// Field renderer registry (D-05). A form field's `type` selects the control
// component; any type without a renderer gets UnsupportedField, the design's
// dashed box, so an unknown type never breaks the form. The relation manager
// is registered like any control but holds no form value: it edits its
// relation through its own endpoints and renders only on an existing record.
// Phase 10.1 adds the plugin extension types: a widget mounts a plugin custom
// element (D-04, D-09) and a partial renders a server template (D-17). They
// hold no form value either, but they render on create and update.
// Phase 12.2 adds the fileupload control: it edits its files through the file
// routes against the form's session key (D-02, D-03), so it holds no form
// value either and renders on create and update. The datepicker control is
// a plain value field: its string value is part of the save body (D-18).
// Phase 12.1 adds the password control: a plain value field whose value the
// server never sends back, so it is empty on load and after every save.
import type { Component } from 'vue'
import CheckboxField from './fields/CheckboxField.vue'
import DatepickerField from './fields/DatepickerField.vue'
import DropdownField from './fields/DropdownField.vue'
import FileuploadField from './fields/FileuploadField.vue'
import NumberField from './fields/NumberField.vue'
import PartialField from './fields/PartialField.vue'
import PasswordField from './fields/PasswordField.vue'
import RelationManager from '../relation/RelationManager.vue'
import RelationField from './fields/RelationField.vue'
import SwitchField from './fields/SwitchField.vue'
import TextField from './fields/TextField.vue'
import TextareaField from './fields/TextareaField.vue'
import UnsupportedField from './fields/UnsupportedField.vue'
import WidgetField from './fields/WidgetField.vue'

// The control helpers live in ./control so the field components never import
// this module: registry -> field -> registry would be an import cycle whose
// evaluation order decides whether a renderer is registered at all.
export { controlAttributes, controlClass, toggleOn, toggleValue } from './control'
export type { FieldControlProps } from './control'

/** The relation manager's field type (design screen 5). */
export const RELATION_MANAGER = 'relation-manager'

// The relation manager renders child forms (FormGrid -> FormField -> this
// registry), so it sits on an import cycle with this module. It is looked up
// when a field renders, never while this module evaluates: whichever module
// of the cycle loads first, the binding is complete by then.
const lazyRenderers = new Map<string, () => Component>([[RELATION_MANAGER, () => RelationManager]])

const renderers = new Map<string, Component>([
  ['text', TextField],
  ['textarea', TextareaField],
  ['number', NumberField],
  ['dropdown', DropdownField],
  ['switch', SwitchField],
  ['checkbox', CheckboxField],
  ['relation', RelationField],
  ['widget', WidgetField],
  ['partial', PartialField],
  ['fileupload', FileuploadField],
  ['datepicker', DatepickerField],
  ['password', PasswordField],
])

/** Types whose control shows the label itself (toggle cards, relation manager). */
const selfLabelled = new Set<string>(['switch', 'checkbox', RELATION_MANAGER])

/**
 * Types that need a saved record: never rendered on create (D-05, design
 * screen 5), except a relation manager whose field is deferrable (Phase
 * 12.2, D-03): FormView keeps it and it works on owner id 0.
 */
const recordBound = new Set<string>([RELATION_MANAGER])

/** Types that hold no form value: never part of the save body (D-09). */
const valueless = new Set<string>([RELATION_MANAGER, 'widget', 'partial', 'fileupload'])

/**
 * Types whose control is a group rather than one focusable element: the
 * visible label is a span the group points at, not a label for an input.
 */
const groupLabelledTypes = new Set<string>(['widget', 'partial', 'fileupload'])

export function rendererFor(type: string): Component {
  return renderers.get(type) ?? lazyRenderers.get(type)?.() ?? UnsupportedField
}

/** Whether the SPA can edit values of this field type. */
export function isRegistered(type: string): boolean {
  return (renderers.has(type) || lazyRenderers.has(type)) && !valueless.has(type)
}

/** Whether a field type renders only on an existing record (relation manager). */
export function needsRecord(type: string): boolean {
  return recordBound.has(type)
}

export function ownsLabel(type: string): boolean {
  return selfLabelled.has(type)
}

/**
 * Whether a field type's label names a group (widget, partial) instead of a
 * control. Such a row shows no label row when the field declares no label.
 */
export function groupLabelled(type: string): boolean {
  return groupLabelledTypes.has(type)
}