import {
    Component, ElementRef, OnInit, OnDestroy, Input, forwardRef, Output, EventEmitter,
    ViewChild, ChangeDetectionStrategy, ViewEncapsulation, ChangeDetectorRef
} from '@angular/core';
import { NG_VALUE_ACCESSOR, ControlValueAccessor } from '@angular/forms';

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

@Component({
    selector: 'farris-input-masked, f-input-masked',
    template: `<input #input [attr.id]="inputId" [attr.type]="type" [attr.name]="name"
                [ngStyle]="style" [ngClass]="styleClass" [attr.placeholder]="placeholder" [attr.title]="title"
                [attr.size]="size" [attr.autocomplete]="autocomplete" [attr.maxlength]="maxlength" [attr.tabindex]="tabindex"
                [attr.aria-label]="ariaLabel" [attr.aria-required]="ariaRequired"
                [disabled]="disabled" [readonly]="readonly" [attr.required]="required"
                (focus)="onInputFocus($event)" (blur)="onInputBlur($event)" (keydown)="onInputKeydown($event)"
                (keypress)="onKeyPress($event)" [attr.autofocus]="autoFocus"
        (input)="onInputChange($event)" (paste)="handleInputChange($event)">`,
    providers: [INPUTMASK_VALUE_ACCESSOR],
    changeDetection: ChangeDetectionStrategy.OnPush,
    encapsulation: ViewEncapsulation.None
})
export class InputMaskedComponent implements OnInit, OnDestroy, ControlValueAccessor {
    @Input() type = 'text';
    @Input() slotChar = '_';
    @Input() autoClear = true;
    @Input() style: any;
    @Input() inputId: string;
    @Input() styleClass: string;
    @Input() placeholder: string;
    @Input() size: number;
    @Input() maxlength: number;
    @Input() tabindex: string;
    @Input() title: string;
    @Input() ariaLabel: string;
    @Input() ariaRequired: boolean;
    @Input() disabled: boolean;
    @Input() readonly: boolean;
    @Input() unmask: boolean;
    @Input() name: string;
    @Input() required: boolean;
    @Input() characterPattern = '[A-Za-z]';
    @Input() autoFocus: boolean;
    @Input() autocomplete: string;
    @ViewChild('input') inputViewChild: ElementRef;
    @Output() completed: EventEmitter<any> = new EventEmitter();
    @Output() focus: EventEmitter<any> = new EventEmitter();
    @Output() blur: EventEmitter<any> = new EventEmitter();
    @Output() input: EventEmitter<any> = new EventEmitter();
    @Output() keydown: EventEmitter<any> = new EventEmitter();
    value: any;
    _mask: string;
    filled: boolean;
    defs: any;
    tests: any[];
    partialPosition: any;
    firstNonMaskPos: number;
    lastRequiredNonMaskPos: any;
    len: number;
    oldVal: string;
    buffer: any;
    defaultBuffer: string;
    focusText: string;
    caretTimeoutId: any;
    androidChrome: boolean;
    focused: boolean;

    onModelChange = (val) => { };
    onModelTouched = () => { };
    constructor(public el: ElementRef, private cd: ChangeDetectorRef) { }
    ngOnInit() {
        this.initMask();
    }
    @Input() get mask(): string {
        return this._mask;
    }
    set mask(val: string) {
        this._mask = val;
        this.initMask();
        this.writeValue('');
        this.onModelChange(this.value);
    }

    initMask() {
        this.tests = [];
        this.partialPosition = this.mask.length;
        this.len = this.mask.length;
        this.firstNonMaskPos = null;
        this.defs = {
            9: '[0-9]',
            a: this.characterPattern,
            '*': `${this.characterPattern}|[0-9]`
        };
        const maskTokens = this.mask.split('');
        for (let i = 0; i < maskTokens.length; i++) {
            const c = maskTokens[i];
            if (c === '?') {
                this.len--;
                this.partialPosition = i;
            } else if (this.defs[c]) {
                this.tests.push(new RegExp(this.defs[c]));
                if (this.firstNonMaskPos === null) {
                    this.firstNonMaskPos = this.tests.length - 1;
                }
                if (i < this.partialPosition) {
                    this.lastRequiredNonMaskPos = this.tests.length - 1;
                }
            } else {
                this.tests.push(null);
            }
        }
        this.buffer = [];
        for (let i = 0; i < maskTokens.length; i++) {
            const c = maskTokens[i];
            if (c !== '?') {
                if (this.defs[c]) {
                    this.buffer.push(this.getPlaceholder(i));
                } else {
                    this.buffer.push(c);
                }
            }
        }
        this.defaultBuffer = this.buffer.join('');
    }

    writeValue(value: any): void {
        this.value = value;
        if (this.inputViewChild && this.inputViewChild.nativeElement) {
            if (this.value === undefined || this.value == null) {
                this.inputViewChild.nativeElement.value = '';
            } else {
                this.inputViewChild.nativeElement.value = this.value;
            }
            this.checkVal();
            this.focusText = this.inputViewChild.nativeElement.value;
            this.updateFilledState();
        }
    }

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

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

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

    caret(first?: number, last?: number) {
        let range, begin, end;
        if (!this.inputViewChild.nativeElement.offsetParent ||
            this.inputViewChild.nativeElement !== this.inputViewChild.nativeElement.ownerDocument.activeElement) {
            return;
        }
        if (typeof first === 'number') {
            begin = first;
            end = (typeof last === 'number') ? last : begin;
            if (this.inputViewChild.nativeElement.setSelectionRange) {
                this.inputViewChild.nativeElement.setSelectionRange(begin, end);
            } else if (this.inputViewChild.nativeElement['createTextRange']) {
                range = this.inputViewChild.nativeElement['createTextRange']();
                range.collapse(true);
                range.moveEnd('character', end);
                range.moveStart('character', begin);
                range.select();
            }
        } else {
            if (this.inputViewChild.nativeElement.setSelectionRange) {
                begin = this.inputViewChild.nativeElement.selectionStart;
                end = this.inputViewChild.nativeElement.selectionEnd;
            } else if (document['selection'] && document['selection'].createRange) {
                range = document['selection'].createRange();
                begin = 0 - range.duplicate().moveStart('character', -100000);
                end = begin + range.text.length;
            }
            return { begin, end };
        }
    }

    isCompleted(): boolean {
        for (let i = this.firstNonMaskPos; i <= this.lastRequiredNonMaskPos; i++) {
            if (this.tests[i] && this.buffer[i] === this.getPlaceholder(i)) {
                return false;
            }
        }
        return true;
    }

    getPlaceholder(i: number) {
        if (i < this.slotChar.length) {
            return this.slotChar.charAt(i);
        }
        return this.slotChar.charAt(0);
    }

    seekNext(pos) {
        while (++pos < this.len && !this.tests[pos]);
        return pos;
    }

    seekPrev(pos) {
        while (--pos >= 0 && !this.tests[pos]);
        return pos;
    }

    shiftL(begin: number, end: number) {
        let i, j;
        if (begin < 0) {
            return;
        }
        for (i = begin, j = this.seekNext(end); i < this.len; i++) {
            if (this.tests[i]) {
                if (j < this.len && this.tests[i].test(this.buffer[j])) {
                    this.buffer[i] = this.buffer[j];
                    this.buffer[j] = this.getPlaceholder(j);
                } else {
                    break;
                }
                j = this.seekNext(j);
            }
        }
        this.writeBuffer();
        this.caret(Math.max(this.firstNonMaskPos, begin));
    }

    shiftR(pos) {
        let i, c, j, t;
        for (i = pos, c = this.getPlaceholder(pos); i < this.len; i++) {
            if (this.tests[i]) {
                j = this.seekNext(i);
                t = this.buffer[i];
                this.buffer[i] = c;
                if (j < this.len && this.tests[j].test(t)) {
                    c = t;
                } else {
                    break;
                }
            }
        }
    }

    handleAndroidInput(e) {
        const curVal = this.inputViewChild.nativeElement.value;
        const pos = this.caret();
        if (this.oldVal && this.oldVal.length && this.oldVal.length > curVal.length) {
            // a deletion or backspace happened
            this.checkVal(true);
            while (pos.begin > 0 && !this.tests[pos.begin - 1]) {
                pos.begin--;
            }
            if (pos.begin === 0) {
                while (pos.begin < this.firstNonMaskPos && !this.tests[pos.begin]) {
                    pos.begin++;
                }
            }
            setTimeout(() => {
                this.caret(pos.begin, pos.begin);
                this.updateModel(e);
                if (this.isCompleted()) {
                    this.completed.emit();
                }
            }, 0);
        } else {
            this.checkVal(true);
            while (pos.begin < this.len && !this.tests[pos.begin]) {
                pos.begin++;
            }
            setTimeout(() => {
                this.caret(pos.begin, pos.begin);
                this.updateModel(e);
                if (this.isCompleted()) {
                    this.completed.emit();
                }
            }, 0);
        }
    }

    onInputBlur(e) {
        this.focused = false;
        this.onModelTouched();
        this.checkVal();
        this.updateFilledState();
        this.blur.emit(e);
        if (this.inputViewChild.nativeElement.value !== this.focusText || this.inputViewChild.nativeElement.value !== this.value) {
            this.updateModel(e);
            const event = document.createEvent('HTMLEvents');
            event.initEvent('change', true, false);
            this.inputViewChild.nativeElement.dispatchEvent(event);
        }
    }

    onInputKeydown(e) {
        if (this.readonly) {
            return;
        }
        const k = e.which || e.keyCode;
        let pos;
        let begin;
        let end;

        this.oldVal = this.inputViewChild.nativeElement.value;
        this.keydown.emit(e);
        if (k === 8 || k === 46) {
            pos = this.caret();
            begin = pos.begin;
            end = pos.end;
            if (end - begin === 0) {
                begin = k !== 46 ? this.seekPrev(begin) : (end = this.seekNext(begin - 1));
                end = k === 46 ? this.seekNext(end) : end;
            }
            this.clearBuffer(begin, end);
            this.shiftL(begin, end - 1);
            this.updateModel(e);
            this.input.emit(e);
            e.preventDefault();
        } else if (k === 13) { // enter
            this.onInputBlur(e);
            this.updateModel(e);
        } else if (k === 27) { // escape
            this.inputViewChild.nativeElement.value = this.focusText;
            this.caret(0, this.checkVal());
            this.updateModel(e);
            e.preventDefault();
        }
    }

    onKeyPress(e) {
        if (this.readonly) {
            return;
        }
        const k = e.which || e.keyCode;
        const pos = this.caret();
        let p;
        let c;
        let next;
        let completed;
        if (e.ctrlKey || e.altKey || e.metaKey || k < 32 || (k > 34 && k < 41)) {// Ignore
            return;
        } else if (k && k !== 13) {
            if (pos.end - pos.begin !== 0) {
                this.clearBuffer(pos.begin, pos.end);
                this.shiftL(pos.begin, pos.end - 1);
            }
            p = this.seekNext(pos.begin - 1);
            if (p < this.len) {
                c = String.fromCharCode(k);
                if (this.tests[p].test(c)) {
                    this.shiftR(p);
                    this.buffer[p] = c;
                    this.writeBuffer();
                    next = this.seekNext(p);
                    this.caret(next);
                    if (pos.begin <= this.lastRequiredNonMaskPos) {
                        completed = this.isCompleted();
                    }
                    this.input.emit(e);
                }
            }
            e.preventDefault();
        }
        this.updateModel(e);
        this.updateFilledState();
        if (completed) {
            this.completed.emit();
        }
    }

    clearBuffer(start, end) {
        let i;
        for (i = start; i < end && i < this.len; i++) {
            if (this.tests[i]) {
                this.buffer[i] = this.getPlaceholder(i);
            }
        }
    }

    writeBuffer() {
        this.inputViewChild.nativeElement.value = this.buffer.join('');
    }

    checkVal(allow?: boolean) {
        // try to place characters where they belong
        const test = this.inputViewChild.nativeElement.value;
        let lastMatch = -1;
        let i;
        let c;
        let pos;
        for (i = 0, pos = 0; i < this.len; i++) {
            if (this.tests[i]) {
                this.buffer[i] = this.getPlaceholder(i);
                while (pos++ < test.length) {
                    c = test.charAt(pos - 1);
                    if (this.tests[i].test(c)) {
                        this.buffer[i] = c;
                        lastMatch = i;
                        break;
                    }
                }
                if (pos > test.length) {
                    this.clearBuffer(i + 1, this.len);
                    break;
                }
            } else {
                if (this.buffer[i] === test.charAt(pos)) {
                    pos++;
                }
                if (i < this.partialPosition) {
                    lastMatch = i;
                }
            }
        }
        if (allow) {
            this.writeBuffer();
        } else if (lastMatch + 1 < this.partialPosition) {
            if (this.autoClear || this.buffer.join('') === this.defaultBuffer) {
                // Invalid value. Remove it and replace it with the
                // mask, which is the default behavior.
                if (this.inputViewChild.nativeElement.value) {
                    this.inputViewChild.nativeElement.value = '';
                }
                this.clearBuffer(0, this.len);
            } else {
                // Invalid value, but we opt to show the value to the
                // user and allow them to correct their mistake.
                this.writeBuffer();
            }
        } else {
            this.writeBuffer();
            this.inputViewChild.nativeElement.value = this.inputViewChild.nativeElement.value.substring(0, lastMatch + 1);
        }
        return (this.partialPosition ? i : this.firstNonMaskPos);
    }

    onInputFocus(event) {
        if (this.readonly) {
            return;
        }
        this.focused = true;
        clearTimeout(this.caretTimeoutId);
        let pos;
        this.focusText = this.inputViewChild.nativeElement.value;
        pos = this.checkVal();
        this.caretTimeoutId = setTimeout(() => {
            if (this.inputViewChild.nativeElement !== this.inputViewChild.nativeElement.ownerDocument.activeElement) {
                return;
            }
            this.writeBuffer();
            if (pos == this.mask.replace('?', '').length) {
                this.caret(0, pos);
            } else {
                this.caret(pos);
            }
        }, 10);
        this.focus.emit(event);
    }

    onInputChange(event) {
        if (this.androidChrome) {
            this.handleAndroidInput(event);
        } else {
            this.handleInputChange(event);
        }
        this.input.emit(event);
    }

    handleInputChange(event) {
        if (this.readonly) {
            return;
        }
        setTimeout(() => {
            const pos = this.checkVal(true);
            this.caret(pos);
            this.updateModel(event);
            if (this.isCompleted()) {
                this.completed.emit();
            }
        }, 0);
    }

    getUnmaskedValue() {
        const unmaskedBuffer = [];
        for (let i = 0; i < this.buffer.length; i++) {
            const c = this.buffer[i];
            if (this.tests[i] && c !== this.getPlaceholder(i)) {
                unmaskedBuffer.push(c);
            }
        }
        return unmaskedBuffer.join('');
    }

    updateModel(e) {
        const updatedValue = this.unmask ? this.getUnmaskedValue() : e.target.value;
        if (updatedValue !== null || updatedValue !== undefined) {
            this.value = updatedValue;
            this.onModelChange(this.value);
        }
    }

    updateFilledState() {
        this.filled = this.inputViewChild.nativeElement && this.inputViewChild.nativeElement.value != '';
    }

    setFocus() {
        this.inputViewChild.nativeElement.focus();
    }

    ngOnDestroy() {
    }
}