/*
 * Copyright (c) 2010, 2023 BSI Business Systems Integration AG
 *
 * This program and the accompanying materials are made
 * available under the terms of the Eclipse Public License 2.0
 * which is available at https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 */
import {aria, Device, Form, FormField, FormFieldLayout, GroupBox, icons, InitModelOf, inspector, scout, scrollbars, strings, tooltips, WizardProgressFieldEventMap, WizardProgressFieldLayout, WizardProgressFieldModel} from '../../../index';
import $ from 'jquery';

export class WizardProgressField extends FormField implements WizardProgressFieldModel {
  declare model: WizardProgressFieldModel;
  declare eventMap: WizardProgressFieldEventMap;
  declare self: WizardProgressField;

  activeStepIndex: number;
  steps: WizardStep[];

  /** Used to determine direction of transition ("going backward" or "going forward") */
  previousActiveStepIndex: number;
  /**
   * Helper map to find a step by step index. The step index does not necessarily correspond to the
   * array index, because invisible model steps can produce "holes" in the sequence of indices.
   */
  stepsMap: Record<number, WizardStep>;
  keepActiveStepAtLeftBorder: boolean;
  animateScrolling: boolean;
  $wizardStepsBody: JQuery;
  $screenReaderStatus: JQuery;

  constructor() {
    super();

    this.activeStepIndex = -1;
    this.steps = [];
    this.previousActiveStepIndex = -1;
    this.stepsMap = {};
    this.$wizardStepsBody = null;
    this.keepActiveStepAtLeftBorder = Device.get().type === Device.Type.MOBILE;
    this.animateScrolling = Device.get().type === Device.Type.MOBILE;
    this.$screenReaderStatus = null;
  }

  protected override _init(model: InitModelOf<this>) {
    super._init(model);
    this._updateStepsMap();
  }

  protected override _render() {
    this.addContainer(this.$parent, 'wizard-progress-field', new WizardProgressFieldLayout(this));
    this.addField(this.$parent.makeDiv('wizard-steps'));
    this.addStatus();
    this.addLabel();

    // Add compact class on mobile. It is not based on width because height will be smaller too which is not desired on desktop or tablet
    // (field would not be correctly aligned with other components anymore)
    this.$field.toggleClass('compact', Device.get().type === Device.Type.MOBILE);
    let layout = this.htmlComp.layout as FormFieldLayout;
    layout.compactFieldWidth = -1; // disable compact toggling

    this.$wizardStepsBody = this.$field.appendDiv('wizard-steps-body');

    this._addScreenReaderStatus();

    this._installScrollbars({
      axis: 'x',
      scrollShadow: 'none'
    });

    // If this field is the first field in a form's main box, mark the form as "wizard-container-form"
    if (this.parent instanceof GroupBox && this.parent.controls[0] === this && this.parent.parent instanceof Form) {
      let form = this.parent.parent;
      form.$container.addClass('wizard-container-form');
    }
  }

  protected _addScreenReaderStatus() {
    this.$screenReaderStatus = this.$field.appendDiv('screen-reader-steps-description');
    aria.role(this.$screenReaderStatus, 'status');
    aria.screenReaderOnly(this.$screenReaderStatus);
  }

  protected override _renderProperties() {
    super._renderProperties();
    this._renderSteps();
    this._renderActiveStepIndex();
  }

  protected _setSteps(steps: WizardStep[]) {
    this._setProperty('steps', steps);
    this._updateStepsMap();
  }

  protected _renderSteps() {
    this.$wizardStepsBody.children('.wizard-step').each(function() {
      // Tooltips are only uninstalled if user clicked outside container. However, the steps
      // may be updated by clicking inside the container. Therefore, manually make sure all
      // tooltips are uninstalled before destroying the DOM elements.
      tooltips.uninstall($(this));
    });
    this.$wizardStepsBody.empty();

    this.steps.forEach((step, index) => {
      // Step
      let $step = this.$wizardStepsBody
        .appendDiv('wizard-step')
        .addClass(step.cssClass)
        .data('wizard-step', step);
      step.$step = $step;
      this._updateStepClasses(step);

      // Inspector info
      if (this.session.inspector) {
        inspector.applyInfo(step, $step);
        $step.attr('data-step-index', step.index);
      }

      if (strings.hasText(step.tooltipText)) {
        tooltips.install($step, {
          parent: this,
          text: step.tooltipText,
          tooltipPosition: 'bottom'
        });
      }

      // Icon
      let $icon = $step.appendDiv('icon');
      if (step.iconId) {
        $icon.icon(step.iconId);
      } else if (step.finished) {
        $icon.icon(icons.CHECKED_BOLD);
      } else {
        $icon.text(index + 1);
      }
      // Text
      let $text = $step.appendDiv('text');
      $text.appendDiv('title').textOrNbsp(step.title).attr('data-text', step.title);
      if (step.subTitle) {
        $text.appendDiv('sub-title').textOrNbsp(step.subTitle);
      }

      // Separator
      if (index < this.steps.length - 1) {
        this.$wizardStepsBody
          .appendDiv('wizard-step-separator');
      }
    });

    this.invalidateLayoutTree(false);
  }

  protected _renderScreenReaderStatus($statusContainer: JQuery) {
    $statusContainer.empty();
    let activeStepIndex = this.steps.indexOf(this.stepsMap[this.activeStepIndex]);
    this.steps.forEach((step, index) => {
      let $stepDescription = $statusContainer.appendDiv('sr-step-description');

      let stepIndex = this.steps.indexOf(step);
      let stepType = '';
      if (stepIndex === activeStepIndex) {
        stepType += this.session.text('ui.Current');
      } else if (stepIndex > activeStepIndex) {
        stepType += this.session.text('ui.Subsequent');
      } else {
        stepType += this.session.text('ui.Previous');
      }
      $stepDescription.appendDiv('text').text(strings.join(' ', this.session.text('ui.Step'), String(index + 1), stepType));
      if (strings.hasText(step.title)) {
        $stepDescription.appendDiv('text').text(step.title);
      }
      if (strings.hasText(step.subTitle)) {
        $stepDescription.appendDiv('text').text(step.subTitle);
      }
      if (strings.hasText(step.tooltipText)) {
        $stepDescription.appendDiv('text').text(step.tooltipText);
      }
    });
  }

  protected _setActiveStepIndex(activeStepIndex: number) {
    this.previousActiveStepIndex = this.activeStepIndex;
    // Ensure this.activeStepIndex always has a value. If the server has no active step set (may
    // happen during transition between steps), we use -1 as dummy value
    this._setProperty('activeStepIndex', scout.nvl(activeStepIndex, -1));
  }

  protected _renderActiveStepIndex() {
    this.steps.forEach(this._updateStepClasses.bind(this));
    this._renderScreenReaderStatus(this.$screenReaderStatus);
    this.invalidateLayoutTree(false);
  }

  protected _updateStepClasses(step: WizardStep) {
    let $step = step.$step;
    $step.removeClass('selected first last action-enabled disabled');
    $step.off('click.selected');

    // Important: those indices correspond to the UI's data structures (this.steps) and are not necessarily
    // consistent with the server indices (because the server does not send invisible steps).
    let stepIndex = this.steps.indexOf(step);
    let activeStepIndex = this.steps.indexOf(this.stepsMap[this.activeStepIndex]);

    if (this.enabledComputed && step.enabled && step.actionEnabled && stepIndex !== this.activeStepIndex) {
      $step.addClass('action-enabled');
      $step.on('click.selected', this._onStepClick.bind(this));
    } else if (!this.enabledComputed || !step.enabled) {
      $step.addClass('disabled');
    }
    $step.toggleClass('finished', step.finished);

    if (stepIndex >= 0 && activeStepIndex >= 0) {
      // Active
      if (stepIndex === activeStepIndex) {
        $step.addClass('selected');
      }
      // First / last
      if (stepIndex === 0) {
        $step.addClass('first');
      }
      if (stepIndex === this.steps.length - 1) {
        $step.addClass('last');
      }
    }

    // update background color for this.$wizardStepsBody, use same as for last step (otherwise there might be white space after last step)
    if (stepIndex === this.steps.length - 1) {
      this.$wizardStepsBody.css('background-color', $step.css('background-color'));
    }
  }

  protected _stepIndex($step: JQuery): number {
    if ($step) {
      let step = $step.data('wizard-step') as WizardStep;
      if (step) {
        return step.index;
      }
    }
    return -1;
  }

  protected _updateStepsMap() {
    this.stepsMap = {};
    this.steps.forEach(step => {
      this.stepsMap[step.index] = step;
    });
  }

  protected _resolveStep(stepIndex: number): WizardStep {
    // Because "step index" does not necessarily correspond to the array indices
    // (invisible model steps produce "holes"), we have to loop over the array.
    for (let i = 0; i < this.steps.length; i++) {
      let step = this.steps[i];
      if (step.index === stepIndex) {
        return step;
      }
    }
    return null;
  }

  protected _onStepClick(event: JQuery.ClickEvent) {
    let $step = $(event.currentTarget); // currentTarget instead of target to support event bubbling from inner divs
    let targetStepIndex = this._stepIndex($step);
    if (targetStepIndex >= 0 && targetStepIndex !== this.activeStepIndex) {
      this.trigger('stepAction', {
        stepIndex: targetStepIndex
      });
    }
  }

  scrollToActiveStep() {
    let currentStep = this.stepsMap[this.activeStepIndex];
    if (!currentStep) {
      return;
    }
    let $currentStep = currentStep.$step;
    let currentStepLeft = $currentStep.position().left;
    let animate = this.animateScrolling && this.htmlComp.layouted;
    if (this.keepActiveStepAtLeftBorder) {
      let $firstStep = this.steps[0].$step;
      let scrollLeft = currentStepLeft - $firstStep.cssPaddingLeft() + $currentStep.cssPaddingLeft();
      scrollbars.scrollLeft(this.$field, scrollLeft, {animate: animate});
    } else {
      let scrollLeft = this.$field.scrollLeft();
      let currentStepWidth = $currentStep.width();
      let fieldWidth = this.$field.width();

      // If going forward, try to scroll the steps such that the center of active step is not after 75% of the available space.
      // If going backward, try to scroll the steps such that the center of the active step is not before 25% of the available space.
      let goingBack = (this.previousActiveStepIndex > this.activeStepIndex);
      let p1 = scrollLeft + Math.floor(fieldWidth * (goingBack ? 0.25 : 0.75));
      let p2 = currentStepLeft + Math.floor(currentStepWidth / 2);
      if ((goingBack && p2 < p1) || (!goingBack && p2 > p1)) {
        scrollbars.scrollLeft(this.$field, scrollLeft + (p2 - p1), {animate: animate});
      }
    }
  }
}

export interface WizardStep {
  index?: number;
  title?: string;
  subTitle?: string;
  tooltipText?: string;
  iconId?: string;
  enabled?: boolean;
  actionEnabled?: boolean;
  cssClass?: string;
  finished?: boolean;
  modelClass?: string;
  classId?: string;

  $step?: JQuery;
}