/**
 * COPYRIGHT © 2022 JOHN PEARCEY
 * All rights reserved
*/
 
/**
 * The last nonce we just got from the server
 */
var g_svr_nonce = [];
 
/**
 * Every 10secs, we get the state of the backup list from the server. This is so that we can keep the front end up-to-date
 * for the user. I'm sure that there are better ways with modern HTML5 but polling is easy and the application is not
 * time critical. This is sufficient.
 */
var g_bu_list_state = [];
 
/**
 * This var g_stack_pages contains the app navigation pages in order. The top most page being the
 * current page. So, to go back, you would remove the top most page and navigate to the new top page.
*/
var g_stack_pages = [];
	
function clear_page_state(){
	g_bu_list_state = [];
	g_stack_pages = [];
}
			
function push_page( pagename ){
	g_stack_pages.push( pagename );
}
 
/**
 * Pops the current page off the stack and returns the penultimate one.
 */
function back_page( ){
	g_stack_pages.pop( );
	return g_stack_pages[g_stack_pages.length - 1];
}
 
function index_onload(){	
	update_bu_state( false );
	set_main_content( true );	
}
 
function update_bu_state( bCheckPage = true ){
	
	setTimeout( () => { 
		update_bu_state();
	}, 10000);
 
	if(bCheckPage){
		//console.log( "update_bu_state pages:", g_stack_pages );
		if( g_stack_pages[g_stack_pages.length - 1] != 'backup-list' ) return;
	}
 
	//console.log( "update_bu_state polling" );
 
	map_params = new Map();
	map_params.set('action', 'backup-list-state' );
	
	postData( "post_handler.php", function( success, data, m ){
			
		if(data[1][0]=='login'){
			console.log( 'Cannot get backup-list-state: Not logged in' );
			return;
		}		
 
		let new_state = data[1][1];
		
		//console.log( 'backup-list-state' + new_state );
		
		if( g_bu_list_state.length == 0 ){
			//just store the new state
			g_bu_list_state = new_state;
			return;
		}
		
		//compare the two arrays, if different length, then refresh the UI.
		if( g_bu_list_state.length != new_state.length ){
			g_bu_list_state = new_state;
			set_main_content( false );
			return;
		}
			
		//check each row in turn
		let bFound = false;
		for( j=0; j<g_bu_list_state.length; j++){
			curr_state_j = g_bu_list_state[j];
			bFound = false;
			
			//console.log("looking for ID = " + curr_state_j[0] );				
			
			for( i=0; i<new_state.length; i++){
				
				new_state_i = new_state[i];						
				//console.log("compare with", new_state_i );
				
				
				if( new_state_i[0] == curr_state_j[0]){							
					bFound = (new_state_i[1] == curr_state_j[1]);
					break;
				}
			}
			if(!bFound){
				//at least one ID or value does not match
				g_bu_list_state = new_state;
				set_main_content( false );
				break;
			}
		}
		
	}, map_params );
 
}
 
 
 
 
function set_main_content( bPushPage ){
 
	//console.log("3");
 
	map_params = new Map();
	map_params.set('action', 'backup-list' );
	
	postData( "post_handler.php", function( success, data, m ){
			
		if(data[0]!="OK"){
			console.log( data );
			return;
		}
 
		let elem = document.getElementById('page_content');
		
		//display page from server
		[ page_type, elem.innerHTML ] = data[1];
		console.log('set_main_content page_type: ', page_type );
		
		if(page_type=='login'){
			//clear client side data
			clear_page_state();
			g_svr_nonce = data[1][2];
			return;
		}
		
		if(bPushPage) push_page('backup-list');
		
	}, map_params );
			
}
 
/**
 * Button clicked and we require a new page from the server to be placed in the page_content area.
 * instr(uction) is usually the page name except where a 'back' navigation is required.
 */
async function btn_clk_nav( elem, instr, id=0 ){
 
	// instr can now also be a space separated list of instructions
	//we split them out
	instrArr = instr.split(" ");
	instr = instrArr[0];
	
	//noTest
 
	map_params = new Map();
	map_params.set('id', id );	
	
	let b_is_db_type = false;
	
	switch(instr){
 
	case 'btn_login':
		if( !valid_btn_login() )		return;
		await set_btn_login( map_params );		
		map_params.set('svr_nonce', g_svr_nonce );		
		map_params.set('final-page', 'backup-list' );
		navigate_page( instr, map_params, false );			
		return;
		
	case 'btn_run_bu':
		bIsBuTest = (instrArr.length==2 && instrArr[1]=='noTest');
		if( bIsBuTest ){
			map_params.set('isTest', 'false' );
		}else{
			map_params.set('isTest', 'true' );
			console.log("running a test backup");
		
		}
		exec_instruction( instr, map_params );
		
		if(!bIsBuTest){
			monitorBuOutput( true, id, -1 );
		}
		return;
	
	case 'delete-bu':
		if( !confirm('Are you sure you wish to delete backup item ' + id ) ) return;
		map_params.set('final-page', 'backup-list' );
		navigate_page( instr, map_params, false );
		return;
		
	case 'btn_edit_shed_bu':
		if( !valid_btn_edit_shed_bu() )		return;		
		set_btn_edit_shed_bu( map_params );		
		map_params.set('final-page', back_page() );	//server to return previous page (usually backup-list) after processing
		navigate_page( 'edit_shed_bu', map_params, false );
		return;
	
	case 'btn_new_bu_db':
		b_is_db_type=true;
		//drop through
	case 'btn_new_bu_file':		
		if( !valid_btn_new_bu( b_is_db_type ) )	return;
		set_btn_new_bu( b_is_db_type, map_params );
		map_params.set('final-page', back_page() );	//server to return previous page (usually backup-list) after processing
		navigate_page( 'new-item-bu', map_params, false );
		return;
		
	case 'btn_edit_bu_db':
		b_is_db_type=true;
		//drop through
	case 'btn_edit_bu_file':		
		if( !valid_btn_new_bu( b_is_db_type ) )	return;
		set_btn_new_bu( b_is_db_type, map_params );
		map_params.set('final-page', back_page() );	//server to return previous page (usually backup-list) after processing
		navigate_page( 'edit-item-bu', map_params, false );
		return;
 
	case 'btn_cancel_new_bu':
	case 'btn_cancel':
		navigate_page( back_page(), map_params, false );
		return;		
	}
	
	navigate_page( instr, map_params, true );
}
 
 
function navigate_page( goto_page, map_params, bPushPage ){
 
	//console.log( 'navigate_page: ', goto_page );
	
	map_params.set('action', goto_page );
	//map_params.set('updateList', JSON.stringify( usrUpdates )  );
	
	postData( "post_handler.php", function( success, data, m ){
		
		if(data[0]!="OK"){
			console.log( data[0], data[1] );
			if(!bPushPage){
				//we need to put back the page that we dropped off or maybe an error page
				//but use goto_page for now
				push_page( goto_page ); 
			}
			return;
		}
		
		let elem = document.getElementById('page_content');
		[ page_type, elem.innerHTML ] = data[1];		
		console.log('navigate_page page_type: ', page_type);
		
		if(page_type=='login'){
			//clear client side data
			clear_page_state();
			g_svr_nonce = data[1][2];
			return;
		}
 
		if(page_type=='authenticated'){
			elem = document.getElementById('anc_login');
			elem.innerHTML="Logout";
			elem.setAttribute("href","post_handler.php?action=logout");
			push_page( map_params.get('final-page') );
			return;
		}
 
		if(bPushPage)	push_page( goto_page );		
		
	}, map_params );
			
}
 
function setTextAreaFromArray( elem, arr ){	
	elem.value = arr.toString().replaceAll(',', "\r\n" );	
}
 
function exec_instruction( instr, map_params ){
 
	console.log( 'exec_instruction: ', instr );
	let id = map_params.get('id');
	
	map_params.set('action', instr );
	//map_params.set('updateList', JSON.stringify( usrUpdates )  );
	
	postData( "post_handler.php", function( success, data, m ){
		
		if(data[0]!="OK"){
			console.log( data );
			return;
		}
		
		bu_result = data[1][0];	//was it ok or err?		
		
		switch(instr){
		case 'btn_run_bu':		
						
			if(bu_result!='ok:'){
				//latest msg contains similar format as used by the server rpc layer
				console.log("odd message: " + bu_result );
				console.log( data );
				return;
			}
			bu_status = data[1][1]; //extra info
			
			if(bu_status=='running'){
 
				// is it a test run? -  by rights, I should send back the 'test' flag				
				let elem = document.getElementById( "ta_testoutput" );
				if(elem==null){
					//not a test - set the tick	
					let elem = document.getElementById( "td_run_" + id );
					elem.innerHTML = "<img id=\"td_run_\"" + id + " src=\"img/green-tick.png\">";
					
					//ensure the state map is also adjusted
					for( j=0; j<g_bu_list_state.length; j++){				
						if(g_bu_list_state[j][0]==id){
							g_bu_list_state[j][1] = 1;
						}
					}
 
				}else{
					//test run
					setTextAreaFromArray( elem, bu_result + " " + bu_status );	
				}
				
			}else{
				
				console.log("unknown message: " + bu_status );
				console.log( data );
			}
			
			break;
			
		default:			
			console.log( data[1] );
				
		}
		
	}, map_params );
			
}
 
function monitorBuOutput( bMonitor, buid, from_line_num ){
	
	if(from_line_num==-1){
		//first call, just set the timer and give some time for the test to kick off
		setTimeout( () => { 
			monitorBuOutput(true, buid, 0);
		}, 1000);
		return ;
	}
	
	console.log("Fetch output from line: " + from_line_num );
	
	let e_ta_testoutput = document.getElementById( "ta_testoutput" );
	if(e_ta_testoutput==null){
		// page gone (should terminate server open file?)
		return;
	}
 
	let map_params = new Map();
	map_params.set('action', 'bu-test-file-lines' );
	map_params.set('buid', buid );		
	map_params.set('from-line-num', from_line_num );		
	
	postData( "post_handler.php", function( success, data, m ){
		//console.log( data );
		let cnt=0;
		let rtm_msg = data[1][cnt++]; //'f:bu-test-file-lines'
		let line_count = data[1][cnt++];
		let line_data = '';
		if(line_count>0){
			line_data = data[1][cnt++];
		}
		
		e_ta_testoutput = document.getElementById( "ta_testoutput" );
		if(e_ta_testoutput==null){
			// page gone (should terminate server open file?)
			return;
		}
 
		if(line_count>0){
			//setTextAreaFromArray( e_ta_testoutput, line_data );
			e_ta_testoutput.value += "\n" + line_data;
			
			setTimeout( () => { 
				monitorBuOutput(true, buid, line_count + from_line_num );
			}, 1000);
			return ;
		}else{
			console.log("No more lines to fetch" );
		}		
		
	}, map_params);
	
}
 
 
function valid_btn_login(){
	
	let login_name = document.getElementById('login_name').value;
	if(login_name=='') {
		alert("Please enter your login name");
		return false;
	}
	
	let login_pwd = document.getElementById('login_pwd').value;
	if(login_pwd=='') {
		alert("Please enter your password");
		return false;
	}
	return true;
}
 
/**
 * Collect data from login form
 */
async function set_btn_login( map_params ){
	
	let raw_pwd = document.getElementById('login_pwd').value;
 
	console.log("pwd = "+raw_pwd);
	console.log("nonce = " + g_svr_nonce);
 
	const pwd_hash = await getHash256(raw_pwd+g_svr_nonce);	
	map_params.set( 'username', document.getElementById('login_name').value );	
	map_params.set( 'password', pwd_hash );
}
 
async function getHash256(message) {
	//https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto/digest
	const encoder = new TextEncoder();
	const data = encoder.encode(message);
	const hashBuffer = await window.crypto.subtle.digest("SHA-256", data);  
	const hashArray = Array.from(new Uint8Array(hashBuffer)); // convert buffer to byte array
	const hashHex = hashArray
		.map((b) => b.toString(16).padStart(2, "0"))
		.join(""); // convert bytes to hex string
	return hashHex;
}
 
/**
 * Validate the form for a new backup entry
 * b_is_db_type is true for DB entry and false for file entry.
 */
function valid_btn_new_bu( b_is_db_type ){
	return true;
}
 
/**
 * Collect the form data together.
 * b_is_db_type is true for DB entry and false for file entry.
 */
function set_btn_new_bu( b_is_db_type, map_params ){
	
	map_params.set( 'new_bu_is_dbType', b_is_db_type?1:0 );
	map_params.set( 'new_bu_name', document.getElementById('new_bu_name').value );
	map_params.set( 'new_bu_source', document.getElementById('new_bu_source').value );	
	map_params.set( 'new_bu_dest', document.getElementById('new_bu_dest').value );
	if(b_is_db_type){
		console.log("Setting DB params username=" + document.getElementById('db_usr_name').value );
		map_params.set( 'db_usr_name', document.getElementById('db_usr_name').value );
		map_params.set( 'db_usr_pwd', document.getElementById('db_usr_pwd').value );
	}else{
		console.log("Setting File params");
		map_params.set( 'new_bu_exf', document.getElementById('new_bu_exf').value );		
	}
}
 
/**
 * Validate the form for the backup scheduling page
 */
function valid_btn_edit_shed_bu(){
	
	sched_date = document.getElementById('sched_date').value;
	if(sched_date=='') {
		alert("Please choose a date");
		return false;
	}
	
	sched_time = document.getElementById('sched_time').value;
	if(sched_time=='') {
		alert("Please choose a time");
		return false;
	}
	
	let dt_chosen = new Date( sched_date + 'T' + sched_time + ':00Z');
	let now = new Date();
	
	if(dt_chosen<=now){
		alert("Please choose a time in the future, not the past: ", dt_chosen, now );
		return false;
	}
	
	console.log("dates: ", dt_chosen, now );
	
	return true;
}
	
/**
 * Collect the form data together for the backup scheduling page
 */
function set_btn_edit_shed_bu( map_params ){
		
	map_params.set( 'sched_date', document.getElementById('sched_date').value );	
	map_params.set( 'sched_time',  document.getElementById('sched_time').value );	
	
	switch(document.querySelector('input[name="sched_period"]:checked').id){
	case 'sched_ip_daily':
		map_params.set( 'sched_period', 'D' );
		break;
 
	case 'sched_ip_weekly':
		map_params.set( 'sched_period', 'W' );
		break;
 
	case 'sched_ip_monthly':
		map_params.set( 'sched_period', 'M' );
		break;
		
	case 'sched_ip_none':
	default:
		map_params.set( 'sched_period', 'N' );
	}
	
	
}