#include "rive/nested_artboard_mesh_host.hpp"
#include "rive/artboard.hpp"
#include "rive/bitmap_cache.hpp"
#include "rive/layout_component.hpp"
#include "rive/nested_artboard.hpp"
#include "rive/shapes/mesh_drawable.hpp"
#ifdef RIVE_CANVAS
#include "rive/renderer/cmd/deferred_canvas_host.hpp"
#endif

using namespace rive;

ArtboardInstance* NestedArtboardMeshHost::instance() const
{
  return m_owner->m_Instance.get();
}

void NestedArtboardMeshHost::resetRaster()
{
#ifdef RIVE_CANVAS
  // Revisions are per artboard, and a new instance can reuse a freed
  // one's address: never let a raster outlive the instance it drew.
  m_raster.release();
  m_rasterSource = nullptr;
  m_uvValid = false;
#endif
}

void NestedArtboardMeshHost::setMesh(MeshDrawable* mesh)
{
  if (m_mesh == mesh)
  {
    return;
  }
  m_mesh = mesh;
#ifdef RIVE_CANVAS
  m_uvValid = false;
  if (mesh == nullptr)
  {
    m_raster.release();
    m_rasterSource = nullptr;
  }
#endif
}

// The instance when mounted, else the resolved source: the editor
// triangulates right after nest(source), before any instance exists.
const Artboard* NestedArtboardMeshHost::sizeSource() const
{
  if (instance() != nullptr)
  {
    return instance();
  }
  return m_owner->m_referencedArtboard;
}

float NestedArtboardMeshHost::meshHostWidth() const
{
  const Artboard* a = sizeSource();
  return a != nullptr ? a->bounds().width() : 0.0f;
}

float NestedArtboardMeshHost::meshHostHeight() const
{
  const Artboard* a = sizeSource();
  return a != nullptr ? a->bounds().height() : 0.0f;
}

Vec2D NestedArtboardMeshHost::meshHostOrigin() const
{
  if (instance() == nullptr)
  {
    return Vec2D();
  }
  // frameOrigin is off when hosted, so bounds() starts at -size*origin.
  const AABB box = instance()->bounds();
  const float w = box.width();
  const float h = box.height();
  return Vec2D(
      w != 0.0f ? -box.left() / w : 0.0f,
      h != 0.0f ? -box.top() / h : 0.0f);
}

Mat2D NestedArtboardMeshHost::meshHostWorldTransform() const
{
  // Matches the vector draw: host world, then the artboard's self transform.
  if (instance() == nullptr || !instance()->hasSelfTransform())
  {
    return m_owner->worldTransform();
  }
  return m_owner->worldTransform() * instance()->selfTransform();
}

float NestedArtboardMeshHost::meshRasterResolution() const
{
  if (instance() != nullptr && instance()->bitmapCache() != nullptr)
  {
    return instance()->bitmapCache()->resolution();
  }
  return 1.0f;
}

Mat2D NestedArtboardMeshHost::meshHostUVTransform() const
{
#ifdef RIVE_CANVAS
  if (instance() == nullptr)
  {
    return Mat2D();
  }
  // The raster is ceil()ed, so the box covers slightly under [0,1].
  offscreen::RasterPlan plan;
  if (!offscreen::planFixedRasterSize(
          instance()->bounds(),
          meshRasterResolution(),
          &plan))
  {
    return Mat2D();
  }
  return Mat2D::fromScale(
      plan.box.width() * plan.rasterScale / static_cast<float>(plan.widthPx),
      plan.box.height() * plan.rasterScale / static_cast<float>(plan.heightPx));
#else
  return Mat2D();
#endif
}

#ifdef RIVE_CANVAS
// Any clip in force where this draws: its own clipping shapes, a clipping
// layout or artboard above it, and the same for every host above that.
bool NestedArtboardMeshHost::underClip() const
{
  for (const Component* c = m_owner; c != nullptr;)
  {
    if (c->is<Drawable>() && !c->as<Drawable>()->clippingShapes().empty())
    {
      return true;
    }
    if (c != m_owner && c->is<LayoutComponent>() &&
        c->as<LayoutComponent>()->clip())
    {
      return true;
    }
    const ContainerComponent* parent = c->parent();
    if (parent != nullptr)
    {
      c = parent;
      continue;
    }
    // The artboard root: continue from whatever hosts it.
    const Artboard* ab = c->is<Artboard>() ? c->as<Artboard>() : nullptr;
    ArtboardHost* host = ab != nullptr ? ab->host() : nullptr;
    c = host != nullptr ? host->hostComponent() : nullptr;
  }
  return false;
}

// A fresh composite renderer (WebGL) inherits no clip.
bool NestedArtboardMeshHost::compositeDropsClip() const
{
  if (instance() == nullptr || !underClip())
  {
    return false;
  }
  Factory* f = instance()->factory();
  cmd::DeferredCanvasHost* host = f ? f->canvasContentHost() : nullptr;
  return host != nullptr && host->compositeDropsClips();
}

bool NestedArtboardMeshHost::draw(Renderer* renderer)
{
  ArtboardInstance* instance = this->instance();
  if (instance == nullptr)
  {
    return true;
  }
  if (m_rasterSource != instance)
  {
    // Data-bound swap: the old raster and UVs don't apply.
    m_raster.release();
    m_rasterSource = instance;
    m_uvValid = false;
  }
  if (instance->consumeInvisibleChange())
  {
    return true;
  }

  // Ignores Bitmap Cache Enabled: a deformed instance needs a bitmap.
  offscreen::RasterPlan plan;
  cmd::DeferredCanvasHost* host = nullptr;
  rcp<RenderImage> image = instance->rasterImage(
      renderer,
      m_raster,
      meshRasterResolution(),
      /*fixedSize=*/true,
      &plan,
      &host);
  if (image == nullptr)
  {
    return false;
  }

  const Mat2D uvTransform = meshHostUVTransform();
  if (!m_uvValid || !(uvTransform == m_uvTransform))
  {
    m_uvTransform = uvTransform;
    m_uvValid = true;
    m_mesh->uvTransformChanged(uvTransform);
  }

  // Opacity is in the raster; only an enclosing modulateOpacity() remains.
  auto placement = offscreen::beginPlacement(renderer, host, plan);
  m_mesh->draw(
      placement.renderer,
      image.get(),
      ImageSampler::LinearClamp(),
      m_owner->blendMode(),
      placement.opacity,
      0.0f);
  offscreen::endComposite(placement);
  return true;
}
#endif

bool NestedArtboardMeshHost::pointersFollowMesh() const
{
#ifdef RIVE_CANVAS
  return m_mesh != nullptr && m_drewThroughMesh && instance() != nullptr;
#else
  return false;
#endif
}

bool NestedArtboardMeshHost::localThroughMesh(
    Vec2D world,
    Vec2D* local,
    bool* offMesh,
    Mat2D* toLocal)
{
#ifdef RIVE_CANVAS
  if (!pointersFollowMesh())
  {
    return false;
  }
  Vec2D uv;
  bool inside;
  Mat2D toUV;
  if (!m_mesh->uvAt(world, &uv, &inside, toLocal != nullptr ? &toUV : nullptr))
  {
    return false;
  }
  // The raster spans the artboard's bounds, so its UVs do too.
  ArtboardInstance* instance = this->instance();
  const AABB box = instance->bounds();
  const Vec2D content(
      box.left() + uv.x * box.width(),
      box.top() + uv.y * box.height());
  *local = instance->hasSelfTransform() ? instance->selfTransform() * content
                                        : content;
  *offMesh = !inside;
  if (toLocal != nullptr)
  {
    *toLocal = Mat2D::fromScaleAndTranslation(
                   box.width(),
                   box.height(),
                   box.left(),
                   box.top()) *
               toUV;
    if (instance->hasSelfTransform())
    {
      *toLocal = instance->selfTransform() * *toLocal;
    }
  }
  m_pointerWorld = world;
  m_pointerContent = content;
  m_hasPointer = true;
  return true;
#else
  return false;
#endif
}

bool NestedArtboardMeshHost::worldThroughMesh(Vec2D content, Vec2D* world) const
{
#ifdef RIVE_CANVAS
  if (!pointersFollowMesh())
  {
    return false;
  }
  // The inner hit tests asking are testing the pointer just mapped, so
  // answer with where it was. Mapping back can't always: UVs repeat across
  // repeated N-Slice tiles, and the last tile holding them would win.
  // Content positions come back through the artboard's self transform and
  // its inverse, so allow a little rounding.
  if (m_hasPointer &&
      Vec2D::distanceSquared(content, m_pointerContent) <= 1e-6f)
  {
    *world = m_pointerWorld;
    return true;
  }
  const AABB box = instance()->bounds();
  if (box.width() == 0.0f || box.height() == 0.0f)
  {
    return false;
  }
  return m_mesh->positionAtUV(
      Vec2D(
          (content.x - box.left()) / box.width(),
          (content.y - box.top()) / box.height()),
      world);
#else
  return false;
#endif
}

float NestedArtboardMeshHost::meshHostScaleX() const
{
  return m_owner->scaleX();
}

float NestedArtboardMeshHost::meshHostScaleY() const
{
  return m_owner->scaleY();
}

bool NestedArtboardMeshHost::meshHostReady() const
{
  return instance() != nullptr;
}