import type { SanitizedCollectionConfig } from '../../../collections/config/types.js'
import type { SanitizedGlobalConfig } from '../../../globals/config/types.js'
import type { Operation, PayloadRequest, RequestContext } from '../../../types/index.js'

import { ValidationError } from '../../../errors/index.js'
import { deepCopyObject } from '../../../utilities/deepCopyObject.js'
import { traverseFields } from './traverseFields.js'

type Args<T> = {
  collection: SanitizedCollectionConfig | null
  context: RequestContext
  data: Record<string, unknown> | T
  doc: Record<string, unknown> | T
  docWithLocales: Record<string, unknown>
  duplicate?: boolean
  global: SanitizedGlobalConfig | null
  id?: number | string
  operation: Operation
  req: PayloadRequest
  skipValidation?: boolean
}

/**
 * This function is responsible for the following actions, in order:
 * - Run condition
 * - Execute field hooks
 * - Validate data
 * - Transform data for storage
 * - beforeDuplicate hooks (if duplicate)
 * - Unflatten locales
 */
export const beforeChange = async <T extends Record<string, unknown>>({
  id,
  collection,
  context,
  data: incomingData,
  doc,
  docWithLocales,
  duplicate = false,
  global,
  operation,
  req,
  skipValidation,
}: Args<T>): Promise<T> => {
  const data = deepCopyObject(incomingData)
  const mergeLocaleActions = []
  const errors: { field: string; message: string }[] = []

  await traverseFields({
    id,
    collection,
    context,
    data,
    doc,
    docWithLocales,
    duplicate,
    errors,
    fields: collection?.fields || global?.fields,
    global,
    mergeLocaleActions,
    operation,
    path: '',
    req,
    siblingData: data,
    siblingDoc: doc,
    siblingDocWithLocales: docWithLocales,
    skipValidation,
  })

  if (errors.length > 0) {
    throw new ValidationError(errors, req.t)
  }

  await mergeLocaleActions.reduce(async (priorAction, action) => {
    await priorAction
    await action()
  }, Promise.resolve())

  return data
}
