import { ElementRef, Injector } from '@angular/core';
import { NgControl } from '@angular/forms';
import { hostElementError } from '../exceptions';
import { ControlDetector } from '../../../interfaces';

export enum FormatType{
    uppercase,
    lowercase,
    capital,
    titlecase,
    trim,
    combine,
    normalize,
}


export class Format implements ControlDetector {

    native: HTMLInputElement | HTMLTextAreaElement;

    constructor(
        protected ref: ElementRef, 
        protected injector: Injector,
    ){this.native = this.ref.nativeElement;};

    private _uppercase(value: string): string {
        return value.toUpperCase();
    }

    private _lowercase(value: string): string {
        return value.toLowerCase();
    }

    private _capital(value: string): string {
        return value[0].toUpperCase() + value.slice(1);
    }

    private _titlecase(value: string): string {
        return value.split(' ').map(word => word ? this._capital(word) : '').join(' ');
    }

    private _trim(value: string): string {
        return value.trim();
    }

    private _combine(value: string): string {
        return value.split(' ').join('');
    }

    private _normalize(value: string): string {
        return value.split(' ').filter(str => str).join(' ');
    }


    protected blurHandler(formatType: FormatType | Function): void {

        const isCompitable = 
        this.native instanceof HTMLInputElement ||
        this.native instanceof HTMLTextAreaElement;

        if(!isCompitable)hostElementError(this.native.tagName);

        const valueAtBlur: string = this.native.value;

        let formattedValue: string;

        switch (formatType){
            case FormatType.uppercase: 
                formattedValue = this._uppercase(valueAtBlur);
                break;
            case FormatType.lowercase: 
                formattedValue = this._lowercase(valueAtBlur);
                break;
            case FormatType.capital: 
                formattedValue = this._capital(valueAtBlur);
                break;
            case FormatType.titlecase: 
                formattedValue = this._titlecase(valueAtBlur);
                break;
            case FormatType.trim: 
                formattedValue = this._trim(valueAtBlur);
                break;
            case FormatType.combine: 
                formattedValue = this._combine(valueAtBlur);
                break;
            case FormatType.normalize:
                formattedValue = this._normalize(valueAtBlur);
                break;

            /* --- for custom callbacks --- */
            default: formattedValue = formatType(valueAtBlur)
        }
    
        this.detectAndSet(this.native,formattedValue);
    
    }

    public detectAndSet(elem, value){

        let abstractController: NgControl;
        try{
            abstractController = this.injector.get(NgControl);
            abstractController.control.setValue(value)
        }catch{
            elem.value = value;
        }
    }

}