const std = @import("std");

pub fn build(b: *std.Build) void {
    const target = b.standardTargetOptions(.{});
    const optimize = b.standardOptimizeOption(.{});

    const options = b.addOptions();

    const day = b.option(u8, "day", "Which day to run");
    const day_path: ?[]const u8 = blk: {
        if (day) |d| {
            const dp = std.fmt.allocPrint(b.allocator, "days/day{}.zig", .{d}) catch |err| {
                std.log.err("Unable to create path to file day{}: {}", .{ d, err });
                return;
            };
            break :blk dp;
        }
        break :blk null;
    };

    options.addOption(?[]const u8, "day_path", day_path);
    options.addOption(?u8, "day", day);

    const lib = b.addStaticLibrary(.{
        .name = "aoc-2022",
        .root_source_file = b.path("src/root.zig"),
        .target = target,
        .optimize = optimize,
    });

    b.installArtifact(lib);

    const exe = b.addExecutable(.{
        .name = "aoc-2022",
        .root_source_file = b.path("src/main.zig"),
        .target = target,
        .optimize = optimize,
    });
    exe.root_module.addOptions("build-options", options);
    b.installArtifact(exe);

    const run_cmd = b.addRunArtifact(exe);

    run_cmd.step.dependOn(b.getInstallStep());

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

    const run_step = b.step("run", "Run the app");
    run_step.dependOn(&run_cmd.step);

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

    const run_exe_unit_tests = b.addRunArtifact(exe_unit_tests);
    const test_step = b.step("test", "Run unit tests");
    test_step.dependOn(&run_exe_unit_tests.step);

    if (day) |d| {
        const day_path_test = std.fmt.allocPrint(b.allocator, "src/days/day{}.zig", .{d}) catch |err| {
            std.log.err("Unable to create path to file day{}: {}", .{ d, err });
            return;
        };
        const day_unit_tests = b.addTest(.{
            .optimize = optimize,
            .target = target,
            .root_source_file = b.path(day_path_test),
        });
        const run_day_unit_tests = b.addRunArtifact(day_unit_tests);
        test_step.dependOn(&run_day_unit_tests.step);
    }
}