const std = @import("std");

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

    const Examples = enum {
        Layout,
        Scrollable,
    };

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

    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/zterm.zig"),
        .target = target,
        .optimize = optimize,
    });
    lib.addImport("code_point", zg.module("code_point"));

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

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

    // mapping of user selected example to compile step
    const exe = switch (example) {
        .Layout => layout,
        .Scrollable => scrollable,
    };
    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/zterm.zig"),
        .target = target,
        .optimize = optimize,
    });
    lib_unit_tests.root_module.addImport("code_point", zg.module("code_point"));

    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);
}