/* Composer — оркестратор Phase 11b.
 *
 * Owns:
 *   - SourcePool (cuframes-источники + motion state)
 *   - vector<LayoutTemplate> (loaded from JSON или builtins)
 *   - Layout (текущее состояние cells)
 *   - OutputSurface (CudaBuffer для NV12 output)
 *
 * Compose loop (по кадру):
 *   1. select_template_and_active() → (LayoutTemplate*, vector<PoolEntry*>)
 *      по правилам: motion_mode? motion-based best-fit : idle top-1 single
 *   2. hysteresis: рост сразу, уменьшение — wait shrink_hysteresis_ms
 *   3. если sig != committed → layout_.apply(template, active, W, H)
 *   4. compose_clear() → output буфер чёрный
 *   5. layout_.render(stream, NV12Ref)
 *
 * Public API экспортируется через composer_c_api.cpp с extern "C" для
 * совместимости с control.c, grid_record.c, frigate_mqtt.c.
 *
 * Лицензия: LGPL-2.1+
 */

#ifndef CUFRAMES_COMPOSER_CPP_COMPOSER_HPP
#define CUFRAMES_COMPOSER_CPP_COMPOSER_HPP

#include "../overlay.h"           /* C API — backward compat для CLI overlays */
#include "cuda_raii.hpp"
#include "layout.hpp"
#include "source_pool.hpp"
#include "template.hpp"
#include "types.hpp"

#include <cuda_runtime.h>
#include <memory>
#include <mutex>
#include <string>
#include <vector>

namespace cfc {

struct ComposerConfig {
    int width = 1920;
    int height = 1080;
    int cuda_device = 0;
    int bg_y = 16, bg_u = 128, bg_v = 128;

    /* Motion-mode параметры. */
    int motion_ttl_ms = 45000;
    int shrink_hysteresis_ms = 3000;

    /* Templates JSON path (empty → built-in). */
    std::string templates_path;
};

class Composer {
public:
    explicit Composer(const ComposerConfig& cfg);
    ~Composer();

    Composer(const Composer&) = delete;
    Composer& operator=(const Composer&) = delete;

    bool ok() const noexcept { return output_.ok(); }

    SourcePool& pool() noexcept { return pool_; }
    const SourcePool& pool() const noexcept { return pool_; }

    /* Motion mode + relayout policy. */
    void set_motion_mode(bool on, int ttl_ms = 0);
    bool motion_mode() const noexcept { return motion_mode_; }

    /* Загрузить templates из JSON. Возвращает количество, либо <0. */
    int load_templates(const std::string& path);

    /* Перейти на named template (только если motion_mode == false). */
    bool set_layout(const std::string& name);

    const std::string& current_layout_name() const noexcept {
        return layout_.name();
    }
    int templates_count() const noexcept {
        return static_cast<int>(templates_.size());
    }
    const std::vector<LayoutTemplate>& templates() const noexcept {
        return templates_;
    }

    /* Overlays — backward compat для grid_record.c CLI (--text/--icon/--border)
     * и Frigate detection_boxes. Рисуются на выходе compose_frame ПОСЛЕ Layout.
     * Composer takes ownership — destroy()'ит на ~Composer(). */
    int add_overlay(cfc_overlay_t* ov);
    cfc_overlay_t* find_overlay(const std::string& id) const;

    /* Health отчёт для C ABI shim. */
    struct Health {
        int total = 0;
        int active = 0;
        int stale = 0;
        int dead = 0;
    };
    Health get_health() const;

    /* Manual cells — для C API без motion-mode (grid_record --cell без --motion-mode).
     * Каждый вход {source_key, rect} рендерится CameraCell без template'а. */
    void set_manual_cells(const std::vector<std::pair<std::string, Rect>>& cells);

    /* Один кадр: relayout (если нужно) + clear + render.
     * Возвращает NV12Ref на output (ptr действителен до следующего compose). */
    NV12Ref compose_frame();

private:
    /* Selection + hysteresis. */
    const LayoutTemplate* pick_best_fit(int need) const;
    std::vector<PoolEntry*> collect_active() const;
    void maybe_relayout();
    static std::string build_signature(const std::string& tpl_name,
                                         const std::vector<PoolEntry*>& active);

    ComposerConfig cfg_;
    SourcePool pool_;
    std::vector<LayoutTemplate> templates_;
    Layout layout_;

    /* Output NV12 буфер (VMM, zero-copy для NVENC). */
    CudaBuffer output_;
    int pitch_y_ = 0;
    int pitch_uv_ = 0;

    cudaStream_t stream_ = nullptr;          /* default = 0 */

    bool motion_mode_ = false;
    std::int64_t committed_at_ms_ = 0;
    std::int64_t pending_first_seen_ms_ = 0;
    std::string committed_signature_;
    std::string pending_signature_;

    /* Manual override (PTZ через set_layout): пока now < manual_override_until_ms_
     * motion-mode "заморожен", композитор держит зафиксированный layout. */
    std::int64_t manual_override_until_ms_ = 0;
    int manual_override_duration_ms_ = 60000;

    /* Backward-compat overlay list (CLI overlays + detbox). */
    std::vector<cfc_overlay_t*> overlays_;

    /* Manual cells — alternative режим без motion-mode (grid_record --cell). */
    std::vector<std::pair<std::string, Rect>> manual_cells_;
    bool manual_applied_ = false;
};

} // namespace cfc

#endif /* CUFRAMES_COMPOSER_CPP_COMPOSER_HPP */