feat: discard a card to end the turn

src/main.zig

@@ -1080,6 +1080,31 @@ fn playerTurnHandler(arena: std.mem.Allocator, request: Request) HandlerError!Re
                 .can_undo = true,
                 .reset_selection = false,
             } };
+        } else if (std.mem.eql(u8, command, "discard")) {
+            if (request.game_state.marked_cards.count() == 1) {
+                var new_game_state = try request.game_state.clone(arena);
+
+                try new_game_state.discard_pile.ensureUnusedCapacity(arena, 1);
+
+                new_game_state.hands[0].clearRetainingCapacity();
+                new_game_state.marked_cards.clearRetainingCapacity();
+
+                for (request.game_state.hands[0].items) |card| {
+                    if (request.game_state.marked_cards.contains(card)) {
+                        new_game_state.discard_pile.appendAssumeCapacity(card);
+                    } else {
+                        new_game_state.hands[0].appendAssumeCapacity(card);
+                    }
+                }
+
+                new_game_state.handler = &endOfTurnConfirmHandler;
+
+                return Response{ .transition = .{
+                    .game_state = new_game_state,
+                    .can_undo = true,
+                    .reset_selection = false,
+                } };
+            }
         }
     }
 
@@ -1098,6 +1123,9 @@ fn playerTurnHandler(arena: std.mem.Allocator, request: Request) HandlerError!Re
     draw_pile.hidden = true;
 
     var discard_pile = try Pile.create(arena, request.game_state.discard_pile.items);
+    if (request.game_state.marked_cards.count() == 1) {
+        discard_pile.command = "discard";
+    }
 
     var hand = try HBox.create(arena);
     for (request.game_state.hands[0].items) |card| {
@@ -1121,6 +1149,60 @@ fn playerTurnHandler(arena: std.mem.Allocator, request: Request) HandlerError!Re
     return Response{ .page = page.element() };
 }
 
+fn endOfTurnConfirmHandler(arena: std.mem.Allocator, request: Request) HandlerError!Response {
+    if (request.command) |command| {
+        if (std.mem.eql(u8, command, "end_turn")) {
+            var new_game_state = try request.game_state.clone(arena);
+            new_game_state.handler = &drawCardHandler;
+
+            return Response{ .transition = .{
+                .game_state = new_game_state,
+                .can_undo = false,
+            } };
+        }
+    }
+
+    var new_meld_text = try TextElement.create(arena, .{
+        .text = "New Meld",
+        .command = null,
+    });
+
+    var melds_hbox = try HBox.create(arena);
+    try melds_hbox.addElement(new_meld_text.element());
+
+    var draw_pile = try Pile.create(arena, request.game_state.draw_pile.items);
+    draw_pile.hidden = true;
+
+    var discard_pile = try Pile.create(arena, request.game_state.discard_pile.items);
+
+    var hand = try HBox.create(arena);
+    for (request.game_state.hands[0].items) |card| {
+        var card_element = try CardElement.create(arena, .{
+            .visual = .{ .card = card },
+            .command = null,
+            .marked = false,
+        });
+        try hand.addElement(card_element.element());
+    }
+
+    var draw_discard_hbox = try HBox.create(arena);
+    try draw_discard_hbox.addElement(draw_pile.element());
+    try draw_discard_hbox.addElement(discard_pile.element());
+
+    var end_turn_text = try TextElement.create(arena, .{
+        .text = "End Turn",
+        .command = "end_turn",
+    });
+
+    var page = try Page.create(arena);
+    try page.addElement(.{ 0.5, 0.5 }, .{ 0.5, 0.5 }, draw_discard_hbox.element());
+    try page.addElement(.{ 0.5, 1 }, .{ 0.5, 1 }, hand.element());
+    try page.addElement(.{ 0.5, 0 }, .{ 0.5, 0 }, melds_hbox.element());
+    try page.addElement(.{ 0.5, 0.5 }, .{ 0.5, 0.5 }, end_turn_text.element());
+
+    return Response{ .page = page.element() };
+}
+
 fn isValidRummyMeld(cards: []const Card) bool {
     std.debug.assert(std.sort.isSorted(Card, cards, {}, rummyHandSort));
     if (cards.len < 3) {