import {
    Component,
    Input,
    OnChanges,
    Output,
    EventEmitter,
    ChangeDetectorRef,
    LOCALE_ID,
    Inject,
    OnInit,
    OnDestroy,
    TemplateRef
} from '@angular/core';
import {
    CalendarEvent,
    DayView,
    DayViewHour,
    DayViewHourSegment,
    DayViewEvent,
    CalendarEventTimesChangedEvent,
    getDayView,
    getDayViewHourGrid
} from '../../../utils/calendar-utils/CalendarUtils';
import { Subject } from 'rxjs/Subject';
import { Subscription } from 'rxjs/Subscription';
//import { ResizeEvent } from 'angular-resizable-element';
// import * as dateFns from 'date-fns';
// import { CalendarDragHelper } from '../../providers/calendarDragHelper.provider';
// import { CalendarResizeHelper } from '../../providers/calendarResizeHelper.provider';
// import { CalendarEventTimesChangedEvent } from '../../interfaces/calendarEventTimesChangedEvent.interface';

/**
 * @hidden
 */
const SEGMENT_HEIGHT: number = 30;

/**
 * @hidden
 */
const MINUTES_IN_HOUR: number = 60;

/**
 * Shows all events on a given day. Example usage:
 *
 * ```typescript
 * <novo-calendar-day
 *  [viewDate]="viewDate"
 *  [events]="events">
 * </novo-calendar-day>
 * ```
 */
@Component({
    selector: 'novo-calendar-day',
    template: `
    <div class="cal-day-view" #dayViewContainer>
      <novo-calendar-all-day-event
        *ngFor="let event of view.allDayEvents"
        [event]="event"
        [customTemplate]="allDayEventTemplate"
        (eventClicked)="eventClicked.emit({event: event})">
      </novo-calendar-all-day-event>
      <div class="cal-hour-rows">
        <div class="cal-events">
          <div
            #event
            *ngFor="let dayEvent of view?.events"
            class="cal-event-container"
            [style.marginTop.px]="dayEvent.top"
            [style.height.px]="dayEvent.height"
            [style.marginLeft.px]="dayEvent.left + 70"
            [style.width.px]="dayEvent.width - 1">
            <novo-calendar-day-event
              [dayEvent]="dayEvent"
              [tooltipPosition]="tooltipPosition"
              [customTemplate]="eventTemplate"
              (eventClicked)="eventClicked.emit($event)">
            </novo-calendar-day-event>
          </div>
        </div>
        <div class="cal-hour" *ngFor="let hour of hours" [style.minWidth.px]="view?.width + 70">
          <novo-calendar-day-hour-segment
            *ngFor="let segment of hour.segments"
            [segment]="segment"
            [locale]="locale"
            [customTemplate]="hourSegmentTemplate"
            (click)="hourSegmentClicked.emit({date: segment.date})">
          </novo-calendar-day-hour-segment>
        </div>
      </div>
    </div>
  `
})
export class NovoCalendarDayViewElement implements OnChanges, OnInit, OnDestroy {

    /**
     * The current view date
     */
    @Input() viewDate: Date;

    /**
     * An array of events to display on view
     */
    @Input() events: CalendarEvent[] = [];

    /**
     * The number of segments in an hour. Must be <= 6
     */
    @Input() hourSegments: number = 2;

    /**
     * The day start hours in 24 hour time. Must be 0-23
     */
    @Input() dayStartHour: number = 0;

    /**
     * The day start minutes. Must be 0-59
     */
    @Input() dayStartMinute: number = 0;

    /**
     * The day end hours in 24 hour time. Must be 0-23
     */
    @Input() dayEndHour: number = 23;

    /**
     * The day end minutes. Must be 0-59
     */
    @Input() dayEndMinute: number = 59;

    /**
     * The width in pixels of each event on the view
     */
    @Input() eventWidth: number = 150;

    /**
     * An observable that when emitted on will re-render the current view
     */
    @Input() refresh: Subject<any>;

    /**
     * The locale used to format dates
     */
    @Input() locale: string;

    /**
     * A function that will be called before each hour segment is called. The first argument will contain the hour segment.
     * If you add the `cssClass` property to the segment it will add that class to the hour segment in the template
     */
    @Input() hourSegmentModifier: Function;

    /**
     * The grid size to snap resizing and dragging of events to
     */
    @Input() eventSnapSize: number = 30;

    /**
     * The placement of the event tooltip
     */
    @Input() tooltipPosition: string = 'top';

    /**
     * A custom template to use to replace the hour segment
     */
    @Input() hourSegmentTemplate: TemplateRef<any>;

    /**
     * A custom template to use for all day events
     */
    @Input() allDayEventTemplate: TemplateRef<any>;

    /**
     * A custom template to use for day view events
     */
    @Input() eventTemplate: TemplateRef<any>;

    /**
     * Called when an event title is clicked
     */
    @Output() eventClicked: EventEmitter<{ event: CalendarEvent }> = new EventEmitter<{ event: CalendarEvent }>();

    /**
     * Called when an hour segment is clicked
     */
    @Output() hourSegmentClicked: EventEmitter<{ date: Date }> = new EventEmitter<{ date: Date }>();

    /**
     * Called when an event is resized or dragged and dropped
     */
    @Output() eventTimesChanged: EventEmitter<CalendarEventTimesChangedEvent> = new EventEmitter<CalendarEventTimesChangedEvent>();

    /**
     * @hidden
     */
    hours: DayViewHour[] = [];

    /**
     * @hidden
     */
    view: DayView;

    /**
     * @hidden
     */
    width: number = 0;

    /**
     * @hidden
     */
    refreshSubscription: Subscription;

    /**
     * @hidden
     */
    currentResize: {
        originalTop: number,
        originalHeight: number,
        edge: string
    };

    /**
     * @hidden
     */
    validateDrag: Function;

    /**
     * @hidden
     */
    validateResize: Function;

    /**
     * @hidden
     */
    constructor(private cdr: ChangeDetectorRef, @Inject(LOCALE_ID) locale: string) {
        this.locale = locale;
    }

    /**
     * @hidden
     */
    ngOnInit(): void {
        if (this.refresh) {
            this.refreshSubscription = this.refresh.subscribe(() => {
                this.refreshAll();
                this.cdr.detectChanges();
            });
        }
    }

    /**
     * @hidden
     */
    ngOnDestroy(): void {
        if (this.refreshSubscription) {
            this.refreshSubscription.unsubscribe();
        }
    }

    /**
     * @hidden
     */
    ngOnChanges(changes: any): void {

        if (
            changes.viewDate ||
            changes.dayStartHour ||
            changes.dayStartMinute ||
            changes.dayEndHour ||
            changes.dayEndMinute
        ) {
            this.refreshHourGrid();
        }

        if (
            changes.viewDate ||
            changes.events ||
            changes.dayStartHour ||
            changes.dayStartMinute ||
            changes.dayEndHour ||
            changes.dayEndMinute ||
            changes.eventWidth
        ) {
            this.refreshView();
        }

    }

    /*
    eventDropped(dropEvent: {dropData?: {event?: CalendarEvent}}, segment: DayViewHourSegment): void {
      if (dropEvent.dropData && dropEvent.dropData.event) {
        this.eventTimesChanged.emit({event: dropEvent.dropData.event, newStart: segment.date});
      }
    }

    resizeStarted(event: DayViewEvent, resizeEvent: ResizeEvent, dayViewContainer: HTMLElement): void {
      this.currentResize = {
        originalTop: event.top,
        originalHeight: event.height,
        edge: typeof resizeEvent.edges.top !== 'undefined' ? 'top' : 'bottom'
      };
      const resizeHelper: CalendarResizeHelper = new CalendarResizeHelper(dayViewContainer);
      this.validateResize = ({rectangle}) => resizeHelper.validateResize({rectangle});
      this.cdr.detectChanges();
    }

    resizing(event: DayViewEvent, resizeEvent: ResizeEvent): void {
      if (resizeEvent.edges.top) {
        event.top = this.currentResize.originalTop + +resizeEvent.edges.top;
        event.height = this.currentResize.originalHeight - +resizeEvent.edges.top;
      } else if (resizeEvent.edges.bottom) {
        event.height = this.currentResize.originalHeight + +resizeEvent.edges.bottom;
      }
    }

    resizeEnded(dayEvent: DayViewEvent): void {

      let pixelsMoved: number;
      if (this.currentResize.edge === 'top') {
        pixelsMoved = (dayEvent.top - this.currentResize.originalTop);
      } else {
        pixelsMoved = (dayEvent.height - this.currentResize.originalHeight);
      }

      dayEvent.top = this.currentResize.originalTop;
      dayEvent.height = this.currentResize.originalHeight;

      const pixelAmountInMinutes: number = MINUTES_IN_HOUR / (this.hourSegments * SEGMENT_HEIGHT);
      const minutesMoved: number = pixelsMoved * pixelAmountInMinutes;
      let newStart: Date = dayEvent.event.start;
      let newEnd: Date = dayEvent.event.end;
      if (this.currentResize.edge === 'top') {
        newStart = addMinutes(newStart, minutesMoved);
      } else if (newEnd) {
        newEnd = addMinutes(newEnd, minutesMoved);
      }

      this.eventTimesChanged.emit({newStart, newEnd, event: dayEvent.event});
      this.currentResize = null;

    }

    dragStart(event: HTMLElement, dayViewContainer: HTMLElement): void {
      const dragHelper: CalendarDragHelper = new CalendarDragHelper(dayViewContainer, event);
      this.validateDrag = ({x, y}) => !this.currentResize && dragHelper.validateDrag({x, y});
      this.cdr.detectChanges();
    }

    eventDragged(dayEvent: DayViewEvent, draggedInPixels: number): void {
      const pixelAmountInMinutes: number = MINUTES_IN_HOUR / (this.hourSegments * SEGMENT_HEIGHT);
      const minutesMoved: number = draggedInPixels * pixelAmountInMinutes;
      const newStart: Date = addMinutes(dayEvent.event.start, minutesMoved);
      let newEnd: Date;
      if (dayEvent.event.end) {
        newEnd = addMinutes(dayEvent.event.end, minutesMoved);
      }
      this.eventTimesChanged.emit({newStart, newEnd, event: dayEvent.event});
    }
    */

    private refreshHourGrid(): void {
        this.hours = getDayViewHourGrid({
            viewDate: this.viewDate,
            hourSegments: this.hourSegments,
            dayStart: {
                hour: this.dayStartHour,
                minute: this.dayStartMinute
            },
            dayEnd: {
                hour: this.dayEndHour,
                minute: this.dayEndMinute
            }
        });
        if (this.hourSegmentModifier) {
            this.hours.forEach(hour => {
                hour.segments.forEach(segment => this.hourSegmentModifier(segment));
            });
        }
    }

    private refreshView(): void {
        this.view = getDayView({
            events: this.events,
            viewDate: this.viewDate,
            hourSegments: this.hourSegments,
            dayStart: {
                hour: this.dayStartHour,
                minute: this.dayStartMinute
            },
            dayEnd: {
                hour: this.dayEndHour,
                minute: this.dayEndMinute
            },
            eventWidth: this.eventWidth,
            segmentHeight: SEGMENT_HEIGHT
        });
    }

    private refreshAll(): void {
        this.refreshHourGrid();
        this.refreshView();
    }

}