
#include "config.h"

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

#include "mp_msg.h"
#include "stream.h"
#include "help_mp.h"
#include "../m_option.h"
#include "../m_struct.h"

static struct stream_priv_s {
  char* filename;
} stream_priv_dflts = {
  NULL
};

#define ST_OFF(f) M_ST_OFF(struct stream_priv_s,f)
/// URL definition
static m_option_t stream_opts_fields[] = {
  {"filename", ST_OFF(filename), CONF_TYPE_STRING, 0, 0 ,0, NULL},
  { NULL, NULL, 0, 0, 0, 0,  NULL }
};
static struct m_struct_st stream_opts = {
  "file",
  sizeof(struct stream_priv_s),
  &stream_priv_dflts,
  stream_opts_fields
};  

static int fill_buffer(stream_t *s, char* buffer, int max_len){
  int r = read(s->fd,buffer,max_len);
  return (r <= 0) ? -1 : r;
}

static int write_buffer(stream_t *s, char* buffer, int len) {
  int r = write(s->fd,buffer,len);
  return (r <= 0) ? -1 : r;
}

static int seek(stream_t *s,off_t newpos) {
  s->pos = newpos;
  if(lseek(s->fd,s->pos,SEEK_SET)<0) {
    s->eof=1;
    return 0;
  }
  return 1;
}

static int seek_forward(stream_t *s,off_t newpos) {
  if(newpos<s->pos){
    mp_msg(MSGT_STREAM,MSGL_INFO,"Cannot seek backward in linear streams!\n");
    return 0;
  }
  while(s->pos<newpos){
    int len=s->fill_buffer(s,s->buffer,STREAM_BUFFER_SIZE);
    if(len<=0){ s->eof=1; s->buf_pos=s->buf_len=0; break; } // EOF
    s->buf_pos=0;
    s->buf_len=len;
    s->pos+=len;
  }
  return 1;
}

static int open_f(stream_t *stream,int mode, void* opts, int* file_format) {
  int f;
  mode_t m = 0;
  off_t len;
  struct stream_priv_s* p = (struct stream_priv_s*)opts;

  if(mode == STREAM_READ)
    m = O_RDONLY;
  else if(mode == STREAM_WRITE)
    m = O_WRONLY;
  else {
    mp_msg(MSGT_OPEN,MSGL_ERR, "[file] Unknown open mode %d\n",mode);
    m_struct_free(&stream_opts,opts);
    return STREAM_UNSUPORTED;
  }

  if(!p->filename) {
    mp_msg(MSGT_OPEN,MSGL_ERR, "[file] No filename\n");
    m_struct_free(&stream_opts,opts);
    return STREAM_ERROR;
  }

#if defined(__CYGWIN__)|| defined(__MINGW32__)
  m |= O_BINARY;
#endif    

  if(!strcmp(p->filename,"-")){
    if(mode == STREAM_READ) {
      // read from stdin
      mp_msg(MSGT_OPEN,MSGL_INFO,MSGTR_ReadSTDIN);
      f=0; // 0=stdin
    } else {
      mp_msg(MSGT_OPEN,MSGL_INFO,"Writing to stdout\n");
      f=1;
    }
  } else {
    f=open(p->filename,m);
    if(f<0) {
      mp_msg(MSGT_OPEN,MSGL_ERR,MSGTR_FileNotFound,p->filename);
      m_struct_free(&stream_opts,opts);
      return STREAM_ERROR;
    }
  }

  len=lseek(f,0,SEEK_END); lseek(f,0,SEEK_SET);
  if(len == -1) {
    stream->seek = seek_forward;
    stream->type = STREAMTYPE_STREAM; // Must be move to STREAMTYPE_FILE
    stream->flags |= STREAM_SEEK_FW;
  } else if(len >= 0) {
    stream->seek = seek;
    stream->end_pos = len;
    stream->type = STREAMTYPE_FILE;
  }

#ifdef _LARGEFILE_SOURCE
  mp_msg(MSGT_OPEN,MSGL_V,"[file] File size is %lld bytes\n", (long long)len);
#else
  mp_msg(MSGT_OPEN,MSGL_V,"[file] File size is %u bytes\n", (unsigned int)len);
#endif 

  stream->fd = f;
  stream->fill_buffer = fill_buffer;
  stream->write_buffer = write_buffer;

  m_struct_free(&stream_opts,opts);
  return STREAM_OK;
}

stream_info_t stream_info_file = {
  "File",
  "file",
  "Albeu",
  "based on the code from ??? (probably Arpi)",
  open_f,
  { "file", "", NULL },
  &stream_opts,
  1 // Urls are an option string
};
