const std = @import("std");

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

    // Public module — other packages can import this via dependency.
    // The image module pulls in the vendored stb/jebp single-header C
    // libraries, so the module needs libc + the C translation unit + the
    // include path for `@cImport`.
    const panto_mod = b.addModule("panto", .{
        .root_source_file = b.path("src/root.zig"),
        .target = target,
        .optimize = optimize,
        .link_libc = true,
    });
    addImageCDeps(b, panto_mod);

    // Unit tests
    const test_module = b.createModule(.{
        .root_source_file = b.path("src/root.zig"),
        .target = target,
        .optimize = optimize,
        .link_libc = true,
    });
    addImageCDeps(b, test_module);

    const unit_tests = b.addTest(.{
        .name = "panto-tests",
        .root_module = test_module,
    });

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

/// Wire the vendored stb/jebp single-header image libraries into `mod`:
/// the include path for `@cImport`, and the single C translation unit
/// that compiles their implementations. Callers must also link libc.
fn addImageCDeps(b: *std.Build, mod: *std.Build.Module) void {
    mod.addIncludePath(b.path("src/cdeps"));
    mod.addCSourceFile(.{
        .file = b.path("src/cdeps/image_impl.c"),
        .flags = &.{ "-std=gnu99", "-O2", "-fno-sanitize=undefined" },
    });
}