const std = @import("std");

pub fn build(b: *std.Build) void {
    const target = b.standardTargetOptions(.{});
    if (target.result.os.tag != .macos and target.result.os.tag != .windows and target.result.os.tag != .linux) @panic("Uhdk supports macOS, Windows and Linux.");
    const optimize = b.standardOptimizeOption(.{});
    const shared = b.option(bool, "shared", "Build libuhdk as a shared library instead of static") orelse false;
    const tracy = b.option(bool, "tracy", "Emit Tracy 0.14.1 on-demand hooks; consumer must link the client") orelse false;
    if (tracy and shared) @panic("Tracy instrumentation requires static linking");
    const lib = createLibraryNamed(b, target, optimize, shared, tracy, "uhdk");
    const module = lib.root_module;
    const install_lib = b.addInstallArtifact(lib, .{});
    const install_headers = b.addInstallDirectory(.{
        .source_dir = b.path("include"),
        .install_dir = .header,
        .install_subdir = "",
    });
    const lib_step = b.step("lib", "Build and install the Uhdk library and headers");
    lib_step.dependOn(&install_lib.step);
    lib_step.dependOn(&install_headers.step);
    b.getInstallStep().dependOn(&install_lib.step);
    b.getInstallStep().dependOn(&install_headers.step);
    const unit = b.addTest(.{ .root_module = module });
    const check_step = b.step("check", "Compile library and core tests without running them");
    check_step.dependOn(&lib.step);
    check_step.dependOn(&unit.step);
    if (target.result.os.tag == .linux) @import("src/linux/build.zig").addTests(b, lib, target, optimize, check_step);
    const unit_run = b.addRunArtifact(unit);
    b.step("test", "Run core library tests").dependOn(&unit_run.step);
    const public_c = b.addTranslateC(.{
        .root_source_file = b.path("include/uhdk.h"),
        .target = target,
        .optimize = optimize,
    });
    public_c.defineCMacro("UHDK_ENABLE_OPENGL", "1");
    public_c.defineCMacro("UHDK_ENABLE_NATIVE", "1");
    public_c.addIncludePath(b.path("include"));
    if (shared) public_c.defineCMacro("UHDK_SHARED", "1");
    const public_module = b.addModule("uhdk", .{
        .root_source_file = public_c.getOutput(),
        .target = target,
        .optimize = optimize,
    });
    public_module.linkLibrary(lib);
}

// Create a library artifact without installing it. Instrumented static builds
// require the consumer to link a matching Tracy client.
pub fn createLibrary(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode, shared: bool, instrumented: bool) *std.Build.Step.Compile {
    return createLibraryNamed(b, target, optimize, shared, instrumented, if (instrumented) "uhdk-instrumented" else "uhdk");
}

fn createLibraryNamed(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode, shared: bool, instrumented: bool, artifact_name: []const u8) *std.Build.Step.Compile {
    std.debug.assert(!shared or !instrumented);
    const module = b.createModule(.{
        .root_source_file = b.path("src/root.zig"),
        .target = target,
        .optimize = optimize,
        .link_libc = true,
    });
    const native = b.addTranslateC(.{
        .root_source_file = b.path("src/native.h"),
        .target = target,
        .optimize = optimize,
    });
    native.addIncludePath(b.path("include"));
    module.addImport("native", native.createModule());
    module.addImport("profile", createProfileModule(b, target, optimize, instrumented));
    module.addIncludePath(b.path("include"));
    module.addIncludePath(b.path("src"));
    if (instrumented) module.addCMacro("UHDK_INTERNAL_TRACY", "1");
    if (target.result.os.tag == .macos) {
        module.addCSourceFile(.{
            .file = b.path("src/macos/native.m"),
            .flags = &.{
                "-fobjc-arc", "-fblocks", "-Wno-deprecated-declarations",
                "-Wall",      "-Wextra",  "-Werror",
            },
        });
        module.linkFramework("Cocoa", .{});
        module.linkFramework("OpenGL", .{});
        module.linkFramework("CoreServices", .{});
    } else if (target.result.os.tag == .linux) {
        @import("src/linux/build.zig").configure(b, module, target, optimize);
    } else {
        module.addCSourceFile(.{ .file = b.path("src/windows/native.c"), .flags = &.{ "-std=c11", "-Wall", "-Wextra", "-Werror", "-DUNICODE", "-D_UNICODE" } });
        for ([_][]const u8{ "user32", "gdi32", "opengl32", "shell32", "ole32", "uuid", "imm32", "comctl32", "shlwapi", "advapi32" }) |name| module.linkSystemLibrary(name, .{});
    }
    module.addCSourceFile(.{ .file = b.path("src/glad.c"), .flags = if (shared) &.{ "-std=c99", "-DGLAD_API_CALL_EXPORT", "-DGLAD_API_CALL_EXPORT_BUILD" } else &.{"-std=c99"} });
    const lib = b.addLibrary(.{
        .name = artifact_name,
        .linkage = if (shared) .dynamic else .static,
        .root_module = module,
    });
    return lib;
}

pub fn createProfileModule(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode, enabled: bool) *std.Build.Module {
    const options = b.addOptions();
    options.addOption(bool, "enabled", enabled);
    const profile = b.createModule(.{
        .root_source_file = b.path("src/Profile.zig"),
        .target = target,
        .optimize = optimize,
    });
    profile.addOptions("profile_options", options);
    return profile;
}