From 2c252b0b2d5282f4a87bce76f93c4c02dd8ff5e3 Mon Sep 17 00:00:00 2001
From: Michael Kret <88898367+michael-radency@users.noreply.github.com>
Date: Wed, 27 Nov 2024 12:42:55 +0200
Subject: [PATCH] feat(AI Transform Node): Support for drag and drop (#11276)

---
 .../ButtonParameter.test.ts                   |   1 +
 .../ButtonParameter/ButtonParameter.vue       |  80 +++++++--
 .../src/components/ButtonParameter/utils.ts   | 166 ++++++++++++++++++
 3 files changed, 235 insertions(+), 12 deletions(-)
 rename packages/editor-ui/src/components/{ => ButtonParameter}/ButtonParameter.test.ts (99%)

diff --git a/packages/editor-ui/src/components/ButtonParameter.test.ts b/packages/editor-ui/src/components/ButtonParameter/ButtonParameter.test.ts
similarity index 99%
rename from packages/editor-ui/src/components/ButtonParameter.test.ts
rename to packages/editor-ui/src/components/ButtonParameter/ButtonParameter.test.ts
index d018e23418..ba5070e335 100644
--- a/packages/editor-ui/src/components/ButtonParameter.test.ts
+++ b/packages/editor-ui/src/components/ButtonParameter/ButtonParameter.test.ts
@@ -45,6 +45,7 @@ describe('ButtonParameter', () => {
 		vi.mocked(useNDVStore).mockReturnValue({
 			ndvInputData: [{}],
 			activeNode: { name: 'TestNode', parameters: {} },
+			isDraggableDragging: false,
 		} as any);
 
 		vi.mocked(useWorkflowsStore).mockReturnValue({
diff --git a/packages/editor-ui/src/components/ButtonParameter/ButtonParameter.vue b/packages/editor-ui/src/components/ButtonParameter/ButtonParameter.vue
index 7bce766ea3..a321f3cc70 100644
--- a/packages/editor-ui/src/components/ButtonParameter/ButtonParameter.vue
+++ b/packages/editor-ui/src/components/ButtonParameter/ButtonParameter.vue
@@ -6,10 +6,18 @@ import { N8nButton, N8nInput, N8nTooltip } from 'n8n-design-system/components';
 import { useI18n } from '@/composables/useI18n';
 import { useToast } from '@/composables/useToast';
 import { useNDVStore } from '@/stores/ndv.store';
-import { getParentNodes, generateCodeForAiTransform } from './utils';
+import {
+	getParentNodes,
+	generateCodeForAiTransform,
+	type TextareaRowData,
+	getUpdatedTextareaValue,
+	getTextareaCursorPosition,
+} from './utils';
 import { useTelemetry } from '@/composables/useTelemetry';
 import { useUIStore } from '@/stores/ui.store';
 
+import { propertyNameFromExpression } from '../../utils/mappingUtils';
+
 const AI_TRANSFORM_CODE_GENERATED_FOR_PROMPT = 'codeGeneratedForPrompt';
 
 const emit = defineEmits<{
@@ -29,6 +37,7 @@ const i18n = useI18n();
 const isLoading = ref(false);
 const prompt = ref(props.value);
 const parentNodes = ref<INodeUi[]>([]);
+const textareaRowsData = ref<TextareaRowData | null>(null);
 
 const hasExecutionData = computed(() => (useNDVStore().ndvInputData || []).length > 0);
 const hasInputField = computed(() => props.parameter.typeOptions?.buttonConfig?.hasInputField);
@@ -159,6 +168,37 @@ function useDarkBackdrop(): string {
 onMounted(() => {
 	parentNodes.value = getParentNodes();
 });
+
+function cleanTextareaRowsData() {
+	textareaRowsData.value = null;
+}
+
+async function onDrop(value: string, event: MouseEvent) {
+	value = propertyNameFromExpression(value);
+
+	prompt.value = getUpdatedTextareaValue(event, textareaRowsData.value, value);
+
+	emit('valueChanged', {
+		name: getPath(props.parameter.name),
+		value: prompt.value,
+	});
+}
+
+async function updateCursorPositionOnMouseMove(event: MouseEvent, activeDrop: boolean) {
+	if (!activeDrop) return;
+
+	const textarea = event.target as HTMLTextAreaElement;
+
+	const position = getTextareaCursorPosition(
+		textarea,
+		textareaRowsData.value,
+		event.clientX,
+		event.clientY,
+	);
+
+	textarea.focus();
+	textarea.setSelectionRange(position, position);
+}
 </script>
 
 <template>
@@ -186,16 +226,25 @@ onMounted(() => {
 					v-text="'Instructions changed'"
 				/>
 			</div>
-			<N8nInput
-				v-model="prompt"
-				:class="$style.input"
-				style="border: 1px solid var(--color-foreground-base)"
-				type="textarea"
-				:rows="6"
-				:maxlength="inputFieldMaxLength"
-				:placeholder="parameter.placeholder"
-				@input="onPromptInput"
-			/>
+			<DraggableTarget type="mapping" :disabled="isLoading" @drop="onDrop">
+				<template #default="{ activeDrop, droppable }">
+					<N8nInput
+						v-model="prompt"
+						:class="[
+							$style.input,
+							{ [$style.activeDrop]: activeDrop, [$style.droppable]: droppable },
+						]"
+						style="border: 1.5px solid var(--color-foreground-base)"
+						type="textarea"
+						:rows="6"
+						:maxlength="inputFieldMaxLength"
+						:placeholder="parameter.placeholder"
+						@input="onPromptInput"
+						@mousemove="updateCursorPositionOnMouseMove($event, activeDrop)"
+						@mouseleave="cleanTextareaRowsData"
+					/>
+				</template>
+			</DraggableTarget>
 		</div>
 		<div :class="$style.controls">
 			<N8nTooltip :disabled="isSubmitEnabled">
@@ -227,7 +276,7 @@ onMounted(() => {
 
 <style module lang="scss">
 .input * {
-	border: 0 !important;
+	border: 1.5px transparent !important;
 }
 .input textarea {
 	font-size: var(--font-size-2xs);
@@ -277,4 +326,11 @@ onMounted(() => {
 	color: var(--color-warning);
 	line-height: 1.2;
 }
+.droppable {
+	border: 1.5px dashed var(--color-ndv-droppable-parameter) !important;
+}
+.activeDrop {
+	border: 1.5px solid var(--color-success) !important;
+	cursor: grabbing;
+}
 </style>
diff --git a/packages/editor-ui/src/components/ButtonParameter/utils.ts b/packages/editor-ui/src/components/ButtonParameter/utils.ts
index f0b09aec18..80893f8667 100644
--- a/packages/editor-ui/src/components/ButtonParameter/utils.ts
+++ b/packages/editor-ui/src/components/ButtonParameter/utils.ts
@@ -12,6 +12,11 @@ import { format } from 'prettier';
 import jsParser from 'prettier/plugins/babel';
 import * as estree from 'prettier/plugins/estree';
 
+export type TextareaRowData = {
+	rows: string[];
+	linesToRowsMap: number[][];
+};
+
 export function getParentNodes() {
 	const activeNode = useNDVStore().activeNode;
 	const { getCurrentWorkflow, getNodeByName } = useWorkflowsStore();
@@ -89,3 +94,164 @@ export async function generateCodeForAiTransform(prompt: string, path: string) {
 
 	return updateInformation;
 }
+
+//------ drag and drop ------
+
+function splitText(textarea: HTMLTextAreaElement, textareaRowsData: TextareaRowData | null) {
+	if (textareaRowsData) return textareaRowsData;
+	const rows: string[] = [];
+	const linesToRowsMap: number[][] = [];
+	const style = window.getComputedStyle(textarea);
+
+	const padding = parseFloat(style.paddingLeft) + parseFloat(style.paddingRight);
+	const border = parseFloat(style.borderLeftWidth) + parseFloat(style.borderRightWidth);
+	const textareaWidth = textarea.clientWidth - padding - border;
+
+	const context = createTextContext(style);
+
+	const lines = textarea.value.split('\n');
+
+	lines.forEach((_) => {
+		linesToRowsMap.push([]);
+	});
+	lines.forEach((line, index) => {
+		if (line === '') {
+			rows.push(line);
+			linesToRowsMap[index].push(rows.length - 1);
+			return;
+		}
+		let currentLine = '';
+		const words = line.split(/(\s+)/);
+
+		words.forEach((word) => {
+			const testLine = currentLine + word;
+			const testWidth = context.measureText(testLine).width;
+
+			if (testWidth <= textareaWidth) {
+				currentLine = testLine;
+			} else {
+				rows.push(currentLine.trimEnd());
+				linesToRowsMap[index].push(rows.length - 1);
+				currentLine = word;
+			}
+		});
+
+		if (currentLine) {
+			rows.push(currentLine.trimEnd());
+			linesToRowsMap[index].push(rows.length - 1);
+		}
+	});
+
+	return { rows, linesToRowsMap };
+}
+
+function createTextContext(style: CSSStyleDeclaration): CanvasRenderingContext2D {
+	const canvas = document.createElement('canvas');
+	const context = canvas.getContext('2d')!;
+	context.font = `${style.fontWeight} ${style.fontSize} ${style.fontFamily}`;
+	return context;
+}
+
+const getRowIndex = (textareaY: number, lineHeight: string) => {
+	const rowHeight = parseInt(lineHeight, 10);
+	const snapPosition = textareaY - rowHeight / 2 - 1;
+	return Math.floor(snapPosition / rowHeight);
+};
+
+const getColumnIndex = (rowText: string, textareaX: number, font: string) => {
+	const span = document.createElement('span');
+	span.style.font = font;
+	span.style.visibility = 'hidden';
+	span.style.position = 'absolute';
+	span.style.whiteSpace = 'pre';
+	document.body.appendChild(span);
+
+	let left = 0;
+	let right = rowText.length;
+	let col = 0;
+
+	while (left <= right) {
+		const mid = Math.floor((left + right) / 2);
+		span.textContent = rowText.substring(0, mid);
+		const width = span.getBoundingClientRect().width;
+
+		if (width <= textareaX) {
+			col = mid;
+			left = mid + 1;
+		} else {
+			right = mid - 1;
+		}
+	}
+
+	document.body.removeChild(span);
+
+	return rowText.length === col ? col : col - 1;
+};
+
+export function getUpdatedTextareaValue(
+	event: MouseEvent,
+	textareaRowsData: TextareaRowData | null,
+	value: string,
+) {
+	const textarea = event.target as HTMLTextAreaElement;
+	const rect = textarea.getBoundingClientRect();
+	const textareaX = event.clientX - rect.left;
+	const textareaY = event.clientY - rect.top;
+	const { lineHeight, font } = window.getComputedStyle(textarea);
+
+	const rowIndex = getRowIndex(textareaY, lineHeight);
+
+	const rowsData = splitText(textarea, textareaRowsData);
+
+	let newText = value;
+
+	if (rowsData.rows[rowIndex] === undefined) {
+		newText = `${textarea.value} ${value}`;
+	}
+	const { rows, linesToRowsMap } = rowsData;
+	const rowText = rows[rowIndex];
+
+	if (rowText === '') {
+		rows[rowIndex] = value;
+	} else {
+		const col = getColumnIndex(rowText, textareaX, font);
+		rows[rowIndex] = [rows[rowIndex].slice(0, col).trim(), value, rows[rowIndex].slice(col).trim()]
+			.join(' ')
+			.trim();
+	}
+
+	newText = linesToRowsMap
+		.map((lineMap) => {
+			return lineMap.map((index) => rows[index]).join(' ');
+		})
+		.join('\n');
+
+	return newText;
+}
+
+export function getTextareaCursorPosition(
+	textarea: HTMLTextAreaElement,
+	textareaRowsData: TextareaRowData | null,
+	clientX: number,
+	clientY: number,
+) {
+	const rect = textarea.getBoundingClientRect();
+	const textareaX = clientX - rect.left;
+	const textareaY = clientY - rect.top;
+	const { lineHeight, font } = window.getComputedStyle(textarea);
+
+	const rowIndex = getRowIndex(textareaY, lineHeight);
+	const { rows } = splitText(textarea, textareaRowsData);
+
+	if (rowIndex < 0 || rowIndex >= rows.length) {
+		return textarea.value.length;
+	}
+
+	const rowText = rows[rowIndex];
+
+	const col = getColumnIndex(rowText, textareaX, font);
+
+	const position = rows.slice(0, rowIndex).reduce((acc, curr) => acc + curr.length + 1, 0) + col;
+
+	return position;
+}