+/**
+ * @param {string} fen
+ */
+var update_imbalance = function(fen) {
+ var hiddenboard = new Chess(fen);
+ var imbalance = {'k': 0, 'q': 0, 'r': 0, 'b': 0, 'n': 0, 'p': 0};
+ for (var row = 0; row < 8; ++row) {
+ for (var col = 0; col < 8; ++col) {
+ var col_text = String.fromCharCode('a1'.charCodeAt(0) + col);
+ var row_text = String.fromCharCode('a1'.charCodeAt(1) + row);
+ var square = col_text + row_text;
+ var contents = hiddenboard.get(square);
+ if (contents !== null) {
+ if (contents.color === 'w') {
+ ++imbalance[contents.type];
+ } else {
+ --imbalance[contents.type];
+ }
+ }
+ }
+ }
+ var white_imbalance = '';
+ var black_imbalance = '';
+ for (var piece in imbalance) {
+ for (var i = 0; i < imbalance[piece]; ++i) {
+ white_imbalance += '<img src="img/chesspieces/wikipedia/w' + piece.toUpperCase() + '.png" alt="" style="width: 15px;height: 15px;">';
+ }
+ for (var i = 0; i < -imbalance[piece]; ++i) {
+ black_imbalance += '<img src="img/chesspieces/wikipedia/b' + piece.toUpperCase() + '.png" alt="" style="width: 15px;height: 15px;">';
+ }
+ }
+ $('#whiteimbalance').html(white_imbalance);
+ $('#blackimbalance').html(black_imbalance);
+}
+
+/** Mark the currently selected move in red.
+ * Also replaces the PV with the current displayed line if it's not shown
+ * anywhere else on the screen.
+ */
+var update_move_highlight = function() {
+ if (highlighted_move !== null) {
+ highlighted_move.removeClass('highlight');
+ }
+ if (current_display_line) {
+ // See if the current displayed line is identical to any of the ones
+ // we have on screen. (It might not be if e.g. the analysis reloaded
+ // since we started looking.)
+ var display_line_num = null;
+ for (var i = 0; i < display_lines.length; ++i) {
+ var line = display_lines[i];
+ if (line.start_display_move_num > 0) continue;
+ if (current_display_line.start_fen !== line.start_fen) continue;
+ if (current_display_line.pretty_pv.length !== line.pretty_pv.length) continue;
+ var ok = true;
+ for (var j = 0; j < line.pretty_pv.length; ++j) {
+ if (current_display_line.pretty_pv[j] !== line.pretty_pv[j]) {
+ ok = false;
+ break;
+ }
+ }
+ if (ok) {
+ display_line_num = i;
+ break;
+ }
+ }
+
+ if (display_line_num === null) {
+ // Replace the PV with the (complete) line.
+ $("#pvtitle").text("Exploring:");
+ current_display_line.start_display_move_num = 0;
+ display_lines.push(current_display_line);
+ $("#pv").html(print_pv(display_lines.length - 1));
+ display_line_num = display_lines.length - 1;
+ }
+
+ highlighted_move = $("#automove" + display_line_num + "-" + (current_display_move - current_display_line.start_display_move_num));
+ highlighted_move.addClass('highlight');
+ }
+}
+
+var update_displayed_line = function() {
+ if (current_display_line === null) {
+ $("#linenav").hide();
+ $("#linemsg").show();
+ display_fen = base_fen;
+ board.position(base_fen);
+ update_imbalance(base_fen);
+ return;
+ }
+
+ $("#linenav").show();
+ $("#linemsg").hide();
+
+ if (current_display_move <= 0) {
+ $("#prevmove").html("Previous");
+ } else {
+ $("#prevmove").html("<a href=\"javascript:prev_move();\">Previous</a></span>");
+ }
+ if (current_display_move == current_display_line.pretty_pv.length - 1) {
+ $("#nextmove").html("Next");
+ } else {
+ $("#nextmove").html("<a href=\"javascript:next_move();\">Next</a></span>");
+ }
+
+ var hiddenboard = chess_from(current_display_line.start_fen, current_display_line.pretty_pv, current_display_move);
+ display_fen = hiddenboard.fen();
+ board_is_animating = true;
+ var old_fen = board.fen();
+ board.position(hiddenboard.fen());
+ if (board.fen() === old_fen) {
+ board_is_animating = false;
+ } else {
+ // Fire off a hash request, since we're now off the main position
+ // and it just changed.
+ explore_hash(display_fen);
+ }
+ update_imbalance(hiddenboard.fen());
+}
+
+/**
+ * @param {boolean} param_enable_sound
+ */
+var set_sound = function(param_enable_sound) {
+ enable_sound = param_enable_sound;
+ if (enable_sound) {
+ $("#soundon").html("<strong>On</strong>");
+ $("#soundoff").html("<a href=\"javascript:set_sound(false)\">Off</a>");
+
+ // Seemingly at least Firefox prefers MP3 over Opus; tell it otherwise,
+ // and also preload the file since the user has selected audio.
+ var ding = document.getElementById('ding');
+ if (ding && ding.canPlayType && ding.canPlayType('audio/ogg; codecs="opus"') === 'probably') {
+ ding.src = 'ding.opus';
+ ding.load();
+ }
+ } else {
+ $("#soundon").html("<a href=\"javascript:set_sound(true)\">On</a>");
+ $("#soundoff").html("<strong>Off</strong>");
+ }
+ if (supports_html5_storage()) {
+ localStorage['enable_sound'] = enable_sound ? 1 : 0;
+ }
+}
+window['set_sound'] = set_sound;
+
+/** Send off a hash probe request to the backend.
+ * @param {string} fen
+ */
+var explore_hash = function(fen) {
+ // If we already have a backend response going, abort it.
+ if (current_hash_xhr) {
+ current_hash_xhr.abort();
+ }
+ if (current_hash_display_timer) {
+ clearTimeout(current_hash_display_timer);
+ current_hash_display_timer = null;
+ }
+ current_hash_xhr = $.ajax({
+ url: backend_hash_url + "?fen=" + fen
+ }).done(function(data, textstatus, xhr) {
+ show_explore_hash_results(data, fen);
+ });
+}
+
+/** Process the JSON response from a hash probe request.
+ * @param {!Object} data
+ * @param {string} fen
+ */
+var show_explore_hash_results = function(data, fen) {
+ if (board_is_animating) {
+ // Updating while the animation is still going causes
+ // the animation to jerk. This is pretty crude, but it will do.
+ current_hash_display_timer = setTimeout(function() { show_explore_hash_results(data, fen); }, 100);
+ return;
+ }
+ current_hash_display_timer = null;
+ hash_refutation_lines = data['lines'];
+ update_board();
+}
+
+/**
+ * @param {string} new_backend_url
+ */
+var switch_backend = function(new_backend_url) {
+ // Stop looking at historic data.
+ current_display_line = null;
+ current_display_move = null;
+ displayed_analysis_data = null;
+ if (current_historic_xhr) {
+ current_historic_xhr.abort();
+ }
+
+ // If we already have a backend response going, abort it.
+ if (current_analysis_xhr) {
+ current_analysis_xhr.abort();
+ }
+ if (current_hash_xhr) {
+ current_hash_xhr.abort();
+ }
+
+ // Otherwise, we should have a timer going to start a new one.
+ // Kill that, too.
+ if (current_analysis_request_timer) {
+ clearTimeout(current_analysis_request_timer);
+ current_analysis_request_timer = null;
+ }
+ if (current_hash_display_timer) {
+ clearTimeout(current_hash_display_timer);
+ current_hash_display_timer = null;
+ }
+
+ // Request an immediate fetch with the new backend.
+ backend_url = new_backend_url;
+ current_analysis_data = null;
+ ims = 0;
+ request_update();
+}
+window['switch_backend'] = switch_backend;
+