const builtin = @import("builtin");
const std = @import("std");

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

    const use_libzodium = b.option(bool, "without-libsodium", "Use the zig standard library instead of libsodium") orelse false;
    const use_static_linking = b.option(bool, "static", "Statically link the binary") orelse false;

    const minisign = b.addExecutable(.{
        .name = "minisign",
        .target = target,
        .optimize = optimize,
        .strip = true,
    });

    if (builtin.zig_version.major == 0 and builtin.zig_version.minor < 14) {
        @compileError("Building requires Zig 0.14.0 or later");
    }

    // fix Mach-O relocation
    minisign.headerpad_max_install_names = true;

    minisign.linkLibC();
    if (use_libzodium) {
        var libzodium = lib: {
            const libzodium_mod = b.createModule(.{
                .root_source_file = b.path("src/libzodium/libzodium.zig"),
                .target = target,
                .optimize = optimize,
            });
            break :lib b.addStaticLibrary(.{
                .name = "zodium",
                .root_module = libzodium_mod,
                .strip = true,
            });
        };
        libzodium.linkLibC();
        b.installArtifact(libzodium);
        minisign.root_module.addCMacro("LIBZODIUM", "1");
        minisign.linkLibrary(libzodium);
    } else {
        var override_pkgconfig = false;
        if (std.posix.getenv("LIBSODIUM_INCLUDE_PATH")) |path| {
            minisign.addSystemIncludePath(.{ .cwd_relative = path });
            override_pkgconfig = true;
        }
        if (std.posix.getenv("LIBSODIUM_LIB_PATH")) |path| {
            minisign.addLibraryPath(.{ .cwd_relative = path });
            override_pkgconfig = true;
        }

        for ([_][]const u8{ "/opt/homebrew/include", "/home/linuxbrew/.linuxbrew/include", "/usr/local/include" }) |path| {
            std.fs.accessAbsolute(path, .{}) catch continue;
            minisign.addSystemIncludePath(.{ .cwd_relative = path });
        }
        for ([_][]const u8{ "/opt/homebrew/lib", "/home/linuxbrew/.linuxbrew/lib", "/usr/local/lib" }) |path| {
            std.fs.accessAbsolute(path, .{}) catch continue;
            minisign.addLibraryPath(.{ .cwd_relative = path });
        }
        if (!use_static_linking) {
            minisign.headerpad_max_install_names = true; // required to compile using Homebrew, see https://github.com/jedisct1/minisign/pull/155
        }
        minisign.root_module.linkSystemLibrary(
            "sodium",
            .{
                .use_pkg_config = if (override_pkgconfig) .no else .yes,
                .preferred_link_mode = if (use_static_linking) .static else .dynamic,
            },
        );
    }
    minisign.addIncludePath(b.path("src"));

    minisign.root_module.addCMacro("_GNU_SOURCE", "1");
    const source_files = &.{ "src/base64.c", "src/get_line.c", "src/helpers.c", "src/minisign.c" };
    minisign.addCSourceFiles(.{ .files = source_files });

    b.installArtifact(minisign);
}