import { isEqual } from 'lodash'

export const whatHasChanged = <T extends object>(
  prevProps: T,
  nextProps: T,
): Record<string, unknown> => {
  const changedProps: Record<string, unknown> = {}

  for (const key in nextProps) {
    if (Object.prototype.hasOwnProperty.call(nextProps, key)) {
      const prevValue = prevProps[key]
      const nextValue = nextProps[key]

      if (!isEqual(prevValue, nextValue)) {
        if (
          nextValue &&
          typeof nextValue === 'object' &&
          prevValue &&
          typeof prevValue === 'object'
        ) {
          const nestedChanges = whatHasChanged(prevValue, nextValue)
          Object.entries(nestedChanges).forEach(([nestedKey, nestedValue]) => {
            changedProps[`${key}.${nestedKey}`] = nestedValue
          })
        } else {
          changedProps[`${key}-old`] = prevValue
          changedProps[`${key}-new`] = nextValue
        }
      }
    }
  }

  return changedProps
}