/*
  Copyright 2009 Nathan Phillip Brink, Ethan Zonca, Matthew Orlando

  This file is a part of DistRen.

  DistRen is free software: you can redistribute it and/or modify
  it under the terms of the GNU Affero General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  DistRen is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU Affero General Public License for more details.

  You should have received a copy of the GNU Affero General Public License
  along with DistRen.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "distrenjob.h"
#include "slavefuncs.h"

#include "common/asprintf.h"
#include "common/execio.h"
#include "common/protocol.h"
#include "common/remoteio.h"

#include <curl/curl.h>
#include <curl/easy.h>
#include <curl/types.h>

#include <archive.h>
#include <archive_entry.h>

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <fcntl.h>


/**
   Sends the server a single request (see protocol.h)
*/
int sendSignal(struct remoteio *rem, char signal)
{
  size_t written;
  size_t towrite;
  char *ssignal;

  _distren_asprintf(&ssignal, "%c", signal);
  towrite = strlen(ssignal);
  while( towrite
	 && !remoteio_write(rem, ssignal, towrite, &written))
    {
      fprintf(stderr, "Sending request...\n");
      towrite -= written;
    }
  if(written)
    return 0;

  /**
     if remoteio_write returned 1, the connection
     is probably dead or there was a real error
   */
  return 1;
}

/**
   Sends the server an extended signal (request + data)
*/
int sendExtSignal(struct remoteio *rem, char signal, char *data){
  size_t written;
  size_t towrite;
  char *ssignal;
  _distren_asprintf(&ssignal, "%c%s", signal, data); // Just append the data FIXME: We should do this differently
  towrite = strlen(ssignal);
  while( towrite
          && !remoteio_write(rem, ssignal, towrite, &written))
     {
       fprintf(stderr, "Sending request...\n");
       towrite -= written;
     }
   if(written)
     return 0;

   /**
      if remoteio_write returned 1, the connection
      is probably dead or there was a real error
    */
   return 1;
}



/**
   Grabs the xml DOM node reached by an XPath.

   @param path an XPath that lead to DOM node
   @return the first node associated with the path or NULL if there is no match
 */
xmlNodePtr xml_quickxpath(xmlXPathContextPtr xpathctxt, xmlChar *path)
{
  xmlNodePtr toreturn;

  xmlXPathObjectPtr xmlxpathobjptr;
  xmlxpathobjptr = xmlXPathEval(path, xpathctxt);
  if(!xmlxpathobjptr
     || !xmlxpathobjptr->nodesetval->nodeNr)
    {
      fprintf(stderr, "XPath resolution failed for ``%s'' in ``%s'' (``%s'')\n", path, xpathctxt->doc->name, xpathctxt->doc->URL);
      return (xmlNodePtr)NULL;
    }

  toreturn = *(xmlxpathobjptr->nodesetval->nodeTab);

  xmlXPathFreeObject(xmlxpathobjptr);

  return toreturn;
}


/** Stub for deleting job data from the disk. @TODO: unstubify me! */
int delete_jobdata(int jobnum, char *datadir)
{
  char *jobpath;
  _distren_asprintf(&jobpath, "%s/%d", datadir, jobnum);
  // rmdir(jobpath);
  fprintf(stderr, "Please manually remove %s. Automatic removal is currently not implemented.\n", jobpath);
  return 0;
}

/** Function referenced by curlget() to write data to disk. */
size_t curl_writetodisk(void *ptr, size_t size, size_t nmemb, FILE *stream)
 {
    return fwrite(ptr, size, nmemb, stream);
  }

/** Helper function for cURL's progress display */
int curl_progress( char *Bar,double t,double d,double ultotal,double ulnow)
{
fprintf(stderr,"Downloading: %f%% complete\r",d/t*100);
return 0;
}

/** Retrieves a URL with cURL and saves it to disk */
int curlget(char *url, char *out){
  fprintf(stderr,"Preparing to download %s",url);
  double *Bar; // Stores cURL progress display info
  CURL *curl;
  CURLcode res;
  FILE *outfile;

  curl = curl_easy_init();
  if(curl) {
	outfile = fopen(out, "w"); // Open where we're writing to

  curl_easy_setopt(curl, CURLOPT_URL, url);
  curl_easy_setopt(curl, CURLOPT_WRITEDATA, outfile);
  curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, curl_writetodisk); // this MUST be set for win32 compat.
  curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 0);
  curl_easy_setopt(curl, CURLOPT_PROGRESSFUNCTION, curl_progress);
  curl_easy_setopt(curl, CURLOPT_PROGRESSDATA, &Bar);
  res = curl_easy_perform(curl);
  curl_easy_cleanup(curl);
  }
  fprintf(stderr,"\n"); // Clears out he progressbar's carriage return
  return res; // 0 is OK, 1 is 404 or other error
}

/** Posts a file to a url with cUrl */
int curlpost(char *filename, char *url){
  char *targetname = "uploadedfile"; // Name of the target in the php file on the server (Don't change me unless you have different PHP code)
  CURL *curl;
  CURLcode res;
  struct curl_httppost *formpost=NULL;
  struct curl_httppost *lastptr=NULL;
  struct curl_slist *headerlist=NULL;
  static const char buf[] = "Expect:";

  curl_global_init(CURL_GLOBAL_ALL);

  /* upload field... */
  curl_formadd(&formpost,
               &lastptr,
               CURLFORM_COPYNAME, targetname,
               CURLFORM_FILE, filename,
               CURLFORM_END);
  /* filename field... */
  curl_formadd(&formpost,
               &lastptr,
               CURLFORM_COPYNAME, "filename",
               CURLFORM_COPYCONTENTS, filename,
               CURLFORM_END);
  /* submit field, not usually needed, just in case... */
  curl_formadd(&formpost,
               &lastptr,
               CURLFORM_COPYNAME, "submit",
               CURLFORM_COPYCONTENTS, "send",
               CURLFORM_END);

  curl = curl_easy_init();
  headerlist = curl_slist_append(headerlist, buf);
  if(curl) {
    /* Setting the URL to get the post, and the contents of the post */
    curl_easy_setopt(curl, CURLOPT_URL, url);
    curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost);
    res = curl_easy_perform(curl);

    curl_easy_cleanup(curl);
    /* cleanup the formpost junk */
    curl_formfree(formpost);
    curl_slist_free_all (headerlist);
  }
  return res;
}


/** Logs the user into the server after ensuring that keys exist */
int login_user(char *username)
{
  // @TODO: Put some telnet-style auth code here unless this is obselete
  return 1; // success
}

/** Replaces wordtoreplace with replacewith in conffile (relative to SYSCONFDIR) */
int conf_replace(char *conffile, char *wordtoreplace, char *replacewith){
  int maxlinelen = 120;
  char *fileOrig;
  char *fileRepl;
  _distren_asprintf(&fileOrig, "%s/%s", SYSCONFDIR, conffile);
  _distren_asprintf(&fileRepl, "%s%s.edited", SYSCONFDIR, conffile);
  char buffer[maxlinelen+2];
  char *buff_ptr, *find_ptr;
  FILE *fp1, *fp2;
  size_t find_len = strlen(wordtoreplace);
  fp1 = fopen(fileOrig,"r");
  fp2 = fopen(fileRepl,"w");
  if (fp1 ==NULL){
    fprintf(stderr, "%s doesn't exist\n",fileOrig);
    return 0;
  }
  else if(fp2 ==NULL){
    fprintf(stderr, "Can't write a file to disk! Check permissions.\n");
    return 0;
  }
  else{
    while(fgets(buffer,maxlinelen+2,fp1))
      {
        buff_ptr = buffer;
        while ((find_ptr = strstr(buff_ptr,wordtoreplace)))
        {
           while(buff_ptr < find_ptr)
             fputc((int)*buff_ptr++,fp2);
           fputs(replacewith,fp2);
           buff_ptr += find_len;
         }
         fputs(buff_ptr,fp2);
      }
    rename(fileRepl, fileOrig);
  }
  fclose(fp2);
  fclose(fp1);
  fprintf(stderr,"Wrote conf file...\n");
return 1; // Success
}


/* Executors */

/** Executor function for Blender operations */
int exec_blender(char *input, char *output, int frame)
{
  fprintf(stderr,"Preparing to execute...\n");
  int ret;
  char *frame_str;

  char *command = "blender"; // @TODO: We currently expect this to be in PATH
  char *cmd[] = { command, "-b", "-o", output, input, "-f", frame_str, (char *)NULL }; // arguments for blender

  char buf[10];
  struct execio *testrem;
  size_t readlen;

  _distren_asprintf(&frame_str, "%i", frame);

  fprintf(stderr,"Executing: %s\n", frame_str);
  ret = execio_open(&testrem, command, cmd);
  buf[9] = '\0';
  while(!execio_read(testrem, buf, 9, &readlen))
    {
      if(readlen > 9) {
        fprintf(stderr, "Something is terribly wrong!\n");
       }
       buf[readlen] = '\0';
       fprintf(stderr, "read \"%s\"\n", buf);
    }
  execio_close(testrem);

  return ret;
}

void xmlinit()
{
  xmlInitParser();
  xmlXPathInit();
}

void xmlcleanup()
{
  xmlCleanupParser();
}


/** Creates directories recursively */
int distren_mkdir_recurse(char *dirname)
{
  size_t counter;
  char *nextdir;

  nextdir = strdup(dirname);
  for(counter = 0; nextdir[counter]; counter ++)
    {
      /** @TODO OS-portabalize the path-separators */
      if(nextdir[counter] == '/')
        {
          nextdir[counter] = '\0';
          mkdir(nextdir, S_IRWXU | S_IRGRP | S_IROTH);
          nextdir[counter] = '/';
        }
    }

  return 0;
}

/**
 @TODO: Use for constructing path to job data locally and/or on data.distren.org
 */
int job_build_path(char *filename, unsigned int jobnum)
{
  return 0;
}


int downloadTar(char *url, char *destinationPath){
  // Prepare to download the job tar if it isn't  present
  struct stat buffer;
  int fstatus = stat(destinationPath, &buffer);
  if(fstatus == -1)
    {
      // Download the Tar
      if( curlget(url, destinationPath) == 0){
        fprintf(stderr, "Job data retrieved successfully\n");
        free(url);
        return 0;
      }
      else {
        fprintf(stderr, "Downloading job data from %s failed. Check your network connection.\n",url);
        free(url);
        return 1; // Eventually make a retry loop
      }
    }
  else{
    fprintf(stderr, "Tar already exists! Download cancelled.\n");
    return 2;
  }
}


int uploadOutput(char *pathtoOutput, char *urltoOutput){
  if( !curlpost(pathtoOutput, urltoOutput)) // Uploads output
    {
      fprintf(stderr,"Upload successful, removing old output...\n");
      remove(pathtoOutput); // Delete the file after its uploaded
      return 0;
    }
  else
    {
      fprintf(stderr,"Upload failed. Check your network connection. Retrying upload...\n");
      int tries=1;
      while(tries<=10 && curlpost(pathtoOutput, urltoOutput))
        {
          fprintf(stderr, "Upload failed. Trying again in 10 seconds... (attempt %d of 10)\n", tries);
          tries++;
          sleep(10);
        }
      return 1; // Upload failed after multiple tries
      // @FUTURE: Keep track of files that we were unable to upload, and upload them later
    }
}


int unpackJob(char *pathtoTar, int jobnum){
  int ret;
  int buffsize = 8192;
  char *buff = "";
  size_t size;
  struct archive_entry *ae = archive_entry_new();
  struct archive *a = archive_read_new();

  archive_read_support_compression_all(a);
  archive_read_support_format_raw(a);
  ret = archive_read_open_filename(a, pathtoTar, 16384);
  if (ret != ARCHIVE_OK) {
    return 1;
  }
  ret = archive_read_next_header(a, &ae);
  if (ret != ARCHIVE_OK) {
    return 1;
  }
   for (;;) {
    size = archive_read_data(a, buff, buffsize);
    if (size < 0) {
      return 1;
    }
    if (size == 0)
      break;
    write(1, buff, size);
  }

  archive_read_finish(a);
  archive_entry_free(ae);

  return 0;

/*
  char *tarcmd;        // Command to run for tar. Migrate to libtar sometime
  char *outdir;        // Output Directory for tar

  _distren_asprintf(&outdir, "/tmp/distren/job%d", jobnum);
  mkdir("/tmp/distren", 0750); // @FIXME: Change to tmpdir once it exists
  mkdir(outdir, 0750);

  _distren_asprintf(&tarcmd, "tar -xvf \"%s\" -C \"%s\"", pathtoTar, outdir); // @FIXME:Use a lib here!
  system(tarcmd);
  free(tarcmd);
  free(pathtoTar);
  free(outdir);
  return 0;
  */
}


void prepareJobPaths(int jobnum,char *datadir, char **urltoTar,char **pathtoTar,char **pathtoJobfile,char **urltoOutput,char **pathtoXml){
  // Variable Preparation
  char *jobdatapath;
   _distren_asprintf(&jobdatapath, "job%d", jobnum);
   _distren_asprintf(urltoTar, "http://data.distren.org/job%d/job%d.tar.gz", jobnum); // Prepares URL to download from
   _distren_asprintf(pathtoTar, "%s/stor/jobdata/job%d.tar.gz", datadir, jobnum); // Prepares destination to save to
   _distren_asprintf(pathtoJobfile, "%s/%s/job.blend", datadir, jobdatapath ); // Prepares the path to the jobfile
   _distren_asprintf(urltoOutput, "http://data.distren.org/tmp/", jobdatapath ); // Prepares the URL where output is posted
   _distren_asprintf(pathtoXml, "%s/job%d/job%d.xml", datadir, jobnum ); // Prepares the path to the job's XML file
   free(jobdatapath);
}

int checkUsername(char *username){
  if(username == NULL || strcmp(username, "!username") == 0 ) {
     fprintf(stderr, "\nPlease ensure that your username is present in distrenslave.conf\n");
     return 0;
   }
   else
     if( username != NULL || strcmp(username, "!username") != 0 )
       {
         // Log in the user
         if(login_user(username) == 1){
           fprintf(stderr, "You should now be logged into distren.\n");
           return 0;
         }
         else
           {
             fprintf(stderr, "Login failed, please check your username. If you have not registered, please do so on the DistRen website.\n");
             return 1;
           }
       }
     else
       {
         fprintf(stderr, "Please check your distrenslave.conf, it appears to be incorrectly formatted.\n");
         return 1;
       }
}