import {NgModule, Component, ElementRef, OnDestroy, Input, Output, EventEmitter, forwardRef, Renderer2,NgZone,ChangeDetectorRef, ViewChild, ChangeDetectionStrategy, ViewEncapsulation} from '@angular/core';
import {CommonModule} from '@angular/common';
import {DomHandler} from 'mirra-ui/dom';
import {NG_VALUE_ACCESSOR, ControlValueAccessor} from '@angular/forms';

export const SLIDER_VALUE_ACCESSOR: any = {
  provide: NG_VALUE_ACCESSOR,
  useExisting: forwardRef(() => Slider),
  multi: true
};

@Component({
    selector: 'p-slider',
    template: `
        <div [ngStyle]="style" [class]="styleClass" [ngClass]="{'p-slider p-component':true,'p-disabled':disabled,
            'p-slider-horizontal':orientation == 'horizontal','p-slider-vertical':orientation == 'vertical','p-slider-animate':animate}"
            (click)="onBarClick($event)">
            <span *ngIf="range && orientation == 'horizontal'" class="p-slider-range" [ngStyle]="{'left':handleValues[0] + '%',width: (handleValues[1] - handleValues[0] + '%')}"></span>
            <span *ngIf="range && orientation == 'vertical'" class="p-slider-range" [ngStyle]="{'bottom':handleValues[0] + '%',height: (handleValues[1] - handleValues[0] + '%')}"></span>
            <span *ngIf="!range && orientation=='vertical'" class="p-slider-range" [ngStyle]="{'height': handleValue + '%'}"></span>
            <span *ngIf="!range && orientation=='horizontal'" class="p-slider-range" [ngStyle]="{'width': handleValue + '%'}"></span>
            <span #sliderHandle *ngIf="!range" [attr.tabindex]="tabindex" (keydown)="onHandleKeydown($event)" class="p-slider-handle" (mousedown)="onMouseDown($event)" (touchstart)="onTouchStart($event)" (touchmove)="onTouchMove($event)" (touchend)="onTouchEnd($event)"
                [style.transition]="dragging ? 'none': null" [ngStyle]="{'left': orientation == 'horizontal' ? handleValue + '%' : null,'bottom': orientation == 'vertical' ? handleValue + '%' : null}"
                [attr.aria-valuemin]="min" [attr.aria-valuenow]="value" [attr.aria-valuemax]="max" [attr.aria-labelledby]="ariaLabelledBy"></span>
            <span #sliderHandleStart *ngIf="range" [attr.tabindex]="tabindex" (keydown)="onHandleKeydown($event,0)" (mousedown)="onMouseDown($event,0)" (touchstart)="onTouchStart($event,0)" (touchmove)="onTouchMove($event,0)" (touchend)="onTouchEnd($event)" [style.transition]="dragging ? 'none': null" class="p-slider-handle"
                [ngStyle]="{'left': rangeStartLeft, 'bottom': rangeStartBottom}" [ngClass]="{'p-slider-handle-active':handleIndex==0}"
                [attr.aria-valuemin]="min" [attr.aria-valuenow]="value ? value[0] : null" [attr.aria-valuemax]="max" [attr.aria-labelledby]="ariaLabelledBy"></span>
            <span #sliderHandleEnd *ngIf="range" [attr.tabindex]="tabindex" (keydown)="onHandleKeydown($event,1)" (mousedown)="onMouseDown($event,1)" (touchstart)="onTouchStart($event,1)" (touchmove)="onTouchMove($event,1)" (touchend)="onTouchEnd($event)" [style.transition]="dragging ? 'none': null" class="p-slider-handle"
                [ngStyle]="{'left': rangeEndLeft, 'bottom': rangeEndBottom}" [ngClass]="{'p-slider-handle-active':handleIndex==1}"
                [attr.aria-valuemin]="min" [attr.aria-valuenow]="value ? value[1] : null" [attr.aria-valuemax]="max" [attr.aria-labelledby]="ariaLabelledBy"></span>
        </div>
    `,
    providers: [SLIDER_VALUE_ACCESSOR],
    changeDetection: ChangeDetectionStrategy.OnPush,
    encapsulation: ViewEncapsulation.None,
    styleUrls: ['./slider.scss']
})
export class Slider implements OnDestroy,ControlValueAccessor {

    @Input() animate: boolean;

    @Input() disabled: boolean;

    @Input() min: number = 0;

    @Input() max: number = 100;

    @Input() orientation: string = 'horizontal';

    @Input() step: number;

    @Input() range: boolean;

    @Input() style: any;

    @Input() styleClass: string;

    @Input() ariaLabelledBy: string;

    @Input() tabindex: number = 0;

    @Output() onChange: EventEmitter<any> = new EventEmitter();

    @Output() onSlideEnd: EventEmitter<any> = new EventEmitter();

    @ViewChild("sliderHandle") sliderHandle: ElementRef;

    @ViewChild("sliderHandleStart") sliderHandleStart: ElementRef;

    @ViewChild("sliderHandleEnd") sliderHandleEnd: ElementRef;

    public value: number;

    public values: number[];

    public handleValue: number;

    public handleValues: number[] = [];

    public onModelChange: Function = () => {};

    public onModelTouched: Function = () => {};

    public dragging: boolean;

    public dragListener: any;

    public mouseupListener: any;

    public initX: number;

    public initY: number;

    public barWidth: number;

    public barHeight: number;

    public sliderHandleClick: boolean;

    public handleIndex: number = 0;

    public startHandleValue: any;

    public startx: number;

    public starty: number;

    constructor(public el: ElementRef, public renderer: Renderer2, private ngZone: NgZone, public cd: ChangeDetectorRef) {}

    onMouseDown(event, index?:number) {
        if (this.disabled) {
            return;
        }

        this.dragging = true;
        this.updateDomData();
        this.sliderHandleClick = true;
        this.handleIndex = index;
        this.bindDragListeners();
        event.target.focus();
        event.preventDefault();

        if (this.animate) {
            DomHandler.removeClass(this.el.nativeElement.children[0], 'p-slider-animate');
        }
    }

    onTouchStart(event, index?:number) {
        if (this.disabled) {
            return;
        }

        var touchobj = event.changedTouches[0];
        this.startHandleValue = (this.range) ? this.handleValues[index] : this.handleValue;
        this.dragging = true;
        this.handleIndex = index;

        if (this.orientation === 'horizontal') {
            this.startx = parseInt(touchobj.clientX, 10);
            this.barWidth = this.el.nativeElement.children[0].offsetWidth;
        }
        else {
            this.starty = parseInt(touchobj.clientY, 10);
            this.barHeight = this.el.nativeElement.children[0].offsetHeight;
        }

        if (this.animate) {
            DomHandler.removeClass(this.el.nativeElement.children[0], 'p-slider-animate');
        }

        event.preventDefault();
    }

    onTouchMove(event, index?:number) {
        if (this.disabled) {
            return;
        }

        var touchobj = event.changedTouches[0],
        handleValue = 0;

        if (this.orientation === 'horizontal') {
            handleValue = Math.floor(((parseInt(touchobj.clientX, 10) - this.startx) * 100) / (this.barWidth)) + this.startHandleValue;
        }
        else {
            handleValue = Math.floor(((this.starty - parseInt(touchobj.clientY, 10)) * 100) / (this.barHeight))  + this.startHandleValue;
        }

        this.setValueFromHandle(event, handleValue);

        event.preventDefault();
    }

    onTouchEnd(event, index?:number) {
        if (this.disabled) {
            return;
        }

        this.dragging = false;

        if (this.range)
            this.onSlideEnd.emit({originalEvent: event, values: this.values});
        else
            this.onSlideEnd.emit({originalEvent: event, value: this.value});

        if (this.animate) {
            DomHandler.addClass(this.el.nativeElement.children[0], 'p-slider-animate');
        }

        event.preventDefault();
    }

    onBarClick(event) {
        if (this.disabled) {
            return;
        }

        if (!this.sliderHandleClick) {
            this.updateDomData();
            this.handleChange(event);
        }

        this.sliderHandleClick = false;
    }

    onHandleKeydown(event, handleIndex?:number) {
        if (event.which == 38 || event.which == 39) {
            this.spin(event, 1, handleIndex);
        }
        else if (event.which == 37 || event.which == 40) {
            this.spin(event, -1, handleIndex);
        }
    }

    spin(event, dir: number, handleIndex?:number) {
        let step = (this.step || 1) * dir;

        if (this.range) {
            this.handleIndex = handleIndex;
            this.updateValue(this.values[this.handleIndex] + step);
            this.updateHandleValue();
        }
        else {
            this.updateValue(this.value + step);
            this.updateHandleValue();
        }

        event.preventDefault();
    }

    handleChange(event: Event) {
        let handleValue = this.calculateHandleValue(event);
        this.setValueFromHandle(event, handleValue);
    }

    bindDragListeners() {
        this.ngZone.runOutsideAngular(() => {
            if (!this.dragListener) {
                this.dragListener = this.renderer.listen('document', 'mousemove', (event) => {
                    if (this.dragging) {
                        this.ngZone.run(() => {
                            this.handleChange(event);
                        });
                    }
                });
            }

            if (!this.mouseupListener) {
                this.mouseupListener = this.renderer.listen('document', 'mouseup', (event) => {
                    if (this.dragging) {
                        this.dragging = false;
                        this.ngZone.run(() => {
                            if (this.range)
                                this.onSlideEnd.emit({originalEvent: event, values: this.values});
                            else
                                this.onSlideEnd.emit({originalEvent: event, value: this.value});

                            if (this.animate) {
                                DomHandler.addClass(this.el.nativeElement.children[0], 'p-slider-animate');
                            }
                        });
                    }
                });
            }
        });
    }

    unbindDragListeners() {
        if (this.dragListener) {
            this.dragListener();
        }

        if (this.mouseupListener) {
            this.mouseupListener();
        }
    }

    setValueFromHandle(event: Event, handleValue: any) {
        let newValue = this.getValueFromHandle(handleValue);

        if (this.range) {
            if (this.step) {
                this.handleStepChange(newValue, this.values[this.handleIndex]);
            }
            else {
                this.handleValues[this.handleIndex] = handleValue;
                this.updateValue(newValue, event);
            }
        }
        else {
            if (this.step) {
                this.handleStepChange(newValue, this.value);
            }
            else {
                this.handleValue = handleValue;
                this.updateValue(newValue, event);
            }
        }
    }

    handleStepChange(newValue: number, oldValue: number) {
        let diff = (newValue - oldValue);
        let val = oldValue;

        if (diff < 0) {
            val = oldValue + Math.ceil(newValue / this.step - oldValue / this.step) * this.step;
        }
        else if (diff > 0) {
            val = oldValue + Math.floor(newValue / this.step - oldValue / this.step) * this.step;
        }

        this.updateValue(val);
        this.updateHandleValue();
    }

    writeValue(value: any) : void {
        if (this.range)
            this.values = value||[0,0];
        else
            this.value = value||0;

        this.updateHandleValue();
        this.cd.markForCheck();
    }

    registerOnChange(fn: Function): void {
        this.onModelChange = fn;
    }

    registerOnTouched(fn: Function): void {
        this.onModelTouched = fn;
    }

    setDisabledState(val: boolean): void {
        this.disabled = val;
    }

    get rangeStartLeft() {
        return this.isVertical() ? 'auto' : this.handleValues[0] + '%';
    }

    get rangeStartBottom() {
        return this.isVertical() ? this.handleValues[0] + '%' : 'auto';
    }

    get rangeEndLeft() {
        return this.isVertical() ? 'auto' : this.handleValues[1] + '%';
    }

    get rangeEndBottom() {
        return this.isVertical() ? this.handleValues[1] + '%' : 'auto';
    }

    isVertical(): boolean {
        return this.orientation === 'vertical';
    }

    updateDomData(): void {
        let rect = this.el.nativeElement.children[0].getBoundingClientRect();
        this.initX = rect.left + DomHandler.getWindowScrollLeft();
        this.initY = rect.top + DomHandler.getWindowScrollTop();
        this.barWidth = this.el.nativeElement.children[0].offsetWidth;
        this.barHeight = this.el.nativeElement.children[0].offsetHeight;
    }

    calculateHandleValue(event): number {
        if (this.orientation === 'horizontal')
            return ((event.pageX - this.initX) * 100) / (this.barWidth);
        else
            return(((this.initY + this.barHeight) - event.pageY) * 100) / (this.barHeight);
    }

    updateHandleValue(): void {
        if (this.range) {
            this.handleValues[0] = (this.values[0] < this.min ? 0 : this.values[0] - this.min) * 100 / (this.max - this.min);
            this.handleValues[1] = (this.values[1] > this.max ? 100 : this.values[1] - this.min) * 100 / (this.max - this.min);
        }
        else {
            if (this.value < this.min)
                this.handleValue = 0;
            else if (this.value > this.max)
                this.handleValue = 100;
            else
                this.handleValue = (this.value - this.min) * 100 / (this.max - this.min);
        }
    }

    updateValue(val: number, event?: Event): void {
        if (this.range) {
            let value = val;

            if (this.handleIndex == 0) {
                if (value < this.min) {
                    value = this.min;
                    this.handleValues[0] = 0;
                }
                else if (value > this.values[1]) {
                    value = this.values[1];
                    this.handleValues[0] = this.handleValues[1];
                }

                this.sliderHandleStart.nativeElement.focus();
            }
            else {
                if (value > this.max) {
                    value = this.max;
                    this.handleValues[1] = 100;
                }
                else if (value < this.values[0]) {
                    value = this.values[0];
                    this.handleValues[1] = this.handleValues[0];
                }

                this.sliderHandleEnd.nativeElement.focus();
            }

            this.values[this.handleIndex] = this.getNormalizedValue(value);
            this.values = this.values.slice();
            this.onModelChange(this.values);
            this.onChange.emit({event: event, values: this.values});
        }
        else {
            if (val < this.min) {
                val = this.min;
                this.handleValue = 0;
            }
            else if (val > this.max) {
                val = this.max;
                this.handleValue = 100;
            }

			this.value = this.getNormalizedValue(val);

            this.onModelChange(this.value);
            this.onChange.emit({event: event, value: this.value});
            this.sliderHandle.nativeElement.focus();
        }
    }

    getValueFromHandle(handleValue: number): number {
        return (this.max - this.min) * (handleValue / 100) + this.min;
    }

	getDecimalsCount(value: number): number {
		if (value && Math.floor(value) !== value)
			return value.toString().split(".")[1].length || 0;
		return 0;
	}

	getNormalizedValue(val: number): number {
		let decimalsCount = this.getDecimalsCount(this.step);
		if (decimalsCount > 0) {
			return +val.toFixed(decimalsCount);
		}
		else {
			return Math.floor(val);
		}
	}

    ngOnDestroy() {
        this.unbindDragListeners();
    }
}

@NgModule({
    imports: [CommonModule],
    exports: [Slider],
    declarations: [Slider]
})
export class SliderModule { }