import { override } from '@microsoft/decorators';
import {
  BaseFieldCustomizer,
  IFieldCustomizerCellEventParameters
} from '@microsoft/sp-listview-extensibility';
import { evaluateExpiry, formatDate, parseSharePointDate } from '../../common/ExpiryDateCalculator';
import { ExpiryConfigService } from '../../common/ExpiryConfigService';
import { ExpiryItemService } from '../../common/ExpiryItemService';
import {
  createDefaultConfig,
  IExpiryConfig,
  IExpiryEvaluation,
  IItemDateValues,
  resolveBehavior
} from '../../common/ExpiryModels';
import styles from './ExpiryIndicatorFieldCustomizer.module.scss';
import * as strings from 'ExpiryIndicatorStrings';

export interface IExpiryIndicatorFieldCustomizerProperties {
}

export default class ExpiryIndicatorFieldCustomizer
  extends BaseFieldCustomizer<IExpiryIndicatorFieldCustomizerProperties> {

  private _config: IExpiryConfig = createDefaultConfig();
  private _itemService: ExpiryItemService;
  private _itemCache: { [id: string]: Promise<IItemDateValues> } = {};

  @override
  public onInit(): Promise<void> {
    if (!this.context.pageContext.list) {
      return Promise.resolve();
    }

    const service: ExpiryConfigService = new ExpiryConfigService(
      this.context.spHttpClient,
      this.context.pageContext.web.absoluteUrl
    );

    this._itemService = new ExpiryItemService(
      this.context.spHttpClient,
      this.context.pageContext.web.absoluteUrl,
      this.context.pageContext.list.id.toString()
    );

    return service.getConfig(this.context.pageContext.list.id.toString())
      .then((config: IExpiryConfig): void => { this._config = config; })
      .catch((): void => { this._config = createDefaultConfig(); });
  }

  @override
  public onRenderCell(event: IFieldCustomizerCellEventParameters): void {
    this._clear(event.domElement);

    const expiry: Date | undefined = parseSharePointDate(event.fieldValue);
    const createdValue: any = event.listItem && event.listItem.getValueByName
      ? event.listItem.getValueByName(this._config.baseField)
      : undefined;
    const created: Date | undefined = parseSharePointDate(createdValue);

    const idValue: any = event.listItem && event.listItem.getValueByName
      ? (event.listItem.getValueByName('ID') || event.listItem.getValueByName('Id'))
      : undefined;
    const itemId: number = Number(idValue);

    if (itemId > 0 && this._itemService) {
      const requestKey: string = String(itemId);
      event.domElement.setAttribute('data-expiry-item-id', requestKey);
      this._renderNeutral(event.domElement, strings.Loading);
      if (!this._itemCache[requestKey]) {
        this._itemCache[requestKey] = this._itemService.getItemDates(itemId, this._config);
      }

      this._itemCache[requestKey].then((item: IItemDateValues): void => {
        if (event.domElement.getAttribute('data-expiry-item-id') !== requestKey) {
          return;
        }
        this._clear(event.domElement);
        this._renderValues(event.domElement, item.created, item.expiry, item.fieldValues);
      }).catch((): void => {
        if (event.domElement.getAttribute('data-expiry-item-id') === requestKey) {
          this._clear(event.domElement);
          this._renderValues(event.domElement, created, expiry, {});
        }
      });
      return;
    }

    this._renderValues(event.domElement, created, expiry, {});
  }

  @override
  public onDisposeCell(event: IFieldCustomizerCellEventParameters): void {
    this._clear(event.domElement);
    super.onDisposeCell(event);
  }

  private _renderEvaluation(container: HTMLElement, evaluation: IExpiryEvaluation): void {
    const wrapper: HTMLSpanElement = document.createElement('span');
    wrapper.className = styles.cell + (evaluation.wasCalculated ? ' ' + styles.calculated : '');

    if (evaluation.matchedRule) {
      wrapper.style.backgroundColor = evaluation.matchedRule.backgroundColor;
      wrapper.style.color = evaluation.matchedRule.textColor;
    }

    const date: HTMLSpanElement = document.createElement('span');
    date.className = styles.date;
    date.textContent = formatDate(evaluation.effectiveExpiryDate);
    wrapper.appendChild(date);

    if (evaluation.matchedRule && evaluation.matchedRule.label) {
      const label: HTMLSpanElement = document.createElement('span');
      label.className = styles.label;
      label.textContent = evaluation.matchedRule.label;
      wrapper.appendChild(label);
    }

    const calculationHint: string = evaluation.wasCalculated ? ' – ' + strings.CalculatedHint : '';
    wrapper.title = strings.DaysUntilExpiry.replace('{0}', String(evaluation.daysUntilExpiry)) + calculationHint;
    container.appendChild(wrapper);
  }

  private _renderValues(
    container: HTMLElement,
    created: Date | undefined,
    expiry: Date | undefined,
    fieldValues: { [fieldName: string]: any }
  ): void {
    if (!expiry && !created) {
      this._renderNeutral(container, this._config.nullText);
      return;
    }

    const evaluation: IExpiryEvaluation = evaluateExpiry(
      created || expiry as Date,
      expiry,
      this._config,
      undefined,
      resolveBehavior(this._config, fieldValues)
    );
    this._renderEvaluation(container, evaluation);
  }

  private _renderNeutral(container: HTMLElement, text: string): void {
    const wrapper: HTMLSpanElement = document.createElement('span');
    wrapper.className = styles.cell + ' ' + styles.neutral;
    wrapper.textContent = text;
    container.appendChild(wrapper);
  }

  private _clear(container: HTMLElement): void {
    while (container.firstChild) {
      container.removeChild(container.firstChild);
    }
  }
}