/*
  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\n",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
    if(outfile == NULL)
      return 2; // Output dir doesn't exist
    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, int jobnum, int framenum, int slavekey){
  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);

  /* jobnum field... */
   curl_formadd(&formpost,
                &lastptr,
                CURLFORM_COPYNAME, "jobnum",
                CURLFORM_COPYCONTENTS, jobnum, CURLFORM_END);
  /* framenum field... */
  curl_formadd(&formpost,
               &lastptr,
               CURLFORM_COPYNAME, "framenum",
               CURLFORM_COPYCONTENTS, framenum, CURLFORM_END);
  /* slavekey field... */
  curl_formadd(&formpost,
               &lastptr,
               CURLFORM_COPYNAME, "slavekey",
               CURLFORM_COPYCONTENTS, slavekey, CURLFORM_END);
  /* 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
      int ret = curlget(url, destinationPath);
      if(ret == 0){
        fprintf(stderr, "Job data retrieved successfully\n");
        // free(url); @FIXME: causes doublefree! Curl must free the url?
        return 0;
      }
      else if(ret == 1){
        fprintf(stderr, "Downloading job data from %s failed. Check your network connection.\n",url);
        free(url);
        return 1; // Eventually make a retry loop
      }
      else if(ret == 2){
        fprintf(stderr, "Output directory \"%s\" does not exist!\n",destinationPath);
        free(url);
        return 3;
      }
    }
  else{
    fprintf(stderr, "Tar already exists! Download cancelled.\n");
    return 2;
  }

}


int uploadOutput(char *pathtoOutput, char *urltoOutput, int jobnum, int framenum, int slavekey){
  if( !curlpost(pathtoOutput, urltoOutput, jobnum, framenum, slavekey)) // 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, jobnum, framenum, slavekey))
        {
          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
    }
}

/**
   Extracts archive to the specified directory, creating this directory
   if necessary (but this directory will not be recursively created).
   @param outdir output directory
   @param pathtoTar filename of the archive to extract
 */
int unpackJob(char *outdir, char *pathtoTar)
{
  int ret;

  struct archive *a;
  struct archive_entry *ae;
  int astatus;

  /* ignore return because directory may exist already */
  mkdir(outdir, 0700);
  ret = chdir(outdir);
  if(ret == -1)
    {
      perror("chdir");
      return 1;
    }

  a = archive_read_new();
  ae = archive_entry_new();

  archive_read_support_compression_all(a);
  archive_read_support_format_raw(a);
  astatus = archive_read_open_filename(a, pathtoTar, 8192);
  if (astatus != ARCHIVE_OK)
    {
      fprintf(stderr, "error opening archive\n");
      return 1;
    }

  for(astatus = ARCHIVE_OK;
      astatus == ARCHIVE_OK
	|| astatus == ARCHIVE_WARN;
      )
    {
      astatus = archive_read_next_header2(a, ae);
      if(astatus == ARCHIVE_WARN)
	fprintf(stderr, "Encountered nonfatal read error somehow\n");

      if(astatus == ARCHIVE_OK
	 || astatus == ARCHIVE_WARN)
	astatus = archive_read_extract(a, ae,
				       ARCHIVE_EXTRACT_NO_OVERWRITE
				       | ARCHIVE_EXTRACT_SECURE_SYMLINKS
				       | ARCHIVE_EXTRACT_SECURE_NODOTDOT);
    }
  archive_entry_free(ae);
  archive_read_finish(a);
  
  if(astatus != ARCHIVE_EOF)
    {
      fprintf(stderr, "Error reading archive\n");
      return 1;
    }

  return 0;
}


void prepareJobPaths(int jobnum, int framenum, char *outputExt, char *datadir, char **urltoTar,char **pathtoTar,char **pathtoJob, char **pathtoJobfile,char **urltoOutput,char **pathtoOutput)
{
  // Variable Preparation
  char *jobdatapath;
   _distren_asprintf(&jobdatapath, "job%d", jobnum);
   _distren_asprintf(urltoTar, "http://data.distren.org/job%d/job%d.tar.gz", jobnum, jobnum); // Prepares URL to download from
   _distren_asprintf(pathtoTar, "%s/%s/job%d.tar.gz", datadir, jobdatapath, jobnum); // Prepares destination to save to
   _distren_asprintf(pathtoJob, "%s/%s/", datadir, jobdatapath);
   _distren_asprintf(pathtoJobfile, "%s/%s/job.blend", datadir, jobdatapath ); // Prepares the path to the jobfile
   _distren_asprintf(urltoOutput, "http://distren.org/slaveUpload.php"); // Prepares the URL where output is posted
   _distren_asprintf(pathtoOutput, "%s/%s/output/job%d-frame%d.%s", datadir, jobdatapath, jobnum, framenum, outputExt );
   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 1;
   }
   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;
       }
}

void slaveTest(char *datadir)
{
  int command;
  int test = 1;
  int jobnum = 0;
  int framenum = 0;
  int slavekey = 0;
  fprintf(stderr,"Hello!\n");
  char tmpString1[100] = "";
  char tmpString2[100] = "";
  char *uploadURL = "http://distren.org/slaveUpload.php";

  while(test == 1)
   {
     fprintf(stderr, "Welcome to DistRenSlave Alpha Interactive Test Mode\n\n");
     fprintf(stderr, "\t1 \tTest posting (uploading) data\n");
     fprintf(stderr, "\t2 \tTest getting frame from server\n");
     fprintf(stderr, "\t3 \tTest data downloading\n");
     fprintf(stderr, "\t4 \tTest archive decompression\n");
     fprintf(stderr, "\t5 \tQuit\n");

     scanf("%d", &command);

     switch(command)
     {
     case 1:
       fprintf(stderr,"Path to output file to upload: ");
       scanf("%99s", tmpString1);
       fprintf(stderr,"Framenum that is being uploaded: ");
       scanf("%d", &framenum);
       fprintf(stderr,"Jobnum that frame belongs to: ");
       scanf("%d", &jobnum);
       fprintf(stderr,"Slavekey that rendered this output: ");
       scanf("%d", &slavekey);
       uploadOutput(tmpString1, uploadURL, jobnum, framenum, slavekey);
       break;
     case 2:
       fprintf(stderr,"Remotio not implemented yet!\n");
       break;
     case 3:
       fprintf(stderr,"URL to file: ");
       scanf("%s", tmpString1);
       fprintf(stderr,"Local save path (including filename): ");
       scanf("%s", tmpString2);
       if(downloadTar(tmpString1, tmpString2))
         fprintf(stderr,"Error downloading!\n");
       else
         fprintf(stderr,"Success!\n");
       break;
     case 4:
       fprintf(stderr,"Jobnum to decompress: ");
       scanf("%d", &jobnum);
       fprintf(stderr,"Path to compressed data: ");
       scanf("%s", tmpString2);
       unpackJob(datadir, tmpString1);
       break;
     case 5:
       test = 0;
       break;
     default:
       fprintf(stderr, "Invalid input, please try again.\n");
       break;
     }
   }
}


/* simpleSlave functions */

/** Memory struct for curl */
struct _web_memorystruct {
  char *memory;
  size_t size;
};

static void *_web_myrealloc(void *ptr, size_t size);

static void *_web_myrealloc(void *ptr, size_t size)
{
  /* There might be a realloc() out there that doesn't like reallocing
     NULL pointers, so we take care of it here */
  if(ptr)
    return realloc(ptr, size);
  else
    return malloc(size);
}

static size_t _web_writememorycallback(void *ptr, size_t size, size_t nmemb, void *data)
{
  size_t realsize = size * nmemb;
  struct _web_memorystruct *mem = (struct _web_memorystruct *)data;

  mem->memory = _web_myrealloc(mem->memory, mem->size + realsize + 1);
  if (mem->memory) {
    memcpy(&(mem->memory[mem->size]), ptr, realsize);
    mem->size += realsize;
    mem->memory[mem->size] = 0;
  }
  return realsize;
}

struct _web_memorystruct _web_getrequest(char *url){
  // fprintf(stderr,"Preparing to get request at %s",url);

  CURL *curl;
  CURLcode res;
  struct _web_memorystruct chunk;

  chunk.memory=NULL; /* we expect realloc(NULL, size) to work */
  chunk.size = 0;    /* no data at this point */

  curl = curl_easy_init();
  if(curl) {
    curl_easy_setopt(curl, CURLOPT_URL, url);
    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, _web_writememorycallback);
    curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void *)&chunk);
    curl_easy_setopt(curl, CURLOPT_USERAGENT, "libcurl-agent/1.0");

    res = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }

  /* we're done with libcurl, so clean it up */
  curl_global_cleanup();

  if(!strncmp(chunk.memory, "ERROR", 5))
    fprintf(stderr, "Web request returned error!\n");
  return chunk; // 0 is OK, 1 is 404 or other error

}

void _web_finishframe(int slavekey, char *slavepass, int jobnum, int framenum){
  char *url;
  _distren_asprintf(&url,"http://dev.distren.org/slave/act.php?mode=finishframe&slavekey=%d&slavepass=%s&jobnum=%d&framenum=%d", slavekey, slavepass, jobnum, framenum);
  struct _web_memorystruct data = _web_getrequest(url);
  free(url);

  fprintf(stderr,"Got data: %s\n", data.memory);
  if(data.memory)
    free(data.memory);
}

void _web_startframe(int slavekey, char *slavepass, int jobnum, int framenum){
  char *url;
  _distren_asprintf(&url,"http://dev.distren.org/slave/act.php?mode=startframe&slavekey=%d&slavepass=%s&jobnum=%d&framenum=%d", slavekey, slavepass, jobnum, framenum);
  struct _web_memorystruct data = _web_getrequest(url);
  free(url);

  fprintf(stderr,"Got data: %s\n", data.memory);
  if(data.memory)
    free(data.memory);
}

int _web_getwork(int slavekey, char *slavepass, int *jobnum, int *framenum){
  char *url;
  _distren_asprintf(&url,"http://dev.distren.org/slave/act.php?mode=getwork&slavekey=%d&slavepass=%s", slavekey, slavepass);
  struct _web_memorystruct data = _web_getrequest(url);
  free(url);

  //fprintf(stderr,"Got data for getwork: %s!\n", data.memory);
  if(!strcmp(data.memory, "ERROR_BADKEY")){
    fprintf(stderr,"*** Slave %d does not exist!\n",slavekey);
    free(data.memory);
    return 0;
  }
  else{
    *jobnum = atoi(data.memory);
    *framenum = atoi(strchr(data.memory, ',') + 1);
    free(data.memory);
    return 1;
  }
}

void _web_setrenderpower(int slavekey, char *slavepass, int jobnum, int framenum){


}