// Copyright 2015 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
/* eslint-disable @devtools/no-imperative-dom-api */
/* eslint-disable @devtools/no-lit-render-outside-of-view */

import './Toolbar.js';

import * as i18n from '../../core/i18n/i18n.js';
import * as Platform from '../../core/platform/platform.js';
import * as Buttons from '../../ui/components/buttons/buttons.js';
import {html, render} from '../lit/lit.js';
import * as VisualLogging from '../visual_logging/visual_logging.js';

import * as ARIAUtils from './ARIAUtils.js';
import listWidgetStyles from './listWidget.css.js';
import {Tooltip} from './Tooltip.js';
import {createInput, createTextButton, ElementFocusRestorer} from './UIUtils.js';
import {VBox} from './Widget.js';

const UIStrings = {
  /**
   * @description Text on a button to start editing text
   */
  editString: 'Edit',
  /**
   * @description Label for an item to remove something
   */
  removeString: 'Remove',
  /**
   * @description Text to save something
   */
  saveString: 'Save',
  /**
   * @description Text to add something
   */
  addString: 'Add',
  /**
   * @description Text to cancel something
   */
  cancelString: 'Cancel',
  /**
   * @description Text for screen reader to announce that an item has been saved.
   */
  changesSaved: 'Changes to item have been saved',
  /**
   * @description Text for screen reader to announce that an item has been removed.
   */
  removedItem: 'Item has been removed',
} as const;
const str_ = i18n.i18n.registerUIStrings('ui/legacy/ListWidget.ts', UIStrings);
const i18nString = i18n.i18n.getLocalizedString.bind(undefined, str_);

export class ListWidget<T> extends VBox {
  private delegate: Delegate<T>;
  private readonly list: HTMLElement;
  private lastSeparator: boolean;
  private focusRestorer: ElementFocusRestorer|null;
  #items: T[];
  private editable: boolean[];
  private elements: HTMLElement[];
  private editor: Editor<T>|null;
  private editItem: T|null;
  private editElement: HTMLElement|null;
  private emptyPlaceholder: Element|null;
  private isTable: boolean;
  constructor(delegate: Delegate<T>, delegatesFocus = true, isTable = false) {
    super({useShadowDom: true, delegatesFocus});
    this.registerRequiredCSS(listWidgetStyles);
    this.delegate = delegate;

    this.list = this.contentElement.createChild('div', 'list');

    this.lastSeparator = false;
    this.focusRestorer = null;
    this.#items = [];
    this.editable = [];
    this.elements = [];
    this.editor = null;
    this.editItem = null;
    this.editElement = null;

    this.emptyPlaceholder = null;

    this.isTable = isTable;
    if (isTable) {
      this.list.role = 'table';
    }

    this.updatePlaceholder();
  }

  get items(): T[] {
    return this.#items;
  }

  clear(): void {
    this.#items = [];
    this.editable = [];
    this.elements = [];
    this.lastSeparator = false;
    this.list.removeChildren();
    this.updatePlaceholder();
    this.stopEditing();
  }

  updateItem(index: number, newItem: T, editable: boolean, focusable = true, controlLabels: {
    edit?: string,
    delete?: string,
  } = {}): void {
    if (index < 0 || index >= this.#items.length) {
      this.appendItem(newItem, editable, focusable, controlLabels);
      return;
    }

    this.#items[index] = newItem;
    this.editable[index] = editable;
    const element = this.elements[index];
    const [content, controls] = element.children;
    if (controls) {
      element.removeChild(controls);
    }
    this.delegate.updateItem?.(content, newItem, editable, index);
    element.classList.toggle('editable', editable);
    if (editable) {
      if (focusable) {
        element.tabIndex = 0;
      }
      element.appendChild(this.createControls(newItem, element, controlLabels));
    }
  }

  appendItem(item: T, editable: boolean, focusable = true, controlLabels: {edit?: string, delete?: string} = {}): void {
    if (this.lastSeparator && this.#items.length) {
      const element = document.createElement('div');
      element.classList.add('list-separator');
      if (this.isTable) {
        element.role = 'rowgroup';
      }
      this.list.appendChild(element);
    }
    this.lastSeparator = false;

    this.#items.push(item);
    this.editable.push(editable);

    const element = this.list.createChild('div', 'list-item');
    if (this.isTable) {
      element.role = 'rowgroup';
    }
    const content = this.delegate.renderItem(item, editable, this.#items.length - 1);
    if (!content.hasAttribute('jslog')) {
      element.setAttribute('jslog', `${VisualLogging.item().track({resize: true})}`);
    }
    element.appendChild(content);
    if (editable) {
      element.classList.add('editable');
      if (focusable) {
        element.tabIndex = 0;
      }
      element.appendChild(this.createControls(item, element, controlLabels));
    }
    this.elements.push(element);
    this.updatePlaceholder();
  }

  appendSeparator(): void {
    this.lastSeparator = true;
  }

  removeItem(index: number): void {
    if (this.editItem === this.#items[index]) {
      this.stopEditing();
    }

    const element = this.elements[index];

    const previous = element.previousElementSibling;
    const previousIsSeparator = previous?.classList.contains('list-separator');

    const next = element.nextElementSibling;
    const nextIsSeparator = next?.classList.contains('list-separator');

    if (previousIsSeparator && (nextIsSeparator || !next)) {
      previous?.remove();
    }
    if (nextIsSeparator && !previous) {
      next?.remove();
    }
    element.remove();

    this.elements.splice(index, 1);
    this.#items.splice(index, 1);
    this.editable.splice(index, 1);
    this.updatePlaceholder();
  }

  addNewItem(index: number, item: T): void {
    this.startEditing(item, null, this.elements[index] || null);
  }

  setEmptyPlaceholder(element: Element|null): void {
    this.emptyPlaceholder = element;
    this.updatePlaceholder();
  }

  private createControls(item: T, element: HTMLElement, controlLabels: {edit?: string, delete?: string}): Element {
    const controls = document.createElement('div');
    controls.classList.add('controls-container');
    controls.classList.add('fill');

    // clang-format off
    render(html`
      <div class="controls-gradient"></div>
      <div class="controls-buttons">
        <devtools-toolbar>
          <devtools-button class=toolbar-button
                           .iconName=${'edit'}
                           .jslogContext=${'edit-item'}
                           .title=${controlLabels?.edit ?? i18nString(UIStrings.editString)}
                           .variant=${Buttons.Button.Variant.ICON}
                           @click=${onEditClicked}></devtools-button>
          <devtools-button class=toolbar-button
                           .iconName=${'bin'}
                           .jslogContext=${'remove-item'}
                           .title=${controlLabels?.delete ?? i18nString(UIStrings.removeString)}
                           .variant=${Buttons.Button.Variant.ICON}
                           @click=${onRemoveClicked}></devtools-button>
        </devtools-toolbar>
      </div>`, controls, {host: this});
    // clang-format on

    return controls;

    function onEditClicked(this: ListWidget<T>): void {
      const index = this.elements.indexOf(element);
      const insertionPoint = this.elements[index + 1] || null;
      this.startEditing(item, element, insertionPoint);
    }

    function onRemoveClicked(this: ListWidget<T>): void {
      const index = this.elements.indexOf(element);
      this.element.focus();
      this.delegate.removeItemRequested(this.#items[index], index);
      ARIAUtils.LiveAnnouncer.alert(i18nString(UIStrings.removedItem));
      if (this.elements.length >= 1) {
        // focus on the next item in the list, or the last item if we're removing the last item
        (this.elements[Math.min(index, this.elements.length - 1)] as HTMLElement).focus();
      }
    }
  }

  override wasShown(): void {
    super.wasShown();
    this.stopEditing();
  }

  private updatePlaceholder(): void {
    if (!this.emptyPlaceholder) {
      return;
    }

    if (!this.elements.length && !this.editor) {
      this.list.appendChild(this.emptyPlaceholder);
    } else {
      this.emptyPlaceholder.remove();
    }
  }

  private startEditing(item: T, element: HTMLElement|null, insertionPoint: Element|null): void {
    if (element && this.editElement === element) {
      return;
    }

    this.stopEditing();
    this.focusRestorer = new ElementFocusRestorer(this.element);

    this.list.classList.add('list-editing');
    this.element.classList.add('list-editing');
    this.editItem = item;
    this.editElement = element;
    if (element) {
      element.classList.add('hidden');
    }

    const index = element ? this.elements.indexOf(element) : -1;
    this.editor = this.delegate.beginEdit(item);
    this.updatePlaceholder();
    this.list.insertBefore(this.editor.element, insertionPoint);
    this.editor.beginEdit(
        item, index, element ? i18nString(UIStrings.saveString) : i18nString(UIStrings.addString),
        this.commitEditing.bind(this), this.stopEditing.bind(this));
  }

  private commitEditing(): void {
    const editItem = this.editItem;
    const isNew = !this.editElement;
    const editor = (this.editor as Editor<T>);
    // Focus on the current item or the new item after committing
    const focusElementIndex = this.editElement ? this.elements.indexOf(this.editElement) : this.elements.length - 1;
    this.stopEditing();
    if (editItem !== null) {
      this.delegate.commitEdit(editItem, editor, isNew);
      ARIAUtils.LiveAnnouncer.alert(i18nString(UIStrings.changesSaved));
      if (this.elements[focusElementIndex]) {
        (this.elements[focusElementIndex] as HTMLElement).focus();
      }
    }
  }

  private stopEditing(): void {
    this.list.classList.remove('list-editing');
    this.element.classList.remove('list-editing');
    if (this.focusRestorer) {
      this.focusRestorer.restore();
    }
    if (this.editElement) {
      this.editElement.classList.remove('hidden');
    }
    if (this.editor?.element.parentElement) {
      this.editor.element.remove();
    }

    this.editor = null;
    this.editItem = null;
    this.editElement = null;
    this.updatePlaceholder();
  }
}

export interface Delegate<T> {
  updateItem?(content: Element, newItem: T, editable: boolean, index: number): void;
  renderItem(item: T, editable: boolean, index: number): Element;
  removeItemRequested(item: T, index: number): void;
  beginEdit(item: T): Editor<T>;
  commitEdit(item: T, editor: Editor<T>, isNew: boolean): void;
}

export interface CustomEditorControl<T> extends HTMLElement {
  value: T;
  validate: () => ValidatorResult;
}

export type EditorControl<T = string> = (HTMLInputElement|HTMLSelectElement|CustomEditorControl<T>);

export class Editor<T> {
  element: HTMLDivElement;
  readonly #contentElement: HTMLElement;
  private commitButton: Buttons.Button.Button;
  private readonly cancelButton: Buttons.Button.Button;
  private errorMessageContainer: HTMLElement;
  private readonly controls: EditorControl[] = [];
  private readonly controlByName = new Map<string, EditorControl>();
  private readonly validators: Array<(arg0: T, arg1: number, arg2: EditorControl) => ValidatorResult> = [];
  private commit: (() => void)|null = null;
  private cancel: (() => void)|null = null;
  private item: T|null = null;
  private index = -1;

  constructor() {
    this.element = document.createElement('div');
    this.element.classList.add('editor-container');
    this.element.setAttribute('jslog', `${VisualLogging.pane('editor').track({resize: true})}`);
    this.element.addEventListener(
        'keydown', onKeyDown.bind(null, Platform.KeyboardUtilities.isEscKey, this.cancelClicked.bind(this)), false);

    this.#contentElement = this.element.createChild('div', 'editor-content');
    this.#contentElement.addEventListener('keydown', onKeyDown.bind(null, event => {
      if (event.key !== 'Enter') {
        return false;
      }
      if (event.target instanceof HTMLSelectElement) {
        // 'Enter' on <select> is supposed to open the drop down, so don't swallow that here.
        return false;
      }
      return true;
    }, this.commitClicked.bind(this)), false);

    const buttonsRow = this.element.createChild('div', 'editor-buttons');
    this.cancelButton = createTextButton(i18nString(UIStrings.cancelString), this.cancelClicked.bind(this), {
      jslogContext: 'cancel',
      variant: Buttons.Button.Variant.OUTLINED,
    });
    this.cancelButton.setAttribute('jslog', `${VisualLogging.action('cancel').track({click: true})}`);
    buttonsRow.appendChild(this.cancelButton);
    this.commitButton = createTextButton('', this.commitClicked.bind(this), {
      jslogContext: 'commit',
      variant: Buttons.Button.Variant.PRIMARY,
    });
    buttonsRow.appendChild(this.commitButton);

    this.errorMessageContainer = this.element.createChild('div', 'list-widget-input-validation-error');
    ARIAUtils.markAsAlert(this.errorMessageContainer);

    function onKeyDown(predicate: (arg0: KeyboardEvent) => boolean, callback: () => void, event: KeyboardEvent): void {
      if (predicate(event)) {
        event.consume(true);
        callback();
      }
    }
  }

  contentElement(): Element {
    return this.#contentElement;
  }

  createInput(
      name: string, type: string, title: string,
      validator: (arg0: T, arg1: number, arg2: EditorControl) => ValidatorResult): HTMLInputElement {
    const input = (createInput('', type));
    input.placeholder = title;
    input.addEventListener('input', this.validateControls.bind(this, false), false);
    input.setAttribute('jslog', `${VisualLogging.textField().track({change: true, keydown: 'Enter'}).context(name)}`);
    ARIAUtils.setLabel(input, title);
    this.controlByName.set(name, input);
    this.controls.push(input);
    this.validators.push(validator);
    return input;
  }

  createSelect(
      name: string, options: string[], validator: (arg0: T, arg1: number, arg2: EditorControl) => ValidatorResult,
      title?: string): HTMLSelectElement {
    const select = document.createElement('select');
    select.setAttribute('jslog', `${VisualLogging.dropDown().track({change: true}).context(name)}`);
    for (let index = 0; index < options.length; ++index) {
      const option = select.createChild('option');
      option.value = options[index];
      option.textContent = options[index];
      option.setAttribute(
          'jslog', `${VisualLogging.item(Platform.StringUtilities.toKebabCase(options[index])).track({click: true})}`);
    }
    if (title) {
      Tooltip.install(select, title);
      ARIAUtils.setLabel(select, title);
    }
    select.addEventListener('input', this.validateControls.bind(this, false), false);
    select.addEventListener('blur', this.validateControls.bind(this, false), false);
    this.controlByName.set(name, select);
    this.controls.push(select);
    this.validators.push(validator);
    return select;
  }

  createCustomControl<S, U extends CustomEditorControl<S>>(
      name: string, ctor: {new(): U},
      validator: (arg0: T, arg1: number, arg2: EditorControl) => ValidatorResult): CustomEditorControl<S> {
    const control = new ctor();
    this.controlByName.set(name, control as unknown as CustomEditorControl<string>);
    this.controls.push(control as unknown as CustomEditorControl<string>);
    this.validators.push(validator);
    return control;
  }

  control(name: string): EditorControl {
    const control = this.controlByName.get(name);
    if (!control) {
      throw new Error(`Control with name ${name} does not exist, please verify.`);
    }
    return control;
  }

  private validateControls(forceValid: boolean): void {
    let allValid = true;
    this.errorMessageContainer.textContent = '';
    for (let index = 0; index < this.controls.length; ++index) {
      const input = this.controls[index];
      const {valid, errorMessage} = this.validators[index].call(null, (this.item as T), this.index, input);

      input.classList.toggle('error-input', !valid && !forceValid);
      if (valid || forceValid) {
        ARIAUtils.setInvalid(input, false);
      } else {
        ARIAUtils.setInvalid(input, true);
      }

      if (!forceValid && errorMessage) {
        if (this.errorMessageContainer.textContent) {
          const br = document.createElement('br');
          this.errorMessageContainer.append(br);
        }
        this.errorMessageContainer.append(errorMessage);
      }

      allValid = allValid && valid;
    }
    this.commitButton.disabled = !allValid;
  }

  requestValidation(): void {
    this.validateControls(false);
  }

  beginEdit(item: T, index: number, commitButtonTitle: string, commit: () => void, cancel: () => void): void {
    this.commit = commit;
    this.cancel = cancel;
    this.item = item;
    this.index = index;

    this.commitButton.textContent = commitButtonTitle;
    this.element.scrollIntoViewIfNeeded(false);
    if (this.controls.length) {
      this.controls[0].focus();
    }
    this.validateControls(true);
  }

  private commitClicked(): void {
    if (this.commitButton.disabled) {
      return;
    }

    const commit = this.commit;
    this.commit = null;
    this.cancel = null;
    this.item = null;
    this.index = -1;
    if (commit) {
      commit();
    }
  }

  private cancelClicked(): void {
    const cancel = this.cancel;
    this.commit = null;
    this.cancel = null;
    this.item = null;
    this.index = -1;
    if (cancel) {
      cancel();
    }
  }
}
export interface ValidatorResult {
  valid: boolean;
  errorMessage?: string;
}