const std = @import("std");

pub fn build(b: *std.Build) !void {
    var arena = std.heap.ArenaAllocator.init(std.heap.page_allocator);
    defer arena.deinit();
    const alloc = arena.allocator();

    const beacon = b.option([]const u8, "beacon", "path to beacon to load") orelse std.debug.panic("Expected a path to a beacon to be provided with -Dbeacon", .{});
    const target_os = b.option([]const u8, "os", "os name to inject in final binary") orelse "linux";
    const fork = b.option(bool, "fork", "whether to fork or take over the process") orelse false;

    const beacon_path = std.Build.LazyPath{ .cwd_relative = beacon };

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

    const tool = b.addExecutable(.{
        .name = "beacon-compress",
        .root_source_file = b.path("src/gzip.zig"),
        .target = b.host,
    });

    const tool_step = b.addRunArtifact(tool);
    tool_step.addFileArg(beacon_path);
    const compressed_beacon = tool_step.addOutputFileArg("beacon.gz");

    const libloader = b.addObject(.{
        .name = "libloader",
        .root_source_file = b.path("src/libloader.zig"),
        .target = target,
        .optimize = optimize,
        .strip = true,
        .pic = true,
    });

    const options = b.addOptions();
    options.addOption(bool, "fork", fork);

    libloader.addIncludePath(b.path("src"));
    libloader.root_module.addAnonymousImport("beacon", .{ .root_source_file = compressed_beacon });
    libloader.root_module.addOptions("config", options);

    if (target.result.os.tag == .freebsd) {
        libloader.linkLibC();
    }

    libloader.step.dependOn(&tool_step.step);

    var lib = b.addSharedLibrary(.{
        .name = try std.fmt.allocPrint(alloc, "unix-loader-{s}", .{target_os}),
        .root_source_file = b.path("src/loader.zig"),
        .target = target,
        .optimize = optimize,
        .strip = true,
    });

    const exe = b.addExecutable(.{
        .name = "unix-loader",
        .root_source_file = b.path("src/run.zig"),
        .target = target,
        .optimize = optimize,
        .strip = true,
    });

    lib.addIncludePath(b.path("src"));
    lib.addObject(libloader);
    exe.addIncludePath(b.path("src"));
    exe.addObject(libloader);

    b.installArtifact(lib);
    b.installArtifact(exe);
}