'use strict';
var gun = Gun(['https://jessemcdonald.info/gun']);

let initialBoard = (function (){
   var init = JSON.stringify({
      'light': [
         'rnbkqbnr',
         'pppppppp',
         '        ',
         '        ',
         '        ',
         '        ',
         '        ',
         '        ',
      ],
      'dark': [
         '        ',
         '        ',
         '        ',
         '        ',
         '        ',
         '        ',
         'pppppppp',
         'rnbkqbnr',
      ],
      'player': 'light',
   });
   return function (){ return JSON.parse(init); }
})();

function cloneJSON(obj){
   return JSON.parse(JSON.stringify(obj));
}

function normalizeSide(side){
   return (side[0] === 'd') ? 'dark' : 'light';
}

function otherSide(side){
   return (side[0] === 'd') ? 'light' : 'dark';
}

function boardGet(board, where, side){
   side = normalizeSide(side);
   if (where === 'phantom') {
      if (!board['phantom'] || board['phantom']['type'][1] !== side[0]) {
         return ' ';
      } else {
         return board['phantom']['type'][0];
      }
   } else {
      var column = 'abcdefgh'.indexOf(where[0]);
      var row = Number(where[1]) - 1;
      return board[side][row][column];
   }
}

function boardPut(board, where, side, piece){
   side = (side[0] === 'd') ? 'dark' : 'light';
   var column = 'abcdefgh'.indexOf(where[0]);
   var row = Number(where[1]) - 1;
   var data = board[side][row];
   var prefix = data.substring(0, column);
   var suffix = data.substring(column + 1, 8);
   board[side][row] = prefix + piece + suffix;
}

function movePiece(priorBoard, side, from, to){
   var other = otherSide(side);
   var type = boardGet(priorBoard, from, side);
   var took = boardGet(priorBoard, to, other);
   var replaced = boardGet(priorBoard, to, side);
   var alongside = (from === 'phantom') ? ' ' : boardGet(priorBoard, from, other);

   var undoBoard = priorBoard;
   if (undoBoard['subsequent']) {
      undoBoard = cloneJSON(undoBoard);
      delete undoBoard['subsequent'];
   }

   var board = cloneJSON(undoBoard);
   board['prior'] = undoBoard;

   board['move'] = {
      'side': normalizeSide(side),
      'type': type,
      'from': from,
      'to': to
   };
   if (took !== ' ') {
      board['move']['took'] = took;
   }
   if (replaced !== ' ') {
      board['move']['replaced'] = replaced;
   }
   if (alongside !== ' ') {
      board['move']['alongside'] = alongside;
   }

   if (from === 'phantom') {
      delete board['phantom'];
   } else {
      boardPut(board, from, side, ' ');
      boardPut(board, from, other, ' ');
   }

   boardPut(board, to, side, type);

   if (alongside !== ' ') {
      boardPut(board, to, other, alongside);
   }

   if (replaced === ' ') {
      board['player'] = otherSide(board['player']);
   } else {
      board['phantom'] = { 'from': to, 'type': replaced + side[0] };
   }

   return board;
}

function renderHistory(board) {
   var list = [];

   while (board && board['move']) {
      list.push(board['move']);
      board = board['prior'];
   }

   var result = '';
   var n = 0;

   while (list.length > 0) {
      var move = list.pop();
      if (move['from'] === 'phantom') {
         var took = move['took'] ? 'x' : '';
         result += '*' + move['type'].toUpperCase() + took + move['to'];
      } else {
         if (n > 0 || move['side'] === 'dark') {
            result += ' ';
         }

         if (move['side'] === 'light') {
            ++n;
            result += String(n) + '. ';
         }

         if (move['pass']) {
            result += '...';
         } else if (move['alongside']) {
            if (move['side'] === 'light') {
               result += move['type'].toUpperCase() + move['alongside'].toUpperCase() + move['from'] + move['to'];
            } else {
               result += move['alongside'].toUpperCase() + move['type'].toUpperCase() + move['from'] + move['to'];
            }
         } else {
            var took = move['took'] ? 'x' : '';
            result += move['type'].toUpperCase() + move['from'] + took + move['to'];
         }
      }
   }

   return result;
}

function pieceStartDrag(ev, ui){
   var board = $('#cb_board').data('board');
   var dragged = $(this);
   var type = dragged.data('type');
   var from = dragged.data('location');
   if (from === 'phantom' || boardGet(board, from, otherSide(type[1])) === ' ') {
      var clss = (type[1] === 'd') ? '.cb-dk-piece' : '.cb-lt-piece';
      var other = (type[1] === 'd') ? '.cb-lt-piece' : '.cb-dk-piece';
      $('.cb-square').not(':has('+clss+')').droppable('enable');
      $('.cb-square').filter(':has('+other+')').droppable('enable');
   } else {
      /* moving together, must go to an empty square */
      $('.cb-square').not(':has(.cb-piece)').droppable('enable');
   }
};

function placePiece(where, type, count){
   var piece_id = 'cb_piece_' + type + '_' + count;
   var piece = $($('#' + piece_id)[0] || $('#cb_piece_' + type + ' img').clone());
   piece.attr('style', '');
   piece.attr('id', piece_id);
   piece.data({ 'type': type, 'location': where });
   piece.appendTo('#cb_' + where);
   piece.draggable({
      disabled: true,
      containment: '#cb_inner',
      revert: 'invalid',
      zIndex: 100,
      start: pieceStartDrag,
   });
   return piece;
}

function renderBoard(board){
   $('#cb_board .cb-piece .ui-draggable').draggable('destroy');
   $('#cb_board .cb-piece').attr('style', '').appendTo('#cb_hidden');
   $('#cb_board .cb-start').removeClass('cb-start');
   $('#cb_board .cb-end').removeClass('cb-end');
   $('#cb_phantom').appendTo('#cb_hidden');

   for (const side of ['light', 'dark']) {
      var counters = {};
      for (var row = 0; row < 8; ++row) {
         for (var column = 0; column < 8; ++column) {
            var here = 'abcdefgh'[column] + String(row+1);
            var type = board[side][row][column];
            if (type !== ' ') {
               if (!counters[type]) {
                  counters[type] = 0;
               }
               var count = ++counters[type];
               placePiece(here, type + side[0], count);
            }
         }
      }
   }

   var clss = board['player'] === 'light' ? '.cb-lt-piece' : '.cb-dk-piece';

   if (board['phantom']) {
      var where = board['phantom']['from'];
      placePiece('phantom', board['phantom']['type'], 'ph');
      $('#cb_phantom').appendTo('#cb_' + where);
      $('#cb_board .ui-draggable').draggable('disable');
      $('#cb_phantom .ui-draggable-disabled').filter(clss).draggable('enable');
   } else {
      $('#cb_board .ui-draggable-disabled').filter(clss).draggable('enable');
   }

   if (board['move']) {
      if (board['move']['from'] === 'phantom') {
         $('#cb_' + board['prior']['move']['to']).addClass('cb-start');
      } else {
         $('#cb_' + board['move']['from']).addClass('cb-start');
      }
      $('#cb_' + board['move']['to']).addClass('cb-end');
   }

   $('#cb_' + otherSide(board['player']) + '_move').hide();
   $('#cb_' + normalizeSide(board['player']) + '_move').show();

   $('#cb_history').text(renderHistory(board));

   $('#cb_undo').attr('disabled', board['prior'] ? false : true);
   $('#cb_redo').attr('disabled', board['subsequent'] ? false : true);
   $('#cb_pass').attr('disabled', board['phantom'] ? true : false);
}

function randomId(){
   var res = '';
   for (var i = 0; i < 4; ++i) {
      var part = Math.floor(Math.random() * 65536).toString(16);
      res = res + ("0000".substring(part.length, 4) + part);
   }
   return res;
}

var PacoSakoUUID = '7c38edd4-c931-49c8-9f1a-84de560815db';

function putState(board){
   var boardElem = $('#cb_board');
   var gameId = boardElem.data('gameId');
   var game = gun.get(PacoSakoUUID).get('games').get(gameId);
   game.put({ 'board': JSON.stringify(board) });
   putMeta();
}

function putMeta(){
   var gameId = $('#cb_board').data('gameId');
   var lightName = $('#cb_light_name').val() || 'Light';
   var darkName = $('#cb_dark_name').val() || 'Dark';
   var meta = gun.get(PacoSakoUUID).get('meta').get(gameId);
   meta.put({ 'gameId': gameId, 'lightName': lightName, 'darkName': darkName, 'timestamp': new Date().getTime() });
}

function switchGameId(newId){
   var boardElem = $('#cb_board');
   var gameId = boardElem.data('gameId');

   if (newId == gameId) {
      return;
   }

   if (gameId) {
      //gun.get(PacoSakoUUID).get('games').get(gameId).off();
      //gun.get(PacoSakoUUID).get('meta').get(gameId).off();
   }

   boardElem.data('gameId', newId);
   location.hash = '#/' + newId;

   /* this will be the starting state if no data is received from peers */
   var newBoard = initialBoard();
   boardElem.data('board', newBoard);
   renderBoard(newBoard);

   gun.get(PacoSakoUUID).get('games').get(newId).on(function(d){
      if (d && d['board'] && $('#cb_board').data('gameId') === newId) {
         var board = JSON.parse(d['board']);
         $('#cb_board').data('board', board);
         renderBoard(board);
      }
   });

   $('#cb_light_name').val('');
   $('#cb_dark_name').val('');

   gun.get(PacoSakoUUID).get('meta').get(newId).on(function(d){
      if (d && $('#cb_board').data('gameId') === newId) {
         if (d['lightName']) {
            $('#cb_light_name').val(d['lightName']);
         }
         if (d['darkName']) {
            $('#cb_dark_name').val(d['darkName']);
         }
      }
   });

   var selOpt = $('#cb_game_' + newId);
   if (selOpt.length === 1) {
      $('#cb_select_game')[0].selectedIndex = selOpt.index();
   } else {
      $('#cb_select_game')[0].selectedIndex = -1;
   }
}

$(function (){
   $('.cb-square').droppable({
      accept: '.cb-piece',
      disabled: true,
      deactivate: function(ev, ui){
         $(this).droppable('disable');
      },
      drop: function(ev, ui) {
         var dragged = ui.draggable;
         var type = dragged.data('type');
         var from = dragged.data('location');
         var to = this.id.replace(/^cb_/, '');
         dragged.appendTo('#cb_hidden');

         var newBoard = movePiece($('#cb_board').data('board'), type[1], from, to);
         putState(newBoard);
      },
   });

   $('#cb_undo').on('click', function(){
      var board = $('#cb_board').data('board');
      if (board['prior']) {
         var newBoard = cloneJSON(board['prior']);
         var redoBoard = cloneJSON(board);
         delete redoBoard['prior'];
         newBoard['subsequent'] = redoBoard;
         putState(newBoard);
      }
   });

   $('#cb_redo').on('click', function(){
      var board = $('#cb_board').data('board');
      if (board['subsequent']) {
         var newBoard = cloneJSON(board['subsequent']);
         var undoBoard = cloneJSON(board);
         delete undoBoard['subsequent'];
         newBoard['prior'] = undoBoard;
         putState(newBoard);
      }
   });

   $('#cb_reset').on('click', function(){
      putState(initialBoard());
   });

   $('#cb_pass').on('click', function(){
      var board = $('#cb_board').data('board');
      if (!board['phantom']) {
         var newBoard = cloneJSON(board);
         newBoard['prior'] = board;
         newBoard['move'] = { 'side': board['player'], 'pass': true };
         newBoard['player'] = otherSide(board['player']);
         putState(newBoard);
      }
   });

   $('#cb_select_game').on('change', function(){
      var optIndex = $('#cb_select_game')[0].selectedIndex;
      if (optIndex === 0) {
         switchGameId(randomId());
      } else if (optIndex >= 1) {
         var opt = $('#cb_select_game option')[optIndex];
         if (opt) {
            switchGameId(opt.id.replace(/^cb_game_/, ''));
         }
      }
   });

   let updateMeta = function() { putMeta(); }
   $('#cb_light_name').on('input', updateMeta);
   $('#cb_dark_name').on('input', updateMeta);

   gun.get(PacoSakoUUID).get('meta').map().on(function(d){
      if (d && d['gameId'] && d['lightName'] && d['darkName']) {
         function updateTitle(opt){
            const then = opt.data('then');
            const now = new Date().getTime();
            var age_str = '';
            if (then > now) {
               age_str = ' (future)';
            } else if ((now - then) < 60*60*1000) {
               age_str = ' (' + Math.floor((now - then) / (60*1000)) + 'm)';
            } else if ((now - then) < 24*60*60*1000) {
               age_str = ' (' + Math.floor((now - then) / (60*60*1000)) + 'h)';
            } else if ((now - then) < 14*24*60*60*1000) {
               age_str = ' (' + Math.floor((now - then) / (24*60*60*1000)) + 'd)';
            } else if (d['gameId'] !== $('#cb_board').data('gameId')) {
               opt.remove();
               return;
            }
            opt.text(opt.data('title') + age_str);
         }

         var opt = $('#cb_game_' + d['gameId']);
         if (opt.length === 0) {
            opt = $('<option></option>');
            opt.attr('id', 'cb_game_' + d['gameId']);

            function refreshTitle(){
               updateTitle(opt);
               window.setTimeout(refreshTitle, 15000);
            };

            window.setTimeout(refreshTitle, 0);
         }

         opt.data('title', d['lightName'] + ' vs. ' + d['darkName']);
         opt.data('then', d['timestamp'] || new Date().getTime());
         opt.addClass('cb-game-option');
         opt.appendTo('#cb_select_game');
         updateTitle(opt);

         var select = $('#cb_select_game');
         var list = select.children('.cb-game-option').get();
         list.sort(function(a,b) {
            const then_a = $(a).data('then');
            const then_b = $(b).data('then');
            return (then_a < then_b) ? 1 : (then_a == then_b) ? 0 : -1;
         });

         for (const e of list) {
            $(e).appendTo(select);
         }

         var selOpt = $('#cb_game_' + $('#cb_board').data('gameId'));
         if (selOpt.length === 1) {
            $('#cb_select_game')[0].selectedIndex = selOpt.index();
         } else {
            $('#cb_select_game')[0].selectedIndex = -1;
         }
      }
   });

   var gameId = location.hash.replace(/^#\//, '');
   if (gameId.length !== 16) {
      gameId = randomId();
   }

   switchGameId(gameId);
});

/* vim:set expandtab sw=3 ts=8: */