={{ textTransform: 'none', minHeight: '3rem' }} />
					))}
				</Tabs>
				<SvodFilters
					year={year}
					selectedOrganizations={selectedOrganizations}
					search={search}
					onChange={updateCurrentSheetFilters}
					searchPlaceholder='ССП/РФ, код, статья или договор'
					emptyOrganizationsPlaceholder='Выберите ССП/РФ'
					allowSelectAll>
					{hasCurrentData && !loading && filteredRows.length !== rows.length && (
						<Typography variant='caption' color='text.secondary' sx={{ flexShrink: 0, whiteSpace: 'nowrap' }}>
							{`Найдено ${filteredRows.length.toLocaleString('ru-RU')} из ${rows.length.toLocaleString('ru-RU')} строк`}
						</Typography>
					)}
					{hasCurrentData ? (
						<Button
							variant='outlined'
							color='default'
							startIcon={<RefreshRoundedIcon />}
							disabled={loading || selectedOrganizations.length === 0}
							onClick={refreshSummary}
							sx={{ ml: 'auto', height: '2.5rem', flexShrink: 0 }}>
							Обновить
						</Button>
					) : (
						<PrimaryButton
							variant='outlined'
							color='default'
							disabled={loading || selectedOrganizations.length === 0}
							onClick={refreshSummary}
							sx={{ ml: 'auto', height: '2.5rem', flexShrink: 0 }}>
							Загрузить
						</PrimaryButton>
					)}
				</SvodFilters>
			</Paper>
			{content}
		</Box>
	);
}