/*****************************************************************
 * gmerlin - a general purpose multimedia framework and applications
 *
 * Copyright (c) 2001 - 2024 Members of the Gmerlin project
 * http://github.com/bplaum
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 * *****************************************************************/



#include <config.h>

#include <gavl/gavl.h>
#include <gavl/metatags.h>
#include <gavl/gavlsocket.h>
#include <gavl/http.h>

#include <gmerlin/http.h>
#include <gmerlin/utils.h>
#include <gmerlin/log.h>

#define LOG_DOMAIN "gmerlin.http"


#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <errno.h>
#include <unistd.h>
#include <pthread.h>


#define META_PROTOCOL   "$PROTOCOL"
#define META_PATH       "$PATH"
#define META_METHOD     "$METHOD"
#define META_STATUS_INT "$STATUS_INT"
#define META_STATUS_STR "$STATUS_STR"
#define META_EMPTY      "$EMPTY"

// Keepalive timeout
#define KA_TIMEOUT (10*GAVL_TIME_SCALE) // 10 Secs

int bg_http_response_write(int fd, gavl_dictionary_t * req)
  {
  int result, len = 0;
  char * line;
  
  line = gavl_http_response_to_string(req, &len);
  
  result = gavl_socket_write_data(fd, (const uint8_t*)line, len);

  if(!result)
    {
    fprintf(stderr, "Writing response failed: %d %d %s\n", len, result, strerror(errno));
    }

  free(line);
  return result;
  }

void bg_http_header_set_empty_var(gavl_dictionary_t * h, const char * name)
  {
  gavl_dictionary_set_string(h, name, META_EMPTY);
  }


int bg_http_response_check_keepalive(gavl_dictionary_t * res)
  {
  const char * protocol;
  const char * var;
  
  protocol = gavl_http_response_get_protocol(res);

  /* Under HTTP/1.1, connections are keep-alive by default */
  if(!strcmp(protocol, "HTTP/1.1"))
    {
    if((var = gavl_dictionary_get_string(res, "Connection")) &&
       !strcasecmp(var, "close"))
      return 0;
    else
      return 1;
    }
  else
    {
    if((var = gavl_dictionary_get_string(res, "Connection")) &&
       !strcasecmp(var, "keep-alive"))
      return 1;
    else
      return 0;
    }
  return 0;
  }

static gavl_io_t * open_io(const char * protocol, const char * host, int port)
  {
  gavl_socket_address_t * addr = NULL;
  int use_tls = 0;
  int fd;
  gavl_io_t * ret = NULL;
  
  if(!strcasecmp(protocol, "https"))
    {
    if(port == -1)
      port = 443;
    
    use_tls = 1;
    }
  else if(strcasecmp(protocol, "http"))
    {
    goto fail;
    }

  if(port == -1)
    port = 80;

  addr = gavl_socket_address_create();
  
  if(!gavl_socket_address_set(addr, host, port, SOCK_STREAM))
    goto fail;
  
  
  if((fd = gavl_socket_connect_inet(addr, 5000)) < 0)
    goto fail;
  
  //  fprintf(stderr, "Request:\n");
  //  gavl_dictionary_dump(&req, 2);

  /* Wrap https */
  
  if(use_tls)
    {
    ret = gavl_io_create_tls_client(fd, host, GAVL_IO_SOCKET_DO_CLOSE);
    }
  else
    {
    ret = gavl_io_create_socket(fd, 30000, GAVL_IO_SOCKET_DO_CLOSE);
    }

  fail:
  if(addr)
    gavl_socket_address_destroy(addr);
  
  return ret;
  }

int bg_http_send_request(const char * url, 
                         int head, const gavl_dictionary_t * vars, gavl_io_t ** io_p)
  {
  gavl_dictionary_t req;

  int ret = 0;
  char * host = NULL;
  char * path = NULL;
  char * protocol = NULL;
  char * request_host = NULL;
  int port = -1;
  //  int status = -1;
  
  gavl_io_t * io = NULL;
  
  gavl_dictionary_init(&req);

  //  fprintf(stderr, "http_get: %s\n", url);
  
  if(!gavl_url_split(url,
                   &protocol,
                   NULL,
                   NULL,
                   &host,
                   &port,
                   &path))
    goto fail;

  /* Keepalive socket */
  if(*io_p)
    io = *io_p;
  else
    io = open_io(protocol, host, port);

  if(!io)
    goto fail;
  
  request_host = bg_url_get_host(host, port);
  
  if(head)
    gavl_http_request_init(&req, "HEAD", path, "HTTP/1.1");
  else
    gavl_http_request_init(&req, "GET", path, "HTTP/1.1");

  gavl_dictionary_set_string(&req, "Host", request_host);
  gavl_dictionary_set_string(&req, "Connection", "Close");

  if(vars)
    gavl_dictionary_merge2(&req, vars);
  
  if(!gavl_http_request_write(io, &req))
    goto fail;


  if(io_p)
    {
    *io_p = io;
    io = NULL;
    }
  
  ret = 1;
  
  fail:

  if(io)
    gavl_io_destroy(io);
  
  return ret;
  }

int bg_http_read_response(gavl_io_t * io,
                          char ** redirect,
                          gavl_dictionary_t * res)
  {
  int ret = 0;
  int status;
  

  if(!gavl_http_response_read(io, res))
    {
    gavl_log(GAVL_LOG_ERROR, LOG_DOMAIN, "Reading response failed");
    goto fail;
    }
  
  status = gavl_http_response_get_status_int(res);

  if(status == 200) // Success
    {
    if(!gavl_dictionary_get_string_i(res, "Content-Type")) // No mimetype
      {
      gavl_log(GAVL_LOG_ERROR, LOG_DOMAIN, "No mimetype given");
      goto fail;
      }
    ret = 1;
    }
  else if((status >= 300) && (status < 400)) // Redirection
    {
    *redirect = gavl_strdup(gavl_dictionary_get_string_i(res, "Location"));
    if(!(*redirect))
      {
      gavl_log(GAVL_LOG_ERROR, LOG_DOMAIN,
             "No location for redirection");
      goto fail;
      }
    ret = 1;
    }
  else // Failure
    {
    gavl_log(GAVL_LOG_ERROR, LOG_DOMAIN, "Downloading failed: %d %s",  
           gavl_http_response_get_status_int(res),
           gavl_http_response_get_status_str(res));
    }

  
  fail:
  

  return ret;
  
  }

int bg_http_get_range(const char * url, gavl_buffer_t * ret, gavl_dictionary_t * dict,
                      int64_t offset, int64_t size)
  {
  gavl_io_t * io;
  io = gavl_http_client_create();

  if((offset > 0) || (size > 0))
    {
    if(size <= 0)
      gavl_http_client_set_range(io, offset, -1);
    else
      gavl_http_client_set_range(io, offset, offset + size);
    }

  gavl_http_client_set_response_body(io, ret);
  
  if(!gavl_http_client_open(io, "GET", url))
    return 0;

  if(dict)
    {
    const gavl_dictionary_t * resp;
    resp = gavl_http_client_get_response(io);
    gavl_dictionary_set_string(dict, GAVL_META_MIMETYPE,
                               gavl_dictionary_get_string_i(resp, "Content-Type"));
    }
  gavl_io_destroy(io);
  return 1;
  }

int bg_http_get(const char * url, gavl_buffer_t * buf, gavl_dictionary_t * dict)
  {
  return bg_http_get_range(url, buf, dict, 0, 0);
  }

#define BYTES_TO_READ (10*1024)

char * bg_http_download(const char * url, const char * out_base)
  {
  gavl_io_t * io;
  
  int ret = 0;
  const char * pos1;
  const char * pos2;
  
  char * extension = NULL;
  char * filename = NULL;
  gavl_buffer_t  buf;
  const gavl_dictionary_t * res;
  FILE * out = NULL;
  int64_t bytes_read;
  
  io = gavl_http_client_create();
  
  //  gavl_dictionary_init(&dict);
  gavl_buffer_init(&buf);

  /* */
  
  //  if(!bg_http_get(url, &buf, &dict))
  //    goto fail;
  
  if(!gavl_http_client_open(io, "GET", url))
    goto fail;

  res = gavl_http_client_get_response(io);
  
  /* Figure out extension */
  if((pos1 = strrchr(url, '.')))
    {
    pos1++;
    
    if((pos2 = strchr(url, '?')))
      extension = gavl_strndup(pos1, pos2);
    else
      extension = gavl_strdup(pos1);

    if(!bg_ext_to_mimetype(extension))
      {
      free(extension);
      extension = NULL;
      }
    }

  if(!extension)
    {
    if((pos1 = gavl_dictionary_get_string_i(res, "Content-Type")))
      extension = gavl_strdup(bg_mimetype_to_ext(pos1));
    }

  if(!extension)
    {
    gavl_log(GAVL_LOG_ERROR, LOG_DOMAIN, "Couldn't download %s, no suitable extension found", url);
    goto fail;
    }

  filename = gavl_sprintf("%s.%s", out_base, extension);

  /* TODO: Download */
  
  gavl_buffer_alloc(&buf, BYTES_TO_READ);

  out = fopen(filename, "w");

  bytes_read = 0;
  
  while(1)
    {
    buf.len = gavl_io_read_data(io, buf.buf, BYTES_TO_READ);

    /* Read error */
    if(buf.len < 0)
      goto fail;
    
    if(buf.len > 0)
      {
      /* Write error */
      if(fwrite(buf.buf, 1, buf.len, out) < buf.len)
        goto fail;
      bytes_read += buf.len;
      }
    
    /* EOF */
    if(buf.len < BYTES_TO_READ)
      break;
    }
  
  
  //  bg_write_file(filename, buf.buf, buf.len);
  gavl_log(GAVL_LOG_INFO, LOG_DOMAIN, "Downloaded %s (%"PRId64" bytes)", url, bytes_read);
  
  ret = 1;
  fail:

  if(out)
    fclose(out);
  
  if(!ret)
    {
    free(filename);
    filename = NULL;
    }

  if(extension)
    free(extension);
  
  gavl_buffer_free(&buf);
  return filename;
  }


int bg_http_write_data(gavl_io_t * io, const uint8_t * data, int len, int chunked)
  {
  if(chunked)
    {
    char buf[128];
    int slen;
    int result;

    /* Length in hex + \r\n */
    snprintf(buf, 128, "%x\r\n", len);
    slen = strlen(buf);
    if(gavl_io_write_data(io, (uint8_t*)buf, slen) < slen)
      return 0;
    
    /* Chunk */
    if((result = gavl_io_write_data(io, data, len) < len))
      return 0;

    /* Trailing \r\n */
    strncpy(buf, "\r\n", 128);
    if(gavl_io_write_data(io, (uint8_t*)buf, 2) < 2)
      return 0;
    return result;
    }
  else
    return gavl_io_write_data(io, data, len);
  }

void bg_http_flush(gavl_io_t * io, int chunked)
  {
  if(chunked)
    {
    char buf[128];
    strncpy(buf, "0\r\n\r\n", 128);
    gavl_io_write_data(io, (uint8_t*)buf, 5);
    }
  }

struct bg_http_keepalive_s
  {
  struct
    {
    int fd;
    gavl_time_t last_active;
    } * sockets;

  int num_sockets;
  int max_sockets;
  pthread_mutex_t mutex;
  };

bg_http_keepalive_t * bg_http_keepalive_create(int max_sockets)
  {
  bg_http_keepalive_t * ret = calloc(1, sizeof(*ret));
  ret->sockets = malloc(max_sockets * sizeof(*ret->sockets));
  pthread_mutex_init(&ret->mutex, NULL);
  ret->max_sockets = max_sockets;
  return ret;
  }

void bg_http_keepalive_destroy(bg_http_keepalive_t * ka)
  {
  int i;
  for(i = 0; i < ka->num_sockets; i++)
    close(ka->sockets[i].fd);
  
  if(ka->sockets)
    free(ka->sockets);

  pthread_mutex_destroy(&ka->mutex);
  
  free(ka);
  }

void bg_http_keepalive_push(bg_http_keepalive_t * ka, int fd,
                            gavl_time_t current_time)
  {
  //  fprintf(stderr, "keepalive_push %d %d %d\n", ka->num_sockets, ka->max_sockets, fd);

  pthread_mutex_lock(&ka->mutex);

  if(ka->num_sockets == ka->max_sockets)
    {
    close(ka->sockets[ka->num_sockets-1].fd);
    ka->num_sockets--;
    }

  if(ka->num_sockets)
    memmove(ka->sockets + 1,  ka->sockets, sizeof(*ka->sockets) * ka->num_sockets);
  
  ka->sockets[0].fd = fd;
  ka->sockets[0].last_active = current_time;
  ka->num_sockets++;
  
  pthread_mutex_unlock(&ka->mutex);
  }

int bg_http_keepalive_accept
(bg_http_keepalive_t * ka, gavl_time_t current_time, int * idx)
  {
  int i;
  int ret = -1;

  pthread_mutex_lock(&ka->mutex);
    
  while(*idx < ka->num_sockets)
    {
    //    
    if(gavl_fd_can_read(ka->sockets[*idx].fd, 0))
      {
      ret = ka->sockets[*idx].fd;

      if(*idx < ka->num_sockets - 1)
        memmove(ka->sockets + (*idx), ka->sockets + (*idx) + 1,
                sizeof(*ka->sockets) * (ka->num_sockets - 1 - (*idx)));
      ka->num_sockets--;
      break;
      }
    (*idx)++;
    }

  /* Remove outdated sockets */
  i = ka->num_sockets - 1;

  while(i >= 0)
    {
    if(current_time - ka->sockets[i].last_active > KA_TIMEOUT)
      {
      close(ka->sockets[i].fd);
      ka->num_sockets--;
      }      
    else
      break;
    i--;
    }
  
  pthread_mutex_unlock(&ka->mutex);
  return ret;
  }