import { createAtom } from '@reatom/core' ; export type FieldValidator < FieldValue > = ( value : FieldValue , allValues : object , meta ? : FieldState < FieldValue > ) => any | Promise < any > ; export type FieldConfig = { validate : FieldValidator < any > | null ; } ; export type FieldState < FieldValue > = { name : string ; value : FieldValue ; error : string | null ; touched : boolean ; validating : boolean ; destroyView : boolean ; } ; export type FormState < FormValues , InitialFormValues = Partial < FormValues > > = { initialValues : InitialFormValues ; pristine : boolean ; submitting : boolean ; valid : boolean ; invalid : boolean ; validating : boolean ; values : FormValues ; } ; type SubmissionErrors = Record < string , any > | undefined ; export type FormConfig < FormValues = any , InitialFormValues = Partial < FormValues > > = { initialValues ? : InitialFormValues ; submit : ( values : FormValues ) => SubmissionErrors | Promise < SubmissionErrors > | void ; } ; const field = { name : '' , value : null , error : null , touched : false , validate : null , validating : false , destroyView : false , } ; const formInitial = { submitting : false , fields : { } , } ; export type CreateFormParams = { onSubmit : FormConfig [ 'submit' ] ; initialValues : FormConfig [ 'initialValues' ] ; } ; export type FieldMetaState < FieldValue > = Pick < FieldState < FieldValue > , Exclude < keyof FieldState < FieldValue > , 'name' | 'value' > > ; export const mapFieldToMeta = ( currentField ) => ( { error : currentField . error , validating : currentField . validating , touched : currentField . touched , destroyView : currentField . destroyView , } ) ; export const createForm = ( { onSubmit , initialValues } ) => { const initial = { ... formInitial , submit : onSubmit , initialValues } ; return createAtom ( { submit : ( callback ) => callback , initialize : ( values ) => values , blur : ( name ) => name , reset : ( name ) => name , focus : ( name ) => name , change : ( name , value ) => ( { name , value } ) , addField : ( name ) => name , destroyView : ( name ) => name , createView : ( name ) => name , setConfig : ( name , config ) => ( { name , config } ) , setConfigForm : ( name , config ) => ( { name , config } ) , _mergeField : ( name , newField ) => ( { name , newField , } ) , _mergeForm : ( newForm ) => newForm , } , ( { onAction , schedule , create } , state = initial ) => { let newState = state ; const getInvalid = ( ) => Object . values ( newState . fields ) . some ( ( { error , destroyView } ) => ( destroyView ? false : error ) ) ; const getValues = ( ) => ( { ... newState . initialValues , ... Object . fromEntries ( Object . values ( newState . fields ) . map ( ( { name , value } ) => [ name , value ] ) ) , } ) ; const mergeFieldByName = ( name , patch ) => { if ( newState === state ) { newState = { ... state } ; } if ( newState . fields === state . fields ) { newState . fields = { ... state . fields } ; } newState . fields [ name ] = { ... newState . fields [ name ] , ... patch } ; } ; const executeValidate = ( name ) => { const currentField = newState . fields [ name ] ; const validate = currentField . validate ; if ( ! validate ) { return ; } schedule ( async ( dispatch ) => { const actions = [ create ( '_mergeField' , currentField . name , { validating : false , } ) , ] ; try { dispatch ( create ( '_mergeField' , currentField . name , { validating : true , } ) ) ; actions . push ( create ( '_mergeField' , currentField . name , { error : await validate ( currentField . value , newState . values , { ... mapFieldToMeta ( currentField ) , value : currentField . value , name : currentField . name , } ) , } ) ) ; } finally { dispatch ( actions ) ; } } ) ; } ; onAction ( 'change' , ( { name , value } ) => { mergeFieldByName ( name , { value } ) ; executeValidate ( name ) ; } ) ; onAction ( 'submit' , ( callback ) => { schedule ( async ( dispatch ) => { const actions = [ create ( '_mergeForm' , { submitting : false , } ) , ] ; try { dispatch ( create ( '_mergeForm' , { submitting : true , fields : Object . fromEntries ( Object . entries ( newState . fields ) . map ( ( [ name , value ] ) => [ name , { ... value , touched : true } ] ) ) , } ) ) ; if ( ! getInvalid ( ) ) { await newState . submit ( getValues ( ) ) ; } } finally { dispatch ( actions ) ; callback ( ) ; } } ) ; } ) ; onAction ( 'reset' , ( name ) => { mergeFieldByName ( name , { ... field , name , value : newState . initialValues ?. [ name ] , } ) ; } ) ; onAction ( 'setConfig' , ( { name , config } ) => { mergeFieldByName ( name , config ) ; if ( config . validate ) { executeValidate ( name ) ; } } ) ; onAction ( 'addField' , ( name ) => { const existField = Boolean ( newState . fields [ name ] ) ; mergeFieldByName ( name , { ... ( existField ? newState . fields [ name ] : field ) , name , value : newState . initialValues ?. [ name ] , destroyView : false , } ) ; } ) ; onAction ( '_mergeField' , ( { name , newField } ) => { mergeFieldByName ( name , newField ) ; } ) ; onAction ( '_mergeForm' , ( newForm ) => { newState = { ... newState , ... newForm , } ; } ) ; onAction ( 'initialize' , ( init ) => { newState = { ... newState , ... { initialValues : init } , fields : Object . fromEntries ( Object . entries ( newState . fields ) . map ( ( [ name , value ] ) => [ name , { ... value , value : init [ name ] } ] ) ) , } ; } ) ; onAction ( 'blur' , ( name ) => { mergeFieldByName ( name , { touched : true } ) ; } ) ; onAction ( 'destroyView' , ( name ) => { mergeFieldByName ( name , { destroyView : true } ) ; } ) ; onAction ( 'createView' , ( name ) => { mergeFieldByName ( name , { destroyView : false } ) ; } ) ; const invalid = getInvalid ( ) ; return { ... newState , valid : ! invalid , invalid , values : getValues ( ) , pristine : Object . entries ( newState . fields ) . every ( ( [ name , { value } ] ) => newState . initialValues [ name ] === value ) , validating : Object . values ( newState . fields ) . some ( ( { validating } ) => validating ) , } ; } ) ; } ;