#include <petscwebclient.h>
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
#pragma gcc diagnostic ignored "-Wdeprecated-declarations"

static BIO *bio_err = NULL;

#define PASSWORD "password"

#if defined(PETSC_USE_SSL_CERTIFICATE)
static int password_cb(char *buf,int num, int rwflag,void *userdata)
{
  if (num < strlen(PASSWORD)+1) return(0);
  strcpy(buf,PASSWORD);
  return(strlen(PASSWORD));
}
#endif

static void sigpipe_handle(int x)
{
}

/*@C
    PetscSSLInitializeContext - Set up an SSL context suitable for initiating HTTPS requests.

    Output Parameter:
.   octx - the SSL_CTX to be passed to PetscHTTPSConnect

    Level: advanced

    If PETSc was ./configure -with-ssl-certificate requires the user have created a self-signed certificate with
$    saws/CA.pl  -newcert  (using the passphrase of password)
$    cat newkey.pem newcert.pem > sslclient.pem

    and put the resulting file in either the current directory (with the application) or in the home directory. This seems kind of
    silly but it was all I could figure out.

.seealso: `PetscSSLDestroyContext()`, `PetscHTTPSConnect()`, `PetscHTTPSRequest()`

@*/
PetscErrorCode PetscSSLInitializeContext(SSL_CTX **octx)
{
    SSL_CTX        *ctx;
#if defined(PETSC_USE_SSL_CERTIFICATE)
    char           keyfile[PETSC_MAX_PATH_LEN];
    PetscBool      exists;
#endif

    PetscFunctionBegin;
    if (!bio_err) {
      SSL_library_init();
      SSL_load_error_strings();
      bio_err = BIO_new_fp(stderr,BIO_NOCLOSE);
    }

    /* Set up a SIGPIPE handler */
    signal(SIGPIPE,sigpipe_handle);

/* suggested at https://mta.openssl.org/pipermail/openssl-dev/2015-May/001449.html */
#if (OPENSSL_VERSION_NUMBER >= 0x10100000L)
    ctx  = SSL_CTX_new(TLS_client_method());
#else
    ctx  = SSL_CTX_new(SSLv23_client_method());
#endif
    SSL_CTX_set_mode(ctx,SSL_MODE_AUTO_RETRY);

#if defined(PETSC_USE_SSL_CERTIFICATE)
    /* Locate keyfile */
    PetscCall(PetscStrcpy(keyfile,"sslclient.pem"));
    PetscCall(PetscTestFile(keyfile,'r',&exists));
    if (!exists) {
      PetscCall(PetscGetHomeDirectory(keyfile,PETSC_MAX_PATH_LEN));
      PetscCall(PetscStrcat(keyfile,"/"));
      PetscCall(PetscStrcat(keyfile,"sslclient.pem"));
      PetscCall(PetscTestFile(keyfile,'r',&exists));
      PetscCheck(exists,PETSC_COMM_SELF,PETSC_ERR_FILE_OPEN,"Unable to locate sslclient.pem file in current directory or home directory");
    }

    /* Load our keys and certificates*/
    PetscCheck(SSL_CTX_use_certificate_chain_file(ctx,keyfile),PETSC_COMM_SELF,PETSC_ERR_FILE_OPEN,"Cannot read certificate file");

    SSL_CTX_set_default_passwd_cb(ctx,password_cb);
    PetscCheck(SSL_CTX_use_PrivateKey_file(ctx,keyfile,SSL_FILETYPE_PEM),PETSC_COMM_SELF,PETSC_ERR_FILE_OPEN,"Cannot read key file");
#endif

    *octx = ctx;
    PetscFunctionReturn(0);
}

/*@C
     PetscSSLDestroyContext - frees a SSL_CTX obtained with PetscSSLInitializeContext()

     Input Parameter:
.     ctx - the SSL_CTX

    Level: advanced

.seealso: `PetscSSLInitializeContext()`, `PetscHTTPSConnect()`
@*/
PetscErrorCode PetscSSLDestroyContext(SSL_CTX *ctx)
{
  PetscFunctionBegin;
  SSL_CTX_free(ctx);
  PetscFunctionReturn(0);
}

static PetscErrorCode PetscHTTPBuildRequest(const char type[],const char url[],const char header[],const char ctype[],const char body[],char **outrequest)
{
  char           *request=0;
  char           contentlength[40],contenttype[80],*path,*host;
  size_t         request_len,headlen,bodylen,contentlen,pathlen,hostlen,typelen,contenttypelen = 0;
  PetscBool      flg;

  PetscFunctionBegin;
  PetscCall(PetscStrallocpy(url,&host));
  PetscCall(PetscStrchr(host,'/',&path));
  PetscCheck(path,PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"url must contain / it is %s",url);
  *path = 0;
  PetscCall(PetscStrlen(host,&hostlen));

  PetscCall(PetscStrchr(url,'/',&path));
  PetscCall(PetscStrlen(path,&pathlen));

  if (header) {
    PetscCall(PetscStrendswith(header,"\r\n",&flg));
    PetscCheck(flg,PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"header must end with \\r\\n");
  }

  PetscCall(PetscStrlen(type,&typelen));
  if (ctype) {
    PetscCall(PetscSNPrintf(contenttype,80,"Content-Type: %s\r\n",ctype));
    PetscCall(PetscStrlen(contenttype,&contenttypelen));
  }
  PetscCall(PetscStrlen(header,&headlen));
  PetscCall(PetscStrlen(body,&bodylen));
  PetscCall(PetscSNPrintf(contentlength,40,"Content-Length: %d\r\n\r\n",(int)bodylen));
  PetscCall(PetscStrlen(contentlength,&contentlen));

  /* Now construct our HTTP request */
  request_len = typelen + 1 + pathlen + hostlen + 100 + headlen + contenttypelen + contentlen + bodylen + 1;
  PetscCall(PetscMalloc1(request_len,&request));
  PetscCall(PetscStrcpy(request,type));
  PetscCall(PetscStrcat(request," "));
  PetscCall(PetscStrcat(request,path));
  PetscCall(PetscStrcat(request," HTTP/1.1\r\nHost: "));
  PetscCall(PetscStrcat(request,host));
  PetscCall(PetscFree(host));
  PetscCall(PetscStrcat(request,"\r\nUser-Agent:PETScClient\r\n"));
  PetscCall(PetscStrcat(request,header));
  if (ctype) {
    PetscCall(PetscStrcat(request,contenttype));
  }
  PetscCall(PetscStrcat(request,contentlength));
  PetscCall(PetscStrcat(request,body));
  PetscCall(PetscStrlen(request,&request_len));
  PetscCall(PetscInfo(NULL,"HTTPS request follows: \n%s\n",request));

  *outrequest = request;
  PetscFunctionReturn(0);
}

/*@C
     PetscHTTPSRequest - Send a request to an HTTPS server

   Input Parameters:
+   type - either "POST" or "GET"
.   url -  URL of request host/path
.   header - additional header information, may be NULL
.   ctype - data type of body, for example application/json
.   body - data to send to server
.   ssl - obtained with PetscHTTPSConnect()
-   buffsize - size of buffer

   Output Parameter:
.   buff - everything returned from server

    Level: advanced

.seealso: `PetscHTTPRequest()`, `PetscHTTPSConnect()`, `PetscSSLInitializeContext()`, `PetscSSLDestroyContext()`, `PetscPullJSONValue()`

@*/
PetscErrorCode PetscHTTPSRequest(const char type[],const char url[],const char header[],const char ctype[],const char body[],SSL *ssl,char buff[],size_t buffsize)
{
  char           *request;
  int            r;
  size_t         request_len,len;
  PetscBool      foundbody = PETSC_FALSE;

  PetscFunctionBegin;
  PetscCall(PetscHTTPBuildRequest(type,url,header,ctype,body,&request));
  PetscCall(PetscStrlen(request,&request_len));

  r = SSL_write(ssl,request,(int)request_len);
  switch (SSL_get_error(ssl,r)) {
    case SSL_ERROR_NONE:
      PetscCheck(request_len == (size_t)r,PETSC_COMM_SELF,PETSC_ERR_LIB,"Incomplete write to SSL socket");
      break;
    default:
      SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"SSL socket write problem");
  }

  /* Now read the server's response, globus sends it in two chunks hence must read a second time if needed */
  PetscCall(PetscArrayzero(buff,buffsize));
  len       = 0;
  foundbody = PETSC_FALSE;
  do {
    char   *clen;
    int    cl;
    size_t nlen;

    r = SSL_read(ssl,buff+len,(int)buffsize);
    len += r;
    switch (SSL_get_error(ssl,r)) {
    case SSL_ERROR_NONE:
      break;
    case SSL_ERROR_ZERO_RETURN:
      foundbody = PETSC_TRUE;
      SSL_shutdown(ssl);
      break;
    case SSL_ERROR_SYSCALL:
      foundbody = PETSC_TRUE;
      break;
    default:
      SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"SSL read problem");
    }

    PetscCall(PetscStrstr(buff,"Content-Length: ",&clen));
    if (clen) {
      clen += 15;
      sscanf(clen,"%d",&cl);
      if (!cl) foundbody = PETSC_TRUE;
      else {
        PetscCall(PetscStrstr(buff,"\r\n\r\n",&clen));
        if (clen) {
          PetscCall(PetscStrlen(clen,&nlen));
          if (nlen-4 == (size_t) cl) foundbody = PETSC_TRUE;
        }
      }
    } else {
      /* if no content length than must leave because you don't know if you can read again */
      foundbody = PETSC_TRUE;
    }
  } while (!foundbody);
  PetscCall(PetscInfo(NULL,"HTTPS result follows: \n%s\n",buff));

  SSL_free(ssl);
  PetscCall(PetscFree(request));
  PetscFunctionReturn(0);
}

/*@C
     PetscHTTPRequest - Send a request to an HTTP server

   Input Parameters:
+   type - either "POST" or "GET"
.   url -  URL of request host/path
.   header - additional header information, may be NULL
.   ctype - data type of body, for example application/json
.   body - data to send to server
.   sock - obtained with PetscOpenSocket()
-   buffsize - size of buffer

   Output Parameter:
.   buff - everything returned from server

    Level: advanced

.seealso: `PetscHTTPSRequest()`, `PetscOpenSocket()`, `PetscHTTPSConnect()`, `PetscPullJSONValue()`
@*/
PetscErrorCode PetscHTTPRequest(const char type[],const char url[],const char header[],const char ctype[],const char body[],int sock,char buff[],size_t buffsize)
{
  char           *request;
  size_t         request_len;

  PetscFunctionBegin;
  PetscCall(PetscHTTPBuildRequest(type,url,header,ctype,body,&request));
  PetscCall(PetscStrlen(request,&request_len));

  PetscCall(PetscBinaryWrite(sock,request,request_len,PETSC_CHAR));
  PetscCall(PetscFree(request));
  PetscBinaryRead(sock,buff,buffsize,NULL,PETSC_CHAR);
  buff[buffsize-1] = 0;
  PetscCall(PetscInfo(NULL,"HTTP result follows: \n%s\n",buff));
  PetscFunctionReturn(0);
}

/*@C
      PetscHTTPSConnect - connect to a HTTPS server

    Input Parameters:
+    host - the name of the machine hosting the HTTPS server
.    port - the port number where the server is hosting, usually 443
-    ctx - value obtained with PetscSSLInitializeContext()

    Output Parameters:
+    sock - socket to connect
-    ssl - the argument passed to PetscHTTPSRequest()

    Level: advanced

.seealso: `PetscOpenSocket()`, `PetscHTTPSRequest()`, `PetscSSLInitializeContext()`
@*/
PetscErrorCode PetscHTTPSConnect(const char host[],int port,SSL_CTX *ctx,int *sock,SSL **ssl)
{
  BIO            *sbio;

  PetscFunctionBegin;
  /* Connect the TCP socket*/
  PetscCall(PetscOpenSocket(host,port,sock));

  /* Connect the SSL socket */
  *ssl = SSL_new(ctx);
  sbio = BIO_new_socket(*sock,BIO_NOCLOSE);
  SSL_set_bio(*ssl,sbio,sbio);
  PetscCheck(SSL_connect(*ssl) > 0,PETSC_COMM_SELF,PETSC_ERR_LIB,"SSL connect error");
  PetscFunctionReturn(0);
}

/*@C
     PetscPullJSONValue - Given a JSON response containing the substring with "key" : "value"  where there may or not be spaces around the : returns the value.

    Input Parameters:
+    buff - the char array containing the possible values
.    key - the key of the requested value
-    valuelen - the length of the array to contain the value associated with the key

    Output Parameters:
+    value - the value obtained
-    found - flag indicating if the value was found in the buff

    Level: advanced

@*/
PetscErrorCode PetscPullJSONValue(const char buff[],const char key[],char value[],size_t valuelen,PetscBool *found)
{
  char           *v,*w;
  char           work[256];
  size_t         len;

  PetscFunctionBegin;
  PetscCall(PetscStrcpy(work,"\""));
  PetscCall(PetscStrlcat(work,key,sizeof(work)));
  PetscCall(PetscStrcat(work,"\":"));
  PetscCall(PetscStrstr(buff,work,&v));
  PetscCall(PetscStrlen(work,&len));
  if (v) {
    v += len;
  } else {
    work[len++-1] = 0;
    PetscCall(PetscStrcat(work," :"));
    PetscCall(PetscStrstr(buff,work,&v));
    if (!v) {
      *found = PETSC_FALSE;
      PetscFunctionReturn(0);
    }
    v += len;
  }
  PetscCall(PetscStrchr(v,'\"',&v));
  if (!v) {
    *found = PETSC_FALSE;
    PetscFunctionReturn(0);
  }
  PetscCall(PetscStrchr(v+1,'\"',&w));
  if (!w) {
    *found = PETSC_FALSE;
    PetscFunctionReturn(0);
  }
  *found = PETSC_TRUE;
  PetscCall(PetscStrncpy(value,v+1,PetscMin((size_t)(w-v),valuelen)));
  PetscFunctionReturn(0);
}

#include <ctype.h>

/*@C
    PetscPushJSONValue -  Puts a "key" : "value" pair onto a string

    Input Parameters:
+   buffer - the char array where the value will be put
.   key - the key value to be set
.   value - the value associated with the key
-   bufflen - the size of the buffer (currently ignored)

    Level: advanced

    Notes:
    Ignores lengths so can cause buffer overflow
@*/
PetscErrorCode PetscPushJSONValue(char buff[],const char key[],const char value[],size_t bufflen)
{
  size_t         len;
  PetscBool      special;

  PetscFunctionBegin;
  PetscCall(PetscStrcmp(value,"null",&special));
  if (!special) {
    PetscCall(PetscStrcmp(value,"true",&special));
  }
  if (!special) {
    PetscCall(PetscStrcmp(value,"false",&special));
  }
  if (!special) {
    PetscInt i;

    PetscCall(PetscStrlen(value,&len));
    special = PETSC_TRUE;
    for (i=0; i<(int)len; i++) {
      if (!isdigit(value[i])) {
        special = PETSC_FALSE;
        break;
      }
    }
  }

  PetscCall(PetscStrcat(buff,"\""));
  PetscCall(PetscStrcat(buff,key));
  PetscCall(PetscStrcat(buff,"\":"));
  if (!special) {
    PetscCall(PetscStrcat(buff,"\""));
  }
  PetscCall(PetscStrcat(buff,value));
  if (!special) {
    PetscCall(PetscStrcat(buff,"\""));
  }
  PetscFunctionReturn(0);
}