#include <petscwebclient.h>

/*
   These variables identify the code as a PETSc application to Box.

   See -   http://stackoverflow.com/questions/4616553/using-oauth-in-free-open-source-software
   Users can get their own application IDs - goto https://developers.box.com

*/
#define PETSC_BOX_CLIENT_ID  "sse42nygt4zqgrdwi0luv79q1u1f0xza"
#define PETSC_BOX_CLIENT_ST  "A0Dy4KgOYLB2JIYZqpbze4EzjeIiX5k4"

#include <mongoose.h>

static volatile char *result = NULL;

/*this is the main handler call. It switched based on what uri is in the request*/
static int PetscBoxWebServer_Private(struct mg_connection *conn)
{
  const struct mg_request_info *request_info = mg_get_request_info(conn);
  printf("Hi %s\n",request_info->uri);
  printf("Hi %s\n",request_info->query_string);
  result = (char*) request_info->query_string;
return 0;
}


static PetscErrorCode PetscBoxStartWebServer_Private(void)
{
  PetscErrorCode      ierr;
  int                 optionsLen = 5;
  const char          *options[optionsLen];
  struct mg_callbacks callbacks;
  struct mg_context   *ctx;

  PetscFunctionBegin;
  options[0] = "listening_ports";
  options[1] = "8081s";
  options[2] = "ssl_certificate";
  options[3] = "/Users/barrysmith/Src/saws/saws.pem";
  options[4] = NULL;


  /* Prepare callbacks structure. We have only one callback, the rest are NULL. */
  ierr = PetscMemzero(&callbacks, sizeof(callbacks));CHKERRQ(ierr);
  callbacks.begin_request = PetscBoxWebServer_Private;
  ctx = mg_start(&callbacks, NULL, options);
  if (!ctx) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"Unable to start up webserver");
  while (!result) {};
  PetscFunctionReturn(0);
}

#include <ctype.h>

char to_hex(char code) {
  static char hex[] = "0123456789abcdef";
  return hex[code & 15];
}

/* Returns a url-encoded version of str */
char *url_encode(char *str) {
  char *pstr = str, *buf = malloc(strlen(str) * 3 + 1), *pbuf = buf;
  while (*pstr) {
    if (isalnum(*pstr) || *pstr == '-' || *pstr == '_' || *pstr == '.' || *pstr == '~') 
      *pbuf++ = *pstr;
    else if (*pstr == ' ') 
      *pbuf++ = '+';
    else 
      *pbuf++ = '%', *pbuf++ = to_hex(*pstr >> 4), *pbuf++ = to_hex(*pstr & 15);
    pstr++;
  }
  *pbuf = '\0';
  return buf;
}

#undef __FUNCT__
#define __FUNCT__ "PetscBoxAuthorize"
/*@C
     PetscBoxAuthorize - Get authorization and refresh token for accessing Box drive from PETSc

   Not collective, only the first process in MPI_Comm does anything

   Input Parameters:
+  comm - the MPI communicator
-  tokensize - size of the token arrays

   Output Parameters:
+  access_token - can be used with PetscBoxUpload() for this one session
-  refresh_token - can be used for ever to obtain new access_tokens with PetscBoxRefresh(), guard this like a password
                   it gives access to your Box Drive

   Notes: This call requires stdout and stdin access from process 0 on the MPI communicator

   You can run src/sys/webclient/examples/tutorials/obtainrefreshtoken to get a refresh token and then in the future pass it to
   PETSc programs with -box_refresh_token XXX

   Developer Notes: For some reason I cannot get this to work! Box always replies with Bad Request and no details. Using Curl works
   if one is fast enough.  Perhaps the problem is the need to urlencode the message?

.seealso: PetscBoxRefresh(), PetscBoxUpload(), PetscURLShorten()

@*/
PetscErrorCode PetscBoxAuthorize(MPI_Comm comm,char access_token[],char refresh_token[],size_t tokensize)
{
  SSL_CTX        *ctx;
  SSL            *ssl;
  int            sock;
  PetscErrorCode ierr;
  char           buff[8*1024],body[1024],*access,*refresh,*ctmp;
  PetscMPIInt    rank;
  PetscBool      flg;

  PetscFunctionBegin;
  ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
  if (!rank) {
    ierr = PetscPrintf(comm,"Cut and paste the following into your browser:\n\n"
                            "https://www.box.com/api/oauth2/authorize?"
                            "response_type=code&"
                            "client_id="
                            PETSC_BOX_CLIENT_ID
                            "&state=PETScState"
                            "\n\n");CHKERRQ(ierr);
    ierr = PetscBoxStartWebServer_Private();CHKERRQ(ierr);
    ierr = PetscStrbeginswith((const char*)result,"state=PETScState&code=",&flg);CHKERRQ(ierr);
    if (!flg) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Did not get expected string from Box got %s",result);
    ierr = PetscStrncpy(buff,(const char*)result+22,sizeof(buff));CHKERRQ(ierr);

    ierr = PetscSSLInitializeContext(&ctx);CHKERRQ(ierr);
    ierr = PetscHTTPSConnect("www.box.com",443,ctx,&sock,&ssl);CHKERRQ(ierr);
    ierr = PetscStrcpy(body,"code=");CHKERRQ(ierr);
    ierr = PetscStrcat(body,buff);CHKERRQ(ierr);
    ierr = PetscStrcat(body,"&client_id=");CHKERRQ(ierr);
    ierr = PetscStrcat(body,PETSC_BOX_CLIENT_ID);CHKERRQ(ierr);
    ierr = PetscStrcat(body,"&client_secret=");CHKERRQ(ierr);
    ierr = PetscStrcat(body,PETSC_BOX_CLIENT_ST);CHKERRQ(ierr);
    ierr = PetscStrcat(body,"&grant_type=authorization_code");CHKERRQ(ierr);

    ierr = PetscHTTPSRequest("POST","https://www.box.com/api/oauth2/token",NULL,"application/x-www-form-urlencoded",body,ssl,buff,sizeof(buff));CHKERRQ(ierr);
    ierr = PetscSSLDestroyContext(ctx);CHKERRQ(ierr);
    close(sock);

    ierr   = PetscStrstr(buff,"\"access_token\" : \"",&access);CHKERRQ(ierr);
    if (!access) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"Did not receive access token from Box");
    access += 18;
    ierr   = PetscStrchr(access,'\"',&ctmp);CHKERRQ(ierr);
    if (!ctmp) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"Access token from Box is misformed");
    *ctmp  = 0;
    ierr   = PetscStrncpy(access_token,access,tokensize);CHKERRQ(ierr);
    *ctmp  = '\"';

    ierr   = PetscStrstr(buff,"\"refresh_token\" : \"",&refresh);CHKERRQ(ierr);
    if (!refresh) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"Did not receive refresh token from Box");
    refresh += 19;
    ierr   = PetscStrchr(refresh,'\"',&ctmp);CHKERRQ(ierr);
    if (!ctmp) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"Refresh token from Box is misformed");
    *ctmp  = 0;
    ierr = PetscStrncpy(refresh_token,refresh,tokensize);CHKERRQ(ierr);

    ierr = PetscPrintf(comm,"Here is your Box refresh token, save it in a save place, in the future you can run PETSc\n");CHKERRQ(ierr);
    ierr = PetscPrintf(comm,"programs with the option -box_refresh_token %d\n",refresh);CHKERRQ(ierr);
    ierr = PetscPrintf(comm,"to access Box Drive automatically\n");CHKERRQ(ierr);
  }
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscBoxRefresh"
/*@C
     PetscBoxRefresh - Get a new authorization token for accessing Box drive from PETSc from a refresh token

   Not collective, only the first process in the MPI_Comm does anything

   Input Parameters:
+   comm - MPI communicator
.   refresh token - obtained with PetscBoxAuthorize(), if NULL PETSc will first look for one in the options data 
                    if not found it will call PetscBoxAuthorize()
-   tokensize - size of the output string access_token

   Output Parameter:
+   access_token - token that can be passed to PetscBoxUpload()
-   new_refresh_token - the old refresh token is no longer valid, not this is different than Google where the same refresh_token is used forever

   Note: This doesn't work I cannot figure out why.

.seealso: PetscURLShorten(), PetscBoxAuthorize(), PetscBoxUpload()

@*/
PetscErrorCode PetscBoxRefresh(MPI_Comm comm,const char refresh_token[],char access_token[],char new_refresh_token[],size_t tokensize)
{
  SSL_CTX        *ctx;
  SSL            *ssl;
  int            sock;
  PetscErrorCode ierr;
  char           buff[8*1024],body[1024],*access,*ctmp;
  PetscMPIInt    rank;
  char           *refreshtoken = (char*)refresh_token;

  PetscFunctionBegin;
  ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
  if (!rank) {
    if (!refresh_token) {
      PetscBool set;
      ierr = PetscMalloc1(512,&refreshtoken);CHKERRQ(ierr);
      ierr = PetscOptionsGetString(NULL,"-box_refresh_token",refreshtoken,512,&set);CHKERRQ(ierr);
      if (!set) {
        ierr = PetscBoxAuthorize(comm,access_token,refreshtoken,512*sizeof(char));CHKERRQ(ierr);
        ierr = PetscFree(refreshtoken);CHKERRQ(ierr);
        PetscFunctionReturn(0);
      }
    }
    ierr = PetscSSLInitializeContext(&ctx);CHKERRQ(ierr);
    ierr = PetscHTTPSConnect("www.box.com",443,ctx,&sock,&ssl);CHKERRQ(ierr);
    ierr = PetscStrcpy(body,"client_id=");CHKERRQ(ierr);
    ierr = PetscStrcat(body,PETSC_BOX_CLIENT_ID);CHKERRQ(ierr);
    ierr = PetscStrcat(body,"&client_secret=");CHKERRQ(ierr);
    ierr = PetscStrcat(body,PETSC_BOX_CLIENT_ST);CHKERRQ(ierr);
    ierr = PetscStrcat(body,"&refresh_token=");CHKERRQ(ierr);
    ierr = PetscStrcat(body,refreshtoken);CHKERRQ(ierr);
    if (!refresh_token) {ierr = PetscFree(refreshtoken);CHKERRQ(ierr);}
    ierr = PetscStrcat(body,"&grant_type=refresh_token");CHKERRQ(ierr);

    ierr = PetscHTTPSRequest("POST","https://www.box.com/api/oauth2/token",NULL,"application/x-www-form-urlencoded",body,ssl,buff,sizeof(buff));CHKERRQ(ierr);
    ierr = PetscSSLDestroyContext(ctx);CHKERRQ(ierr);
    close(sock);

    ierr   = PetscStrstr(buff,"\"access_token\" : \"",&access);CHKERRQ(ierr);
    if (!access) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"Did not receive access token from Box");
    access += 18;
    ierr   = PetscStrchr(access,'\"',&ctmp);CHKERRQ(ierr);
    if (!ctmp) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"Access token from Box is misformed");
    *ctmp  = 0;
    ierr   = PetscStrncpy(access_token,access,tokensize);CHKERRQ(ierr);
    *ctmp  = '\"';
  }
  PetscFunctionReturn(0);
}

#include <sys/stat.h>

#undef __FUNCT__
#define __FUNCT__ "PetscBoxUpload"
/*@C
     PetscBoxUpload - Loads a file to the Box Drive

     Not collective, only the first process in the MPI_Comm uploads the file

  Input Parameters:
+   comm - MPI communicator
.   access_token - obtained with PetscBoxRefresh(), pass NULL to have PETSc generate one
-   filename - file to upload; if you upload multiple times it will have different names each time on Box Drive

  Options Database:
.  -box_refresh_token   XXX

  Usage Patterns:
    With PETSc option -box_refresh_token  XXX given
    PetscBoxUpload(comm,NULL,filename);        will upload file with no user interaction

    Without PETSc option -box_refresh_token XXX given
    PetscBoxUpload(comm,NULL,filename);        for first use will prompt user to authorize access to Box Drive with their processor

    With PETSc option -box_refresh_token  XXX given
    PetscBoxRefresh(comm,NULL,access_token,sizeof(access_token));
    PetscBoxUpload(comm,access_token,filename);

    With refresh token entered in some way by the user
    PetscBoxRefresh(comm,refresh_token,access_token,sizeof(access_token));
    PetscBoxUpload(comm,access_token,filename);

    PetscBoxAuthorize(comm,access_token,refresh_token,sizeof(access_token));
    PetscBoxUpload(comm,access_token,filename);

.seealso: PetscURLShorten(), PetscBoxAuthorize(), PetscBoxRefresh()

@*/
PetscErrorCode PetscBoxUpload(MPI_Comm comm,const char access_token[],const char filename[])
{
  SSL_CTX        *ctx;
  SSL            *ssl;
  int            sock;
  PetscErrorCode ierr;
  char           head[1024],buff[8*1024],*body,*title;
  PetscMPIInt    rank;
  struct stat    sb;
  size_t         len,blen,rd;
  FILE           *fd;

  PetscFunctionBegin;
  ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
  if (!rank) {
    ierr = PetscStrcpy(head,"Authorization: Bearer ");CHKERRQ(ierr);
    ierr = PetscStrcat(head,access_token);CHKERRQ(ierr);
    ierr = PetscStrcat(head,"\r\n");CHKERRQ(ierr);
    ierr = PetscStrcat(head,"uploadType: multipart\r\n");CHKERRQ(ierr);

    ierr = stat(filename,&sb);
    if (ierr) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_FILE_OPEN,"Unable to stat file: %s",filename);
    len = 1024 + sb.st_size;
    ierr = PetscMalloc1(len,&body);CHKERRQ(ierr);
    ierr = PetscStrcpy(body,"--foo_bar_baz\r\n"
                         "Content-Type: application/json\r\n\r\n"
                         "{"
                         "\"title\": \"");
    ierr = PetscStrcat(body,filename);
    ierr = PetscStrcat(body,"\","
                         "\"mimeType\": \"text.html\","
                         "\"description\": \" a file\""
                         "}\r\n\r\n"
                         "--foo_bar_baz\r\n"
                         "Content-Type: text/html\r\n\r\n");
    ierr = PetscStrlen(body,&blen);CHKERRQ(ierr);
    fd = fopen (filename, "r");
    if (!fd) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_FILE_OPEN,"Unable to open file: %s",filename);
    rd = fread (body+blen, sizeof (unsigned char), sb.st_size, fd);
    if (rd != sb.st_size) SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_FILE_OPEN,"Unable to read entire file: %s %d %d",filename,(int)rd,sb.st_size);
    fclose(fd);
    body[blen + rd] = 0;
    ierr = PetscStrcat(body,"\r\n\r\n"
                            "--foo_bar_baz\r\n");
    ierr = PetscSSLInitializeContext(&ctx);CHKERRQ(ierr);
    ierr = PetscHTTPSConnect("www.boxapis.com",443,ctx,&sock,&ssl);CHKERRQ(ierr);
    ierr = PetscHTTPSRequest("POST","https://www.boxapis.com/upload/drive/v2/files/",head,"multipart/related; boundary=\"foo_bar_baz\"",body,ssl,buff,sizeof(buff));CHKERRQ(ierr);
    ierr = PetscFree(body);CHKERRQ(ierr);
    ierr = PetscSSLDestroyContext(ctx);CHKERRQ(ierr);
    close(sock);
    ierr   = PetscStrstr(buff,"\"title\"",&title);CHKERRQ(ierr);
    if (!title) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Upload of file %s failed",filename);
  }
  PetscFunctionReturn(0);
}