#pragma once

#include <easy2d/animation/sprite_frame.h>
#include <easy2d/graphics/texture_pool.h>
#include <unordered_map>
#include <mutex>
#include <string>

namespace easy2d {

// ============================================================================
// SpriteFrameCache - 精灵帧全局缓存（借鉴 Cocos SpriteFrameCache）
// 全局单例管理所有精灵帧，避免重复创建，支持图集自动切割
// ============================================================================
class SpriteFrameCache {
public:
    static SpriteFrameCache& getInstance() {
        static SpriteFrameCache instance;
        return instance;
    }

    // ------ 添加帧 ------

    /// 添加单个精灵帧
    void addSpriteFrame(Ptr<SpriteFrame> frame, const std::string& name) {
        std::lock_guard<std::mutex> lock(mutex_);
        frames_[name] = std::move(frame);
    }

    /// 从纹理和矩形区域创建并添加帧
    void addSpriteFrameFromTexture(Ptr<Texture> texture, const Rect& rect,
                                    const std::string& name) {
        auto frame = SpriteFrame::create(std::move(texture), rect);
        frame->setName(name);
        addSpriteFrame(std::move(frame), name);
    }

    /// 从纹理图集批量切割添加（等宽等高网格）
    void addSpriteFramesFromGrid(const std::string& texturePath,
                                  int frameWidth, int frameHeight,
                                  int frameCount = -1,
                                  int spacing = 0, int margin = 0) {
        auto texture = TexturePool::getInstance().get(texturePath);
        if (!texture) return;
        addSpriteFramesFromGrid(texture, texturePath, frameWidth, frameHeight,
                                frameCount, spacing, margin);
    }

    /// 从纹理对象批量切割添加（等宽等高网格，无需走 TexturePool）
    void addSpriteFramesFromGrid(Ptr<Texture> texture, const std::string& keyPrefix,
                                  int frameWidth, int frameHeight,
                                  int frameCount = -1,
                                  int spacing = 0, int margin = 0) {
        if (!texture) return;

        int texW = texture->getWidth();
        int texH = texture->getHeight();
        int usableW = texW - 2 * margin;
        int usableH = texH - 2 * margin;
        int cols = (usableW + spacing) / (frameWidth + spacing);
        int rows = (usableH + spacing) / (frameHeight + spacing);
        int total = (frameCount > 0) ? frameCount : cols * rows;

        std::lock_guard<std::mutex> lock(mutex_);
        for (int i = 0; i < total; ++i) {
            int col = i % cols;
            int row = i / cols;
            if (row >= rows) break;

            Rect rect(
                static_cast<float>(margin + col * (frameWidth + spacing)),
                static_cast<float>(margin + row * (frameHeight + spacing)),
                static_cast<float>(frameWidth),
                static_cast<float>(frameHeight)
            );

            std::string name = keyPrefix + "#" + std::to_string(i);
            auto frame = SpriteFrame::create(texture, rect);
            frame->setName(name);
            frames_[name] = std::move(frame);
        }
    }

    // ------ 获取帧 ------

    /// 按名称获取
    Ptr<SpriteFrame> getSpriteFrame(const std::string& name) const {
        std::lock_guard<std::mutex> lock(mutex_);
        auto it = frames_.find(name);
        if (it != frames_.end()) return it->second;
        return nullptr;
    }

    /// 通过路径+索引获取或创建（ANI 格式的定位方式）
    Ptr<SpriteFrame> getOrCreateFromFile(const std::string& texturePath,
                                          int index = 0) {
        std::string key = texturePath + "#" + std::to_string(index);

        {
            std::lock_guard<std::mutex> lock(mutex_);
            auto it = frames_.find(key);
            if (it != frames_.end()) return it->second;
        }

        // 缓存未命中，从 TexturePool 加载纹理并创建 SpriteFrame
        auto texture = TexturePool::getInstance().get(texturePath);
        if (!texture) return nullptr;

        // 默认整张纹理作为一帧（index=0），或用整张纹理
        Rect rect(0.0f, 0.0f,
                  static_cast<float>(texture->getWidth()),
                  static_cast<float>(texture->getHeight()));

        auto frame = SpriteFrame::create(texture, rect);
        frame->setName(key);

        std::lock_guard<std::mutex> lock(mutex_);
        frames_[key] = frame;
        return frame;
    }

    // ------ 缓存管理 ------

    bool has(const std::string& name) const {
        std::lock_guard<std::mutex> lock(mutex_);
        return frames_.find(name) != frames_.end();
    }

    void removeSpriteFrame(const std::string& name) {
        std::lock_guard<std::mutex> lock(mutex_);
        frames_.erase(name);
    }

    /// 移除未被外部引用的精灵帧（use_count == 1 表示仅缓存自身持有）
    void removeUnusedSpriteFrames() {
        std::lock_guard<std::mutex> lock(mutex_);
        for (auto it = frames_.begin(); it != frames_.end(); ) {
            if (it->second.use_count() == 1) {
                it = frames_.erase(it);
            } else {
                ++it;
            }
        }
    }

    void clear() {
        std::lock_guard<std::mutex> lock(mutex_);
        frames_.clear();
    }

    size_t count() const {
        std::lock_guard<std::mutex> lock(mutex_);
        return frames_.size();
    }

private:
    SpriteFrameCache() = default;
    ~SpriteFrameCache() = default;
    SpriteFrameCache(const SpriteFrameCache&) = delete;
    SpriteFrameCache& operator=(const SpriteFrameCache&) = delete;

    mutable std::mutex mutex_;
    std::unordered_map<std::string, Ptr<SpriteFrame>> frames_;
};

// 便捷宏
#define E2D_SPRITE_FRAME_CACHE() ::easy2d::SpriteFrameCache::getInstance()

} // namespace easy2d