// raylib-zig (c) Nikolas Wipper 2020-2024

const std = @import("std");
const this = @This();
const rl = @import("raylib");
pub const emsdk = rl.emsdk;

pub const Options = rl.Options;
pub const OpenglVersion = rl.OpenglVersion;
pub const LinuxDisplayBackend = rl.LinuxDisplayBackend;
pub const PlatformBackend = rl.PlatformBackend;

const Program = struct {
    name: []const u8,
    path: []const u8,
    desc: []const u8,
};

fn getModule(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode) *std.Build.Module {
    if (b.modules.contains("raylib")) {
        return b.modules.get("raylib").?;
    }
    return b.addModule("raylib", .{
        .root_source_file = b.path("lib/raylib.zig"),
        .target = target,
        .optimize = optimize,
        .link_libc = true,
    });
}

const gui = struct {
    fn getModule(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode) *std.Build.Module {
        const raylib = this.getModule(b, target, optimize);
        return b.addModule("raygui", .{
            .root_source_file = b.path("lib/raygui.zig"),
            .imports = &.{.{ .name = "raylib-zig", .module = raylib }},
            .target = target,
            .optimize = optimize,
            .link_libc = true,
        });
    }
};

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

    const options = Options.getOptions(b);
    const raylib_dep = b.dependency("raylib", .{
        .target = target,
        .optimize = optimize,
        .raudio = options.raudio,
        .rmodels = options.rmodels,
        .rshapes = options.rshapes,
        .rtext = options.rtext,
        .rtextures = options.rtextures,
        .platform = options.platform,
        .linkage = options.linkage,
        .linux_display_backend = options.linux_display_backend,
        .opengl_version = options.opengl_version,
        .android_api_version = options.android_api_version,
        .android_ndk = options.android_ndk,
        .config = options.config,
        .raygui = true,
    });

    const raylib_artifact = raylib_dep.artifact("raylib");

    b.installArtifact(raylib_artifact);

    const raylib = this.getModule(b, target, optimize);
    const raygui = this.gui.getModule(b, target, optimize);

    raylib.linkLibrary(raylib_artifact);

    const examples = [_]Program{
        .{
            .name = "raw_stream",
            .path = "examples/audio/raw_stream.zig",
            .desc = "Plays a sine wave",
        },
        .{
            .name = "music_stream",
            .path = "examples/audio/music_stream.zig",
            .desc = "Use music stream to play an audio file",
        },
        .{
            .name = "sound_loading",
            .path = "examples/audio/sound_loading.zig",
            .desc = "Load and play a song",
        },
        .{
            .name = "module_playing",
            .path = "examples/audio/module_playing.zig",
            .desc = "Module playing (streaming)",
        },
        .{
            .name = "basic_screen_manager",
            .path = "examples/core/basic_screen_manager.zig",
            .desc = "Illustrates simple screen manager based on a state machine",
        },
        .{
            .name = "basic_window",
            .path = "examples/core/basic_window.zig",
            .desc = "Creates a basic window with text",
        },
        .{
            .name = "delta_time",
            .path = "examples/core/delta_time.zig",
            .desc = "Show how to use frame time (delta time)",
        },
        .{
            .name = "core_monitor_change",
            .path = "examples/core/core_monitor_change.zig",
            .desc = "Simple Monitor Manager",
        },
        .{
            .name = "basic_window_web",
            .path = "examples/core/basic_window_web.zig",
            .desc = "Creates a basic window with text (web)",
        },
        .{
            .name = "input_keys",
            .path = "examples/core/input_keys.zig",
            .desc = "Simple keyboard input",
        },
        .{
            .name = "input_mouse",
            .path = "examples/core/input_mouse.zig",
            .desc = "Simple mouse input",
        },
        .{
            .name = "input_mouse_wheel",
            .path = "examples/core/input_mouse_wheel.zig",
            .desc = "Mouse wheel input",
        },
        .{
            .name = "input_multitouch",
            .path = "examples/core/input_multitouch.zig",
            .desc = "Multitouch input",
        },
        .{
            .name = "2d_camera",
            .path = "examples/core/2d_camera.zig",
            .desc = "Shows the functionality of a 2D camera",
        },
        .{
            .name = "2d_camera_platformer",
            .path = "examples/core/2d_camera_platformer.zig",
            .desc = "2D camera platformer",
        },
        .{
            .name = "3d_camera_first_person",
            .path = "examples/core/3d_camera_first_person.zig",
            .desc = "Simple first person demo",
        },
        .{
            .name = "3d_camera_free",
            .path = "examples/core/3d_camera_free.zig",
            .desc = "Shows basic 3d camera initialization",
        },
        .{
            .name = "2d_camera_mouse_zoom",
            .path = "examples/core/2d_camera_mouse_zoom.zig",
            .desc = "Shows mouse zoom demo",
        },
        .{
            .name = "3d_picking",
            .path = "examples/core/3d_picking.zig",
            .desc = "Shows picking in 3d mode",
        },
        .{
            .name = "drop_files",
            .path = "examples/core/drop_files.zig",
            .desc = "Demonstrates how to implement a drop files functionality",
        },
        .{
            .name = "window_flags",
            .path = "examples/core/window_flags.zig",
            .desc = "Demonstrates various flags used during and after window creation",
        },
        .{
            .name = "gui_message_box",
            .path = "examples/gui/message_box.zig",
            .desc = "Demonstrates showing and hiding a message box",
        },
        .{
            .name = "floating_window",
            .path = "examples/gui/floating_window.zig",
            .desc = "Demonstrates a floating window",
        },
        .{
            .name = "raymarching",
            .path = "examples/shaders/raymarching.zig",
            .desc = "Uses a raymarching in a shader to render shapes",
        },
        .{
            .name = "shaders_ascii_rendering",
            .path = "examples/shaders/shaders_ascii_rendering.zig",
            .desc = "Post-processing to render in ASCII",
        },
        .{
            .name = "shaders_basic_pbr",
            .path = "examples/shaders/shaders_basic_pbr.zig",
            .desc = "Demonstrates physically based rendering",
        },
        .{
            .name = "shaders_hybrid_render",
            .path = "examples/shaders/shaders_hybrid_render.zig",
            .desc = "Demonstrates hybrid rendering",
        },
        .{
            .name = "texture_outline",
            .path = "examples/shaders/texture_outline.zig",
            .desc = "Uses a shader to create an outline around a sprite",
        },
        .{
            .name = "logo_raylib",
            .path = "examples/shapes/logo_raylib.zig",
            .desc = "Renders the raylib-zig logo",
        },
        .{
            .name = "logo_raylib_anim",
            .path = "examples/shapes/logo_raylib_anim.zig",
            .desc = "Animates the raylib logo",
        },
        .{
            .name = "basic_shapes",
            .path = "examples/shapes/basic_shapes.zig",
            .desc = "Renders various shapes",
        },
        .{
            .name = "bouncing_ball",
            .path = "examples/shapes/bouncing_ball.zig",
            .desc = "Bouncing ball animation with collision detection",
        },
        .{
            .name = "collision_area",
            .path = "examples/shapes/collision_area.zig",
            .desc = "Demonstrates collision detection",
        },
        .{
            .name = "colors_palette",
            .path = "examples/shapes/colors_palette.zig",
            .desc = "Renders an interactive color palette",
        },
        .{
            .name = "draw_circle_sector",
            .path = "examples/shapes/draw_circle_sector.zig",
            .desc = "Dynamically renders a circle sector using raygui",
        },
        .{
            .name = "draw_rectangle_rounded",
            .path = "examples/shapes/draw_rectangle_rounded.zig",
            .desc = "Dynamically renders a rounded rectangle using raygui",
        },
        .{
            .name = "draw_ring",
            .path = "examples/shapes/draw_ring.zig",
            .desc = "Dynaically renders a ring using raygui",
        },
        .{
            .name = "easings_ball_anim",
            .path = "examples/shapes/easings_ball_anim.zig",
            .desc = "Renders a ball that demonstrates various easing functions",
        },
        .{
            .name = "easings_box_anim",
            .path = "examples/shapes/easings_box_anim.zig",
            .desc = "Renders a box that demonstrates various easing functions",
        },
        .{
            .name = "easings_rectangle_array",
            .path = "examples/shapes/easings_rectangle_array.zig",
            .desc = "Renders a box that demonstrates various easing functions",
        },
        .{
            .name = "following_eyes",
            .path = "examples/shapes/following_eyes.zig",
            .desc = "Renders eyes that follow mouse movement",
        },
        .{
            .name = "lines_bezier",
            .path = "examples/shapes/lines_bezier.zig",
            .desc = "Renders an interactive line bezier",
        },
        .{
            .name = "rectangle_scaling",
            .path = "examples/shapes/rectangle_scaling.zig",
            .desc = "Renders a resizable rectangle",
        },
        .{
            .name = "splines_drawing",
            .path = "examples/shapes/splines_drawing.zig",
            .desc = "Renders a spline",
        },
        .{
            .name = "top_down_lights",
            .path = "examples/shapes/top_down_lights.zig",
            .desc = "Renders a sceen with shadows and a top down persepective",
        },
        .{
            .name = "sprite_anim",
            .path = "examples/textures/sprite_anim.zig",
            .desc = "Animate a sprite",
        },
        .{
            .name = "textures_background_scrolling",
            .path = "examples/textures/textures_background_scrolling.zig",
            .desc = "Background scrolling & parallax demo",
        },
        .{
            .name = "codepoints_loading",
            .path = "examples/text/codepoints_loading.zig",
            .desc = "Renders UTF-8 text",
        },
        .{
            .name = "draw_3d",
            .path = "examples/text/draw_3d.zig",
            .desc = "Renders an example of text rendered in a 3d world",
        },
        .{
            .name = "font_filters",
            .path = "examples/text/font_filters.zig",
            .desc = "Demonstrates the various font filters",
        },
        .{
            .name = "font_loading",
            .path = "examples/text/font_loading.zig",
            .desc = "Demonstrates how to load fonts",
        },
        .{
            .name = "font_sdf",
            .path = "examples/text/font_sdf.zig",
            .desc = "Demonstrates rending a sdf font",
        },
        .{
            .name = "font_spritefont",
            .path = "examples/text/font_spritefont.zig",
            .desc = "Demonstrates rendering spritefonts",
        },
        .{
            .name = "format_text",
            .path = "examples/text/format_text.zig",
            .desc = "Renders variables as text",
        },
        .{
            .name = "input_box",
            .path = "examples/text/input_box.zig",
            .desc = "Show and example of an input_box",
        },
        .{
            .name = "raylib_fonts",
            .path = "examples/text/raylib_fonts.zig",
            .desc = "Show fonts included with raylib",
        },
        .{
            .name = "rectangle_bounds",
            .path = "examples/text/rectangle_bounds.zig",
            .desc = "demonstrate a flexible, resizeable, text box",
        },
        .{
            .name = "unicode",
            .path = "examples/text/unicode.zig",
            .desc = "demonstrate rendering of unicode",
        },
        .{
            .name = "writing_anim",
            .path = "examples/text/writing_anim.zig",
            .desc = "Simple text animation",
        },
        .{
            .name = "textures_image_loading",
            .path = "examples/textures/textures_image_loading.zig",
            .desc = "Image loading and texture creation",
        },
        .{
            .name = "models_heightmap",
            .path = "examples/models/models_heightmap.zig",
            .desc = "Heightmap loading and drawing",
        },
        .{
            .name = "models_bone_socket",
            .path = "examples/models/models_bone_socket.zig",
            .desc = "Bone socket",
        },
        .{
            .name = "models_box_collisions",
            .path = "examples/models/models_box_collisions.zig",
            .desc = "Box collisions",
        },
        .{
            .name = "models_rlgl_solar_system",
            .path = "examples/models/models_rlgl_solar_system.zig",
            .desc = "Solar System",
        },
        // .{
        //     .name = "shaders_basic_lighting",
        //     .path = "examples/shaders/shaders_basic_lighting.zig",
        //     .desc = "Loads a model and renders it",
        // },
    };

    const raylib_test = b.addTest(.{
        .root_module = raylib,
    });
    raylib_test.root_module.link_libc = true;

    const raygui_test = b.addTest(.{
        .root_module = raygui,
    });
    raygui_test.root_module.addImport("raylib-zig", raylib);
    raygui_test.root_module.link_libc = true;

    const test_step = b.step("test", "Check for library compilation errors");
    test_step.dependOn(&raylib_test.step);
    test_step.dependOn(&raygui_test.step);

    const examples_step = b.step("examples", "Builds all the examples");

    for (examples) |ex| {
        const mod = b.createModule(.{
            .root_source_file = b.path(ex.path),
            .target = target,
            .optimize = optimize,
        });

        if (target.query.os_tag == .emscripten) {
            const wasm = b.addLibrary(.{
                .name = ex.name,
                .root_module = mod,
            });
            wasm.root_module.addImport("raylib", raylib);
            wasm.root_module.addImport("raygui", raygui);

            const install_dir: std.Build.InstallDir = .{ .custom = "web" };
            const emcc_flags = emsdk.emccDefaultFlags(b.allocator, .{
                .optimize = optimize,
                .asyncify = !std.mem.endsWith(u8, ex.name, "web"),
            });
            const emcc_settings = emsdk.emccDefaultSettings(b.allocator, .{
                .optimize = optimize,
            });

            const emcc_step = emsdk.emccStep(b, raylib_artifact, wasm, .{
                .optimize = optimize,
                .flags = emcc_flags,
                .settings = emcc_settings,
                .shell_file_path = emsdk.shell(raylib_dep),
                .install_dir = install_dir,
                .embed_paths = &.{.{ .src_path = "resources/" }},
            });

            const html_filename = try std.fmt.allocPrint(b.allocator, "{s}.html", .{wasm.name});
            const emrun_step = emsdk.emrunStep(
                b,
                b.getInstallPath(install_dir, html_filename),
                &.{},
            );
            emrun_step.dependOn(emcc_step);

            const run_option = b.step(ex.name, ex.desc);
            run_option.dependOn(emrun_step);
            examples_step.dependOn(emcc_step);
        } else {
            const exe = b.addExecutable(.{
                .name = ex.name,
                .root_module = mod,
            });
            exe.root_module.addImport("raylib", raylib);
            exe.root_module.addImport("raygui", raygui);

            const run_cmd = b.addRunArtifact(exe);
            const run_step = b.step(ex.name, ex.desc);

            run_step.dependOn(&run_cmd.step);
            examples_step.dependOn(&exe.step);
        }
    }
}
