import { CdkDragDrop, moveItemInArray } from "@angular/cdk/drag-drop";
import { Injectable } from "@angular/core";
import { ActionColumn, SelectionType, TableColumn } from "../../models";

export interface TableColumnSettings {
  displayedColumns: TableColumn[];
  availableMenuColumns: TableColumn[];
  hasColumnHeaders: boolean;
  hasColumnFilters: boolean;
  tableColspan: number;
}

@Injectable()
export class TableColumnService {

    constructor() {}  

    getInitialColumnSettings(columns: TableColumn[], leftActionColumns: ActionColumn[], selectionType: SelectionType, initialColumns?: string): TableColumnSettings {
      let displayedColumns: TableColumn[] = [];
      let availableMenuColumns: TableColumn[] = [];

      if (initialColumns != null && initialColumns !== '') {
        const columnNames = initialColumns.split(';');
        columnNames.forEach(name => {
          const column = columns.find(x => x.prop === name);
          if (column != null) {
            displayedColumns.push(column);
            availableMenuColumns.push(column);
          }
        });
      }

      if (displayedColumns.length > 0) {
        if (availableMenuColumns.length < columns.length) {
          columns.forEach(column => {
            if (!availableMenuColumns.some(x => x.prop === column.prop)) {
              availableMenuColumns.push(column);
            }
          });
        }        
      } else {
        displayedColumns = columns;
        availableMenuColumns = columns;
      }

      const hasColumnHeaders = displayedColumns.some(x => !x.ignoreHeaders);
      const hasColumnFilters = displayedColumns.some(x => x.hasFilter);
      const tableColspan = this.getTableColspan(displayedColumns, leftActionColumns, selectionType);

      return { displayedColumns, availableMenuColumns, hasColumnHeaders, hasColumnFilters, tableColspan };
    }

    private getTableColspan(displayedColumns: TableColumn[], leftActionColumns: ActionColumn[], selectionType: SelectionType): number {
      let colspan = 0;
      if (selectionType === SelectionType.checkbox) {
        colspan++;
      }
      colspan += displayedColumns.length + leftActionColumns.length;
      return colspan;
    }

    getDisplayedColumnsStrings(displayedColumns: TableColumn[]): string[] {
      if (displayedColumns != null && displayedColumns.length > 0) {
        return displayedColumns.map(x => x.prop);
      }
      return [];
    }

    onMouseDown(event: any, el: any = null): { x: string, y: string, width: string } {
      el = el || event.target;
      return {
        x: el.getBoundingClientRect().left - event.clientX + 'px',
        y: el.getBoundingClientRect().top - event.clientY + 'px',
        width: el.getBoundingClientRect().width + 'px'
      };
    }

    dropColumn(event: CdkDragDrop<string[]>, displayedColumns: TableColumn[]): TableColumn[] {
      moveItemInArray(displayedColumns, event.previousIndex, event.currentIndex);
      return displayedColumns;
    }

    getUpdatedColumnSettings(displayedColumns: TableColumn[], availableMenuColumns: TableColumn[], leftActionColumns: ActionColumn[], selectionType: SelectionType): TableColumnSettings {
      const sortedColumns: TableColumn[] = [];
      displayedColumns.forEach(column => {
        sortedColumns.push(column);
      });
      availableMenuColumns.forEach(column => {
        if (!displayedColumns.some(x => x.prop === column.prop)) {
          sortedColumns.push(column);
        }
      });
      const hasColumnHeaders = displayedColumns.some(x => !x.ignoreHeaders);
      const hasColumnFilters = displayedColumns.some(x => x.hasFilter);
      const tableColspan = this.getTableColspan(displayedColumns, leftActionColumns, selectionType);

      return {
        displayedColumns,
        availableMenuColumns: sortedColumns,
        hasColumnHeaders,
        hasColumnFilters,
        tableColspan
      };
    }
}