aoc2024: make build tool download input & add shared main function

1 files changed, 72 insertions, 39 deletions

diff --git a/aoc24/build.zig b/aoc24/build.zig
index 4648193..7648bf0 100644
--- a/aoc24/build.zig
+++ b/aoc24/build.zig
@@ -15,50 +15,83 @@ pub fn build(b: *std.Build) void {
     // set a preferred release mode, allowing the user to decide how to optimize.
     const optimize = b.standardOptimizeOption(.{});
 
-    for (1..26) |day| for ([_]usize{ 1, 2 }) |part| {
-        const name = b.fmt("day{}p{}", .{ day, part });
-        const path = b.path(b.fmt("src/{s}.zig", .{name}));
-        const exe = b.addExecutable(.{
-            .name = name,
-            .root_source_file = path,
-            .target = target,
-            .optimize = optimize,
-        });
+    const generate_main = b.addExecutable(.{
+        .name = "generate_main",
+        .root_source_file = b.path("tools/generate_main.zig"),
+        .target = b.host,
+    });
 
-        // This declares intent for the executable to be installed into the
-        // standard location when the user invokes the "install" step (the default
-        // step when running `zig build`).
-        b.installArtifact(exe);
+    const download_input = b.addExecutable(.{
+        .name = "download_input",
+        .root_source_file = b.path("tools/download_input.zig"),
+        .target = b.host,
+    });
 
-        // This *creates* a Run step in the build graph, to be executed when another
-        // step is evaluated that depends on it. The next line below will establish
-        // such a dependency.
-        const run_cmd = b.addRunArtifact(exe);
+    for (1..26) |day| {
+        const run_download_input = b.addRunArtifact(download_input);
+        run_download_input.addArg(b.fmt("{}", .{day}));
+        const input_path = run_download_input.addOutputFileArg(b.fmt("{}.txt", .{day}));
+        const path = b.path(b.fmt("src/day{}.zig", .{day}));
 
-        // This allows the user to pass arguments to the application in the build
-        // command itself, like this: `zig build run -- arg1 arg2 etc`
-        if (b.args) |args| {
-            run_cmd.addArgs(args);
-        }
+        for ([_]usize{ 1, 2 }) |part| {
+            const name = b.fmt("day{}p{}", .{ day, part });
+
+            const run_generate_main = b.addRunArtifact(generate_main);
+            run_generate_main.addArg(b.fmt("{}", .{part}));
+            const main_path = run_generate_main.addOutputFileArg(b.fmt("{s}_main.zig", .{name}));
+
+            const exe = b.addExecutable(.{
+                .name = b.fmt("{s}", .{name}),
+                .root_source_file = main_path,
+                .target = target,
+                .optimize = optimize,
+            });
+            exe.root_module.addAnonymousImport("solution", .{
+                .root_source_file = path,
+                .target = target,
+                .optimize = optimize,
+            });
+            exe.root_module.addAnonymousImport("input", .{
+                .root_source_file = input_path,
+                .target = target,
+                .optimize = optimize,
+            });
+
+            // This declares intent for the executable to be installed into the
+            // standard location when the user invokes the "install" step (the default
+            // step when running `zig build`).
+            b.installArtifact(exe);
 
-        // This creates a build step. It will be visible in the `zig build --help` menu,
-        // and can be selected like this: `zig build run`
-        // This will evaluate the `run` step rather than the default, which is "install".
-        const run_step = b.step(name, b.fmt("Run {s}", .{name}));
-        run_step.dependOn(&run_cmd.step);
+            // This *creates* a Run step in the build graph, to be executed when another
+            // step is evaluated that depends on it. The next line below will establish
+            // such a dependency.
+            const run_cmd = b.addRunArtifact(exe);
 
-        const exe_unit_tests = b.addTest(.{
-            .root_source_file = path,
-            .target = target,
-            .optimize = optimize,
-        });
+            // This allows the user to pass arguments to the application in the build
+            // command itself, like this: `zig build run -- arg1 arg2 etc`
+            if (b.args) |args| {
+                run_cmd.addArgs(args);
+            }
 
-        const run_exe_unit_tests = b.addRunArtifact(exe_unit_tests);
+            // This creates a build step. It will be visible in the `zig build --help` menu,
+            // and can be selected like this: `zig build run`
+            // This will evaluate the `run` step rather than the default, which is "install".
+            const run_step = b.step(name, b.fmt("Run {s}", .{name}));
+            run_step.dependOn(&run_cmd.step);
 
-        // Similar to creating the run step earlier, this exposes a `test` step to
-        // the `zig build --help` menu, providing a way for the user to request
-        // running the unit tests.
-        const test_step = b.step(b.fmt("{s}-test", .{name}), b.fmt("Test {s}", .{name}));
-        test_step.dependOn(&run_exe_unit_tests.step);
-    };
+            const exe_unit_tests = b.addTest(.{
+                .root_source_file = path,
+                .target = target,
+                .optimize = optimize,
+            });
+
+            const run_exe_unit_tests = b.addRunArtifact(exe_unit_tests);
+
+            // Similar to creating the run step earlier, this exposes a `test` step to
+            // the `zig build --help` menu, providing a way for the user to request
+            // running the unit tests.
+            const test_step = b.step(b.fmt("{s}-test", .{name}), b.fmt("Test {s}", .{name}));
+            test_step.dependOn(&run_exe_unit_tests.step);
+        }
+    }
 }