make arcade picker

src/subcmds/arcade/arcade.zig

@@ -1,8 +1,95 @@
 const std = @import("std");
+const gpa = std.heap.page_allocator;
 
 const Conway = @import("conway.zig");
 
-const games = enum{ conway };
+const games = enum(u16) {
+    @"Conways Game of Life",
+};
+
+fn ui(width: u32, height: u32, writer: *std.Io.Writer) !void {
+    var fd = [_]std.posix.pollfd{.{
+        .fd = std.posix.STDIN_FILENO,
+        .events = std.posix.POLL.IN,
+        .revents = 0
+    }};
+
+    // here we're disabling character echoing and newline requirements on input
+    const oldios = try std.posix.tcgetattr(std.posix.STDIN_FILENO);
+    defer std.posix.tcsetattr(std.posix.STDIN_FILENO, std.posix.TCSA.NOW, oldios) catch {
+        // oh well we've left the terminal in a shitty state, not much we can
+        // do to fix this.
+    };
+    var newios = oldios;
+
+    newios.lflag.ECHO = false;
+    newios.lflag.ICANON = false;
+    try std.posix.tcsetattr(std.posix.STDIN_FILENO, std.posix.TCSA.NOW, newios);
+
+    _ = try writer.write("\x1B[?25l"); // hide cursor
+    var running = true;
+    var cursor_y: i64 = 0;
+    while (running) {
+        try writer.print("\x1B[1;1H\x1B[2J", .{}); // clear
+
+        try writer.print("\x1B[{};{}H", .{(height - 5) / 2, 0}); // y, x
+        try writer.alignBuffer(" @@@@@@  @@@@@@@   @@@@@@@  @@@@@@  @@@@@@@  @@@@@@@@", width, .center, ' ');
+        try writer.alignBuffer("@@!  @@@ @@!  @@@ !@@      @@!  @@@ @@!  @@@ @@!     ", width, .center, ' ');
+        try writer.alignBuffer("@!@!@!@! @!@!!@!  !@!      @!@!@!@! @!@  !@! @!!!:!  ", width, .center, ' ');
+        try writer.alignBuffer("!!:  !!! !!: :!!  :!!      !!:  !!! !!:  !!! !!:     ", width, .center, ' ');
+        try writer.alignBuffer(" :   : :  :   : :  :: :: :  :   : : :: :  :  : :: :::", width, .center, ' ');
+
+        cursor_y = @intCast(std.math.clamp(cursor_y, 0, @typeInfo(games).@"enum".fields.len - 1));
+        inline for (@typeInfo(games).@"enum".fields, 0..) |f, i| {
+            try writer.print("\x1B[{};{}H", .{ // y, x
+                ((height + i) / 2) + 3,
+                (width - f.name.len) / 2,
+            });
+            try writer.print("{s}{s}\x1B[0m\n", .{
+                if (i == cursor_y) "\x1B[47;30;1m" else "\x1B[40;37m",
+                f.name,
+            });
+        }
+        try writer.flush();
+
+        _ = try std.posix.poll(@constCast(&fd), -1);
+        var buf: [50]u8 = undefined;
+        _ = try std.fs.File.stdin().read(@constCast(&buf));
+        for (buf) |c| switch (c) {
+            'q' => {
+                running = false;
+                break;
+            },
+
+            'j' => cursor_y += 1,
+            'k' => cursor_y -= 1,
+            'g' => cursor_y = 1,
+            'G' => cursor_y = @intFromEnum(games.@"Conways Game of Life"),
+            ' ' => {
+                // reset the terminal state for the game
+                try std.posix.tcsetattr(std.posix.STDIN_FILENO, std.posix.TCSA.NOW, oldios);
+                _ = try writer.write("\x1B[?25h"); // show cursor
+                defer std.posix.tcsetattr(std.posix.STDIN_FILENO, std.posix.TCSA.NOW, newios) catch {
+                    // not much we can do
+                };
+
+                switch (cursor_y) {
+                    @intFromEnum(games.@"Conways Game of Life") => try Conway.play(width, height, writer),
+                    else => @panic("Game does not exist."),
+                }
+
+                _ = try writer.write("\x1B[?25l"); // hide cursor
+                try writer.flush();
+            },
+            else => break,
+        };
+    }
+
+    // Andrew kelly said to not defer writes cause we need to ensure that we
+    // flush properly. He's right.
+    _ = try writer.write("\x1B[?25h"); // show cursor
+    try writer.flush();
+}
 
 pub export fn arcade_subcmd(_: *anyopaque, argc: c_int, argv: [*c]u8) callconv(.c) void {
     _ = argc;
@@ -18,8 +105,8 @@ pub export fn arcade_subcmd(_: *anyopaque, argc: c_int, argv: [*c]u8) callconv(.
         else => unreachable,
     }
 
-    // const title = @embedFile("arcade.txt");
+    const buf: []u8 = gpa.alloc(u8, terminfo.col * terminfo.row) catch @panic("oom");
-    var buf: [4096]u8 = undefined;
+    const writer = std.fs.File.stdout().writer(buf);
-    const writer = std.fs.File.stdout().writer(&buf);
+
-    Conway.play(terminfo.col, terminfo.row, @constCast(&writer.interface)) catch unreachable;
+    ui(terminfo.col, terminfo.row, @constCast(&writer.interface)) catch unreachable;
 }