// NG2
import { Component, Input, Output, EventEmitter, OnDestroy, AfterContentInit, ViewChild, forwardRef, ElementRef, OnInit, OnChanges, SimpleChanges, HostBinding, HostListener, ChangeDetectorRef, NgZone, ChangeDetectionStrategy } from '@angular/core';
import { NG_VALUE_ACCESSOR, ControlValueAccessor } from '@angular/forms';
import { TAB, ENTER, ESCAPE } from '@angular/cdk/keycodes';
import { DOCUMENT } from '@angular/platform-browser';
import { Observable } from 'rxjs/Observable';
import { Subscription } from 'rxjs/Subscription';
// APP
import { NovoOverlayTemplate } from '../overlay/Overlay';
import { KeyCodes } from '../../utils/key-codes/KeyCodes';
import { NovoLabelService } from '../../services/novo-label-service';
import { Helpers } from '../../utils/Helpers';

// Value accessor for the component (supports ngModel)
const SEARCH_VALUE_ACCESSOR = {
    provide: NG_VALUE_ACCESSOR,
    useExisting: forwardRef(() => NovoSearchBoxElement),
    multi: true
};

@Component({
    selector: 'novo-search',
    providers: [SEARCH_VALUE_ACCESSOR],
    changeDetection: ChangeDetectionStrategy.OnPush,
    template: `
        <!-- SEARCH ICON -->
        <button theme="fab" [color]="theme" [icon]="icon" (click)="showSearch()" [tooltip]="hint" tooltipPosition="bottom" data-automation-id="novo-search-fab"></button>
        <!-- SEARCH INPUT -->
        <input type="text" [attr.name]="name" [attr.value]="displayValue" [attr.placeholder]="placeholder" (focus)="onFocus()" (blur)="onBlur()" (keydown)="_handleKeydown($event)" (input)="_handleInput($event)" #input data-automation-id="novo-search-input"/>
        <!-- SEARCH OVERLAY -->
        <novo-overlay-template [parent]="element" [closeOnSelect]="closeOnSelect" (select)="closePanel()" (closing)="onBlur()">
            <ng-content></ng-content>
        </novo-overlay-template>
    `
})
export class NovoSearchBoxElement implements ControlValueAccessor, OnDestroy, AfterContentInit {
    @Input() public name: string;
    @Input() public icon: string = 'search';
    @Input() public placeholder: string = 'Search...';
    @Input() public alwaysOpen: boolean = false;
    @Input() public theme: string = 'positive';
    @Input() public closeOnSelect: boolean = true;
    @Input() public displayField: string;
    @Input() public displayValue: string;
    @Input() public hint: string;
    @Output() public searchChanged: EventEmitter<string> = new EventEmitter<string>();
    @HostBinding('class.focused') focused: boolean = false;
    public value: any;

    /** View -> model callback called when value changes */
    _onChange: (value: any) => void = () => { };
    /** View -> model callback called when autocomplete has been touched */
    _onTouched = () => { };

    /** Element for the panel containing the autocomplete options. */
    @ViewChild(NovoOverlayTemplate) overlay: any;
    @ViewChild('input') input: any;

    private keyboardObserver: Subscription;

    constructor(
        public element: ElementRef,
        public labels: NovoLabelService,
        private _changeDetectorRef: ChangeDetectorRef,
        private _zone: NgZone
    ) {
    }

    public ngAfterContentInit(): void {
        this.keyboardObserver = Observable.fromEvent(this.input.nativeElement, 'keyup')
            .debounceTime(300)
            .subscribe((event: KeyboardEvent) => this.searchChanged.emit(this.input.nativeElement.value))
    }

    public ngOnDestroy(): void {
        this.keyboardObserver.unsubscribe();
    }

    /**
     * @name showFasterFind
     * @description This function shows the picker and adds the active class (for animation)
     */
    showSearch(event?: any, forceClose: boolean = false) {
        if (!this.panelOpen) {
            // Reset search
            // Set focus on search
            setTimeout(() => {
                let element = this.input.nativeElement;
                if (element) {
                    element.focus();
                }
            }, 10);
        }
    }
    onFocus() {
        this._zone.run(() => {
            this.focused = true;
            this.openPanel();
        });
    }
    onBlur() {
        this.focused = false;
    }
    /** BEGIN: Convienient Panel Methods. */
    openPanel(): void {
        this.overlay.openPanel();
    }
    closePanel(): void {
        this.overlay.closePanel();
    }
    get panelOpen(): boolean {
        return this.overlay && this.overlay.panelOpen;
    }
    @HostBinding('class.active')
    get active(): boolean {
        return this.panelOpen || this.alwaysOpen;
    }
    /** END: Convienient Panel Methods. */

    _handleKeydown(event: KeyboardEvent): void {
        if ((event.keyCode === ESCAPE || event.keyCode === ENTER || event.keyCode === TAB) && this.panelOpen) {
            this.closePanel();
            event.stopPropagation();
        }
    }
    _handleInput(event: KeyboardEvent): void {
        if (document.activeElement === event.target) {
            this._onChange((event.target as HTMLInputElement).value);
            //this.openPanel();
        }
    }
    writeValue(value: any): void {
        this._setValue(value);
    }
    registerOnChange(fn: (value: any) => {}): void {
        this._onChange = fn;
    }
    registerOnTouched(fn: () => {}) {
        this._onTouched = fn;
    }
    private _setValue(value: any): void {
        this.value = value;
        let toDisplay = value;
        if (value && this.displayField) {
            toDisplay = value.hasOwnProperty(this.displayField) ? value[this.displayField] : value;
        }
        // Simply falling back to an empty string if the display value is falsy does not work properly.
        // The display value can also be the number zero and shouldn't fall back to an empty string.
        this.displayValue = toDisplay ? toDisplay : '';
        this.input.nativeElement.value = this.displayValue;
        this._changeDetectorRef.markForCheck();
    }

    /**
    * This method closes the panel, and if a value is specified, also sets the associated
    * control to that value. It will also mark the control as dirty if this interaction
    * stemmed from the user.
    */
    public setValueAndClose(event: any | null): void {
        if (event && event.value) {
            this._setValue(event.value);
            this._onChange(event.value);
        }
        this.closePanel();
    }

    /**
     * Clear any previous selected option and emit a selection change event for this option
     */
    public clearValue(skip: any) {
        this.writeValue(null);
        this._onChange(null);
    }
}