// MobileGL - tools/device_bench/p5f/P5fPublicMipmapScenario.cpp
// Copyright (c) 2025-2026 MobileGL-Dev
// Licensed under the GNU Lesser General Public License v3.0:
//   https://www.gnu.org/licenses/gpl-3.0.txt
//   https://www.gnu.org/licenses/lgpl-3.0.txt
// SPDX-License-Identifier: LGPL-3.0-only
// End of Source File Header

// Device-only P5f preparation. Public GL calls, no MobileGL internal symbols.
#include "Harness/ScenarioFixture.h"
#include <array>
#ifdef GLAPI
#undef GLAPI
#endif
#define GL_GLEXT_PROTOTYPES
#include <GL/gl.h>
#include <GL/glcorearb.h>
#undef GL_GLEXT_PROTOTYPES

namespace MGITest {
    class P5fPublicMipmapScenario : public ScenarioTest {
    protected:
        void Check(bool gpuWritten) {
            if (!Ready()) return;
            GLuint texture = 0, fbo = 0;
            glGenTextures(1, &texture);
            glBindTexture(GL_TEXTURE_2D, texture);
            std::array<GLubyte, 4 * 4 * 4> red{};
            for (std::size_t i = 0; i < red.size(); i += 4) {
                red[i] = 255;
                red[i + 3] = 255;
            }
            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 4, 4, 0, GL_RGBA, GL_UNSIGNED_BYTE, red.data());
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_NEAREST);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 2);
            glGenFramebuffers(1, &fbo);
            glBindFramebuffer(GL_FRAMEBUFFER, fbo);
            if (gpuWritten) {
                glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0);
                ASSERT_EQ(glCheckFramebufferStatus(GL_FRAMEBUFFER), GLenum{GL_FRAMEBUFFER_COMPLETE});
                glDisable(GL_SCISSOR_TEST);
                glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
                glClearColor(0.0f, 1.0f, 0.0f, 1.0f);
                glClear(GL_COLOR_BUFFER_BIT);
            }
            glGenerateMipmap(GL_TEXTURE_2D);
            for (GLint level = 0; level <= 2; ++level) {
                glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, level);
                ASSERT_EQ(glCheckFramebufferStatus(GL_FRAMEBUFFER), GLenum{GL_FRAMEBUFFER_COMPLETE}) << level;
                std::array<GLubyte, 4> pixel{71, 72, 73, 74};
                glReadPixels(0, 0, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, pixel.data());
                EXPECT_EQ(pixel[0], gpuWritten ? 0 : 255) << "mip=" << level;
                EXPECT_EQ(pixel[1], gpuWritten ? 255 : 0) << "mip=" << level;
                EXPECT_EQ(pixel[2], 0) << "mip=" << level;
                EXPECT_EQ(pixel[3], 255) << "mip=" << level;
            }
            EXPECT_EQ(glGetError(), GLenum{GL_NO_ERROR});
            glBindFramebuffer(GL_FRAMEBUFFER, 0);
            glBindTexture(GL_TEXTURE_2D, 0);
            glDeleteFramebuffers(1, &fbo);
            glDeleteTextures(1, &texture);
            Gl().EndFrame();
        }
    };

    TEST_F(P5fPublicMipmapScenario, UploadedRgba8BaseGeneratesRedMipChain) {
        Check(false);
    }
    TEST_F(P5fPublicMipmapScenario, GpuWrittenBaseGeneratesGreenMipChainWithoutStaleCpuUpload) {
        Check(true);
    }
} // namespace MGITest