#include "common.hh"

#include <algorithm>
#include <cairo-xcb.h>
#include <iostream>
#include <math.h>
#include <mutex>
#include <pango/pangocairo.h>
#include <string.h>
#include <thread>
#include <xcb/xcb_event.h>
#include <xcb/xcb_icccm.h>
#include <xcb/xcb_keysyms.h>

#include "animation.hh"
#include "animator.hh"
#include "args.hh"
#include "fake_monitor.hh"
#include "io.hh"
#include "monitor.hh"
#include "poll_looper.hh"
#include "x.hh"

namespace {

struct CairoSurfaceDelete {
  void operator()(cairo_surface_t* surface) const {
    cairo_surface_destroy(surface);
  }
};

struct CairoDelete {
  void operator()(cairo_t* cairo) const {
    cairo_destroy(cairo);
  }
};

struct GObjectDelete {
  void operator()(gpointer ptr) const {
    g_object_unref(ptr);
  }
};

struct PangoFontMetricsDelete {
  void operator()(PangoFontMetrics* ptr) const {
    pango_font_metrics_unref(ptr);
  }
};

struct PangoFontDescriptionDelete {
  void operator()(PangoFontDescription* ptr) const {
    pango_font_description_free(ptr);
  }
};

struct CairoPatternDelete {
  void operator()(cairo_pattern_t* pattern) const {
    cairo_pattern_destroy(pattern);
  }
};

struct CairoPathDelete {
  void operator()(cairo_path_t* path) const {
    cairo_path_destroy(path);
  }
};

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

class MonMon : virtual Monitor::Observer, virtual Animator::Observer {
public:
  explicit MonMon(std::shared_ptr<PollLooper> const& looper)
    : looper_(looper), animator_(Animator::create(looper)),
      connected_(false), depth_(0), black_pixel_(0),
      screen_(nullptr), max_jobs_(0), jobs_(0), requests_(0),
      x_(0), y_(0), w_(0), h_(0),
      rootpmap_(XCB_ATOM_NONE), desktop_window_(XCB_NONE),
      desktop_pixmap_(XCB_NONE) {
    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() {
    stop_all_animations();
    unset_desktop_window();
    close_pipe();
    wnd_.reset();
  }

  void 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);

    uint32_t values[2];
    values[0] = screen->black_pixel;
    values[1] = XCB_EVENT_MASK_KEY_PRESS | XCB_EVENT_MASK_EXPOSURE
      | XCB_EVENT_MASK_STRUCTURE_NOTIFY;
    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,
                      XCB_CW_BACK_PIXEL | XCB_CW_EVENT_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;
      }
    }
    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 =
      std::unique_ptr<PangoFontDescription, PangoFontDescriptionDelete>(
          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 = std::unique_ptr<PangoFontMetrics, PangoFontMetricsDelete>(
        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 connect(Args const* args) {
#if FAKE_MONITOR
    monitor_.reset(FakeMonitor::create(looper_));
#else
    monitor_.reset(Monitor::create(looper_));
#endif
    monitor_->add_observer(this);
    monitor_->connect(args->arg("network", ""),
                      args->arg("scheduler", ""));
  }

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

  /*
  void quit_from_main(std::shared_ptr<x::Atoms> const& atoms) {
    // Wake up the event thread by sending an event to our window
    xcb_client_message_event_t event;
    memset(&event, 0, sizeof(event));
    event.response_type = XCB_CLIENT_MESSAGE;
    event.format = 32;
    event.sequence = 0;
    event.window = wnd_.get();
    event.type = atoms->get("__MONMON_QUIT");

    xcb_send_event(wnd_.conn(), false, wnd_.get(), XCB_EVENT_MASK_NO_EVENT,
                   reinterpret_cast<char*>(&event));
    xcb_flush(wnd_.conn());
  }
  */

  void 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);
  }

  bool match(xcb_window_t wnd) const {
    return wnd == wnd_.get();
  }

  void 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;
        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) {
        job_pattern_.reset();
        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 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 update_desktop_window(xcb_window_t window, xcb_atom_t property) {
    if (window != desktop_window_) return;
    if (property != rootpmap_) return;

    update_desktop_pixmap();
  }

private:
  class MachineAnimation;

  struct Machine : virtual Animator::AnimationObserver {
    uint32_t id;
    Monitor::Machine data;
    unsigned jobs;
    unsigned requests;
    double x;
    std::shared_ptr<MachineAnimation> animation;

    explicit Machine(uint32_t id)
      : id(id), jobs(0), requests(0), x(0.0) {
    }

    ~Machine() override {
      assert(!animation);
    }

    bool operator<(Machine const& machine) const {
      if (data.name < machine.data.name) return true;
      if (data.name > machine.data.name) return false;
      return id < machine.id;
    }

    void ticked(Animator*, Animation*, double value) override {
      x = value;
    }

    void stopped(Animator*, Animation*) override {
      x = static_cast<double>(jobs) / data.max_jobs;
      animation.reset();
    }
  };

  class MachineAnimation : public Animation {
  public:
    explicit MachineAnimation(Machine* machine)
      : machine_(machine), last_(0.0) {
    }

    bool tick(double duration, double* value) override {
      auto target = static_cast<double>(machine_->jobs)
        / machine_->data.max_jobs;
      if (duration == 0.0) {
        last_ = duration;
        *value = machine_->x;
        return machine_->x != target;
      } else {
        double diff = target - machine_->x;
        double max = (duration - last_) * .5;
        last_ = duration;
        if (fabs(diff) > max) {
          diff = diff < 0.0 ? -max : max;
          *value = machine_->x + diff;
          return true;
        } else {
          *value = target;
          return false;
        }
      }
    }

  private:
    Machine* machine_;
    double last_;
  };

  void 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 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();

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

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

  void pipe(Looper*, int, uint8_t event) {
    if (event & Looper::EV_READ) {
      char tmp;
      if (io::read(pipe_, &tmp, 1)) {
        if (tmp == 'd') {
          draw();
          return;
        }
      }
    }

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

  void state(Monitor*, Monitor::State state) override {
    switch (state) {
    case Monitor::SEARCHING:
      connected_ = false;
      stop_all_animations();
      machines_.clear();
      max_jobs_ = 0;
      jobs_ = 0;
      requests_ = 0;
      if (!wnd_) return;
      draw();
      break;
    case Monitor::CONNECTED:
      connected_ = true;
      draw();
      break;
    }
  }

  void stop_all_animations() {
    if (!animator_) return;
    for (auto& machine : machines_) {
      if (machine.animation) animator_->stop(machine.animation.get());
    }
  }

  void update(Machine& machine) {
    auto old = machine.data.max_jobs;
    machine.data = monitor_->machine(machine.id);
    if (old < machine.data.max_jobs) {
      max_jobs_ += machine.data.max_jobs - old;
      if (machine.jobs) animate(machine);
    } else if (old > machine.data.max_jobs) {
      max_jobs_ -= old - machine.data.max_jobs;
      if (machine.jobs) animate(machine);
    }
  }

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

  static void 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 internal_draw() {
    std::lock_guard<std::mutex> lock(mutex_);
    if (!desktop_surface_) {
      cairo_set_source_rgb(cairo_.get(), 0, 0, 0);
    } else {
      cairo_set_source_surface(cairo_.get(), desktop_surface_.get(),
                               -x_, -y_);
    }
    cairo_rectangle(cairo_.get(), 0, 0, w_, h_);
    cairo_fill(cairo_.get());
    auto pad_x = std::min(9.0, w_ / 20.0), pad_y = pad_x;
    auto margin_x = std::min(7.5, w_ / 20.0), margin_y = margin_x;
    auto y = pad_y;
    auto box_width = w_ - pad_x * 2;
    auto box_height = box_height_ + margin_y * 2;
    if (!job_pattern_) {
      job_pattern_.reset(cairo_pattern_create_linear(0.0, 0.0, box_width, 0.0));
      cairo_pattern_add_color_stop_rgb(job_pattern_.get(), 0.000000,
                                       0.000000, 0.000000, 0.000000);
      cairo_pattern_add_color_stop_rgb(job_pattern_.get(), 0.594324,
                                       0.729412, 0.000000, 0.000000);
      cairo_pattern_add_color_stop_rgb(job_pattern_.get(), 0.809683,
                                       1.000000, 0.545098, 0.196078);
      cairo_pattern_add_color_stop_rgb(job_pattern_.get(), 0.899833,
                                       0.972549, 0.937255, 0.074510);
      cairo_pattern_add_color_stop_rgb(job_pattern_.get(), 1.000000,
                                       0.976471, 0.968627, 0.831373);
    }
    pango_layout_set_width(layout_.get(),
                           (box_width - margin_x * 2) * PANGO_SCALE);
    for (auto const& machine : machines_) {
      pango_layout_set_text(layout_.get(), machine.data.name.data(),
                            machine.data.name.size());
      rounded_path(cairo_.get(), pad_x, y, box_width, box_height);
      cairo_set_source_rgba(cairo_.get(), 0.1, 0.1, 0.1, 0.7);

      if (machine.x > 0.0) {
        cairo_fill_preserve(cairo_.get());
        auto old = std::unique_ptr<cairo_path_t, CairoPathDelete>(
            cairo_copy_path(cairo_.get()));
        cairo_new_path(cairo_.get());
        cairo_rectangle(cairo_.get(), pad_x, y,
                        machine.x * box_width, box_height);
        cairo_clip(cairo_.get());
        cairo_append_path(cairo_.get(), old.get());
        cairo_set_source(cairo_.get(), job_pattern_.get());
        cairo_fill(cairo_.get());
        cairo_reset_clip(cairo_.get());
      } else {
        cairo_fill(cairo_.get());
      }
      if (machine.requests > 0) {
        auto radius = box_height / 10.0;
        cairo_set_line_width(cairo_.get(), 1.5);
        cairo_new_path(cairo_.get());
        cairo_move_to(cairo_.get(), pad_x + box_width - radius, y);
        cairo_rel_line_to(cairo_.get(),
                          -(machine.requests * (box_width - radius * 2))
                          / requests_, 0);
        cairo_set_source_rgb(cairo_.get(), 0, 0.6, 0);
        cairo_stroke(cairo_.get());
      }

      cairo_move_to(cairo_.get(), pad_x + margin_x, y + margin_y);
      pango_cairo_layout_path(cairo_.get(), layout_.get());
      cairo_set_source_rgb(cairo_.get(), 0.0, 0.0, 0.0);
      cairo_set_line_cap(cairo_.get(), CAIRO_LINE_CAP_ROUND);
      cairo_set_line_width(cairo_.get(), 2.0);
      cairo_stroke(cairo_.get());
      cairo_set_source_rgb(cairo_.get(), 1.0, 1.0, 1.0);
      cairo_move_to(cairo_.get(), pad_x + margin_x, y + margin_y);
      pango_cairo_show_layout(cairo_.get(), layout_.get());
      y += box_height + pad_y * 2;
      if (y >= h_) break;
    }
    cairo_surface_flush(surface_.get());
    xcb_copy_area(wnd_.conn(), pixmap_.get(), wnd_.get(), gcontext_.get(),
                  0, 0, 0, 0, w_, h_);
  }

  void added_machine(Monitor*, uint32_t id) override {
    Machine machine(id);
    update(machine);
    machines_.insert(
        std::lower_bound(machines_.begin(), machines_.end(), machine),
        machine);
    draw();
  }

  void updated_machine(Monitor*, uint32_t id) override {
    for (auto& machine : machines_) {
      if (machine.id == id) {
        auto old = machine.data.name;
        update(machine);
        if (machine.data.name != old) {
          // TODO: Perhaps remove and insert instead?
          std::sort(machines_.begin(), machines_.end());
        }
        draw();
        return;
      }
    }
    assert(false);
  }

  void removed_machine(Monitor*, uint32_t id) override {
    for (auto it = machines_.begin(); it != machines_.end(); ++it) {
      if (it->id == id) {
        max_jobs_ -= it->data.max_jobs;
        requests_ -= it->requests;
        jobs_ -= it->jobs;
        if (animator_) animator_->stop(it->animation.get());
        machines_.erase(it);
        draw();
        return;
      }
    }
    assert(false);
  }

  void added_job(Monitor*, uint32_t source, uint32_t target) override {
    if (source == target) {
      for (auto& machine : machines_) {
        if (machine.id == source) {
          ++machine.jobs;
          animate(machine);
        }
      }
    } else {
      for (auto& machine : machines_) {
        if (machine.id == source) {
          ++machine.requests;
        }
        if (machine.id == target) {
          ++machine.jobs;
          animate(machine);
        }
      }
      ++requests_;
    }
    ++jobs_;
    draw();
  }

  void removed_job(Monitor*, uint32_t source, uint32_t target) override {
    if (source == target) {
      for (auto& machine : machines_) {
        if (machine.id == source) {
          --machine.jobs;
          animate(machine);
        }
      }
    } else {
      for (auto& machine : machines_) {
        if (machine.id == source) {
          --machine.requests;
        }
        if (machine.id == target) {
          --machine.jobs;
          animate(machine);
        }
      }
      --requests_;
    }
    --jobs_;
    draw();
  }

  void tick(Animator*) override {
    internal_draw();
    xcb_flush(wnd_.conn());
  }

  void animate(Machine& machine) {
    if (!animator_) return;
    if (machine.animation) return;
    machine.animation.reset(new MachineAnimation(&machine));
    animator_->start(machine.animation, &machine);
  }

  std::shared_ptr<PollLooper> looper_;
  std::unique_ptr<Monitor> monitor_;
  std::unique_ptr<Animator> animator_;
  bool connected_;
  io::pipe pipe_;
  std::shared_ptr<x::Atoms> atoms_;
  x::unique_window wnd_;
  x::unique_gcontext gcontext_;
  uint8_t depth_;
  uint32_t black_pixel_;
  xcb_screen_t const* screen_;
  double box_height_;
  std::vector<Machine> machines_;
  unsigned max_jobs_;
  unsigned jobs_;
  unsigned requests_;
  std::mutex mutex_;
  std::unique_ptr<cairo_surface_t, CairoSurfaceDelete> surface_;
  std::unique_ptr<cairo_t, CairoDelete> cairo_;
  std::unique_ptr<cairo_pattern_t, CairoPatternDelete> job_pattern_;
  std::unique_ptr<PangoLayout, GObjectDelete> layout_;
  x::unique_pixmap pixmap_;
  int16_t x_, y_;
  uint16_t w_, h_;
  xcb_atom_t rootpmap_;
  xcb_window_t desktop_window_;
  xcb_pixmap_t desktop_pixmap_;
  std::unique_ptr<cairo_surface_t, CairoSurfaceDelete> desktop_surface_;
};

struct XcbKeySymbolsDelete {
  void operator()(xcb_key_symbols_t* ptr) const {
    if (ptr) xcb_key_symbols_free(ptr);
  }
};

struct XcbGenericEventDelete {
  void operator()(xcb_generic_event_t* ptr) const {
    free(ptr);
  }
};

void xcb_event_loop(x::shared_connection const& conn,
                    std::shared_ptr<x::Atoms> const& atoms,
                    std::shared_ptr<MonMon> const& monmon) {
  std::unique_ptr<xcb_key_symbols_t, XcbKeySymbolsDelete> syms;
  syms.reset(xcb_key_symbols_alloc(conn.get()));
  std::unique_ptr<xcb_generic_event_t, XcbGenericEventDelete> event;
  auto const quit = atoms->get("__MONMON_QUIT");
  auto const wm_protocols = atoms->get("WM_PROTOCOLS");
  auto const wm_delete_window = atoms->get("WM_DELETE_WINDOW");
  while (true) {
    event.reset(xcb_wait_for_event(conn.get()));
    if (!event) {
      std::cerr << "fatal error: "
                << xcb_connection_has_error(conn.get()) << std::endl;
      monmon->quit_from_xcb();
      return;
    }
    if (event->response_type == 0) {
      auto e = reinterpret_cast<xcb_generic_error_t*>(event.get());
#ifndef NDEBUG
      std::cerr << "error: " << xcb_event_get_error_label(e->error_code)
                << std::endl;
#endif
      continue;
    }
    switch (XCB_EVENT_RESPONSE_TYPE(event)) {
    case XCB_EXPOSE: {
      auto e = reinterpret_cast<xcb_expose_event_t*>(event.get());
      if (monmon->match(e->window)) {
        monmon->expose(e->x, e->y, e->width, e->height);
      }
      if (e->count != 0) continue;  // Only flush for e->count == 0
      break;
    }
    case XCB_KEY_PRESS: {
      auto e = reinterpret_cast<xcb_key_press_event_t*>(event.get());
      auto sym = xcb_key_press_lookup_keysym(syms.get(), e, 0);
      switch (sym) {
      case 'Q':
      case 'q':
      case 0xff1b: {  // escape
        if (monmon->match(e->event)) {
          monmon->quit_from_xcb();
          return;
        }
        break;
      }
      }
      break;
    }
    case XCB_DESTROY_NOTIFY: {
      auto e = reinterpret_cast<xcb_destroy_notify_event_t*>(event.get());
      if (monmon->match(e->window)) {
        monmon->quit_from_xcb();
        return;
      }
      break;
    }
    case XCB_CONFIGURE_NOTIFY: {
      auto e = reinterpret_cast<xcb_configure_notify_event_t*>(event.get());
      if (monmon->match(e->window)) {
        monmon->configure(e->x, e->y, e->width, e->height);
      }
      break;
    }
    case XCB_CLIENT_MESSAGE: {
      auto e = reinterpret_cast<xcb_client_message_event_t*>(event.get());
      if (e->format == 32
          && e->type == wm_protocols
          && e->data.data32[0] == wm_delete_window) {
        if (monmon->match(e->window)) {
          monmon->quit_from_xcb();
          return;
        }
      } else if (e->format == 32 && e->type == quit) {
        // Do not call quit_from_xcb() here, only reason to end up
        // here is if main already called quit_from_main()
        return;
      }
      break;
    }
    case XCB_MAPPING_NOTIFY: {
      auto e = reinterpret_cast<xcb_mapping_notify_event_t*>(event.get());
      xcb_refresh_keyboard_mapping(syms.get(), e);
      break;
    }
    case XCB_REPARENT_NOTIFY: {
      auto e = reinterpret_cast<xcb_reparent_notify_event_t*>(event.get());
      if (monmon->match(e->window)) {
        monmon->update_desktop_window();
      }
      break;
    }
    case XCB_PROPERTY_NOTIFY: {
      auto e = reinterpret_cast<xcb_property_notify_event_t*>(event.get());
      monmon->update_desktop_window(e->window, e->atom);
      break;
    }
    }
    xcb_flush(conn.get());
  }
}

}  // namespace

int main(int argc, char** argv) {
  std::unique_ptr<Args> args(Args::create());
  args->add("network", "NETNAME",
            "monitor NETNAME instead of default ICECREAM");
  args->add("scheduler", "HOST",
            "connect to scheduler at HOST instead of broadcasting");
  args->add("display", "HOST:VS", "connect to X server at [HOST]:[VS]");
  args->add("no-render", "do not use render extension even if available");
  args->add("titlebar", "create a normal window instead of the default without"
            " titlebar (or other WM addons)");
  args->add("black", "use black background instead of background pixmap");
  args->add("help", "display this text and exit.");
  if (!args->run(argc, argv)) {
    std::cout << "Try `monmon --help` for usage." << std::endl;
    return EXIT_FAILURE;
  }
  if (args->is_set("help")) {
    std::cout << "Usage: `monmon [OPTIONS...]`\n"
              << "icecream (icecc) monitor\n"
              << "\n";
    args->print_help(std::cout);
    return EXIT_FAILURE;
  }
  int screen_index;
  x::shared_connection conn(
      xcb_connect(args->arg("display", nullptr), &screen_index));
  if (xcb_connection_has_error(conn.get())) {
    std::cerr << "Unable to connect to X server." << std::endl;
    return EXIT_FAILURE;
  }
  x::prefetch_extensions(conn.get());
  auto screen = x::get_screen(conn.get(), screen_index);
  auto format = x::get_best_format(conn.get(), screen,
                                   !args->is_set("no-render"));
  if (!format.good()) {
    std::cerr << "Unable to find a good X visual." << std::endl;
    return EXIT_FAILURE;
  }
  std::shared_ptr<PollLooper> looper(PollLooper::create());
  std::shared_ptr<x::Atoms> atoms(x::Atoms::create(conn));
  atoms->preload("WM_DELETE_WINDOW");
  atoms->preload("WM_PROTOCOLS");
  atoms->preload("__MONMON_QUIT");
  atoms->preload("_MOTIF_WM_INFO", false);
  atoms->preload("_MOTIF_WM_HINTS");
  atoms->preload("_XROOTPMAP_ID", false);
  std::shared_ptr<x::Ewmh> ewmh(x::Ewmh::create(conn, screen_index));
  auto monmon = std::make_shared<MonMon>(looper);
  monmon->init(conn, screen, format, atoms, ewmh, 400, 400,
               args->is_set("titlebar"), args->is_set("black"));
  monmon->connect(args.get());
  std::thread xcb_thread(xcb_event_loop, conn, atoms, monmon);
  conn.reset();
  looper->run();
  xcb_thread.join();
  return EXIT_SUCCESS;
}