import {
	NodeOperationError,
	type IExecuteFunctions,
	type INodeExecutionData,
	type INodeType,
	type INodeTypeDescription,
} from 'n8n-workflow';
import { generatePairedItemData } from '../../../utils/utilities';
import {
	type Aggregations,
	NUMERICAL_AGGREGATIONS,
	type SummarizeOptions,
	aggregationToArray,
	checkIfFieldExists,
	fieldValueGetter,
	splitData,
} from './utils';

export class Summarize implements INodeType {
	description: INodeTypeDescription = {
		displayName: 'Summarize',
		name: 'summarize',
		icon: 'file:summarize.svg',
		group: ['transform'],
		subtitle: '',
		version: 1,
		description: 'Sum, count, max, etc. across items',
		defaults: {
			name: 'Summarize',
		},
		inputs: ['main'],
		outputs: ['main'],
		properties: [
			{
				displayName: 'Fields to Summarize',
				name: 'fieldsToSummarize',
				type: 'fixedCollection',
				placeholder: 'Add Field',
				default: { values: [{ aggregation: 'count', field: '' }] },
				typeOptions: {
					multipleValues: true,
				},
				options: [
					{
						displayName: '',
						name: 'values',
						values: [
							{
								displayName: 'Aggregation',
								name: 'aggregation',
								type: 'options',
								options: [
									{
										name: 'Append',
										value: 'append',
									},
									{
										name: 'Average',
										value: 'average',
									},
									{
										name: 'Concatenate',
										value: 'concatenate',
									},
									{
										name: 'Count',
										value: 'count',
									},
									{
										name: 'Count Unique',
										value: 'countUnique',
									},
									{
										name: 'Max',
										value: 'max',
									},
									{
										name: 'Min',
										value: 'min',
									},
									{
										name: 'Sum',
										value: 'sum',
									},
								],
								default: 'count',
								description: 'How to combine the values of the field you want to summarize',
							},
							//field repeated to have different descriptions for different aggregations --------------------------------
							{
								displayName: 'Field',
								name: 'field',
								type: 'string',
								default: '',
								description: 'The name of an input field that you want to summarize',
								placeholder: 'e.g. cost',
								hint: ' Enter the field name as text',
								displayOptions: {
									hide: {
										aggregation: [...NUMERICAL_AGGREGATIONS, 'countUnique', 'count', 'max', 'min'],
									},
								},
								requiresDataPath: 'single',
							},
							{
								displayName: 'Field',
								name: 'field',
								type: 'string',
								default: '',
								description:
									'The name of an input field that you want to summarize. The field should contain numerical values; null, undefined, empty strings would be ignored.',
								placeholder: 'e.g. cost',
								hint: ' Enter the field name as text',
								displayOptions: {
									show: {
										aggregation: NUMERICAL_AGGREGATIONS,
									},
								},
								requiresDataPath: 'single',
							},
							{
								displayName: 'Field',
								name: 'field',
								type: 'string',
								default: '',
								description:
									'The name of an input field that you want to summarize; null, undefined, empty strings would be ignored',
								placeholder: 'e.g. cost',
								hint: ' Enter the field name as text',
								displayOptions: {
									show: {
										aggregation: ['countUnique', 'count', 'max', 'min'],
									},
								},
								requiresDataPath: 'single',
							},
							// ----------------------------------------------------------------------------------------------------------
							{
								displayName: 'Include Empty Values',
								name: 'includeEmpty',
								type: 'boolean',
								default: false,
								displayOptions: {
									show: {
										aggregation: ['append', 'concatenate'],
									},
								},
							},
							{
								displayName: 'Separator',
								name: 'separateBy',
								type: 'options',
								default: ',',
								// eslint-disable-next-line n8n-nodes-base/node-param-options-type-unsorted-items
								options: [
									{
										name: 'Comma',
										value: ',',
									},
									{
										name: 'Comma and Space',
										value: ', ',
									},
									{
										name: 'New Line',
										value: '\n',
									},
									{
										name: 'None',
										value: '',
									},
									{
										name: 'Space',
										value: ' ',
									},
									{
										name: 'Other',
										value: 'other',
									},
								],
								hint: 'What to insert between values',
								displayOptions: {
									show: {
										aggregation: ['concatenate'],
									},
								},
							},
							{
								displayName: 'Custom Separator',
								name: 'customSeparator',
								type: 'string',
								default: '',
								displayOptions: {
									show: {
										aggregation: ['concatenate'],
										separateBy: ['other'],
									},
								},
							},
						],
					},
				],
			},
			// fieldsToSplitBy repeated to have different displayName for singleItem and separateItems -----------------------------
			{
				displayName: 'Fields to Split By',
				name: 'fieldsToSplitBy',
				type: 'string',
				placeholder: 'e.g. country, city',
				default: '',
				description: 'The name of the input fields that you want to split the summary by',
				hint: 'Enter the name of the fields as text (separated by commas)',
				displayOptions: {
					hide: {
						'/options.outputFormat': ['singleItem'],
					},
				},
				requiresDataPath: 'multiple',
			},
			{
				displayName: 'Fields to Group By',
				name: 'fieldsToSplitBy',
				type: 'string',
				placeholder: 'e.g. country, city',
				default: '',
				description: 'The name of the input fields that you want to split the summary by',
				hint: 'Enter the name of the fields as text (separated by commas)',
				displayOptions: {
					show: {
						'/options.outputFormat': ['singleItem'],
					},
				},
				requiresDataPath: 'multiple',
			},
			// ----------------------------------------------------------------------------------------------------------
			{
				displayName: 'Options',
				name: 'options',
				type: 'collection',
				placeholder: 'Add Option',
				default: {},
				options: [
					{
						displayName: 'Continue if Field Not Found',
						name: 'continueIfFieldNotFound',
						type: 'boolean',
						default: false,
						description:
							"Whether to continue if field to summarize can't be found in any items and return single empty item, owerwise an error would be thrown",
					},
					{
						displayName: 'Disable Dot Notation',
						name: 'disableDotNotation',
						type: 'boolean',
						default: false,
						description:
							'Whether to disallow referencing child fields using `parent.child` in the field name',
					},
					{
						displayName: 'Output Format',
						name: 'outputFormat',
						type: 'options',
						default: 'separateItems',
						options: [
							{
								name: 'Each Split in a Separate Item',
								value: 'separateItems',
							},
							{
								name: 'All Splits in a Single Item',
								value: 'singleItem',
							},
						],
					},
					{
						// eslint-disable-next-line n8n-nodes-base/node-param-display-name-miscased
						displayName: 'Ignore items without valid fields to group by',
						name: 'skipEmptySplitFields',
						type: 'boolean',
						default: false,
					},
				],
			},
		],
	};

	async execute(this: IExecuteFunctions): Promise<INodeExecutionData[][]> {
		const items = this.getInputData();
		const newItems = items.map(({ json }, i) => ({ ...json, _itemIndex: i }));

		const options = this.getNodeParameter('options', 0, {}) as SummarizeOptions;

		const fieldsToSplitBy = (this.getNodeParameter('fieldsToSplitBy', 0, '') as string)
			.split(',')
			.map((field) => field.trim())
			.filter((field) => field);

		const fieldsToSummarize = this.getNodeParameter(
			'fieldsToSummarize.values',
			0,
			[],
		) as Aggregations;

		if (fieldsToSummarize.filter((aggregation) => aggregation.field !== '').length === 0) {
			throw new NodeOperationError(
				this.getNode(),
				"You need to add at least one aggregation to 'Fields to Summarize' with non empty 'Field'",
			);
		}

		const getValue = fieldValueGetter(options.disableDotNotation);

		const nodeVersion = this.getNode().typeVersion;

		if (nodeVersion < 2.1) {
			try {
				checkIfFieldExists.call(this, newItems, fieldsToSummarize, getValue);
			} catch (error) {
				if (options.continueIfFieldNotFound) {
					const itemData = generatePairedItemData(items.length);

					return [[{ json: {}, pairedItem: itemData }]];
				} else {
					throw error;
				}
			}
		}

		const aggregationResult = splitData(
			fieldsToSplitBy,
			newItems,
			fieldsToSummarize,
			options,
			getValue,
		);

		if (options.outputFormat === 'singleItem') {
			const executionData: INodeExecutionData = {
				json: aggregationResult,
				pairedItem: newItems.map((_v, index) => ({
					item: index,
				})),
			};
			return [[executionData]];
		} else {
			if (!fieldsToSplitBy.length) {
				const { pairedItems, ...json } = aggregationResult;
				const executionData: INodeExecutionData = {
					json,
					pairedItem: ((pairedItems as number[]) || []).map((index: number) => ({
						item: index,
					})),
				};
				return [[executionData]];
			}
			const returnData = aggregationToArray(aggregationResult, fieldsToSplitBy);
			const executionData = returnData.map((item) => {
				const { pairedItems, ...json } = item;
				return {
					json,
					pairedItem: ((pairedItems as number[]) || []).map((index: number) => ({
						item: index,
					})),
				};
			});
			return [executionData];
		}
	}
}