#include "passes/column_detection_pass.hpp"
#include "passes/line_detection_pass.hpp"
#include "passes/paragraph_detection_pass.hpp"
#include "passes/region_detection_pass.hpp"

#include <pdfengine/layout_engine.hpp>

namespace pdfengine {

LayoutEngine& LayoutEngine::instance() {
    static LayoutEngine s_instance;
    return s_instance;
}

LayoutEngine::LayoutEngine() {
    // Register default pipeline passes in order
    m_registry.registerPass(std::make_unique<LineDetectionPass>());
    m_registry.registerPass(std::make_unique<ParagraphDetectionPass>());
    m_registry.registerPass(std::make_unique<ColumnDetectionPass>());
    m_registry.registerPass(std::make_unique<RegionDetectionPass>());
}

std::shared_ptr<PhysicalLayoutTree>
LayoutEngine::processPage(const std::string& documentId, int pageIndex, float width, float height) {
    // Check MultiLevelCache first
    CacheKey key{documentId, pageIndex, 1, 1};
    auto cached = MultiLevelCache::instance().getLayoutTree(key);
    if (cached) {
        return cached;
    }

    LayoutSession session(documentId, pageIndex, width, height);
    bool ok = m_registry.executeAll(session);
    session.finish();

    if (ok && session.context().physicalTree) {
        MultiLevelCache::instance().putLayoutTree(key, session.context().physicalTree);
        if (session.context().spatialIndex) {
            MultiLevelCache::instance().putSpatialIndex(key, session.context().spatialIndex);
        }
        return session.context().physicalTree;
    }

    return nullptr;
}

} // namespace pdfengine