import {TOutletChangeData} from '../outlet_manager_controller/outlet_manager_controller'
import SyncedBooleanAttributesController from '../synced_boolean_attributes_controller/synced_boolean_attributes_controller'

type TOptionKey = string | number
type TActiveOptions = {[k: TOptionKey]: boolean}
export interface OptionsOutlet extends SyncedBooleanAttributesController<TActiveOptions> {
  select: (e: Event, updateTo?: TOutletChangeData<TActiveOptions>) => void
}

export default class OptionsController
  extends SyncedBooleanAttributesController<TActiveOptions>
  implements OptionsOutlet
{
  static outlets = SyncedBooleanAttributesController.outlets
  static targets = ['option']

  static values = {
    ...SyncedBooleanAttributesController.values,
    activeOptions: Object, // The currently active elements in TActiveOptions format
    isMulti: {type: Boolean, default: false}, // Allows more than one selection
    toggleable: {type: Boolean, default: false}, // If true, selecting the same value twice will turn it off. If false, nothing happens
  }

  // Targets
  declare readonly optionTargets: Array<Element>

  // Values
  declare activeOptionsValue: TActiveOptions
  declare readonly isMultiValue: boolean
  declare readonly toggleableValue: boolean

  select(event: Event, updateTo: TOutletChangeData<TActiveOptions> = {}) {
    const activeOptions = updateTo.data
    for (const index in this.optionTargets) {
      const target = this.optionTargets[index]
      const wasSelected = target === event.currentTarget
      const isCurrentlyActive = this.getValueForElement(target) ?? false
      const optionKey = this.#getElementKey(target)
      const shouldChangeState =
        activeOptions !== undefined
          ? !!activeOptions[optionKey] !== isCurrentlyActive
          : this.#shouldChangeState(isCurrentlyActive, wasSelected)

      if (shouldChangeState) {
        const willBeActive = !isCurrentlyActive
        this.updateAttributesForElement(target, willBeActive)
        willBeActive ? this.#activateKey(optionKey) : this.#deactivateKey(optionKey)
      }
    }

    this.sendToOutlets(event, {...updateTo, data: this.activeOptionsValue})
  }

  optionTargetConnected(element: Element) {
    const key = this.#getElementKey(element)
    const isActive = this.activeOptionsValue[key] || this.doesElementHaveOnAttrs(element)
    if (isActive) {
      this.#activateKey(key)
    } else {
      this.#deactivateKey(key)
    }

    this.updateAttributesForElement(element, isActive)
  }

  #shouldChangeState(isCurrentlyActive: boolean, wasSelected: boolean) {
    if (!wasSelected && !isCurrentlyActive) {
      // Not currently on and wasn't selected, no reason to change
      return false
    }

    if (!wasSelected && isCurrentlyActive && this.isMultiValue) {
      // It wasn't selected and it is on. However, multi value is on so just leave it
      return false
    }

    if (wasSelected && isCurrentlyActive && !this.toggleableValue) {
      // It was selected and it's on. But toggle isn't on so just leave it
      return false
    }

    // Wasn't selected and it's active but only one can be active
    // Was selected and it's active but toggling behavior means it should deactivate
    // Was selected and it's not on, so it just needs to be turned on
    return true
  }

  #activateKey(key: TOptionKey) {
    this.activeOptionsValue = {...this.activeOptionsValue, [key]: true}
  }

  #deactivateKey(key: TOptionKey) {
    const copy = {...this.activeOptionsValue}
    delete copy[key]
    this.activeOptionsValue = copy
  }

  #getElementKey(element: Element) {
    const elementValue = element?.getAttribute('data-option-value')
    if (elementValue) return elementValue

    const content = (element as HTMLElement)?.textContent
    if (content === null) {
      throw new Error(
        `${element.tagName} was given as an options target without a data-option-value or textContent. One must be provided to identify the target.`,
      )
    }

    return content.trim()
  }

  getValueForElement(element: Element) {
    const optionKey = this.#getElementKey(element)
    return this.activeOptionsValue[optionKey] ?? false
  }

  getState() {
    return this.activeOptionsValue
  }

  outletUpdate = this.select
}