#include "renderer_gl/opengl_capabilities.h"
#include "test_harness.h"

#include <array>
#include <cstdint>
#include <string_view>

namespace {

void detects_common_extension_capabilities(pp::tests::Harness& h)
{
    constexpr std::array<std::string_view, 2> extensions {
        "GL_EXT_shader_framebuffer_fetch",
        "GL_ARB_map_buffer_alignment",
    };

    const auto capabilities = pp::renderer::gl::detect_opengl_capabilities(
        extensions,
        pp::renderer::gl::OpenGlRuntime {});

    PP_EXPECT(h, capabilities.framebuffer_fetch);
    PP_EXPECT(h, capabilities.map_buffer_alignment);
    PP_EXPECT(h, !capabilities.float32_textures);
    PP_EXPECT(h, !capabilities.float16_textures);
}

void treats_desktop_gl_float_rendering_as_core(pp::tests::Harness& h)
{
    const auto capabilities = pp::renderer::gl::detect_opengl_capabilities(
        {},
        pp::renderer::gl::OpenGlRuntime { .desktop_gl = true });

    PP_EXPECT(h, capabilities.float32_textures);
    PP_EXPECT(h, capabilities.float32_linear);
    PP_EXPECT(h, capabilities.float16_textures);
}

void detects_gles_texture_float_extensions(pp::tests::Harness& h)
{
    constexpr std::array<std::string_view, 3> extensions {
        "GL_OES_texture_float",
        "GL_OES_texture_float_linear",
        "GL_EXT_color_buffer_half_float",
    };

    const auto capabilities = pp::renderer::gl::detect_opengl_capabilities(
        extensions,
        pp::renderer::gl::OpenGlRuntime { .gles = true });

    PP_EXPECT(h, capabilities.float32_textures);
    PP_EXPECT(h, capabilities.float32_linear);
    PP_EXPECT(h, capabilities.float16_textures);
}

void ignores_gles_texture_extensions_for_webgl_runtime(pp::tests::Harness& h)
{
    constexpr std::array<std::string_view, 3> extensions {
        "GL_OES_texture_float",
        "GL_OES_texture_float_linear",
        "GL_EXT_color_buffer_half_float",
    };

    const auto capabilities = pp::renderer::gl::detect_opengl_capabilities(
        extensions,
        pp::renderer::gl::OpenGlRuntime { .gles = true, .web = true });

    PP_EXPECT(h, !capabilities.float32_textures);
    PP_EXPECT(h, !capabilities.float32_linear);
    PP_EXPECT(h, !capabilities.float16_textures);
}

void selects_texture_upload_type_from_internal_format(pp::tests::Harness& h)
{
    constexpr std::uint32_t gl_unsigned_byte = 0x1401U;
    constexpr std::uint32_t gl_float = 0x1406U;
    constexpr std::uint32_t gl_half_float = 0x140BU;
    constexpr std::uint32_t gl_rgba8 = 0x8058U;
    constexpr std::uint32_t gl_rgba32f = 0x8814U;
    constexpr std::uint32_t gl_rgba16f = 0x881AU;

    PP_EXPECT(h, pp::renderer::gl::texture_upload_type_for_internal_format(gl_rgba8) == gl_unsigned_byte);
    PP_EXPECT(h, pp::renderer::gl::texture_upload_type_for_internal_format(gl_rgba32f) == gl_float);
    PP_EXPECT(h, pp::renderer::gl::texture_upload_type_for_internal_format(gl_rgba16f) == gl_half_float);
    PP_EXPECT(h, pp::renderer::gl::texture_upload_type_for_internal_format(0U) == gl_unsigned_byte);
}

void maps_image_channel_count_to_texture_format(pp::tests::Harness& h)
{
    constexpr std::uint32_t gl_red = 0x1903U;
    constexpr std::uint32_t gl_rgb = 0x1907U;
    constexpr std::uint32_t gl_rgba = 0x1908U;
    constexpr std::uint32_t gl_rg = 0x8227U;
    constexpr std::uint32_t gl_r8 = 0x8229U;
    constexpr std::uint32_t gl_rg8 = 0x822BU;
    constexpr std::uint32_t gl_rgb8 = 0x8051U;
    constexpr std::uint32_t gl_rgba8 = 0x8058U;

    const auto r = pp::renderer::gl::texture_format_for_channel_count(1U);
    const auto rg = pp::renderer::gl::texture_format_for_channel_count(2U);
    const auto rgb = pp::renderer::gl::texture_format_for_channel_count(3U);
    const auto rgba = pp::renderer::gl::texture_format_for_channel_count(4U);
    const auto invalid = pp::renderer::gl::texture_format_for_channel_count(5U);

    PP_EXPECT(h, r.internal_format == gl_r8);
    PP_EXPECT(h, r.pixel_format == gl_red);
    PP_EXPECT(h, rg.internal_format == gl_rg8);
    PP_EXPECT(h, rg.pixel_format == gl_rg);
    PP_EXPECT(h, rgb.internal_format == gl_rgb8);
    PP_EXPECT(h, rgb.pixel_format == gl_rgb);
    PP_EXPECT(h, rgba.internal_format == gl_rgba8);
    PP_EXPECT(h, rgba.pixel_format == gl_rgba);
    PP_EXPECT(h, invalid.channel_count == 0U);
    PP_EXPECT(h, invalid.internal_format == 0U);
    PP_EXPECT(h, invalid.pixel_format == 0U);
}

}

int main()
{
    pp::tests::Harness harness;
    harness.run("detects_common_extension_capabilities", detects_common_extension_capabilities);
    harness.run("treats_desktop_gl_float_rendering_as_core", treats_desktop_gl_float_rendering_as_core);
    harness.run("detects_gles_texture_float_extensions", detects_gles_texture_float_extensions);
    harness.run("ignores_gles_texture_extensions_for_webgl_runtime", ignores_gles_texture_extensions_for_webgl_runtime);
    harness.run("selects_texture_upload_type_from_internal_format", selects_texture_upload_type_from_internal_format);
    harness.run("maps_image_channel_count_to_texture_format", maps_image_channel_count_to_texture_format);
    return harness.finish();
}