/**
 * COPYRIGHT © 2022 JOHN PEARCEY
 * All rights reserved
*/

/*
 * pagename:
 * 	The name of the server-side script to handle this post.
 *	fnCallback:
 * 	The javascript callback function, called after the AJAX call completes.
 * map_params:
 * 	A map containing name value pairs required by the script.
 * 	e.g.
 * 	map_params = new Map();
		map_params.set('username', document.getElementById('username').value );
		map_params.set('pwdhash', document.getElementById('pwd').value );
 */
function postData( pagename, fnCallback, map_params ){		
							
	//console.log( 'postData called' );
	
	let formData = new FormData();		
	map_params.forEach((value, key, map) => {
		//if(key=='action') console.log("postData: ", pagename, value );
		formData.append( key, value );
	});
		
	//https://www.digitalocean.com/community/tutorials/how-to-use-the-javascript-fetch-api-to-get-data
	//https://jsonplaceholder.typicode.com/users
	//https://javascript.info/fetch						
	fetch( pagename, {
		method: 'POST',
		body: formData,
		
	})
	/*.then((response) => {
		return response.json(); */

	.then(response => response.text()) 
    .then((dataStr) => {
		
		//console.log(dataStr);
		
		//there's a whole bunch of warnings and errors that might be sent by PHP. It is not possible
		//to catch them in the serverside PHP code. So here we search for our json encoded return string which
		//must be either Error or OK.
		let pos = dataStr.indexOf("[\"OK\"");
		let additional=null;
		if(pos==-1){
			pos = dataStr.indexOf("[\"Error\"");
			if(pos==-1){
				//the PHP is pretty fucked up if you get here!
				console.warn( dataStr );
				let encodedStr = JSON.stringify( ["Illegal return from server. Did not find Error or OK.", dataStr ] );
				return JSON.parse( encodedStr );
			}
		}			
		//console.log(dataStr);
      return JSON.parse(dataStr);
        		
	}).then((data) => {
		fnCallback( true, data, map_params );
	
	}).catch(function(error) {
		console.log( error );
		fnCallback( false, error, map_params );
	});
	
}

function checkReturn( success, data, bGetErr=false ){

	if(!success){
		console.warn( "callback error: " + data );
		return false;
	}

	if(data[0]=="Error"){
		if(bGetErr) return data;
		alert( "Error: " + data[1] );
		for( i=2; i<data.length; i++){
			console.warn( data[i] );
		}		
		return false;
	}

	if(data[0]!="OK"){
		console.warn( "Unkown server return string ", data );
		if(bGetErr) return data;
		return false;
	}
	if(bGetErr) return null;
	return true;
}

function stripHtml( txt ){	
	txt =	txt.replace(/<div>/gi, '\n');	
	txt =	txt.replace(/<\/?[^>]+>/gi, ''); //strip HTML	
	return txt;
}