/*
   Copyright (c) 2013-2014 Anton Titov.

   Copyright (c) 2013-2014 pCloud Ltd.  All rights reserved.

   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions are
   met: Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.
   Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.
   Neither the name of pCloud Ltd nor the names of its contributors may
   be used to endorse or promote products derived from this software
   without specific prior written permission.

   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL pCloud Ltd BE
   LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
   BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
   OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
   IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include <string.h>

#include "pfoldersync.h"
#include "plibs.h"
#include "pmem.h"
#include "plist.h"
#include "pqevent.h"
#include "prun.h"
#include "psys.h"

#define MAX_STATUS_STR_LEN 64
#define DONT_SHOW_TIME_IF_SEC_OVER (2 * 86400)
#define DONT_SHOW_TIME_IF_SPEED_BELOW (4 * 1024)

#define cat_const(src, app) cat_lstr(src, app, sizeof(app) - 1)

static pthread_mutex_t statusmutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t statuscond = PTHREAD_COND_INITIALIZER;
static int statuschanges = 0;
static int statusthreadrunning = 0;

static pthread_mutex_t eventmutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t eventcond = PTHREAD_COND_INITIALIZER;
static psync_list eventlist;
static int eventthreadrunning = 0;
static pstatus_t status_old = {0, 0, 0, 0, 0, 0, 0, 0, 0,
                               0, 0, 0, 0, 0, 0, 0, 0};

typedef struct {
  psync_list list;
  psync_eventdata_t data;
  psync_eventtype_t event;
  int freedata;
} event_list_t;

static char *cat_lstr(char *src, const char *app, size_t len) {
  return (char *)memcpy(src, app, len) + len;
}

static char *cat_str(char *src, const char *app) {
  return cat_lstr(src, app, strlen(app));
}

PSYNC_NOINLINE static char *cat_uint32l(char *src, uint32_t num) {
  char str[16];
  uint32_t rem;
  int unsigned len;
  len = 0;
  do {
    rem = num % 10;
    str[sizeof(str) - ++len] = '0' + rem;
  } while (num /= 10);
  memcpy(src, str + sizeof(str) - len, len);
  return src + len;
}

static char *cat_uint32(char *src, uint32_t num) {
  if (num >= 1000)
    return cat_uint32l(src, num);
  if (num < 100) {
    if (num < 10)
      goto format10;
    else
      goto format100;
  }
  *src++ = '0' + num / 100;
  num %= 100;
format100:
  *src++ = '0' + num / 10;
  num %= 10;
format10:
  *src++ = '0' + num;
  return src;
}

static char *fill_formatted_bytes(char *str, uint64_t bytes) {
  const static char *sizes[] = {"Bytes", "KB", "MB", "GB", "TB"};
  uint32_t rem, sz;
  rem = 0;
  sz = 0;
  while (bytes >= 1024 && sz < ARRAY_SIZE(sizes) - 1) {
    rem = bytes % 1024;
    bytes /= 1024;
    sz++;
  }
  str = cat_uint32(str, (uint32_t)bytes);
  if (sz && bytes < 100) {
    rem = rem * 1000 / 1024;
    pdbg_assert(rem <= 999);
    *str++ = '.';
    if (bytes < 10) {
      rem /= 10;
      *str++ = '0' + rem / 10;
      *str++ = '0' + rem % 10;
    } else
      *str++ = '0' + rem / 100;
  }
  return cat_str(str, sizes[sz]);
}

static char *fill_remaining(char *str, uint32_t files, uint64_t bytes) {
  str = cat_const(str, "Remaining: ");
  str = cat_uint32(str, files);
  str = cat_const(str, " files, ");
  return fill_formatted_bytes(str, bytes);
}

static char *fill_formatted_time(char *str, uint64_t totalsec) {
  uint32_t d, h, m, s;
  s = totalsec % 60;
  totalsec /= 60;
  m = totalsec % 60;
  totalsec /= 60;
  h = totalsec % 24;
  d = totalsec / 24;
  if (d) {
    str = cat_uint32(str, d);
    *str++ = 'd';
    *str++ = ' ';
    if (m >= 30)
      h++;
    str = cat_uint32(str, h);
    *str++ = 'h';
  } else if (h) {
    str = cat_uint32(str, h);
    *str++ = 'h';
    *str++ = ' ';
    if (s >= 30)
      m++;
    str = cat_uint32(str, m);
    *str++ = 'm';
  } else if (m) {
    str = cat_uint32(str, m);
    *str++ = 'm';
    *str++ = ' ';
    str = cat_uint32(str, s);
    *str++ = 's';
  } else {
    if (!s)
      s = 1;
    str = cat_uint32(str, s);
    *str++ = 's';
  }
  return str;
}

static uint64_t sub_no_underf(uint64_t a, uint64_t b) {
  if (likely(b < a))
    return a - b;
  else
    return 0;
}

static void status_fill_formatted_str(pstatus_t *status, char *downloadstr,
                                      char *uploadstr) {
  char *up, *dw;
  uint64_t remsec;
  uint32_t speed;
  dw = downloadstr;
  up = uploadstr;

  if (status->filestodownload) {
    speed = status->downloadspeed;
    if (status->status == PSTATUS_PAUSED || status->status == PSTATUS_STOPPED ||
        status->localisfull || speed == 0) {
      if (status->status == PSTATUS_PAUSED)
        dw = cat_const(dw, "Paused. ");
      else if (status->status == PSTATUS_STOPPED)
        dw = cat_const(dw, "Stopped. ");
      else if (status->localisfull)
        dw = cat_const(dw, "Disk full. ");
      dw = fill_remaining(
          dw, status->filestodownload,
          sub_no_underf(status->bytestodownload, status->bytesdownloaded));
    } else {
      dw = fill_formatted_bytes(dw, speed);
      dw = cat_const(dw, "/sec, ");
      dw = fill_remaining(
          dw, status->filestodownload,
          sub_no_underf(status->bytestodownload, status->bytesdownloaded));
      remsec = (status->bytestodownload - status->bytesdownloaded) / speed;
      if (remsec < DONT_SHOW_TIME_IF_SEC_OVER ||
          speed >= DONT_SHOW_TIME_IF_SPEED_BELOW) {
        *dw++ = ' ';
        dw = fill_formatted_time(dw, remsec);
      }
    }
  } else
    dw = cat_const(dw, "Everything Downloaded");

  if (status->filestoupload) {
    speed = status->uploadspeed;
    if (status->status == PSTATUS_PAUSED || status->status == PSTATUS_STOPPED ||
        status->remoteisfull || speed == 0) {
      if (status->status == PSTATUS_PAUSED)
        up = cat_const(up, "Paused. ");
      else if (status->status == PSTATUS_STOPPED)
        up = cat_const(up, "Stopped. ");
      else if (status->remoteisfull)
        up = cat_const(up, "Account full. ");
      up = fill_remaining(
          up, status->filestoupload,
          sub_no_underf(status->bytestoupload, status->bytesuploaded));
    } else {
      up = fill_formatted_bytes(up, speed);
      up = cat_const(up, "/sec, ");
      up = fill_remaining(
          up, status->filestoupload,
          sub_no_underf(status->bytestoupload, status->bytesuploaded));
      remsec = (status->bytestoupload - status->bytesuploaded) / speed;
      if (remsec < DONT_SHOW_TIME_IF_SEC_OVER ||
          speed >= DONT_SHOW_TIME_IF_SPEED_BELOW) {
        *up++ = ' ';
        up = fill_formatted_time(up, remsec);
      }
    }
  } else
    up = cat_const(up, "Everything Uploaded");

  pdbg_assert(dw < downloadstr + MAX_STATUS_STR_LEN);
  pdbg_assert(up < uploadstr + MAX_STATUS_STR_LEN);
  *dw = 0;
  *up = 0;
  status->downloadstr = downloadstr;
  status->uploadstr = uploadstr;
}

static void status_change_thread(void *ptr) {
  char downloadstr[MAX_STATUS_STR_LEN], uploadstr[MAX_STATUS_STR_LEN];
  pstatus_change_callback_t callback = (pstatus_change_callback_t)ptr;
  while (1) {
    // Maximum 2 updates/sec
    psys_sleep_milliseconds(500);
    pthread_mutex_lock(&statusmutex);
    while (statuschanges <= 0) {
      statuschanges = -1;
      pthread_cond_wait(&statuscond, &statusmutex);
    }
    statuschanges = 0;
    uint32_t cur_status = __atomic_load_n(&psync_status.status, __ATOMIC_RELAXED);
    uint32_t cur_filestodownload = __atomic_load_n(&psync_status.filestodownload, __ATOMIC_RELAXED);
    uint32_t cur_filestoupload = __atomic_load_n(&psync_status.filestoupload, __ATOMIC_RELAXED);
    uint8_t cur_localisfull = __atomic_load_n(&psync_status.localisfull, __ATOMIC_RELAXED);
    uint8_t cur_remoteisfull = __atomic_load_n(&psync_status.remoteisfull, __ATOMIC_RELAXED);
    if (((status_old.filestodownload > 0) &&
         (cur_filestodownload == 0)) ||
        ((cur_filestodownload > 0) &&
         (status_old.filestodownload == 0)) ||
        ((status_old.filestoupload > 0) && (cur_filestoupload == 0)) ||
        ((cur_filestoupload > 0) && (status_old.filestoupload == 0)) ||
        ((cur_localisfull != status_old.localisfull)) ||
        ((cur_remoteisfull != status_old.remoteisfull)) ||
        ((cur_status != status_old.status) &&
         ((cur_status == PSTATUS_STOPPED) ||
          (cur_status == PSTATUS_PAUSED) ||
          (cur_status == PSTATUS_OFFLINE) ||
          (status_old.status == PSTATUS_STOPPED) ||
          (status_old.status == PSTATUS_PAUSED) ||
          (status_old.status == PSTATUS_OFFLINE)))) {
      status_old = psync_status;
      status_old.status = cur_status;
      status_old.filestodownload = cur_filestodownload;
      status_old.filestoupload = cur_filestoupload;
      status_old.localisfull = cur_localisfull;
      status_old.remoteisfull = cur_remoteisfull;
    }
    pthread_mutex_unlock(&statusmutex);
    if (!psync_do_run)
      break;
    status_fill_formatted_str(&psync_status, downloadstr, uploadstr);
    pdbg_logf(D_NOTICE, "sending status update, dwlstr: %s, uplstr: %s",
          psync_status.downloadstr, psync_status.uploadstr);
    callback(&psync_status);
  }
}

static void proc_send_event(void *ptr) {
  pevent_callback_t callback = (pevent_callback_t)ptr;
  event_list_t *event;

  while (1) {
    pthread_mutex_lock(&eventmutex);

    while (psync_list_isempty(&eventlist))
      pthread_cond_wait(&eventcond, &eventmutex);

    event = psync_list_remove_head_element(&eventlist, event_list_t, list);

    pthread_mutex_unlock(&eventmutex);

    if (!psync_do_run)
      break;

    callback(event->event, event->data);

    if (event->freedata)
      pmem_free(PMEM_SUBSYS_OTHER, event->data.ptr);

    pmem_free(PMEM_SUBSYS_OTHER, event);
  }
}

void pstatus_get_cb(pstatus_t *status) {
  static char downloadstr[MAX_STATUS_STR_LEN], uploadstr[MAX_STATUS_STR_LEN];
  memcpy(status, &psync_status, sizeof(pstatus_t));
  status_fill_formatted_str(status, downloadstr, uploadstr);
}

void pstatus_set_cb(pstatus_change_callback_t callback) {
  pthread_mutex_lock(&statusmutex);
  statusthreadrunning = 1;
  pthread_mutex_unlock(&statusmutex);
  prun_thread1("status change", status_change_thread, callback);
}

void pstatus_send_status_update() {
  if (statusthreadrunning) {
    pthread_mutex_lock(&statusmutex);
    if (++statuschanges == 0) {
      statuschanges++;
      pthread_cond_signal(&statuscond);
    }
    pthread_mutex_unlock(&statusmutex);
  }
}

void pqevent_process(pevent_callback_t callback) {
  pthread_mutex_lock(&statusmutex);
  eventthreadrunning = 1;
  pthread_mutex_unlock(&statusmutex);
  psync_list_init(&eventlist);
  prun_thread1("event", proc_send_event, callback);
}

void pqevent_queue_sync_event_id(psync_eventtype_t eventid, psync_syncid_t syncid,
                            const char *localpath,
                            psync_fileorfolderid_t remoteid) {
  if (eventthreadrunning) {
    char *remotepath;
    if (eventid & PEVENT_TYPE_FOLDER)
      remotepath = pfolder_path(remoteid, NULL);
    else
      remotepath = pfolder_file_path(remoteid, NULL);
    if (pdbg_unlikely(!remotepath))
      return;
    pqevent_queue_sync_event_path(eventid, syncid, localpath, remoteid, remotepath);
    pmem_free(PMEM_SUBSYS_OTHER, remotepath);
  }
}

void pqevent_queue_sync_event_path(psync_eventtype_t eventid, psync_syncid_t syncid,
                              const char *localpath,
                              psync_fileorfolderid_t remoteid,
                              const char *remotepath) {
  if (eventthreadrunning) {
    event_list_t *event;
    size_t llen, rlen, slen;
    char *lcopy, *rcopy, *strct, *name;
    llen = strlen(localpath) + 1;
    rlen = strlen(remotepath) + 1;
    if (eventid & PEVENT_TYPE_FOLDER)
      slen = sizeof(psync_folder_event_t);
    else
      slen = sizeof(psync_file_event_t);
    event =
        (event_list_t *)pmem_malloc(PMEM_SUBSYS_OTHER, sizeof(event_list_t) + slen + llen + rlen);
    strct = (char *)(event + 1);
    lcopy = strct + slen;
    rcopy = lcopy + llen;
    memcpy(lcopy, localpath, llen);
    memcpy(rcopy, remotepath, rlen);
    name = strrchr(rcopy, '/') + 1;
    if (eventid & PEVENT_TYPE_FOLDER) {
      psync_folder_event_t *f = (psync_folder_event_t *)strct;
      f->folderid = remoteid;
      f->name = name;
      f->localpath = lcopy;
      f->remotepath = rcopy;
      f->syncid = syncid;
      event->data.folder = f;
    } else {
      psync_file_event_t *f = (psync_file_event_t *)strct;
      f->fileid = remoteid;
      f->name = name;
      f->localpath = lcopy;
      f->remotepath = rcopy;
      f->syncid = syncid;
      event->data.file = f;
    }
    event->event = eventid;
    event->freedata = 0;
    pthread_mutex_lock(&eventmutex);
    psync_list_add_tail(&eventlist, &event->list);
    pthread_cond_signal(&eventcond);
    pthread_mutex_unlock(&eventmutex);
  }
}

void pqevent_queue_eventid(psync_eventtype_t eventid) {
  if (eventthreadrunning) {
    event_list_t *event;

    event = pmem_malloc(PMEM_SUBSYS_OTHER, sizeof(event_list_t));
    event->data.ptr = NULL;
    event->event = eventid;
    event->freedata = 0;

    pthread_mutex_lock(&eventmutex);
    psync_list_add_tail(&eventlist, &event->list);
    pthread_cond_signal(&eventcond);
    pthread_mutex_unlock(&eventmutex);
  }
}

void pqevent_queue_event(psync_eventtype_t eventid, void *eventdata) {
  if (eventthreadrunning) {
    event_list_t *event;

    event = pmem_malloc(PMEM_SUBSYS_OTHER, sizeof(event_list_t));
    event->data.ptr = eventdata;
    event->event = eventid;
    event->freedata = 1;

    pthread_mutex_lock(&eventmutex);
    psync_list_add_tail(&eventlist, &event->list);
    pthread_cond_signal(&eventcond);
    pthread_mutex_unlock(&eventmutex);
  } else
    pmem_free(PMEM_SUBSYS_OTHER, eventdata);
}