From a7052d25f52465dc11c48b052a8dcad1425971f9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Krzysztof=20Wi=C5=9Bniewski?= <argmaster.world@gmail.com>
Date: Sun, 30 Mar 2025 17:03:19 +0200
Subject: [PATCH] Add `/redo` command (#1238)

* Add undo and redo commands

* Remove unintended change

* Remove redo code

* Revert "Remove redo code"

This reverts commit 80aeca1dc2d0f7b3f3570b95937a8f7fd87cac5d.

* Fix variable name in /redo

* Update import
---
 src/server/command/_list.zig           |  1 +
 src/server/command/worldedit/paste.zig |  1 +
 src/server/command/worldedit/redo.zig  | 37 ++++++++++++++++++++++++++
 src/server/command/worldedit/undo.zig  | 14 ++++++++++
 src/server/server.zig                  |  4 ++-
 5 files changed, 56 insertions(+), 1 deletion(-)
 create mode 100644 src/server/command/worldedit/redo.zig

diff --git a/src/server/command/_list.zig b/src/server/command/_list.zig
index 77e407ab..e70188d7 100644
--- a/src/server/command/_list.zig
+++ b/src/server/command/_list.zig
@@ -7,6 +7,7 @@ pub const time = @import("time.zig");
 pub const tp = @import("tp.zig");
 
 pub const undo = @import("worldedit/undo.zig");
+pub const redo = @import("worldedit/redo.zig");
 pub const pos1 = @import("worldedit/pos1.zig");
 pub const pos2 = @import("worldedit/pos2.zig");
 pub const deselect = @import("worldedit/deselect.zig");
diff --git a/src/server/command/worldedit/paste.zig b/src/server/command/worldedit/paste.zig
index 27da5afb..8bace8da 100644
--- a/src/server/command/worldedit/paste.zig
+++ b/src/server/command/worldedit/paste.zig
@@ -31,6 +31,7 @@ pub fn execute(args: []const u8, source: *User) void {
 		switch(undo) {
 			.success => |blueprint| {
 				source.worldEditData.undoHistory.push(.init(blueprint, pos, "paste"));
+				source.worldEditData.redoHistory.clear();
 			},
 			.failure => {
 				source.sendMessage("#ff0000Error: Could not capture undo history.", .{});
diff --git a/src/server/command/worldedit/redo.zig b/src/server/command/worldedit/redo.zig
new file mode 100644
index 00000000..dbef436f
--- /dev/null
+++ b/src/server/command/worldedit/redo.zig
@@ -0,0 +1,37 @@
+const std = @import("std");
+
+const main = @import("main");
+const User = main.server.User;
+
+const Block = main.blocks.Block;
+const Blueprint = main.blueprint.Blueprint;
+
+pub const description = "Redo last change done to world with world editing commands.";
+pub const usage = "/redo";
+
+pub fn execute(args: []const u8, source: *User) void {
+	if(args.len != 0) {
+		source.sendMessage("#ff0000Too many arguments for command /redo. Expected no arguments.", .{});
+		return;
+	}
+	if(source.worldEditData.redoHistory.pop()) |action| {
+		const undo = Blueprint.capture(main.globalAllocator, action.position, .{
+			action.position[0] + @as(i32, @intCast(action.blueprint.blocks.width)) - 1,
+			action.position[1] + @as(i32, @intCast(action.blueprint.blocks.depth)) - 1,
+			action.position[2] + @as(i32, @intCast(action.blueprint.blocks.height)) - 1,
+		});
+		action.blueprint.paste(action.position);
+
+		switch(undo) {
+			.success => |blueprint| {
+				source.worldEditData.undoHistory.push(.init(blueprint, action.position, action.message));
+			},
+			.failure => {
+				source.sendMessage("#ff0000Error: Could not capture undo history.", .{});
+			},
+		}
+		source.sendMessage("#00ff00Re-done last {s}.", .{action.message});
+	} else {
+		source.sendMessage("#ccccccNothing to redo.", .{});
+	}
+}
diff --git a/src/server/command/worldedit/undo.zig b/src/server/command/worldedit/undo.zig
index a7cefc48..5849d52b 100644
--- a/src/server/command/worldedit/undo.zig
+++ b/src/server/command/worldedit/undo.zig
@@ -15,7 +15,21 @@ pub fn execute(args: []const u8, source: *User) void {
 		return;
 	}
 	if(source.worldEditData.undoHistory.pop()) |action| {
+		const redo = Blueprint.capture(main.globalAllocator, action.position, .{
+			action.position[0] + @as(i32, @intCast(action.blueprint.blocks.width)) - 1,
+			action.position[1] + @as(i32, @intCast(action.blueprint.blocks.depth)) - 1,
+			action.position[2] + @as(i32, @intCast(action.blueprint.blocks.height)) - 1,
+		});
 		action.blueprint.paste(action.position);
+
+		switch(redo) {
+			.success => |blueprint| {
+				source.worldEditData.redoHistory.push(.init(blueprint, action.position, action.message));
+			},
+			.failure => {
+				source.sendMessage("#ff0000Error: Could not capture redo history.", .{});
+			},
+		}
 		source.sendMessage("#00ff00Un-done last {s}.", .{action.message});
 	} else {
 		source.sendMessage("#ccccccNothing to undo.", .{});
diff --git a/src/server/server.zig b/src/server/server.zig
index 232a17c5..9ce286f6 100644
--- a/src/server/server.zig
+++ b/src/server/server.zig
@@ -30,6 +30,7 @@ pub const WorldEditData = struct {
 	selectionPosition2: ?Vec3i = null,
 	clipboard: ?Blueprint = null,
 	undoHistory: History,
+	redoHistory: History,
 
 	const History = struct {
 		changes: CircularBufferQueue(Value),
@@ -69,13 +70,14 @@ pub const WorldEditData = struct {
 		}
 	};
 	pub fn init() WorldEditData {
-		return .{.undoHistory = History.init()};
+		return .{.undoHistory = History.init(), .redoHistory = History.init()};
 	}
 	pub fn deinit(self: *WorldEditData) void {
 		if(self.clipboard != null) {
 			self.clipboard.?.deinit(main.globalAllocator);
 		}
 		self.undoHistory.deinit();
+		self.redoHistory.deinit();
 	}
 };