import type {
	AddDataTableColumnDto,
	CreateDataTableDto,
	DeleteDataTableRowsDto,
	ListDataTableContentQueryDto,
	MoveDataTableColumnDto,
	RenameDataTableColumnDto,
	DataTableListOptions,
	UpsertDataTableRowDto,
	UpdateDataTableDto,
	UpdateDataTableRowDto,
} from '@n8n/api-types';
import { Logger } from '@n8n/backend-common';
import { ProjectRelationRepository, type User } from '@n8n/db';
import { Service } from '@n8n/di';
import { DateTime } from 'luxon';
import type {
	DataTableColumnJsType,
	DataTableFilter,
	DataTableRow,
	DataTableRowReturn,
	DataTableRows,
	DataTableInsertRowsReturnType,
	DataTableInsertRowsResult,
	DataTablesSizeResult,
	DataTableInfoById,
	DataTableColumnType,
	DataTableRowReturnWithState,
} from 'n8n-workflow';
import { DATA_TABLE_SYSTEM_COLUMN_TYPE_MAP, validateFieldType } from 'n8n-workflow';

import { CsvParserService } from './csv-parser.service';
import { DataTableColumn } from './data-table-column.entity';
import { DataTableColumnRepository } from './data-table-column.repository';
import { DataTableFileCleanupService } from './data-table-file-cleanup.service';
import { DataTableRowsRepository } from './data-table-rows.repository';
import { DataTableSizeValidator } from './data-table-size-validator.service';
import { DataTableRepository } from './data-table.repository';
import { columnTypeToFieldType } from './data-table.types';
import { DataTableColumnNotFoundError } from './errors/data-table-column-not-found.error';
import { FileUploadError } from './errors/data-table-file-upload.error';
import { DataTableNameConflictError } from './errors/data-table-name-conflict.error';
import { DataTableNotFoundError } from './errors/data-table-not-found.error';
import { DataTableValidationError } from './errors/data-table-validation.error';
import { normalizeRows } from './utils/sql-utils';

import { RoleService } from '@/services/role.service';

@Service()
export class DataTableService {
	constructor(
		private readonly dataTableRepository: DataTableRepository,
		private readonly dataTableColumnRepository: DataTableColumnRepository,
		private readonly dataTableRowsRepository: DataTableRowsRepository,
		private readonly logger: Logger,
		private readonly dataTableSizeValidator: DataTableSizeValidator,
		private readonly projectRelationRepository: ProjectRelationRepository,
		private readonly roleService: RoleService,
		private readonly csvParserService: CsvParserService,
		private readonly fileCleanupService: DataTableFileCleanupService,
	) {
		this.logger = this.logger.scoped('data-table');
	}

	async start() {}
	async shutdown() {}

	async createDataTable(projectId: string, dto: CreateDataTableDto) {
		await this.validateUniqueName(dto.name, projectId);

		const result = await this.dataTableRepository.createDataTable(projectId, dto.name, dto.columns);

		if (dto.fileId) {
			try {
				await this.importDataFromFile(projectId, result.id, dto.fileId, dto.hasHeaders ?? true);
				await this.fileCleanupService.deleteFile(dto.fileId);
			} catch (error) {
				await this.deleteDataTable(result.id, projectId);
				throw error;
			}
		}

		this.dataTableSizeValidator.reset();

		return result;
	}

	private async importDataFromFile(
		projectId: string,
		dataTableId: string,
		fileId: string,
		hasHeaders: boolean,
	) {
		try {
			const tableColumns = await this.getColumns(dataTableId, projectId);

			const csvMetadata = await this.csvParserService.parseFile(fileId, hasHeaders);

			const columnMapping = new Map<string, string>();
			csvMetadata.columns.forEach((csvColumn, index) => {
				if (tableColumns[index]) {
					columnMapping.set(csvColumn.name, tableColumns[index].name);
				}
			});

			const csvRows = await this.csvParserService.parseFileData(fileId, hasHeaders);

			const transformedRows = csvRows.map((csvRow) => {
				const transformedRow: DataTableRow = {};
				for (const [csvColName, value] of Object.entries(csvRow)) {
					const tableColName = columnMapping.get(csvColName);
					if (tableColName) {
						transformedRow[tableColName] = value;
					}
				}
				return transformedRow;
			});

			if (transformedRows.length > 0) {
				await this.insertRows(dataTableId, projectId, transformedRows);
			}
		} catch (error) {
			this.logger.error('Failed to import data from CSV file', { error, fileId, dataTableId });
			throw new FileUploadError(error instanceof Error ? error.message : 'Failed to read CSV file');
		}
	}

	// Updates data table properties (currently limited to renaming)
	async updateDataTable(dataTableId: string, projectId: string, dto: UpdateDataTableDto) {
		await this.validateDataTableExists(dataTableId, projectId);
		await this.validateUniqueName(dto.name, projectId);

		await this.dataTableRepository.update({ id: dataTableId }, { name: dto.name });

		return true;
	}

	async transferDataTablesByProjectId(fromProjectId: string, toProjectId: string) {
		return await this.dataTableRepository.transferDataTableByProjectId(fromProjectId, toProjectId);
	}

	async deleteDataTableByProjectId(projectId: string) {
		const result = await this.dataTableRepository.deleteDataTableByProjectId(projectId);

		if (result) {
			this.dataTableSizeValidator.reset();
		}

		return result;
	}

	async deleteDataTableAll() {
		const result = await this.dataTableRepository.deleteDataTableAll();

		if (result) {
			this.dataTableSizeValidator.reset();
		}

		return result;
	}

	async deleteDataTable(dataTableId: string, projectId: string) {
		await this.validateDataTableExists(dataTableId, projectId);

		await this.dataTableRepository.deleteDataTable(dataTableId);

		this.dataTableSizeValidator.reset();

		return true;
	}

	async addColumn(dataTableId: string, projectId: string, dto: AddDataTableColumnDto) {
		await this.validateDataTableExists(dataTableId, projectId);

		const result = await this.dataTableColumnRepository.addColumn(dataTableId, dto);

		await this.dataTableRepository.touchUpdatedAt(dataTableId);

		return result;
	}

	async moveColumn(
		dataTableId: string,
		projectId: string,
		columnId: string,
		dto: MoveDataTableColumnDto,
	) {
		await this.validateDataTableExists(dataTableId, projectId);
		const existingColumn = await this.validateColumnExists(dataTableId, columnId);

		await this.dataTableColumnRepository.moveColumn(dataTableId, existingColumn, dto.targetIndex);

		return true;
	}

	async deleteColumn(dataTableId: string, projectId: string, columnId: string) {
		await this.validateDataTableExists(dataTableId, projectId);
		const existingColumn = await this.validateColumnExists(dataTableId, columnId);

		await this.dataTableColumnRepository.deleteColumn(dataTableId, existingColumn);

		await this.dataTableRepository.touchUpdatedAt(dataTableId);

		return true;
	}

	async renameColumn(
		dataTableId: string,
		projectId: string,
		columnId: string,
		dto: RenameDataTableColumnDto,
	) {
		await this.validateDataTableExists(dataTableId, projectId);
		const existingColumn = await this.validateColumnExists(dataTableId, columnId);

		return await this.dataTableColumnRepository.renameColumn(dataTableId, existingColumn, dto.name);
	}

	async getManyAndCount(options: DataTableListOptions) {
		return await this.dataTableRepository.getManyAndCount(options);
	}

	async getManyRowsAndCount(
		dataTableId: string,
		projectId: string,
		dto: ListDataTableContentQueryDto,
	) {
		await this.validateDataTableExists(dataTableId, projectId);

		return await this.dataTableColumnRepository.manager.transaction(async (em) => {
			const columns = await this.dataTableColumnRepository.getColumns(dataTableId, em);
			const transformedDto = dto.filter
				? { ...dto, filter: this.validateAndTransformFilters(dto.filter, columns) }
				: dto;
			const result = await this.dataTableRowsRepository.getManyAndCount(
				dataTableId,
				transformedDto,
				columns,
				em,
			);
			return {
				count: result.count,
				data: normalizeRows(result.data, columns),
			};
		});
	}

	async getColumns(dataTableId: string, projectId: string) {
		await this.validateDataTableExists(dataTableId, projectId);

		return await this.dataTableColumnRepository.getColumns(dataTableId);
	}

	async insertRows<T extends DataTableInsertRowsReturnType = 'count'>(
		dataTableId: string,
		projectId: string,
		rows: DataTableRows,
		returnType?: T,
	): Promise<DataTableInsertRowsResult<T>>;
	async insertRows(
		dataTableId: string,
		projectId: string,
		rows: DataTableRows,
		returnType: DataTableInsertRowsReturnType = 'count',
	) {
		await this.validateDataTableSize();
		await this.validateDataTableExists(dataTableId, projectId);

		const result = await this.dataTableColumnRepository.manager.transaction(async (trx) => {
			const columns = await this.dataTableColumnRepository.getColumns(dataTableId, trx);
			const transformedRows = this.validateAndTransformRows(rows, columns);

			return await this.dataTableRowsRepository.insertRows(
				dataTableId,
				transformedRows,
				columns,
				returnType,
				trx,
			);
		});

		this.dataTableSizeValidator.reset();

		await this.dataTableRepository.touchUpdatedAt(dataTableId);

		return result;
	}

	async upsertRow<T extends boolean | undefined>(
		dataTableId: string,
		projectId: string,
		dto: Omit<UpsertDataTableRowDto, 'returnData' | 'dryRun'>,
		returnData: true,
		dryRun?: boolean,
	): Promise<DataTableRowReturn[] | DataTableRowReturnWithState[]>;
	async upsertRow(
		dataTableId: string,
		projectId: string,
		dto: Omit<UpsertDataTableRowDto, 'returnData' | 'dryRun'>,
		returnData?: boolean,
		dryRun?: true,
	): Promise<DataTableRowReturnWithState[]>;
	async upsertRow(
		dataTableId: string,
		projectId: string,
		dto: Omit<UpsertDataTableRowDto, 'returnData' | 'dryRun'>,
		returnData?: false,
		dryRun?: false,
	): Promise<true>;
	async upsertRow(
		dataTableId: string,
		projectId: string,
		dto: Omit<UpsertDataTableRowDto, 'returnData' | 'dryRun'>,
		returnData: boolean = false,
		dryRun: boolean = false,
	) {
		await this.validateDataTableSize();
		await this.validateDataTableExists(dataTableId, projectId);

		const result = await this.dataTableColumnRepository.manager.transaction(async (trx) => {
			const columns = await this.dataTableColumnRepository.getColumns(dataTableId, trx);
			const { data, filter } = this.validateAndTransformUpdateParams(dto, columns);

			if (dryRun) {
				return await this.dataTableRowsRepository.dryRunUpsertRow(
					dataTableId,
					data,
					filter,
					columns,
					trx,
				);
			}

			const updated = await this.dataTableRowsRepository.updateRows(
				dataTableId,
				data,
				filter,
				columns,
				true,
				trx,
			);

			if (updated.length > 0) {
				return returnData ? updated : true;
			}

			// No rows were updated, so insert a new one
			const inserted = await this.dataTableRowsRepository.insertRows(
				dataTableId,
				[data],
				columns,
				returnData ? 'all' : 'id',
				trx,
			);
			return returnData ? inserted : true;
		});

		if (!dryRun) {
			this.dataTableSizeValidator.reset();

			await this.dataTableRepository.touchUpdatedAt(dataTableId);
		}

		return result;
	}

	validateAndTransformUpdateParams(
		{ filter, data }: Pick<UpdateDataTableRowDto, 'filter' | 'data'>,
		columns: DataTableColumn[],
	): { data: DataTableRow; filter: DataTableFilter } {
		if (columns.length === 0) {
			throw new DataTableValidationError(
				'No columns found for this data table or data table not found',
			);
		}

		if (!filter?.filters || filter.filters.length === 0) {
			throw new DataTableValidationError('Filter must not be empty');
		}
		if (!data || Object.keys(data).length === 0) {
			throw new DataTableValidationError('Data columns must not be empty');
		}

		const [transformedData] = this.validateAndTransformRows([data], columns, false);
		const transformedFilter = this.validateAndTransformFilters(filter, columns);

		return { data: transformedData, filter: transformedFilter };
	}

	async updateRows<T extends boolean | undefined>(
		dataTableId: string,
		projectId: string,
		dto: Omit<UpdateDataTableRowDto, 'returnData' | 'dryRun'>,
		returnData: true,
		dryRun?: boolean,
	): Promise<DataTableRowReturn[] | DataTableRowReturnWithState[]>;
	async updateRows(
		dataTableId: string,
		projectId: string,
		dto: Omit<UpdateDataTableRowDto, 'returnData' | 'dryRun'>,
		returnData?: boolean,
		dryRun?: true,
	): Promise<DataTableRowReturnWithState[]>;
	async updateRows(
		dataTableId: string,
		projectId: string,
		dto: Omit<UpdateDataTableRowDto, 'returnData' | 'dryRun'>,
		returnData?: false,
		dryRun?: false,
	): Promise<true>;
	async updateRows(
		dataTableId: string,
		projectId: string,
		dto: Omit<UpdateDataTableRowDto, 'returnData' | 'dryRun'>,
		returnData: boolean = false,
		dryRun: boolean = false,
	) {
		await this.validateDataTableSize();
		await this.validateDataTableExists(dataTableId, projectId);

		const result = await this.dataTableColumnRepository.manager.transaction(async (trx) => {
			const columns = await this.dataTableColumnRepository.getColumns(dataTableId, trx);
			const { data, filter } = this.validateAndTransformUpdateParams(dto, columns);

			if (dryRun) {
				return await this.dataTableRowsRepository.dryRunUpdateRows(
					dataTableId,
					data,
					filter,
					columns,
					trx,
				);
			}

			return await this.dataTableRowsRepository.updateRows(
				dataTableId,
				data,
				filter,
				columns,
				returnData,
				trx,
			);
		});

		if (!dryRun) {
			this.dataTableSizeValidator.reset();

			await this.dataTableRepository.touchUpdatedAt(dataTableId);
		}

		return result;
	}

	async deleteRows(
		dataTableId: string,
		projectId: string,
		dto: Omit<DeleteDataTableRowsDto, 'returnData' | 'dryRun'>,
		returnData: true,
		dryRun?: boolean,
	): Promise<DataTableRowReturn[]>;
	async deleteRows(
		dataTableId: string,
		projectId: string,
		dto: Omit<DeleteDataTableRowsDto, 'returnData' | 'dryRun'>,
		returnData?: boolean,
		dryRun?: true,
	): Promise<DataTableRowReturn[]>;
	async deleteRows(
		dataTableId: string,
		projectId: string,
		dto: Omit<DeleteDataTableRowsDto, 'returnData' | 'dryRun'>,
		returnData?: false,
		dryRun?: false,
	): Promise<true>;
	async deleteRows(
		dataTableId: string,
		projectId: string,
		dto: Omit<DeleteDataTableRowsDto, 'returnData' | 'dryRun'>,
		returnData: boolean = false,
		dryRun: boolean = false,
	) {
		await this.validateDataTableExists(dataTableId, projectId);

		const result = await this.dataTableColumnRepository.manager.transaction(async (trx) => {
			const columns = await this.dataTableColumnRepository.getColumns(dataTableId, trx);

			if (!dto.filter?.filters || dto.filter.filters.length === 0) {
				throw new DataTableValidationError(
					'Filter is required for delete operations to prevent accidental deletion of all data',
				);
			}

			const transformedFilter = this.validateAndTransformFilters(dto.filter, columns);

			return await this.dataTableRowsRepository.deleteRows(
				dataTableId,
				columns,
				transformedFilter,
				returnData,
				dryRun,
				trx,
			);
		});

		if (!dryRun) {
			this.dataTableSizeValidator.reset();

			await this.dataTableRepository.touchUpdatedAt(dataTableId);
		}

		return result;
	}

	private validateAndTransformRows(
		rows: DataTableRows,
		columns: Array<{ name: string; type: DataTableColumnType }>,
		includeSystemColumns = false,
		skipDateTransform = false,
	): DataTableRows {
		// Include system columns like 'id' if requested
		const allColumns = includeSystemColumns
			? [
					...Object.entries(DATA_TABLE_SYSTEM_COLUMN_TYPE_MAP).map(([name, type]) => ({
						name,
						type,
					})),
					...columns,
				]
			: columns;
		const columnNames = new Set(allColumns.map((x) => x.name));
		const columnTypeMap = new Map(allColumns.map((x) => [x.name, x.type]));

		return rows.map((row) => {
			const transformedRow: DataTableRow = {};
			const keys = Object.keys(row);
			for (const key of keys) {
				if (!columnNames.has(key)) {
					throw new DataTableValidationError(`unknown column name '${key}'`);
				}
				transformedRow[key] = this.validateAndTransformCell(
					row[key],
					key,
					columnTypeMap,
					skipDateTransform,
				);
			}
			return transformedRow;
		});
	}

	private validateAndTransformCell(
		cell: DataTableColumnJsType,
		key: string,
		columnTypeMap: Map<string, string>,
		skipDateTransform = false,
	): DataTableColumnJsType {
		if (cell === null) return null;

		const columnType = columnTypeMap.get(key);
		if (!columnType) return cell;

		const fieldType = columnTypeToFieldType[columnType];
		if (!fieldType) return cell;

		const validationResult = validateFieldType(key, cell, fieldType, {
			strict: false, // Allow type coercion (e.g., string numbers to numbers)
			parseStrings: false,
		});

		if (!validationResult.valid) {
			throw new DataTableValidationError(
				`value '${String(cell)}' does not match column type '${columnType}': ${validationResult.errorMessage}`,
			);
		}

		if (columnType === 'date') {
			if (skipDateTransform && cell instanceof Date) {
				return cell;
			}
			try {
				// Convert to UTC to ensure consistent timezone handling
				const dateInISO = (validationResult.newValue as DateTime).toUTC().toISO();
				return dateInISO;
			} catch {
				throw new DataTableValidationError(
					`value '${String(cell)}' does not match column type 'date'`,
				);
			}
		}

		return validationResult.newValue as DataTableColumnJsType;
	}

	private async validateDataTableExists(dataTableId: string, projectId: string) {
		const existingTable = await this.dataTableRepository.findOneBy({
			id: dataTableId,
			project: {
				id: projectId,
			},
		});

		if (!existingTable) {
			throw new DataTableNotFoundError(dataTableId);
		}

		return existingTable;
	}

	private async validateColumnExists(dataTableId: string, columnId: string) {
		const existingColumn = await this.dataTableColumnRepository.findOneBy({
			id: columnId,
			dataTableId,
		});

		if (existingColumn === null) {
			throw new DataTableColumnNotFoundError(dataTableId, columnId);
		}

		return existingColumn;
	}

	private async validateUniqueName(name: string, projectId: string) {
		const hasNameClash = await this.dataTableRepository.existsBy({
			name,
			projectId,
		});

		if (hasNameClash) {
			throw new DataTableNameConflictError(name);
		}
	}

	private validateAndTransformFilters(
		filterObject: DataTableFilter,
		columns: DataTableColumn[],
	): DataTableFilter {
		// Skip date transformation for filters - TypeORM needs Date objects for parameterized queries
		const transformedRows = this.validateAndTransformRows(
			filterObject.filters.map((f) => {
				return {
					[f.columnName]: f.value,
				};
			}),
			columns,
			true,
			true,
		);

		const transformedFilters = filterObject.filters.map((filter, index) => {
			const transformedValue = transformedRows[index][filter.columnName];

			if (['like', 'ilike'].includes(filter.condition)) {
				if (transformedValue === null || transformedValue === undefined) {
					throw new DataTableValidationError(
						`${filter.condition.toUpperCase()} filter value cannot be null or undefined`,
					);
				}
				if (typeof transformedValue !== 'string') {
					throw new DataTableValidationError(
						`${filter.condition.toUpperCase()} filter value must be a string`,
					);
				}

				const valueWithWildcards = transformedValue.includes('%')
					? transformedValue
					: `%${transformedValue}%`;

				return { ...filter, value: valueWithWildcards };
			}

			if (['gt', 'gte', 'lt', 'lte'].includes(filter.condition)) {
				if (transformedValue === null || transformedValue === undefined) {
					throw new DataTableValidationError(
						`${filter.condition.toUpperCase()} filter value cannot be null or undefined`,
					);
				}
			}

			return { ...filter, value: transformedValue };
		});

		return { ...filterObject, filters: transformedFilters };
	}

	private async validateDataTableSize() {
		await this.dataTableSizeValidator.validateSize(
			async () => await this.dataTableRepository.findDataTablesSize(),
		);
	}

	async getDataTablesSize(user: User): Promise<DataTablesSizeResult> {
		const allSizeData = await this.dataTableSizeValidator.getCachedSizeData(
			async () => await this.dataTableRepository.findDataTablesSize(),
		);

		const roles = await this.roleService.rolesWithScope('project', ['dataTable:listProject']);

		const accessibleProjectIds = await this.projectRelationRepository.getAccessibleProjectsByRoles(
			user.id,
			roles,
		);

		const accessibleProjectIdsSet = new Set(accessibleProjectIds);

		// Filter the cached data based on user's accessible projects
		const accessibleDataTables: DataTableInfoById = Object.fromEntries(
			Object.entries(allSizeData.dataTables).filter(([, dataTableInfo]) =>
				accessibleProjectIdsSet.has(dataTableInfo.projectId),
			),
		);

		return {
			totalBytes: allSizeData.totalBytes,
			quotaStatus: this.dataTableSizeValidator.sizeToState(allSizeData.totalBytes),
			dataTables: accessibleDataTables,
		};
	}

	async generateDataTableCsv(
		dataTableId: string,
		projectId: string,
	): Promise<{ csvContent: string; dataTableName: string }> {
		const dataTable = await this.validateDataTableExists(dataTableId, projectId);

		const columns = await this.dataTableColumnRepository.getColumns(dataTableId);

		const { data: rows } = await this.dataTableRowsRepository.getManyAndCount(
			dataTableId,
			{
				skip: 0,
			},
			columns,
		);

		const csvContent = this.buildCsvContent(rows, columns);

		return {
			csvContent,
			dataTableName: dataTable.name,
		};
	}

	private buildCsvContent(rows: DataTableRowReturn[], columns: DataTableColumn[]): string {
		const sortedColumns = [...columns].sort((a, b) => a.index - b.index);

		const userHeaders = sortedColumns.map((col) => col.name);
		const headers = ['id', ...userHeaders, 'createdAt', 'updatedAt'];

		const csvRows: string[] = [headers.map((h) => this.escapeCsvValue(h)).join(',')];

		for (const row of rows) {
			const values: string[] = [];

			values.push(this.escapeCsvValue(row.id));

			for (const column of sortedColumns) {
				const value = row[column.name];
				values.push(this.escapeCsvValue(this.formatValueForCsv(value, column.type)));
			}

			values.push(this.escapeCsvValue(this.formatDateForCsv(row.createdAt)));
			values.push(this.escapeCsvValue(this.formatDateForCsv(row.updatedAt)));

			csvRows.push(values.join(','));
		}

		return csvRows.join('\n');
	}

	private formatValueForCsv(value: unknown, columnType: DataTableColumnType): string {
		if (value === null || value === undefined) {
			return '';
		}

		if (columnType === 'date') {
			if (value instanceof Date || typeof value === 'string') {
				return this.formatDateForCsv(value);
			}
		}

		if (columnType === 'boolean') {
			return String(value);
		}

		if (columnType === 'number') {
			return String(value);
		}

		return String(value);
	}

	private formatDateForCsv(date: Date | string): string {
		if (date instanceof Date) {
			return date.toISOString();
		}
		// If it's already a string, try to parse and format
		const parsed = new Date(date);
		return !isNaN(parsed.getTime()) ? parsed.toISOString() : String(date);
	}

	private escapeCsvValue(value: unknown): string {
		const str = String(value);

		// RFC 4180 compliant escaping:
		// - If value contains comma, quote, or newline, wrap in quotes
		// - Also wrap if value has leading/trailing spaces to prevent trimming
		// - Escape quotes by doubling them
		const hasLeadingOrTrailingSpace =
			str.length > 0 && (str[0] === ' ' || str[str.length - 1] === ' ');

		if (
			str.includes(',') ||
			str.includes('"') ||
			str.includes('\n') ||
			str.includes('\r') ||
			hasLeadingOrTrailingSpace
		) {
			return `"${str.replace(/"/g, '""')}"`;
		}

		return str;
	}
}