#include "minimal_multipart_parser.h"
#include <llhttp.h>
#include <libowfat/buffer.h>
#include <libowfat/errmsg.h>
#include <unistd.h>

#undef die
#undef diesys
#define die(n,...) \
  do {                                                     \
    carp(__VA_ARGS__,(char*)0);                          \
    dieservererr(n,__VA_ARGS__,(char*)0);                    \
  } while(0)
#define diesys(n,...) \
  do {                                                     \
    carpsys(__VA_ARGS__,(char*)0);                          \
    dieservererr(n,__VA_ARGS__,(char*)0);                    \
  } while(0)

static buffer topipe;

static void dieservererr(int n,char *args,...)
{
  char *header = "HTTP/1.0 500 Internal Server Error\r\n"
    "Connection: close\r\n"
    "\r\n";
  msg(header,args);
  exit(n);
}

static void dienodata(void)
{
  char *header = "HTTP/1.0 400 Bad Request\r\n"
    "Connection: close\r\n"
    "\r\n";
  msg(header,"HTTP multipart/form-data field expected.");
  exit(100);
}

static void run(void) {
  MinimalMultipartParserContext ctx = {0};
  unsigned int ev;
  int r;
  char c;

  for (;;) {
    r = buffer_getc(buffer_0,&c);
    if (r==0) break;
    if (r<0) diesys(111,"read stdin");

    ev = minimal_multipart_parser_process(&ctx,c);
    if (ev==MultipartParserEvent_DataBufferAvailable) {
      if (buffer_put(&topipe,
          minimal_multipart_parser_get_data_buffer(&ctx),
          minimal_multipart_parser_get_data_size(&ctx))<0
      ) diesys(111,"write to pipe");
    } else if (ev==MultipartParserEvent_DataStreamCompleted)
      break;
  }

  if (!minimal_multipart_parser_is_file_received(&ctx))
    dienodata();
  if (buffer_flush(&topipe)<0)
    diesys(111,"flush pipe write");
}

int main(int argc,char **argv)
{
  char buf[4096];
  int pipefds[2];
  argc--; argv++;
  (void)argc;

  if (pipe(pipefds)<0) diesys(111,"pipe");
  buffer_init_write(&topipe,pipefds[1],buf,sizeof buf);

  run();
  if (dup2(pipefds[0],0)<0) diesys(111,"dup2");
  execvp(*argv,argv);
  diesys(111,"exec ",*argv);
}