//
// Created by loki on 6/21/19.
//

#include "sunshine/platform/common.h"

#include <fstream>
#include <bitset>

#include <arpa/inet.h>
#include <ifaddrs.h>

#include <X11/X.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/extensions/Xfixes.h>
#include <X11/extensions/Xrandr.h>
#include <xcb/shm.h>
#include <xcb/xfixes.h>
#include <sys/ipc.h>
#include <sys/shm.h>

#include <pulse/simple.h>
#include <pulse/error.h>

#include "sunshine/task_pool.h"
#include "sunshine/config.h"
#include "sunshine/main.h"

namespace platf
{
using namespace std::literals;

void freeImage(XImage*);
void freeX(XFixesCursorImage*);

using ifaddr_t = util::safe_ptr<ifaddrs, freeifaddrs>;
using xcb_connect_t = util::safe_ptr<xcb_connection_t, xcb_disconnect>;
using xcb_img_t = util::c_ptr<xcb_shm_get_image_reply_t>;
using xcb_cursor_img = util::c_ptr<xcb_xfixes_get_cursor_image_reply_t>;

using xdisplay_t = util::safe_ptr_v2<Display, int, XCloseDisplay>;
using ximg_t = util::safe_ptr<XImage, freeImage>;
using xcursor_t = util::safe_ptr<XFixesCursorImage, freeX>;

class shm_id_t {
public:
  shm_id_t() : id { -1 } {}
  shm_id_t(int id) : id { id } {}
  shm_id_t(shm_id_t &&other) noexcept : id(other.id) {
    other.id = -1;
  }

  ~shm_id_t() {
    if (id != -1) {
      shmctl(id, IPC_RMID, nullptr);
      id = -1;
    }
  }
  int id;
};

class shm_data_t {
public:
  shm_data_t() : data { (void*) -1 }
  {
  }
  shm_data_t(void *data) : data { data }
  {
  }

  shm_data_t(shm_data_t &&other) noexcept : data(other.data)
  {
    other.data = (void*) -1;
  }

  ~shm_data_t()
  {
    if ((std::uintptr_t) data != -1)
    {
      shmdt(data);
      data = (void*) -1;
    }
  }

  void *data;
};

struct x11_img_t: public img_t {
  ximg_t img;
};

struct shm_img_t: public img_t {
  ~shm_img_t() override
  {
    delete[] data;
    data = nullptr;
  }
};

void blend_cursor(Display *display, img_t &img, int offsetX, int offsetY) {
  xcursor_t overlay { XFixesGetCursorImage(display) };

  if (!overlay) {
    BOOST_LOG(error)
    << "Couldn't get cursor from XFixesGetCursorImage"sv;
    return;
  }

  overlay->x -= overlay->xhot;
  overlay->y -= overlay->yhot;

  overlay->x -= offsetX;
  overlay->y -= offsetY;

  overlay->x = std::max((short) 0, overlay->x);
  overlay->y = std::max((short) 0, overlay->y);

  auto pixels = (int*) img.data;

  auto screen_height = img.height;
  auto screen_width = img.width;

  auto delta_height = std::min<uint16_t>(overlay->height,std::max(0, screen_height - overlay->y));
  auto delta_width = std::min<uint16_t>(overlay->width,std::max(0, screen_width - overlay->x));
  for (auto y = 0; y < delta_height; ++y) {
    auto overlay_begin = &overlay->pixels[y * overlay->width];
    auto overlay_end = &overlay->pixels[y * overlay->width + delta_width];

    auto pixels_begin = &pixels[(y + overlay->y)* (img.row_pitch / img.pixel_pitch) + overlay->x];

    std::for_each(overlay_begin, overlay_end,[&](long pixel) {
      int *pixel_p = (int*) &pixel;

      auto colors_in = (uint8_t*) pixels_begin;

      auto alpha = (*(uint*) pixel_p) >> 24u;
      if (alpha == 255) {
        *pixels_begin = *pixel_p;
      }
      else {
        auto colors_out = (uint8_t*) pixel_p;
        colors_in[0] = colors_out[0] + (colors_in[0] * (255 - alpha) +255 /2) / 255;
        colors_in[1] = colors_out[1] + (colors_in[1] * (255 - alpha) + 255 / 2) / 255;
        colors_in[2] = colors_out[2] + (colors_in[2] * (255 - alpha) + 255 / 2) / 255;
      }
      ++pixels_begin;
    });
  }
}
struct x11_attr_t: public display_t
{
  xdisplay_t xdisplay;
  Window xwindow;
  XWindowAttributes xattr;

  Display* displayDisplay;

  /*
   * Remember last X (NOT the streamed monitor!) size. This way we can trigger reinitialization if the dimensions changed while streaming
   */
  int lastWidth,lastHeight;

  /*
   * Offsets for when streaming a specific monitor. By default, they are 0.
   */
  int displayOffsetX,displayOffsetY;

  x11_attr_t() : xdisplay { displayDisplay = XOpenDisplay(nullptr) }, xwindow { }, xattr { }
  {
    XInitThreads();
    if (!xdisplay) {
      BOOST_LOG(fatal) << "Could not open x11 display"sv;
      log_flush();
      std::abort();
    }

    xwindow = DefaultRootWindow(xdisplay.get());

    refresh();

    int streamedMonitor = -1;
    if(!config::video.output_name.empty()) {
      streamedMonitor = (int)util::from_view(config::video.output_name);
    }

    //If the value has been set at all
    if (streamedMonitor != -1) {

      BOOST_LOG(info) << "Configuring selected monitor ("<< streamedMonitor<<") to stream. If it fails here, you may need Xrandr >= 1.5"sv;
      XRRScreenResources *screenr = XRRGetScreenResources(displayDisplay, xwindow);
      // This is the key right here. Use XRRScreenResources::noutput
      int output = screenr->noutput;

      if (streamedMonitor >= output) {
        BOOST_LOG(error)<< "Could not stream selected display number because there aren't so many."sv;
      }
      else {
        XRROutputInfo* out_info = XRRGetOutputInfo(displayDisplay, screenr, screenr->outputs[streamedMonitor]);
        if (NULL == out_info || out_info->connection != RR_Connected)
        {
          BOOST_LOG(error)<< "Could not stream selected display because it doesn't seem to be connected"sv;
        }
        else
        {
          XRRCrtcInfo* crt_info = XRRGetCrtcInfo(displayDisplay, screenr, out_info->crtc);
          BOOST_LOG(info)<<"Streaming display: "<<out_info->name<<" with res "<<crt_info->width<<" x "<<crt_info->height<<+" offset by "<<crt_info->x<<" x "<<crt_info->y<<"."sv;

          width = crt_info -> width;
          height = crt_info -> height;
          displayOffsetX = crt_info -> x;
          displayOffsetY = crt_info -> y;

          XRRFreeCrtcInfo(crt_info);
        }
        XRRFreeOutputInfo(out_info);
      }
      XRRFreeScreenResources(screenr);
    }
    else {
      width = xattr.width;
      height = xattr.height;
    }

    lastWidth = xattr.width;
    lastHeight = xattr.height;
  }

  /**
   * Called when the display attributes should change.
   */
  void refresh()
  {
    XGetWindowAttributes(xdisplay.get(), xwindow, &xattr); //Update xattr's
  }

  capture_e snapshot(img_t *img_out_base, std::chrono::milliseconds timeout, bool cursor) override {
    refresh();

    //The whole X server changed, so we gotta reinit everything
    if (xattr.width != lastWidth || xattr.height  != lastHeight) {
      BOOST_LOG(warning)<< "X dimensions changed in non-SHM mode, request reinit"sv;
      return capture_e::reinit;
    }
    XImage *img { XGetImage(xdisplay.get(), xwindow, displayOffsetX, displayOffsetY, width,height, AllPlanes, ZPixmap) };

    auto img_out = (x11_img_t*) img_out_base;
    img_out->width = img->width;
    img_out->height = img->height;
    img_out->data = (uint8_t*) img->data;
    img_out->row_pitch = img->bytes_per_line;
    img_out->pixel_pitch = img->bits_per_pixel / 8;
    img_out->img.reset(img);

    if (cursor) {
      blend_cursor(xdisplay.get(), *img_out_base,displayOffsetX,displayOffsetY);
    }

    return capture_e::ok;
  }

  std::shared_ptr<img_t> alloc_img() override {
    return std::make_shared<x11_img_t>();
  }

  int dummy_img(img_t *img) override {
    snapshot(img, 0s, true);
    return 0;
  }
};

struct shm_attr_t: public x11_attr_t {
  xdisplay_t shm_xdisplay; // Prevent race condition with x11_attr_t::xdisplay
  xcb_connect_t xcb;
  xcb_screen_t *display;
  std::uint32_t seg;

  shm_id_t shm_id;

  shm_data_t data;

  util::TaskPool::task_id_t refresh_task_id;

  void delayed_refresh() {
    refresh();

    refresh_task_id = task_pool.pushDelayed(&shm_attr_t::delayed_refresh,2s, this).task_id;
  }

  shm_attr_t() : x11_attr_t(), shm_xdisplay { XOpenDisplay(nullptr) } {
    refresh_task_id = task_pool.pushDelayed(&shm_attr_t::delayed_refresh,2s, this).task_id;
  }

  ~shm_attr_t() override {
    while (!task_pool.cancel(refresh_task_id));
  }

  capture_e snapshot(img_t *img, std::chrono::milliseconds timeout, bool cursor) override {
    //The whole X server changed, so we gotta reinit everything
    if (xattr.width != lastWidth || xattr.height  != lastHeight) {
      BOOST_LOG(warning)<< "X dimensions changed in SHM mode, request reinit"sv;
      return capture_e::reinit;
    }
    else {
      auto img_cookie = xcb_shm_get_image_unchecked(xcb.get(), display->root,displayOffsetX, displayOffsetY, width, height, ~0, XCB_IMAGE_FORMAT_Z_PIXMAP, seg, 0);

      xcb_img_t img_reply { xcb_shm_get_image_reply(xcb.get(), img_cookie,nullptr) };
      if (!img_reply) {
        BOOST_LOG(error)
        << "Could not get image reply"sv;
        return capture_e::reinit;
      }

      std::copy_n((std::uint8_t*) data.data, frame_size(), img->data);

      if (cursor) {
        blend_cursor(shm_xdisplay.get(), *img,displayOffsetX,displayOffsetY);
      }

      return capture_e::ok;
    }
  }

  std::shared_ptr<img_t> alloc_img() override {
    auto img = std::make_shared<shm_img_t>();
    img->width = width;
    img->height = height;
    img->pixel_pitch = 4;
    img->row_pitch = img->pixel_pitch * width;
    img->data = new std::uint8_t[height * img->row_pitch];

    return img;
  }

  int dummy_img(platf::img_t *img) override {
    return 0;
  }

  int init() {
    shm_xdisplay.reset(XOpenDisplay(nullptr));
    xcb.reset(xcb_connect(nullptr, nullptr));
    if (xcb_connection_has_error(xcb.get()))
    {
      return -1;
    }

    if (!xcb_get_extension_data(xcb.get(), &xcb_shm_id)->present)
    {
      BOOST_LOG(error)
      << "Missing SHM extension"sv;

      return -1;
    }

    auto iter = xcb_setup_roots_iterator(xcb_get_setup(xcb.get()));
    display = iter.data;
    seg = xcb_generate_id(xcb.get());

    shm_id.id = shmget(IPC_PRIVATE, frame_size(), IPC_CREAT | 0777);
    if (shm_id.id == -1)
    {
      BOOST_LOG(error)
      << "shmget failed"sv;
      return -1;
    }

    xcb_shm_attach(xcb.get(), seg, shm_id.id, false);
    data.data = shmat(shm_id.id, nullptr, 0);

    if ((uintptr_t) data.data == -1)
    {
      BOOST_LOG(error)
      << "shmat failed"sv;

      return -1;
    }

    /*
     * Commented out resetting of the sizes when intializing X in SHM mode. It might be wrong. Expect issues. This is the default mode, so poisoning those variables is not desired
     */
//    width = display->width_in_pixels;
//    height = display->height_in_pixels;

    return 0;
  }

  std::uint32_t frame_size() {
    return width * height * 4;
  }
};

struct mic_attr_t: public mic_t {
  pa_sample_spec ss;
  util::safe_ptr<pa_simple, pa_simple_free> mic;

  explicit mic_attr_t(pa_sample_format format, std::uint32_t sample_rate,
      std::uint8_t channels) : ss { format, sample_rate, channels }, mic { } { }

  capture_e sample(std::vector<std::int16_t> &sample_buf) override {
    auto sample_size = sample_buf.size();

    auto buf = sample_buf.data();
    int status;
    if (pa_simple_read(mic.get(), buf, sample_size * 2, &status))
    {
      BOOST_LOG(error)
      << "pa_simple_read() failed: "sv << pa_strerror(status);

      return capture_e::error;
    }

    return capture_e::ok;
  }
};

std::shared_ptr<display_t> shm_display() {
  auto shm = std::make_shared<shm_attr_t>();

  if (shm->init()) {
    return nullptr;
  }

  return shm;
}

std::shared_ptr<display_t> display(platf::dev_type_e hwdevice_type) {
  if (hwdevice_type != platf::dev_type_e::none) {
    BOOST_LOG(error)<< "Could not initialize display with the given hw device type."sv;
    return nullptr;
  }

  auto shm_disp = shm_display(); //Attempt to use shared memory X11 to avoid copying the frame

  if (!shm_disp) {
    return std::make_shared<x11_attr_t>(); //Fallback to standard way if else
  }

  return shm_disp;
}

std::unique_ptr<mic_t> microphone(std::uint32_t sample_rate) {
  auto mic = std::make_unique<mic_attr_t>(PA_SAMPLE_S16LE, sample_rate, 2);

  int status;

  const char *audio_sink = "@DEFAULT_MONITOR@";
  if (!config::audio.sink.empty()) {
    audio_sink = config::audio.sink.c_str();
  }

  mic->mic.reset(
    pa_simple_new(nullptr, "sunshine",
   pa_stream_direction_t::PA_STREAM_RECORD, audio_sink,
      "sunshine-record", &mic->ss, nullptr, nullptr, &status));

  if (!mic->mic) {
    auto err_str = pa_strerror(status);
    BOOST_LOG(error) << "pa_simple_new() failed: "sv << err_str;

    log_flush();
    std::abort();
  }

  return mic;
}

ifaddr_t get_ifaddrs() {
  ifaddrs *p { nullptr };

  getifaddrs(&p);

  return ifaddr_t { p };
}

std::string from_sockaddr(const sockaddr *const ip_addr) {
  char data[INET6_ADDRSTRLEN];

  auto family = ip_addr->sa_family;
  if (family == AF_INET6) {
    inet_ntop(AF_INET6, &((sockaddr_in6*) ip_addr)->sin6_addr, data,
    INET6_ADDRSTRLEN);
  }

  if (family == AF_INET) {
    inet_ntop(AF_INET, &((sockaddr_in*) ip_addr)->sin_addr, data,
    INET_ADDRSTRLEN);
  }

  return std::string { data };
}

std::pair<std::uint16_t, std::string> from_sockaddr_ex(const sockaddr *const ip_addr) {
  char data[INET6_ADDRSTRLEN];

  auto family = ip_addr->sa_family;
  std::uint16_t port;
  if (family == AF_INET6) {
    inet_ntop(AF_INET6, &((sockaddr_in6*) ip_addr)->sin6_addr, data,
    INET6_ADDRSTRLEN);
    port = ((sockaddr_in6*) ip_addr)->sin6_port;
  }

  if (family == AF_INET) {
    inet_ntop(AF_INET, &((sockaddr_in*) ip_addr)->sin_addr, data,
    INET_ADDRSTRLEN);
    port = ((sockaddr_in*) ip_addr)->sin_port;
  }

  return
  { port, std::string {data}};
}

std::string get_mac_address(const std::string_view &address) {
  auto ifaddrs = get_ifaddrs();
  for (auto pos = ifaddrs.get(); pos != nullptr; pos = pos->ifa_next) {
    if (pos->ifa_addr && address == from_sockaddr(pos->ifa_addr)) {
      std::ifstream mac_file("/sys/class/net/"s + pos->ifa_name + "/address");
      if (mac_file.good()) {
        std::string mac_address;
        std::getline(mac_file, mac_address);
        return mac_address;
      }
    }
  }
  BOOST_LOG(warning)
  << "Unable to find MAC address for "sv << address;
  return "00:00:00:00:00:00"s;
}

void freeImage(XImage *p) {
  XDestroyImage(p);
}
void freeX(XFixesCursorImage *p) {
  XFree(p);
}
}