1 files changed, 70 insertions, 0 deletions

diff --git a/src/subcommand.zig b/src/subcommand.zig
new file mode 100644
index 0000000..ebd57ed
--- /dev/null
+++ b/src/subcommand.zig
@@ -0,0 +1,70 @@
+const clap = @import("clap");
+const std = @import("std");
+const zup = @import("zup");
+
+const Allocator = std.mem.Allocator;
+const ArgIterator = std.process.ArgIterator;
+
+const parsers = .{
+    .COMMAND = clap.parsers.string,
+    .NAME = clap.parsers.string,
+};
+
+pub fn SubCommand(comptime template: type) type {
+    return struct {
+        pub const base = template;
+
+        const params = clap.parseParamsComptime(
+            \\-H, --help  Display this help and exit
+            \\-V, --version  Display the version of Zup and exit
+            \\
+        ++ template.params);
+
+        pub fn help(name: []const u8) !void {
+            const writer = std.io.getStdErr().writer();
+            try writer.print("USAGE: zup {s} ", .{name});
+            try clap.usage(writer, clap.Help, &params);
+            try writer.writeAll("\n\n");
+            try clap.help(writer, clap.Help, &params, .{
+                .description_on_new_line = false,
+                .description_indent = 0,
+                .indent = 2,
+                .max_width = 120,
+                .spacing_between_parameters = 0,
+            });
+            try writer.writeAll("\n" ++ template.description ++ "\n");
+        }
+
+        pub fn main(name: []const u8, allocator: Allocator, args: *ArgIterator) !void {
+            var diag = clap.Diagnostic{};
+            var res = clap.parseEx(clap.Help, &params, parsers, args, .{
+                .allocator = allocator,
+                .diagnostic = &diag,
+            }) catch |err| {
+                diag.report(std.io.getStdErr().writer(), err) catch {};
+                try help(name);
+                return err;
+            };
+            defer res.deinit();
+
+            if (res.args.help) {
+                return help(name);
+            }
+
+            if (res.args.version) {
+                return zup.printVersion();
+            }
+
+            if (res.positionals.len < template.min_args or res.positionals.len > template.max_args) {
+                try help(name);
+                return error.ArgError;
+            }
+
+            return template.main(
+                clap.ResultEx(clap.Help, &params, parsers),
+                allocator,
+                res,
+            );
+        }
+    };
+}