/*
  * Copyright (c) 2014 Lukasz Marek <lukasz.m.luki@gmail.com>
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg 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
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include <libsmbclient.h>
 #include "libavutil/avstring.h"
 #include "libavutil/opt.h"
 #include "avformat.h"
 #include "internal.h"
 #include "url.h"
 
 typedef struct {
     const AVClass *class;
     SMBCCTX *ctx;

     int dh;

     int fd;
     int64_t filesize;
     int trunc;
     int timeout;
     char *workgroup;
 } LIBSMBContext;
 
 static void libsmbc_get_auth_data(SMBCCTX *c, const char *server, const char *share,
                                   char *workgroup, int workgroup_len,
                                   char *username, int username_len,
                                   char *password, int password_len)
 {
     /* Do nothing yet. Credentials are passed via url.
      * Callback must exists, there might be a segmentation fault otherwise. */
 }
 
 static av_cold int libsmbc_connect(URLContext *h)
 {
     LIBSMBContext *libsmbc = h->priv_data;
 
     libsmbc->ctx = smbc_new_context();
     if (!libsmbc->ctx) {

         int ret = AVERROR(errno);

         av_log(h, AV_LOG_ERROR, "Cannot create context: %s.\n", strerror(errno));

         return ret;

     }
     if (!smbc_init_context(libsmbc->ctx)) {

         int ret = AVERROR(errno);

         av_log(h, AV_LOG_ERROR, "Cannot initialize context: %s.\n", strerror(errno));

         return ret;

     }
     smbc_set_context(libsmbc->ctx);
 
     smbc_setOptionUserData(libsmbc->ctx, h);
     smbc_setFunctionAuthDataWithContext(libsmbc->ctx, libsmbc_get_auth_data);
 
     if (libsmbc->timeout != -1)
         smbc_setTimeout(libsmbc->ctx, libsmbc->timeout);
     if (libsmbc->workgroup)
         smbc_setWorkgroup(libsmbc->ctx, libsmbc->workgroup);
 
     if (smbc_init(NULL, 0) < 0) {

         int ret = AVERROR(errno);

         av_log(h, AV_LOG_ERROR, "Initialization failed: %s\n", strerror(errno));

         return ret;

     }
     return 0;
 }
 
 static av_cold int libsmbc_close(URLContext *h)
 {
     LIBSMBContext *libsmbc = h->priv_data;
     if (libsmbc->fd >= 0) {
         smbc_close(libsmbc->fd);
         libsmbc->fd = -1;
     }
     if (libsmbc->ctx) {
         smbc_free_context(libsmbc->ctx, 1);
         libsmbc->ctx = NULL;
     }
     return 0;
 }
 
 static av_cold int libsmbc_open(URLContext *h, const char *url, int flags)
 {
     LIBSMBContext *libsmbc = h->priv_data;
     int access, ret;
     struct stat st;
 
     libsmbc->fd = -1;
     libsmbc->filesize = -1;
 
     if ((ret = libsmbc_connect(h)) < 0)
         goto fail;
 
     if ((flags & AVIO_FLAG_WRITE) && (flags & AVIO_FLAG_READ)) {
         access = O_CREAT | O_RDWR;
         if (libsmbc->trunc)
             access |= O_TRUNC;
     } else if (flags & AVIO_FLAG_WRITE) {
         access = O_CREAT | O_WRONLY;
         if (libsmbc->trunc)
             access |= O_TRUNC;
     } else
         access = O_RDONLY;
 
     /* 0666 = -rw-rw-rw- = read+write for everyone, minus umask */
     if ((libsmbc->fd = smbc_open(url, access, 0666)) < 0) {
         ret = AVERROR(errno);
         av_log(h, AV_LOG_ERROR, "File open failed: %s\n", strerror(errno));
         goto fail;
     }
 
     if (smbc_fstat(libsmbc->fd, &st) < 0)
         av_log(h, AV_LOG_WARNING, "Cannot stat file: %s\n", strerror(errno));
     else
         libsmbc->filesize = st.st_size;
 
     return 0;
   fail:
     libsmbc_close(h);
     return ret;
 }
 
 static int64_t libsmbc_seek(URLContext *h, int64_t pos, int whence)
 {
     LIBSMBContext *libsmbc = h->priv_data;
     int64_t newpos;
 
     if (whence == AVSEEK_SIZE) {
         if (libsmbc->filesize == -1) {
             av_log(h, AV_LOG_ERROR, "Error during seeking: filesize is unknown.\n");
             return AVERROR(EIO);
         } else
             return libsmbc->filesize;
     }
 
     if ((newpos = smbc_lseek(libsmbc->fd, pos, whence)) < 0) {
         int err = errno;
         av_log(h, AV_LOG_ERROR, "Error during seeking: %s\n", strerror(err));
         return AVERROR(err);
     }
 
     return newpos;
 }
 
 static int libsmbc_read(URLContext *h, unsigned char *buf, int size)
 {
     LIBSMBContext *libsmbc = h->priv_data;
     int bytes_read;
 
     if ((bytes_read = smbc_read(libsmbc->fd, buf, size)) < 0) {

         int ret = AVERROR(errno);

         av_log(h, AV_LOG_ERROR, "Read error: %s\n", strerror(errno));

         return ret;

     }
 

     return bytes_read ? bytes_read : AVERROR_EOF;

 }
 
 static int libsmbc_write(URLContext *h, const unsigned char *buf, int size)
 {
     LIBSMBContext *libsmbc = h->priv_data;
     int bytes_written;
 
     if ((bytes_written = smbc_write(libsmbc->fd, buf, size)) < 0) {

         int ret = AVERROR(errno);

         av_log(h, AV_LOG_ERROR, "Write error: %s\n", strerror(errno));

         return ret;

     }
 
     return bytes_written;
 }
 

 static int libsmbc_open_dir(URLContext *h)
 {
     LIBSMBContext *libsmbc = h->priv_data;
     int ret;
 
     if ((ret = libsmbc_connect(h)) < 0)
         goto fail;
 
     if ((libsmbc->dh = smbc_opendir(h->filename)) < 0) {
         ret = AVERROR(errno);
         av_log(h, AV_LOG_ERROR, "Error opening dir: %s\n", strerror(errno));
         goto fail;
     }
 
     return 0;
 
   fail:
     libsmbc_close(h);
     return ret;
 }
 
 static int libsmbc_read_dir(URLContext *h, AVIODirEntry **next)
 {
     LIBSMBContext *libsmbc = h->priv_data;
     AVIODirEntry *entry;
     struct smbc_dirent *dirent = NULL;
     char *url = NULL;
     int skip_entry;
 
     *next = entry = ff_alloc_dir_entry();
     if (!entry)
         return AVERROR(ENOMEM);
 
     do {
         skip_entry = 0;
         dirent = smbc_readdir(libsmbc->dh);
         if (!dirent) {
             av_freep(next);
             return 0;
         }
         switch (dirent->smbc_type) {
         case SMBC_DIR:
             entry->type = AVIO_ENTRY_DIRECTORY;
             break;
         case SMBC_FILE:
             entry->type = AVIO_ENTRY_FILE;
             break;
         case SMBC_FILE_SHARE:
             entry->type = AVIO_ENTRY_SHARE;
             break;
         case SMBC_SERVER:
             entry->type = AVIO_ENTRY_SERVER;
             break;
         case SMBC_WORKGROUP:
             entry->type = AVIO_ENTRY_WORKGROUP;
             break;
         case SMBC_COMMS_SHARE:
         case SMBC_IPC_SHARE:
         case SMBC_PRINTER_SHARE:
             skip_entry = 1;
             break;
         case SMBC_LINK:
         default:
             entry->type = AVIO_ENTRY_UNKNOWN;
             break;
         }
     } while (skip_entry || !strcmp(dirent->name, ".") ||
              !strcmp(dirent->name, ".."));
 
     entry->name = av_strdup(dirent->name);
     if (!entry->name) {
         av_freep(next);
         return AVERROR(ENOMEM);
     }
 
     url = av_append_path_component(h->filename, dirent->name);
     if (url) {
         struct stat st;
         if (!smbc_stat(url, &st)) {
             entry->group_id = st.st_gid;
             entry->user_id = st.st_uid;
             entry->size = st.st_size;
             entry->filemode = st.st_mode & 0777;
             entry->modification_timestamp = INT64_C(1000000) * st.st_mtime;
             entry->access_timestamp =  INT64_C(1000000) * st.st_atime;
             entry->status_change_timestamp = INT64_C(1000000) * st.st_ctime;
         }
         av_free(url);
     }
 
     return 0;
 }
 
 static int libsmbc_close_dir(URLContext *h)
 {
     LIBSMBContext *libsmbc = h->priv_data;
     if (libsmbc->dh >= 0) {
         smbc_closedir(libsmbc->dh);
         libsmbc->dh = -1;
     }
     libsmbc_close(h);
     return 0;
 }
 

 static int libsmbc_delete(URLContext *h)
 {
     LIBSMBContext *libsmbc = h->priv_data;
     int ret;
     struct stat st;
 
     if ((ret = libsmbc_connect(h)) < 0)
         goto cleanup;
 
     if ((libsmbc->fd = smbc_open(h->filename, O_WRONLY, 0666)) < 0) {
         ret = AVERROR(errno);
         goto cleanup;
     }
 
     if (smbc_fstat(libsmbc->fd, &st) < 0) {
         ret = AVERROR(errno);
         goto cleanup;
     }
 
     smbc_close(libsmbc->fd);
     libsmbc->fd = -1;
 
     if (S_ISDIR(st.st_mode)) {
         if (smbc_rmdir(h->filename) < 0) {
             ret = AVERROR(errno);
             goto cleanup;
         }
     } else {
         if (smbc_unlink(h->filename) < 0) {
             ret = AVERROR(errno);
             goto cleanup;
         }
     }
 
     ret = 0;
 
 cleanup:
     libsmbc_close(h);
     return ret;
 }
 
 static int libsmbc_move(URLContext *h_src, URLContext *h_dst)
 {
     LIBSMBContext *libsmbc = h_src->priv_data;
     int ret;
 
     if ((ret = libsmbc_connect(h_src)) < 0)
         goto cleanup;
 
     if ((libsmbc->dh = smbc_rename(h_src->filename, h_dst->filename)) < 0) {
         ret = AVERROR(errno);
         goto cleanup;
     }
 
     ret = 0;
 
 cleanup:
     libsmbc_close(h_src);
     return ret;
 }
 

 #define OFFSET(x) offsetof(LIBSMBContext, x)
 #define D AV_OPT_FLAG_DECODING_PARAM
 #define E AV_OPT_FLAG_ENCODING_PARAM
 static const AVOption options[] = {
     {"timeout",   "set timeout in ms of socket I/O operations",    OFFSET(timeout), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, D|E },
     {"truncate",  "truncate existing files on write",              OFFSET(trunc),   AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, E },
     {"workgroup", "set the workgroup used for making connections", OFFSET(workgroup), AV_OPT_TYPE_STRING, { 0 }, 0, 0, D|E },
     {NULL}
 };
 
 static const AVClass libsmbclient_context_class = {
     .class_name     = "libsmbc",
     .item_name      = av_default_item_name,
     .option         = options,
     .version        = LIBAVUTIL_VERSION_INT,
 };
 

 const URLProtocol ff_libsmbclient_protocol = {

     .name                = "smb",
     .url_open            = libsmbc_open,
     .url_read            = libsmbc_read,
     .url_write           = libsmbc_write,
     .url_seek            = libsmbc_seek,
     .url_close           = libsmbc_close,

     .url_delete          = libsmbc_delete,
     .url_move            = libsmbc_move,

     .url_open_dir        = libsmbc_open_dir,
     .url_read_dir        = libsmbc_read_dir,
     .url_close_dir       = libsmbc_close_dir,

     .priv_data_size      = sizeof(LIBSMBContext),
     .priv_data_class     = &libsmbclient_context_class,
     .flags               = URL_PROTOCOL_FLAG_NETWORK,
 };