refactor(editor): ♻️ Undo / Redo buttons + structure refacto

Yet another huge refacto... While implementing undo and redo features I understood that I updated the stored typebot too many times (i.e. on each key input) so I had to rethink it entirely. I also moved around some files.

apps/builder/components/editor/StepsSideBar/StepCard.tsx

@@ -0,0 +1,78 @@
+import { Flex, HStack, StackProps, Text } from '@chakra-ui/react'
+import { StepType, DraggableStepType } from 'models'
+import { useStepDnd } from 'contexts/StepDndContext'
+import React, { useEffect, useState } from 'react'
+import { StepIcon } from './StepIcon'
+import { StepTypeLabel } from './StepTypeLabel'
+
+export const StepCard = ({
+  type,
+  onMouseDown,
+}: {
+  type: DraggableStepType
+  onMouseDown: (e: React.MouseEvent, type: DraggableStepType) => void
+}) => {
+  const { draggedStepType } = useStepDnd()
+  const [isMouseDown, setIsMouseDown] = useState(false)
+
+  useEffect(() => {
+    setIsMouseDown(draggedStepType === type)
+  }, [draggedStepType, type])
+
+  const handleMouseDown = (e: React.MouseEvent) => onMouseDown(e, type)
+
+  return (
+    <Flex pos="relative">
+      <HStack
+        borderWidth="1px"
+        rounded="lg"
+        flex="1"
+        cursor={'grab'}
+        opacity={isMouseDown ? '0.4' : '1'}
+        onMouseDown={handleMouseDown}
+        bgColor="white"
+        shadow="sm"
+        px="4"
+        py="2"
+        _hover={{ shadow: 'md' }}
+        transition="box-shadow 200ms"
+      >
+        {!isMouseDown ? (
+          <>
+            <StepIcon type={type} />
+            <StepTypeLabel type={type} />
+          </>
+        ) : (
+          <Text color="white" userSelect="none">
+            Placeholder
+          </Text>
+        )}
+      </HStack>
+    </Flex>
+  )
+}
+
+export const StepCardOverlay = ({
+  type,
+  ...props
+}: StackProps & { type: StepType }) => {
+  return (
+    <HStack
+      borderWidth="1px"
+      rounded="lg"
+      cursor={'grabbing'}
+      w="147px"
+      transition="none"
+      pointerEvents="none"
+      px="4"
+      py="2"
+      bgColor="white"
+      shadow="xl"
+      zIndex={2}
+      {...props}
+    >
+      <StepIcon type={type} />
+      <StepTypeLabel type={type} />
+    </HStack>
+  )
+}