#include <renderer/texture.h>
#include <renderer/rhi_module.h>
#include <utils/logger.h>
#define STB_IMAGE_IMPLEMENTATION
#include <stb/stb_image.h>

namespace extra2d {

Texture::Texture() = default;

Texture::~Texture() {
    // RHI 纹理句柄是轻量级句柄，不需要显式释放
    // 实际的纹理资源由 RHI 设备管理
    handle_ = TextureHandle();
}

bool Texture::loadFromFile(const std::string& path) {
    // 加载图片
    int channels;
    stbi_set_flip_vertically_on_load(true);
    unsigned char* data = stbi_load(path.c_str(), &width_, &height_, &channels, 0);
    
    if (!data) {
        E2D_LOG_ERROR("Failed to load texture: {}", path);
        return false;
    }
    
    // 根据通道数确定格式
    TextureFormat format;
    switch (channels) {
        case 1: format = TextureFormat::R8; break;
        case 2: format = TextureFormat::RG8; break;
        case 3: format = TextureFormat::RGB8; break;
        case 4: format = TextureFormat::RGBA8; break;
        default: format = TextureFormat::RGBA8; break;
    }
    
    bool result = loadFromMemory(data, width_, height_, format);
    stbi_image_free(data);
    
    if (result) {
        E2D_LOG_DEBUG("Texture loaded: {} ({}x{})", path, width_, height_);
    }
    
    return result;
}

bool Texture::loadFromMemory(const uint8_t* data, int width, int height, TextureFormat format) {
    // 释放旧纹理
    handle_ = TextureHandle();
    
    width_ = width;
    height_ = height;
    format_ = format;
    
    // 获取 RHI 设备
    auto* rhiModule = RHIModule::get();
    if (!rhiModule) {
        E2D_LOG_ERROR("RHIModule not available");
        return false;
    }
    
    auto* device = rhiModule->getDevice();
    if (!device) {
        E2D_LOG_ERROR("RHIDevice not available");
        return false;
    }
    
    // 创建纹理描述
    TextureDesc desc;
    desc.width = static_cast<uint32_t>(width);
    desc.height = static_cast<uint32_t>(height);
    desc.format = format;
    desc.mipLevels = 1; // 初始创建 1 层，后续生成 mipmap
    
    // 创建 RHI 纹理
    auto texture = device->createTexture(desc);
    if (!texture) {
        E2D_LOG_ERROR("Failed to create RHI texture");
        return false;
    }
    
    // 上传纹理数据
    if (data) {
        // 注意：update 方法的参数需要根据实际 RHI 接口调整
        // 这里假设 update 接受数据指针
        texture->update(data, static_cast<size_t>(width * height * getBytesPerPixel(format)));
        // 生成 mipmap
        // 注意：generateMipmap 方法需要在 RHI 接口中实现
    }
    
    // 获取纹理句柄
    handle_ = TextureHandle(texture.release());
    
    return true;
}

bool Texture::create(int width, int height, TextureFormat format) {
    // 释放旧纹理
    handle_ = TextureHandle();
    
    width_ = width;
    height_ = height;
    format_ = format;
    
    // 获取 RHI 设备
    auto* rhiModule = RHIModule::get();
    if (!rhiModule) {
        E2D_LOG_ERROR("RHIModule not available");
        return false;
    }
    
    auto* device = rhiModule->getDevice();
    if (!device) {
        E2D_LOG_ERROR("RHIDevice not available");
        return false;
    }
    
    // 创建纹理描述
    TextureDesc desc;
    desc.width = static_cast<uint32_t>(width);
    desc.height = static_cast<uint32_t>(height);
    desc.format = format;
    desc.mipLevels = 1; // 不生成 mipmap
    
    // 创建 RHI 纹理
    auto texture = device->createTexture(desc);
    if (!texture) {
        E2D_LOG_ERROR("Failed to create RHI texture");
        return false;
    }
    
    // 获取纹理句柄
    handle_ = TextureHandle(texture.release());
    
    return true;
}

bool Texture::reloadFromFile(const std::string& path) {
    // 加载图片
    int channels;
    stbi_set_flip_vertically_on_load(true);
    unsigned char* data = stbi_load(path.c_str(), &width_, &height_, &channels, 0);
    
    if (!data) {
        E2D_LOG_ERROR("Failed to reload texture: {}", path);
        return false;
    }
    
    // 根据通道数确定格式
    TextureFormat format;
    switch (channels) {
        case 1: format = TextureFormat::R8; break;
        case 2: format = TextureFormat::RG8; break;
        case 3: format = TextureFormat::RGB8; break;
        case 4: format = TextureFormat::RGBA8; break;
        default: format = TextureFormat::RGBA8; break;
    }
    
    bool result = reloadFromMemory(data, width_, height_, format);
    stbi_image_free(data);
    
    if (result) {
        E2D_LOG_INFO("Texture reloaded: {} ({}x{})", path, width_, height_);
    }
    
    return result;
}

bool Texture::reloadFromMemory(const uint8_t* data, int width, int height, TextureFormat format) {
    // 更新尺寸和格式
    width_ = width;
    height_ = height;
    format_ = format;
    
    // 获取 RHI 设备
    auto* rhiModule = RHIModule::get();
    if (!rhiModule) {
        E2D_LOG_ERROR("RHIModule not available");
        return false;
    }
    
    auto* device = rhiModule->getDevice();
    if (!device) {
        E2D_LOG_ERROR("RHIDevice not available");
        return false;
    }
    
    // 创建新的纹理描述
    TextureDesc desc;
    desc.width = static_cast<uint32_t>(width);
    desc.height = static_cast<uint32_t>(height);
    desc.format = format;
    desc.mipLevels = 1;
    
    // 创建新的 RHI 纹理
    auto texture = device->createTexture(desc);
    if (!texture) {
        E2D_LOG_ERROR("Failed to create RHI texture during reload");
        return false;
    }
    
    // 上传纹理数据
    if (data) {
        texture->update(data, static_cast<size_t>(width * height * getBytesPerPixel(format)));
    }
    
    // 替换旧的纹理句柄
    handle_ = TextureHandle(texture.release());
    
    return true;
}

// 辅助函数：获取每个像素的字节数
uint32_t Texture::getBytesPerPixel(TextureFormat format) {
    switch (format) {
        case TextureFormat::R8: return 1;
        case TextureFormat::RG8: return 2;
        case TextureFormat::RGB8: return 3;
        case TextureFormat::RGBA8:
        case TextureFormat::RGBA8_SRGB: return 4;
        case TextureFormat::Depth16: return 2;
        case TextureFormat::Depth24: return 3;
        case TextureFormat::Depth32F: return 4;
        case TextureFormat::Depth24Stencil8: return 4;
        case TextureFormat::Depth32FStencil8: return 5;
        default: return 4;
    }
}

} // namespace extra2d