#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
 
#include <pthread.h>
#include <sys/socket.h>
#include <sys/un.h>

/* State of the server. */
#define STATE_PLAY	0x01
#define STATE_STOP	0x02
#define STATE_PAUSE	0x03
#define CMD_GET_STATE	0x13 /* get the state */
#define CMD_GET_CTIME	0x0d /* get the current song time */
#define CMD_GET_TAGS	0x2c /* get tags for the currently played file */
#define CMD_GET_FILE_TAGS	0x2f	/* get tags for the specified file */
#define CMD_GET_SNAME	0x0f /* get the stream file name */
#define MAX_SEND_STRING	4096
#define RANGE(min, val, max) ((val) >= (min) && (val) <= (max))


/* Definition of events sent by server to the client. */
#define EV_STATE	0x01 /* server has changed the state */
#define EV_CTIME	0x02 /* current time of the song has changed */
#define EV_SRV_ERROR	0x04 /* an error occurred */
#define EV_BUSY		0x05 /* another client is connected to the server */
#define EV_DATA		0x06 /* data in response to a request will arrive */
#define EV_BITRATE	0x07 /* the bitrate has changed */
#define EV_RATE		0x08 /* the rate has changed */
#define EV_CHANNELS	0x09 /* the number of channels has changed */
#define EV_EXIT		0x0a /* the server is about to exit */
#define EV_PONG		0x0b /* response for CMD_PING */
#define EV_OPTIONS	0x0c /* the options has changed */
#define EV_SEND_PLIST	0x0d /* request for sending the playlist */
#define EV_TAGS		0x0e /* tags for the current file have changed */
#define EV_STATUS_MSG	0x0f /* followed by a status message */
#define EV_MIXER_CHANGE	0x10 /* the mixer channel was changed */
#define EV_FILE_TAGS	0x11 /* tags in a response for tags request */
#define EV_AVG_BITRATE  0x12 /* average bitrate has changed (new song) */
#define EV_AUDIO_START	0x13 /* playing of audio has started */
#define EV_AUDIO_STOP	0x14 /* playing of audio has stopped */

/* Events caused by a client that wants to modify the playlist (see
 * CMD_CLI_PLIST* commands). */
#define EV_PLIST_ADD	0x50 /* add an item, followed by the file name */
#define EV_PLIST_DEL	0x51 /* delete an item, followed by the file name */
#define EV_PLIST_MOVE	0x52 /* move an item, followed by 2 file names */
#define EV_PLIST_CLEAR	0x53 /* clear the playlist */

/* These events, though similar to the four previous are caused by server
 * which takes care of clients' queue synchronization. */
#define EV_QUEUE_ADD	0x54
#define EV_QUEUE_DEL	0x55
#define EV_QUEUE_MOVE	0x56
#define EV_QUEUE_CLEAR	0x57
/* Flags for the info decoder function. */
enum tags_select
{
  TAGS_COMMENTS	= 0x01, /* artist, title, etc. */
  TAGS_TIME	= 0x02 /* time of the file. */
};

enum moc_state {
  STOPPED,
  PLAYING,
  PAUSED
};

enum moc_status {
  INITIALIZING,
  CONNECTED,
  FAILED_TO_CONNECT,
  ERROR,
  RECONNECTING,
  
};

struct moc { 
  pthread_mutex_t lock;
  enum moc_status status;
  enum moc_state state;

  char *filename;
  char *title;
  char *album;
  char *artist;
  int track;
  int time;
  int filled;
  int length;
};

extern const char * moc_str_status(enum moc_status s) {
    static const char *strings[] = { "INITIALIZING", "CONNECTED", "FAILED_TO_CONNECT", "ERROR", "RECONNECTING" };
    return strings[s];
}

extern const char * moc_str_state(enum moc_state s) {
    static const char *strings[] = { "STOPPED", "PLAYING", "PAUSED"};
    return strings[s];

}

static char *get_curr_file(int sock);
int send_str (int sock, const char *str);
char *get_str (int sock);
int send_int (int sock, int i);
int get_int (int sock, int *i);

  
void reset_data(struct moc *data) {
  data->filename = NULL;
  data->title = NULL;
  data->album = NULL;
  data->artist = NULL;
  data->time = -1;
  data->length = -1;
  data->state = STOPPED;
}

static char *get_curr_file (const int sock) {
  send_int (sock, CMD_GET_SNAME);
  int ev;
  while(ev != EV_DATA) {
    get_int(sock, &ev);
  }
    return get_str(sock);
}


int send_str (int sock, const char *str)
{
  int len;

  len = strlen (str);
  if (!send_int (sock, len))
    return 0;

  if (send (sock, str, len, 0) != len)
    return 0;

  return 1;
}
char *get_str (int sock) {
  int len;
  int res, nread = 0;
  char *str;

  if (!get_int(sock, &len))
    return NULL;

  if (!RANGE(0, len, MAX_SEND_STRING)) {
    printf("Bad string length.");
    return NULL;
  }

  str = (char *)malloc (sizeof(char) * (len + 1));
  while (nread < len) {
    res = recv (sock, str + nread, len - nread, 0);
    if (res == -1) {
      printf("recv() failed when getting string: %s\n",
          strerror(errno));
      free (str);
      return NULL;
    }
    if (res == 0) {
      printf("Unexpected EOF when getting string\n");
      free (str);
      return NULL;
    }
    nread += res;
  }
  str[len] = 0;

  return str;
}
int send_int (int sock, int i)
{
  int res;

  res = send (sock, &i, sizeof(int), 0);
  if (res == -1)
    printf("send() failed: %s", strerror(errno));

  return res == sizeof(int) ? 1 : 0;
}

int get_int (int sock, int *i)
{
  int res;

  res = recv (sock, i, sizeof(int), 0);
  if (res == -1)
    printf("recv() failed when getting int: %s", strerror(errno));

  return res == sizeof(int) ? 1 : 0;
}

static int moc_server_connect ()
{
  struct sockaddr_un sock_name;
  int sock;
  /* Create a socket */
  if ((sock = socket (PF_LOCAL, SOCK_STREAM, 0)) == -1)
    return -1;

  sock_name.sun_family = AF_LOCAL;

  snprintf(sock_name.sun_path, sizeof(sock_name.sun_path), "%s/.moc/socket2", getenv("HOME"));

  if (connect(sock, (struct sockaddr *)&sock_name,
        SUN_LEN(&sock_name)) == -1) {
    close (sock);
    fprintf(stderr, "%s at (%s)\n", strerror(errno), sock_name.sun_path);
    return -1;
  }

  return sock;
}


void update_state(struct moc *data, int state) {
    if(state == STATE_PLAY) {
        data->state = PLAYING;
    }
    if(state == STATE_PAUSE) {
        data->state = PAUSED;
    }
    if(state == STATE_STOP) {
        data->state = STOPPED;
    }
}

static int moc_reconnect(struct moc *data) {
 int srv_sock = -1;

 while(srv_sock == -1) { 
   fprintf(stderr, "moc: reconnecting\n");
   srv_sock = moc_server_connect();
   sleep(1);
 }

  pthread_mutex_lock(&data->lock);
  data->status = CONNECTED;
  pthread_mutex_unlock(&data->lock);
  return srv_sock;
}

void *moc_loop(void *input) {


  struct moc *data = (struct moc*)input;

  int srv_sock = -1;

  fprintf(stderr, "moc: connecting\n");
  srv_sock = moc_reconnect(data);
  fprintf(stderr, "moc: connected: %d\n", srv_sock);


  int last_cmd = -1;
  int event = -1;

  send_int(srv_sock, CMD_GET_STATE);
  last_cmd = EV_STATE;

  while(1) {
    get_int(srv_sock, &event); 
    switch (event) {
      // handle our data. we MUST know what the last request was otherwise we
      // don't know how to parse it.
      case EV_DATA:
        fprintf(stderr, "moc: EV_DATA\n");
        if(last_cmd == EV_CTIME) {
          get_int(srv_sock, &data->time);
          fprintf(stderr, "moc: update ctime\n");
          if(data->state == 0) {
            send_int(srv_sock, CMD_GET_STATE);
            last_cmd = EV_STATE;
          }
        }
        //  on state change, we need to figure out what file we have and what
        //  tags it has.
        else if(last_cmd == EV_STATE) {
          int state;
          get_int(srv_sock, &state);
          pthread_mutex_lock(&data->lock);
          update_state(data, state);

          if(state != STATE_STOP) {
            char *file = get_curr_file(srv_sock);
            fprintf(stderr, "moc: current file %s\n", file);
            // if it's the same file as we had, don't update.
            if(data->filename == NULL || strcmp(file, data->filename) != 0) {
              fprintf(stderr, "moc: new file, asking for tags\n");
              data->filename = file;
              // get tags.
              send_int(srv_sock, CMD_GET_FILE_TAGS);
              send_str(srv_sock, file);
              send_int(srv_sock,TAGS_COMMENTS | TAGS_TIME);
              last_cmd = EV_FILE_TAGS;
            }
          } else {
            reset_data(data);
          }
          pthread_mutex_unlock(&data->lock);
        }
        else {
          fprintf(stderr, "moc: UNKNOWN STATE\n");
        }
        last_cmd = -1;

        break;
      case EV_BUSY:
        fprintf(stderr, "moc: EV_BUSY\n");
        break;
      case EV_CTIME:
        fprintf(stderr, "moc: EV_CTIME\n");
        last_cmd = EV_CTIME;
        send_int(srv_sock, CMD_GET_CTIME);
        break;
      case EV_STATE:
        fprintf(stderr, "moc: EV_STATE\n");
        last_cmd = EV_STATE;
        send_int(srv_sock, CMD_GET_STATE);
        break;
      case EV_EXIT:
        fprintf(stderr,"moc: EV_EXIT\n");
        data->status = RECONNECTING;
        reset_data(data);
        srv_sock = moc_reconnect(data);
        break;
      case EV_BITRATE:
        fprintf(stderr, "moc: EV_BITRATE\n");
        break;
      case EV_RATE:
        fprintf(stderr, "moc: EV_RATE\n");
        break;
      case EV_CHANNELS:
        printf("moc: EV_CHANNELS\n");
        break;
      case EV_SRV_ERROR:
          get_str(srv_sock);
        break;
      case EV_OPTIONS:
        printf("moc: EV_OPTIONS\n");
        break;
      case EV_SEND_PLIST:
      case EV_PLIST_ADD:
      case EV_PLIST_CLEAR:
      case EV_PLIST_DEL:
      case EV_PLIST_MOVE:
        printf("moc: EV_PLAYLIST\n");
      case EV_TAGS:
        last_cmd = EV_TAGS;
        printf("moc: EV_TAGS\n");
        break;
      case EV_STATUS_MSG:
        printf("moc: EV_STATUS_MSG\n");
        printf("moc: status update: %s\n", get_str(srv_sock));
        break;
      case EV_MIXER_CHANGE:
        printf("moc: EV_MIXER_CHANGE\n");
        break;
      case EV_FILE_TAGS:
        printf("moc: EV_FILE_TAGS\n");

        pthread_mutex_lock(&data->lock);
        if (!(data->filename = get_str(srv_sock))) {
          fprintf(stderr, "Error while receiving filename\n");
        }

        if (!(data->title = get_str(srv_sock))) {
          fprintf(stderr, "Error while receiving title\n");
        }

        if (!(data->artist = get_str(srv_sock))) {
          fprintf(stderr, "Error while receiving artist\n");
        }

        if (!(data->album = get_str(srv_sock))) {
          fprintf(stderr, "Error while receiving album\n");
        }

        if (!get_int(srv_sock, &data->track)) {
          fprintf(stderr, "Error while receiving track\n");
        }

        if (!get_int(srv_sock, &data->length)) {
          fprintf(stderr, "Error while receiving length\n");
        }

        if (!get_int(srv_sock, &data->filled)) {
          fprintf(stderr, "Error while receiving filled\n");
        }
        pthread_mutex_unlock(&data->lock);

        break;
      case EV_AVG_BITRATE:
        printf("moc: EV_AVG_BITRATE\n");
        break;
      case EV_AUDIO_START:
        printf("moc: AUDIO START\n");
        break;
      case EV_AUDIO_STOP:
        printf("moc: AUDIO STOP\n");
        break;
      default:
        fprintf(stderr, "Unknown event: 0x%02x!\n", event);
        break;
    }
  }
  fprintf(stderr, "loop died, you're fucked\n");
}

extern struct moc *moc_init() {

  struct moc *moc = (struct moc*)malloc(sizeof(struct moc));
  reset_data(moc);
  pthread_t thread_id;

  if (pthread_mutex_init(&moc->lock, NULL) != 0) {
    printf("\n mutex init has failed\n");
    return NULL;
  }
  moc->status = INITIALIZING;

  pthread_create(&thread_id, NULL, moc_loop, (void *)moc);
  return moc;
}