// DXGI Desktop Duplication frame source — M3 step 1 (docs/m3-product-shape.md).
//
// Captures one monitor via IDXGIOutputDuplication on a private D3D11 device
// (same adapter as the render device), composites the pointer shape, builds
// a mip chain (GenerateMips — a 4K desktop on a 2 m quad is heavily
// minified), and publishes into shared textures the D3D12 render device
// opened at start.
//
// Resilience (M1 invariants extended): ACCESS_LOST — display-mode change,
// UAC secure desktop, fullscreen exclusive — drops into a reacquire loop
// with backoff; never wedges, never affects tracking. A mode change that
// alters the desktop size recreates the texture set and bumps generation().

#pragma once

#include "capture/frame_source.h"

#include <cstdint>
#include <memory>

namespace sauna {

class DuplicationSource : public FrameSource {
 public:
  // outputIndex = DXGI EnumOutputs index on the render adapter.
  explicit DuplicationSource(int outputIndex = 0);
  ~DuplicationSource() override;

  bool start(ID3D12Device* renderDev) override;
  void stop() override;  // releases ALL GPU resources (frees VRAM); keeps object
  void setPaused(bool paused) override;  // SteamVR coexistence park

  // Doze VRAM lever (M5): rebuild the GPU side (D3D11 device + ring + worker)
  // after stop() freed it. Reuses the cached render device. Call only while the
  // present loop is idle (dozing) so the consumer is not sampling mid-rebuild;
  // the consumer skips the source (published = -1) until the first frame
  // republishes, then the generation bump triggers an SRV rebuild.
  bool resume();

  // Rate cap (M4 step 3): process at most one desktop frame per this many
  // ms (0 = every frame). The copy+cursor+GenerateMips pipeline runs per
  // captured frame; content redrawing faster than the panel refresh costs
  // pure GPU contention for zero visible benefit. Set before start();
  // the app passes the panel period.
  void setMinFramePeriodMs(double ms);

  // Cursor overlay policy: -1 auto (= on), 0 never (for machines whose
  // duplicated image already contains a software cursor — overlay would
  // double it), 1 always. Live-settable.
  void setCursorOverlay(int mode);

  uint32_t width() const override;
  uint32_t height() const override;
  uint32_t mipLevels() const override;
  uint32_t textureCount() const override;
  ID3D12Resource* texture(uint32_t i) const override;
  int latest(uint32_t* gen) const override;

  struct Stats {
    uint64_t frames = 0;      // desktop frames captured + published
    uint64_t reacquires = 0;  // duplication losses survived
    bool capturing = false;   // false while in the reacquire loop
  };
  Stats stats() const;

 private:
  struct Impl;
  std::unique_ptr<Impl> impl_;
};

}  // namespace sauna