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

    const Examples = enum {
        all,
        demo,
        // elements:
        button,
        input,
        scrollable,
        // layouts:
        vertical,
        horizontal,
        grid,
        mixed,
        // styles:
        text,
        palette,
        // error handling
        errors,
    };

    const example = b.option(Examples, "example", "Example to build and/or run. (default: all)") orelse .all;

    const options = b.addOptions();
    options.addOption(Examples, "example", example);

    // dependencies
    const zg = b.dependency("zg", .{
        .target = target,
        .optimize = optimize,
    });

    // library
    const lib = b.addModule("zterm", .{
        .root_source_file = b.path("src/root.zig"),
        .target = target,
        .optimize = optimize,
    });
    lib.addImport("code_point", zg.module("code_point"));

    //--- Examples ---

    // demo:
    const demo = b.addExecutable(.{
        .name = "demo",
        .root_source_file = b.path("examples/demo.zig"),
        .target = target,
        .optimize = optimize,
    });
    demo.root_module.addImport("zterm", lib);

    // elements:
    const button = b.addExecutable(.{
        .name = "button",
        .root_source_file = b.path("examples/elements/button.zig"),
        .target = target,
        .optimize = optimize,
    });
    button.root_module.addImport("zterm", lib);

    const input = b.addExecutable(.{
        .name = "input",
        .root_source_file = b.path("examples/elements/input.zig"),
        .target = target,
        .optimize = optimize,
    });
    input.root_module.addImport("zterm", lib);

    const scrollable = b.addExecutable(.{
        .name = "scrollable",
        .root_source_file = b.path("examples/elements/scrollable.zig"),
        .target = target,
        .optimize = optimize,
    });
    scrollable.root_module.addImport("zterm", lib);

    // layouts:
    const vertical = b.addExecutable(.{
        .name = "vertical",
        .root_source_file = b.path("examples/layouts/vertical.zig"),
        .target = target,
        .optimize = optimize,
    });
    vertical.root_module.addImport("zterm", lib);

    const horizontal = b.addExecutable(.{
        .name = "horizontal",
        .root_source_file = b.path("examples/layouts/horizontal.zig"),
        .target = target,
        .optimize = optimize,
    });
    horizontal.root_module.addImport("zterm", lib);

    const grid = b.addExecutable(.{
        .name = "grid",
        .root_source_file = b.path("examples/layouts/grid.zig"),
        .target = target,
        .optimize = optimize,
    });
    grid.root_module.addImport("zterm", lib);

    const mixed = b.addExecutable(.{
        .name = "mixed",
        .root_source_file = b.path("examples/layouts/mixed.zig"),
        .target = target,
        .optimize = optimize,
    });
    mixed.root_module.addImport("zterm", lib);

    // styles:
    const palette = b.addExecutable(.{
        .name = "palette",
        .root_source_file = b.path("examples/styles/palette.zig"),
        .target = target,
        .optimize = optimize,
    });
    palette.root_module.addImport("zterm", lib);

    const text = b.addExecutable(.{
        .name = "text",
        .root_source_file = b.path("examples/styles/text.zig"),
        .target = target,
        .optimize = optimize,
    });
    text.root_module.addImport("zterm", lib);

    // error handling:
    const errors = b.addExecutable(.{
        .name = "errors",
        .root_source_file = b.path("examples/errors.zig"),
        .target = target,
        .optimize = optimize,
    });
    errors.root_module.addImport("zterm", lib);

    // mapping of user selected example to compile step
    const exe = switch (example) {
        .demo => demo,
        // elements:
        .button => button,
        .input => input,
        .scrollable => scrollable,
        // layouts:
        .vertical => vertical,
        .horizontal => horizontal,
        .grid => grid,
        .mixed => mixed,
        // styles:
        .text => text,
        .palette => palette,
        // error handling:
        .errors => errors,
        else => blk: {
            b.installArtifact(button);
            b.installArtifact(input);
            b.installArtifact(scrollable);
            b.installArtifact(vertical);
            b.installArtifact(horizontal);
            b.installArtifact(grid);
            b.installArtifact(mixed);
            b.installArtifact(text);
            b.installArtifact(palette);
            b.installArtifact(errors);
            break :blk demo;
        },
    };
    b.installArtifact(exe);

    // zig build run
    const run_cmd = b.addRunArtifact(exe);
    run_cmd.step.dependOn(b.getInstallStep());
    // Allow additional arguments, 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);

    // zig build test
    const lib_unit_tests = b.addTest(.{
        .root_source_file = b.path("src/root.zig"),
        .target = target,
        .optimize = optimize,
    });
    lib_unit_tests.root_module.addImport("code_point", zg.module("code_point"));
    lib_unit_tests.root_module.addImport("DisplayWidth", zg.module("DisplayWidth"));

    const run_lib_unit_tests = b.addRunArtifact(lib_unit_tests);

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

const std = @import("std");