const std = @import("std");

pub fn build(b: *std.Build) void {
    const target = b.standardTargetOptions(.{});
    const optimize = b.standardOptimizeOption(.{});
    const exe = b.addExecutable(.{
        .name = "nyotun",
        .root_source_file = b.path("src/main.zig"),
        .target = target,
        .optimize = optimize,
    });

    const setcap = b.option(bool, "setcap", "run setcap before executing the test binary") orelse false;
    const sudo = b.option([]const u8, "sudo", "sudo command for setcap command") orelse null;

    // 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 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);

    // By making the run step depend on the install step, it will be run from the
    // installation directory rather than directly from within the cache directory.
    // This is not necessary, however, if the application depends on other installed
    // files, this ensures they will be present and in the expected location.
    run_cmd.step.dependOn(b.getInstallStep());

    // 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);
    }

    // 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("run", "Run the app");
    run_step.dependOn(&run_cmd.step);

    const unit_tests = b.addTest(.{
        .root_source_file = b.path("src/test_all.zig"),
        .target = target,
        .optimize = optimize,
    });

    const run_unit_tests = b.addRunArtifact(unit_tests);

    // TODO learn `zig build` and complain only during unit tests.
    if (setcap) {
        if (sudo == null) {
            std.log.warn("non-null setcap and no sudo command probably won't work. Add sudo.", .{});
        }
        const set_cap_cmd = b.addSystemCommand(if (sudo) |cmd|
            &.{ cmd, "setcap", "cap_net_admin=+ep" }
        else
            &.{ "setcap", "cap_net_admin=+ep" });
        set_cap_cmd.addArtifactArg(unit_tests);
        run_unit_tests.step.dependOn(&set_cap_cmd.step);
    } else {
        std.log.warn("-Dsetcap not set. Unit tests will probably fail.", .{});
    }

    // 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("test", "Run unit tests");
    test_step.dependOn(&run_unit_tests.step);
}