From a8de28ba85240f66b6ef0928d68ab73825efd8df Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hendrik=20Niel=C3=A4nder?= <hendrik@nielaender.de>
Date: Wed, 1 May 2024 15:30:04 +0200
Subject: [PATCH 1/2] fix: add fallback when set zig version fails

---
 src/alias.zig | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/alias.zig b/src/alias.zig
index 30bf54e..d1ef8a7 100644
--- a/src/alias.zig
+++ b/src/alias.zig
@@ -10,8 +10,33 @@ pub fn setZigVersion(version: []const u8) !void {
     const symlinkPath = try std.fs.path.join(allocator, &[_][]const u8{ userHome, ".zm", "current" });
     defer allocator.free(symlinkPath);
 
+    const previousVersionPath = try getCurrentVersionSymlink(allocator, symlinkPath);
+    defer allocator.free(previousVersionPath);
+
     try updateSymlink(zigPath, symlinkPath);
-    try verifyZigVersion(allocator, version);
+    verifyZigVersion(allocator, version) catch |err| switch (err) {
+        error.WrongVersion => {
+            std.debug.print("Failed to set Zig version {s}. Reverting to previous version.\n", .{version});
+            try updateSymlink(previousVersionPath, symlinkPath);
+            std.debug.print("Reverted to previous Zig version successfully.\n", .{});
+        },
+        else => return err,
+    };
+}
+
+fn getCurrentVersionSymlink(allocator: std.mem.Allocator, symlinkPath: []const u8) ![]u8 {
+    // Create a buffer to store the symlink target
+    var buffer: [1000]u8 = undefined; // You can adjust the size based on expected path lengths
+
+    // Resolve the current symlink if it exists
+    if (doesFileExist(symlinkPath)) {
+        const linkTarget = try std.fs.cwd().readLink(symlinkPath, &buffer);
+        // Allocate memory to return a copy of the link target
+        const linkTargetCopy = try allocator.dupe(u8, linkTarget);
+        return linkTargetCopy;
+    }
+    // Return an empty string if no symlink exists
+    return try allocator.dupe(u8, "");
 }
 
 fn getUserHome() []const u8 {
@@ -48,6 +73,7 @@ fn verifyZigVersion(allocator: std.mem.Allocator, expectedVersion: []const u8) !
 
     if (!std.mem.eql(u8, expectedVersion, actualVersion)) {
         std.debug.print("Expected Zig version {s}, but currently using {s}. Please check.\n", .{ expectedVersion, actualVersion });
+        return error.WrongVersion;
     } else {
         std.debug.print("Now using Zig version {s}\n", .{expectedVersion});
     }

From 11ad58e884da48764ae7cd6ab8a9d58cd6199168 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hendrik=20Niel=C3=A4nder?= <hendrik@nielaender.de>
Date: Wed, 1 May 2024 15:31:40 +0200
Subject: [PATCH 2/2] fix: remove comments

---
 src/alias.zig | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/src/alias.zig b/src/alias.zig
index d1ef8a7..e6b0cc0 100644
--- a/src/alias.zig
+++ b/src/alias.zig
@@ -25,10 +25,8 @@ pub fn setZigVersion(version: []const u8) !void {
 }
 
 fn getCurrentVersionSymlink(allocator: std.mem.Allocator, symlinkPath: []const u8) ![]u8 {
-    // Create a buffer to store the symlink target
-    var buffer: [1000]u8 = undefined; // You can adjust the size based on expected path lengths
+    var buffer: [1000]u8 = undefined;
 
-    // Resolve the current symlink if it exists
     if (doesFileExist(symlinkPath)) {
         const linkTarget = try std.fs.cwd().readLink(symlinkPath, &buffer);
         // Allocate memory to return a copy of the link target