const std = @import("std");

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

    const exe = b.addExecutable(.{
        .name = "pardes",
        .root_module = b.createModule(.{
            .target = target,
            .optimize = optimize,
            .root_source_file = b.path("main.zig"),
        }),
    });
    const tests = b.addExecutable(.{
        .name = "pardes-e2e",
        .root_module = b.createModule(.{
            .target = target,
            .optimize = optimize,
            .root_source_file = b.path("tests.zig"),
            .link_libc = true,
        }),
    });

    // ghostty-vt and vaxis both depend on uucode, but Zig 0.16 forbids the
    // same source file from belonging to two modules, so they can't each have
    // their own uucode instance. We build a single uucode module here (with our
    // own uucode_config.zig) and hand it to both.
    //
    // Our config matches ghostty's exactly except the tables are `.unpacked`;
    // see uucode_config.zig for why that's required on Zig 0.16.
    const uucode_config = b.path("uucode_config.zig");
    const uucode_tables = b.dependency("uucode", .{
        .target = target,
        .optimize = optimize,
        .build_config_path = uucode_config,
    }).namedLazyPath("tables.zig");
    const uucode_mod = b.dependency("uucode", .{
        .target = target,
        .optimize = optimize,
        .build_config_path = uucode_config,
        .tables_path = uucode_tables,
    }).module("uucode");

    // vaxis is built with `external_uucode = true` so it skips its built-in
    // uucode dependency and lets us wire one in.
    const vaxis_dep = b.dependency("vaxis", .{
        .target = target,
        .optimize = optimize,
        .external_uucode = true,
    });
    const vaxis_mod = vaxis_dep.module("vaxis");

    // You'll want to use a lazy dependency here so that ghostty is only
    // downloaded if you actually need it.
    if (b.lazyDependency("ghostty", .{
        // Setting simd to false will force a pure static build that
        // doesn't even require libc, but it has a significant performance
        // penalty. If your embedding app requires libc anyway, you should
        // always keep simd enabled.
        // .simd = false,
    })) |dep| {
        // Accessing ghostty's modules runs its build(), which (because vaxis is
        // a shared dependency, deduplicated to the same module) wires ghostty's
        // own uucode into vaxis. We undo that below by overriding both imports
        // with ours — order matters, so this must happen after this point.
        const ghostty_vt = dep.module("ghostty-vt");
        ghostty_vt.addImport("uucode", uucode_mod);
        exe.root_module.addImport("ghostty-vt", ghostty_vt);
    }

    // Override uucode on vaxis last, so it wins over ghostty's build() above.
    vaxis_mod.addImport("uucode", uucode_mod);
    exe.root_module.addImport("vaxis", vaxis_mod);

    const run_exe = b.addRunArtifact(exe);

    const run = b.step("run", "descend to the pardes");
    run.dependOn(&run_exe.step);

    const run_tests = b.addRunArtifact(tests);
    run_tests.addArtifactArg(exe);
    const test_step = b.step("test", "run deterministic tests");
    test_step.dependOn(&run_tests.step);
}