import {FormControl} from '@angular/forms';

/* PORTS RANGE VALIDATOR (5000 is reserved for socket connection) */
function validatePortRange(c:FormControl) {
    let portNumber = c.value;
    /*
    * port can't be 5000 --> websocket communication port
    * port can't be 3001 --> BrowserSync UI port
    * port can't be 4200 --> PMP UI port
    */
    if (0 <= portNumber && portNumber <= 65535 && portNumber !== 5000 && portNumber !== 3001 && portNumber !== 4200) { return null; }

    return {
        validatePortNumber: { valid:false }
    };
}

/* check if a string is a well formed URL */
function validURLChecker(c:FormControl) {
    if(document) {
        // do the checking via anchor tag technique
        let url = document.createElement('a');
        url.href = c.value;

        /* has valid protocol & has host */
        // check for external URLs
        if((url.protocol === 'http:' || url.protocol === 'https:') && url.host !== '') return null;
        // check for local URLs
        if(url.protocol === 'localhost:') return null;

    } else {
        // validate anyway
        return null;
    }

    return {
        validateURL: { valid:false }
    }
}

export const CustomValidators = {
    portRange: validatePortRange,
    validURL: validURLChecker
};