const std = @import("std");

pub fn build(b: *std.Build) void {
    // Both of these read flags from the command line, e.g.:
    //   zig build -Dtarget=x86_64-windows -Doptimize=ReleaseSafe
    const target = b.standardTargetOptions(.{});

    const optimize = b.standardOptimizeOption(.{});

    const exe = b.addExecutable(.{
        .name = "_2048zig",
        .root_module = b.createModule(.{
            .root_source_file = b.path("src/main.zig"),

            .target = target,
            .optimize = optimize,

            .imports = &.{},
        }),
    });

    // Plain `zig build` runs this: copies the binary into zig-out/bin.
    b.installArtifact(exe);

    // `zig build run`: execute the freshly built program.
    const run_step = b.step("run", "Run the app");

    const run_cmd = b.addRunArtifact(exe);
    run_step.dependOn(&run_cmd.step);

    // Chaining run onto install guarantees the exe is rebuilt first.
    run_cmd.step.dependOn(b.getInstallStep());

    if (b.args) |args| {
        run_cmd.addArgs(args);
    }

    // `zig build test`: builds a special binary whose "main" collects every
    // `test` block reachable from the root source file (main.zig) — which is
    // exactly why the `_ = Board;` bridge block lives there and not in board.zig.
    const exe_tests = b.addTest(.{
        .root_module = exe.root_module,
    });

    const run_exe_tests = b.addRunArtifact(exe_tests);

    const test_step = b.step("test", "Run tests");
    test_step.dependOn(&run_exe_tests.step);
}