#include "common.hh"

#include <iostream>
#include <math.h>
#include <xcb/xcb_icccm.h>

#include "monmon.hh"

namespace {

struct MwmHints {
  uint32_t flags;
  uint32_t functions;
  uint32_t decorations;
  int32_t input_mode;
  uint32_t status;
};

}  // namespace

MonMon::MonMon(std::shared_ptr<PollLooper> const& looper)
  : looper_(looper), animator_(Animator::create(looper)),
    depth_(0), black_pixel_(0), screen_(nullptr), x_(0), y_(0), w_(0), h_(0),
    rootpmap_(XCB_ATOM_NONE), desktop_window_(XCB_NONE),
    desktop_pixmap_(XCB_NONE), draw_requested_(false) {
  pipe_.open();
  looper_->add(pipe_.read(), Looper::EV_READ,
               std::bind(&MonMon::pipe, this, std::placeholders::_1,
                         std::placeholders::_2, std::placeholders::_3));
  animator_->add_observer(this);
}

MonMon::~MonMon() {
  stop_all_animations();
  unset_desktop_window();
  close_pipe();
  wnd_.reset();
}

void MonMon::init(x::shared_connection const& conn, xcb_screen_t const* screen,
                  x::Format format, std::shared_ptr<x::Atoms> const& atoms,
                  std::shared_ptr<x::Ewmh> const& ewmh,
                  uint16_t width, uint16_t height, bool normal, bool black) {
  screen_ = screen;
  wnd_.reset(conn);
  pixmap_.reset(conn);
  gcontext_.reset(conn);
  cmap_.reset();

  uint32_t values[4];
  size_t i = 0;
  uint32_t mask = XCB_CW_BACK_PIXEL;
  values[i++] = screen->black_pixel;
  if (format.need_border()) {
    mask |= XCB_CW_BORDER_PIXEL;
    values[i++] = screen->black_pixel;
  }
  mask |= XCB_CW_EVENT_MASK;
  values[i++] = XCB_EVENT_MASK_KEY_PRESS | XCB_EVENT_MASK_EXPOSURE
    | XCB_EVENT_MASK_STRUCTURE_NOTIFY;
  if (format.need_colormap()) {
    mask |= XCB_CW_COLORMAP;
    cmap_.reset(conn);
    xcb_create_colormap(cmap_.conn(), XCB_COLORMAP_ALLOC_NONE, cmap_.get(),
                        screen->root, format.visual->visual_id);
    values[i++] = cmap_.get();
  }
  xcb_create_window(wnd_.conn(), format.depth,
                    wnd_.get(), screen->root,
                    0, 0, width, height, 0,
                    XCB_WINDOW_CLASS_INPUT_OUTPUT,
                    format.visual->visual_id,
                    mask, values);
  if (!normal) {
    if (atoms->get("_MOTIF_WM_INFO", false) != XCB_ATOM_NONE) {
      auto atom = atoms->get("_MOTIF_WM_HINTS");
      MwmHints hints;
      hints.flags = 1 << 1;  // MWM_HINTS_DECORATIONS
      hints.decorations = 0;
      xcb_change_property(wnd_.conn(), XCB_PROP_MODE_REPLACE, wnd_.get(),
                          atom, atom, 32, sizeof(hints) / 4, &hints);
    } else {
#ifndef NDEBUG
      // There is no way to know how the window manager will implement
      // utility window type, some might show them without titlebar ...
      std::cerr << "Warning: No motif support detected, falling back to "
                << "NETWM utility window type." << std::endl;
#endif
      auto wm = ewmh->conn();
      if (wm && ewmh->supported(wm->_NET_WM_WINDOW_TYPE_UTILITY)) {
        xcb_atom_t values[1];
        values[0] = wm->_NET_WM_WINDOW_TYPE_UTILITY;
        xcb_ewmh_set_wm_window_type(wm, wnd_.get(), 1, values);
      } else {
        // TODO: Fallback to override-redirect?
      }
    }
  }
  if (!black) {
    rootpmap_ = atoms->get("_XROOTPMAP_ID", false);
    if (rootpmap_ == XCB_ATOM_NONE) {
      std::cerr << "Warning: No support for Eterm style background pixmap"
                << std::endl;
    }
  }
  auto wm = ewmh->conn();
  auto title_str = title();
  if (wm) {
    xcb_ewmh_set_wm_name(wm, wnd_.get(), title_str.size(), title_str.data());
  } else {
    xcb_icccm_set_wm_name(wnd_.conn(), wnd_.get(), XCB_ATOM_STRING, 8,
                          title_str.size(), title_str.data());
  }
  xcb_create_gc(gcontext_.conn(), gcontext_.get(), wnd_.get(), 0, nullptr);
  auto atom = atoms->get("WM_DELETE_WINDOW");
  xcb_icccm_set_wm_protocols(wnd_.conn(), wnd_.get(),
                             atoms->get("WM_PROTOCOLS"),
                             1, &atom);
  xcb_create_pixmap(pixmap_.conn(), format.depth, pixmap_.get(), wnd_.get(),
                    width, height);
  if (format.render) {
    surface_.reset(
        cairo_xcb_surface_create_with_xrender_format(
            pixmap_.conn(),
            const_cast<xcb_screen_t*>(screen),
            pixmap_.get(),
            format.render,
            width, height));
    if (cairo_surface_status(surface_.get()) != CAIRO_STATUS_SUCCESS) {
      surface_.reset();
    }
  }
  if (!surface_) {
    surface_.reset(
        cairo_xcb_surface_create(pixmap_.conn(), pixmap_.get(),
                                 format.visual, width, height));
  }
  cairo_.reset(cairo_create(surface_.get()));
  layout_.reset(pango_cairo_create_layout(cairo_.get()));
  pango_layout_set_ellipsize(layout_.get(), PANGO_ELLIPSIZE_MIDDLE);
  pango_layout_set_alignment(layout_.get(), PANGO_ALIGN_CENTER);
  pango_layout_set_height(layout_.get(), 0);
  auto font = pango::unique_font_description(pango_font_description_new());
  pango_font_description_set_size(font.get(), 10 * PANGO_SCALE);
  pango_layout_set_font_description(layout_.get(), font.get());
  auto context = pango_layout_get_context(layout_.get());
  auto metrics = pango::unique_font_metrics(
      pango_context_get_metrics(context, nullptr, nullptr));
  box_height_ = static_cast<double>(
      pango_font_metrics_get_ascent(metrics.get()) +
      pango_font_metrics_get_descent(metrics.get())) / PANGO_SCALE;
  x_ = 0;
  y_ = 0;
  w_ = width;
  h_ = height;
  depth_ = format.depth;
  black_pixel_ = screen->black_pixel;
  update_desktop_window();

  internal_draw();
  xcb_map_window(wnd_.conn(), wnd_.get());
  xcb_flush(wnd_.conn());
}

void MonMon::quit_from_xcb() {
  io::write(pipe_, "q", 1);
}

#if FAKE_MONITOR
void MonMon::toggle_fakes() {
  io::write(pipe_, " ", 1);
}
#endif

void MonMon::expose(int16_t x, int16_t y, uint16_t w, uint16_t h) {
  std::lock_guard<std::mutex> lock(mutex_);
  xcb_copy_area(wnd_.conn(), pixmap_.get(), wnd_.get(), gcontext_.get(),
                x, y, x, y, w, h);
}

void MonMon::configure(int16_t x, int16_t y, uint16_t w, uint16_t h) {
  bool draw = false;
  if (rootpmap_ && (x != x_ || y != y_)) {
    x_ = x;
    y_ = y;
    if (desktop_surface_) {
      draw = true;
      mark_all_dirty();
      io::write(pipe_, "d", 1);
    }
  }
  if (w == w_ && h == h_) return;
  {
    std::lock_guard<std::mutex> lock(mutex_);
    x::unique_pixmap tmp(pixmap_.shared_conn());
    x::unique_gcontext gc(tmp.shared_conn());
    cairo_surface_flush(surface_.get());
    xcb_create_pixmap(tmp.conn(), depth_, tmp.get(), wnd_.get(), w, h);
    uint32_t value[1];
    value[0] = black_pixel_;
    xcb_create_gc(gc.conn(), gc.get(), tmp.get(), XCB_GC_FOREGROUND, value);
    uint32_t count = 0;
    xcb_rectangle_t rect[2];
    uint16_t copy_width, copy_height;
    if (w > w_) {
      copy_width = w_;
      rect[count].x = w_;
      rect[count].width = w - w_;
      rect[count].y = 0;
      rect[count].height = h_;
      ++count;
    } else {
      copy_width = w;
    }
    if (h > h_) {
      copy_height = h_;
      rect[count].x = 0;
      rect[count].width = w;
      rect[count].y = h_;
      rect[count].height = h - h_;
      ++count;
    } else {
      copy_height = h;
    }
    if (count) {
      xcb_poly_fill_rectangle(tmp.conn(), tmp.get(), gc.get(), count, rect);
    }
    xcb_copy_area(tmp.conn(), pixmap_.get(), tmp.get(), gc.get(), 0, 0, 0, 0,
                  copy_width, copy_height);
    cairo_xcb_surface_set_drawable(surface_.get(), tmp.get(), w, h);
    if (w_ != w) {
      width_changed();
      w_ = w;
    }
    h_ = h;
    pixmap_ = std::move(tmp);
    xcb_copy_area(wnd_.conn(), pixmap_.get(), wnd_.get(), gcontext_.get(),
                  0, 0, 0, 0, w, h);
  }
  if (!draw) io::write(pipe_, "d", 1);
}

void MonMon::update_desktop_window() {
  if (rootpmap_ == XCB_ATOM_NONE) return;

  xcb_window_t desktop_window = XCB_NONE;

  auto last = wnd_.get();
  while (true) {
    auto cookie = xcb_query_tree(wnd_.conn(), last);
    auto reply = xcb_query_tree_reply(wnd_.conn(), cookie, nullptr);
    if (!reply) break;
    auto cookie2 = xcb_get_property(wnd_.conn(), 0, reply->parent, rootpmap_,
                                    XCB_GET_PROPERTY_TYPE_ANY, 0, 1);
    auto reply2 = xcb_get_property_reply(wnd_.conn(), cookie2, nullptr);
    if (reply2) {
      if (reply2->type != 0 && reply2->format != 0 && reply2->length != 0) {
        desktop_window = reply->parent;
        free(reply2);
        free(reply);
        break;
      }
      free(reply2);
    }
    if (reply->parent == reply->root) {
      free(reply);
      break;
    }
    last = reply->parent;
    free(reply);
  }

  if (desktop_window == desktop_window_) return;
  unset_desktop_window();
  if (desktop_window == XCB_NONE) return;

  uint32_t values[1];
  values[0] = XCB_EVENT_MASK_PROPERTY_CHANGE;
  xcb_change_window_attributes(wnd_.conn(), desktop_window,
                               XCB_CW_EVENT_MASK,
                               values);
  desktop_window_ = desktop_window;
  update_desktop_pixmap();
}

void MonMon::update_desktop_window(xcb_window_t window, xcb_atom_t property) {
  if (window != desktop_window_) return;
  if (property != rootpmap_) return;

  update_desktop_pixmap();
}

void MonMon::unset_desktop_window() {
  if (desktop_window_ == XCB_NONE) return;
  uint32_t values[1];
  values[0] = 0;
  xcb_change_window_attributes(wnd_.conn(), desktop_window_,
                               XCB_CW_EVENT_MASK,
                               values);
  desktop_window_ = XCB_NONE;
  update_desktop_pixmap();
}

void MonMon::update_desktop_pixmap() {
  xcb_pixmap_t pixmap = XCB_NONE;

  if (desktop_window_ != XCB_NONE) {
    auto cookie = xcb_get_property(wnd_.conn(), 0, desktop_window_, rootpmap_,
                                   XCB_GET_PROPERTY_TYPE_ANY, 0, 1);
    auto reply = xcb_get_property_reply(wnd_.conn(), cookie, nullptr);
    if (reply) {
      if (reply->type == XCB_ATOM_PIXMAP) {
        pixmap = *reinterpret_cast<xcb_pixmap_t*>(
            xcb_get_property_value(reply));
      }
      free(reply);
    }
  }

  if (pixmap == desktop_pixmap_) return;

  auto geometry_cookie = xcb_get_geometry(wnd_.conn(), pixmap);
  auto attr_cookie = xcb_get_window_attributes(wnd_.conn(), desktop_window_);

  auto geometry_reply = xcb_get_geometry_reply(wnd_.conn(), geometry_cookie,
                                               nullptr);
  uint16_t w, h;
  uint8_t depth;
  if (geometry_reply) {
    depth = geometry_reply->depth;
    w = geometry_reply->width;
    h = geometry_reply->height;
    free(geometry_reply);
  } else {
    pixmap = XCB_NONE;
    depth = 0;
  }

  auto attr_reply = xcb_get_window_attributes_reply(wnd_.conn(), attr_cookie,
                                                    nullptr);
  if (attr_reply) {
    auto iter = xcb_screen_allowed_depths_iterator(screen_);
    auto count = xcb_screen_allowed_depths_length(screen_);
    while (count--) {
      if (iter.data->depth == depth) {
        auto visuals = xcb_depth_visuals(iter.data);
        auto visual_count = xcb_depth_visuals_length(iter.data);
        while (visual_count--) {
          if (visuals->visual_id == attr_reply->visual) {
            if (pixmap != XCB_NONE) {
              desktop_surface_.reset(cairo_xcb_surface_create(
                                         wnd_.conn(), pixmap,
                                         visuals, w, h));
            }
            break;
          }
          ++visuals;
        }
      }
      xcb_depth_next(&iter);
    }
    free(attr_reply);
  } else {
    pixmap = XCB_NONE;
  }

  desktop_pixmap_ = pixmap;
  if (desktop_pixmap_ == XCB_NONE) desktop_surface_.reset();

  mark_all_dirty();
  io::write(pipe_, "d", 1);
}

void MonMon::close_pipe() {
  if (!pipe_) return;
  looper_->remove(pipe_.read());
  pipe_.reset();
}

pango::unique_layout MonMon::make_layout() const {
  return pango::unique_layout(pango_layout_copy(layout_.get()));
}

void MonMon::fill_background(cairo_t* cairo, xcb_rectangle_t const& r) {
  cairo_save(cairo);
  cairo_rectangle(cairo, r.x, r.y, r.width, r.height);
  cairo_clip(cairo);
  if (!desktop_surface_) {
    cairo_set_source_rgb(cairo, 0, 0, 0);
  } else {
    cairo_set_source_surface(cairo, desktop_surface_.get(), -x_, -y_);
  }
  cairo_paint(cairo);
  cairo_restore(cairo);
}

void MonMon::request_draw() {
  if (draw_requested_ || !pipe_) return;
  draw_requested_ = true;
  io::write(pipe_, "d", 1);
}

void MonMon::pipe(Looper*, int, uint8_t event) {
  if (event & Looper::EV_READ) {
    char tmp;
    if (io::read(pipe_, &tmp, 1)) {
      if (tmp == 'd') {
        draw_requested_ = false;
        force_draw();
        return;
      }
#if FAKE_MONITOR
      if (tmp == ' ') {
        do_toggle_fakes();
        return;
      }
#endif
    }
  }

  stop_all_animations();
  animator_.reset();
  internal_quit();
  looper_->exit_when_empty();
  close_pipe();
}

void MonMon::draw() {
  // Animator will draw soon anyway, so let it
  if (animator_ && animator_->active()) return;
  force_draw();
}

// static
void MonMon::rounded_path(cairo_t* cr, double x, double y,
                          double width, double height) {
  auto radius = height / 10.0;
  auto degrees = M_PI / 180.0;

  cairo_new_sub_path(cr);
  cairo_arc(cr, x + width - radius, y + radius, radius,
            -90 * degrees, 0 * degrees);
  cairo_arc(cr, x + width - radius, y + height - radius, radius,
            0 * degrees, 90 * degrees);
  cairo_arc(cr, x + radius, y + height - radius, radius,
            90 * degrees, 180 * degrees);
  cairo_arc(cr, x + radius, y + radius, radius, 180 * degrees, 270 * degrees);
  cairo_close_path(cr);
}

void MonMon::internal_draw() {
  std::lock_guard<std::mutex> lock(mutex_);
  std::vector<xcb_rectangle_t> dirty;
  draw_content(cairo_.get(), layout_.get(), w_, h_, dirty);
  if (dirty.empty()) return;
  cairo_surface_flush(surface_.get());
  for (auto const& r : dirty) {
    xcb_copy_area(wnd_.conn(), pixmap_.get(), wnd_.get(), gcontext_.get(),
                  r.x, r.y, r.x, r.y, r.width, r.height);
  }
}

void MonMon::force_draw() {
  internal_draw();
  xcb_flush(wnd_.conn());
}

void MonMon::tick(Animator*) {
  force_draw();
}

// static
void MonMon::preload(x::Atoms* atoms) {
  atoms->preload("_MOTIF_WM_INFO", false);
  atoms->preload("_MOTIF_WM_HINTS");
  atoms->preload("_XROOTPMAP_ID", false);
}