import {ContentChildren, ElementRef, EventEmitter, Input, Output, QueryList,} from '@angular/core';
import {ControlValueAccessor, NgModel} from '@angular/forms';
import {isNull, isUndefined} from 'lodash';
import {FValidateRegexComponent} from '../components/f-validate-regex/f-validate-regex.component';
import {ValidationResponse} from '../objects/validation-response';
import {HFormService} from '../services/h-form.service';
import {MessageService} from '../services/message.service';
import {JsfOutput} from './jsf-output';

export abstract class JsfInput extends JsfOutput implements ControlValueAccessor {
    @Input()
    validatorMessage: string;

    @Input()
    converterMessage: string;

    @Input()
    requiredMessage: string;

    @Input()
    required: boolean;

    @Input()
    disabled: boolean;

    @Input()
    maxLength: number;

    @Input()
    validator: (elem: JsfInput) => Promise<ValidationResponse>;

    @Output()
    onchange = new EventEmitter<any>();

    protected abstract model: NgModel;

    @ContentChildren(FValidateRegexComponent)
    private regexValidators: QueryList<FValidateRegexComponent>;

    private changeListener = [];
    private touchListener = [];
    private converterError = false;

    constructor(hFromService: HFormService, private messageService: MessageService,
                elementRef: ElementRef) {
        super(hFromService, elementRef);
    }

    // same as in JsfOutput but for some reason angular won't use the getter
    get value(): any {
        if (this.converter && this.innerValue) {
            return this.converter.transform(this.innerValue);
        }
        return this.innerValue;
    }

    set value(value: any) {
        if (this.innerValue !== value) {
            // converter given? then convert
            if (this.converter) {
                try {
                    this.innerValue = this.converter.transformToObject(value);
                    this.converterError = false;
                } catch (e) {
                    // we have to save the value anyway, otherwise the input of the user is deleted
                    this.innerValue = value;
                    this.converterError = true;
                }
            } else {
                this.innerValue = value;
            }
            this.changeListener.forEach(f => f(this.innerValue));
        }
    }

    async jsfOnRender(): Promise<void> {
        try {
            await super.jsfOnRender();
            await this.validate();
        } catch (e) {
            console.error(e);
        }
    }

    /**
     *
     * add more events if required
     * don't forget to use them in the actual .html File
     *
     */
    async callAjax(event: string): Promise<void> {
        for (const ajax of this.ajax.toArray()) {
            if (ajax.event === event) {
                // if input is invalid and ajax is not set to immediate exec
                // prevent call
                let valid = true;
                if (!ajax.immediate) {
                    valid = await this.validate();
                }

                if (valid) {
                    ajax.call(this);
                }
            }
        }
    }

    async onBlur() {
        try {
            await this.validate();
            await this.callAjax('blur');
        } catch (e) {
            console.error(e);
        }
    }

    async onChange() {
        this.onchange.emit(this.innerValue);
        try {
            await this.callAjax('change');
        } catch (e) {
            console.error(e);
        }
    }

    /**
     *
     * @returns {Promise<boolean>} true when input ok
     */
    async validate(): Promise<boolean> {
        let valid = true;
        let message = '';

        // check for converter error
        if (this.converterError) {
            valid = false;
            message = this.converterMessage;
        }

        // check for regex validators
        for (const validator of this.regexValidators.toArray()) {
            if (!validator.validate(this.innerValue)) {
                valid = false;
                message = this.validatorMessage;
            }
        }

        // check for required
        if ((isNull(this.innerValue) || isUndefined(this.innerValue) ||
                this.innerValue === '') &&
            this.required && valid) {
            valid = false;
            message = this.requiredMessage;
        }

        // check for additional custom validators
        if (valid && this.validator) {
            const result = await this.validator(this);
            if (result.error) {
                valid = false;
                message = result.message;
            }
        }

        if (valid && this.maxLength && typeof this.innerValue === 'string' &&
            this.innerValue.length > this.maxLength) {
            valid = false;
            message = `Input is too long. Maximum ${this.maxLength} characters allowed`;
        }

        if (valid) {
            const result = await this.triggerEvent('postValidate');
            valid = !result.error;
            message = result.message;
        }

        this.messageService.submitError(this.simpleId, !valid, message);

        return valid;
    }

    /**
     * ng specific input functions
     */
    touch() {
        this.touchListener.forEach(f => f());
    }

    writeValue(value: any) {
        this.innerValue = value;
    }

    registerOnChange(fn: (value: any) => void) {
        this.changeListener.push(fn);
    }

    registerOnTouched(fn: () => void) {
        this.touchListener.push(fn);
    }
}