/*****************************************************************************
 * messages.c: messages interface
 * This library provides an interface to the message queue to be used by other
 * modules, especially intf modules. See config.h for output configuration.
 *****************************************************************************
 * Copyright (C) 1998-2002 VideoLAN
 * $Id: messages.c,v 1.27 2002/12/18 12:18:06 sam Exp $
 *
 * Authors: Vincent Seguin <seguin@via.ecp.fr>
 *          Samuel Hocevar <sam@zoy.org>
 *
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
 *****************************************************************************/

/*****************************************************************************
 * Preamble
 *****************************************************************************/
#include <stdio.h>                                               /* required */
#include <stdarg.h>                                       /* va_list for BSD */
#include <stdlib.h>                                              /* malloc() */
#include <string.h>                                            /* strerror() */

#include <vlc/vlc.h>

#ifdef HAVE_FCNTL_H
#   include <fcntl.h>                  /* O_CREAT, O_TRUNC, O_WRONLY, O_SYNC */
#endif

#ifdef HAVE_ERRNO_H
#   include <errno.h>                                               /* errno */
#endif

#ifdef HAVE_UNISTD_H
#include <unistd.h>                                      /* close(), write() */
#endif

#include "interface.h"

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
static void QueueMsg ( vlc_object_t *, int , const char *,
                       const char *, va_list );
static void FlushMsg ( msg_bank_t * );
static void PrintMsg ( vlc_object_t *, msg_item_t * );

/*****************************************************************************
 * msg_Create: initialize messages interface
 *****************************************************************************
 * This functions has to be called before any call to other msg_* functions.
 * It set up the locks and the message queue if it is used.
 *****************************************************************************/
void __msg_Create( vlc_object_t *p_this )
{
    /* Message queue initialization */
    vlc_mutex_init( p_this, &p_this->p_libvlc->msg_bank.lock );

    p_this->p_libvlc->msg_bank.b_configured = VLC_FALSE;
    p_this->p_libvlc->msg_bank.b_overflow = VLC_FALSE;

    p_this->p_libvlc->msg_bank.i_start = 0;
    p_this->p_libvlc->msg_bank.i_stop = 0;

    p_this->p_libvlc->msg_bank.i_sub = 0;
    p_this->p_libvlc->msg_bank.pp_sub = NULL;

#ifdef UNDER_CE
    p_this->p_libvlc->msg_bank.logfile =
        CreateFile( L"vlc-log.txt", GENERIC_WRITE,
                    FILE_SHARE_READ|FILE_SHARE_WRITE, NULL,
                    CREATE_ALWAYS, 0, NULL );
    SetFilePointer( p_this->p_libvlc->msg_bank.logfile, 0, NULL, FILE_END );
#endif
}

/*****************************************************************************
 * msg_Flush: flush the message queue
 *****************************************************************************/
void __msg_Flush( vlc_object_t *p_this )
{
    int i_index;

    vlc_mutex_lock( &p_this->p_libvlc->msg_bank.lock );

    p_this->p_libvlc->msg_bank.b_configured = VLC_TRUE;

    for( i_index = p_this->p_libvlc->msg_bank.i_start;
         i_index != p_this->p_libvlc->msg_bank.i_stop;
         i_index = (i_index+1) % VLC_MSG_QSIZE )
    {
        PrintMsg( p_this, &p_this->p_libvlc->msg_bank.msg[i_index] );
    }

    FlushMsg( &p_this->p_libvlc->msg_bank );

    vlc_mutex_unlock( &p_this->p_libvlc->msg_bank.lock );
}

/*****************************************************************************
 * msg_Destroy: free resources allocated by msg_Create
 *****************************************************************************
 * This functions prints all messages remaining in queue, then free all the
 * resources allocated by msg_Create.
 * No other messages interface functions should be called after this one.
 *****************************************************************************/
void __msg_Destroy( vlc_object_t *p_this )
{
    if( p_this->p_libvlc->msg_bank.i_sub )
    {
        msg_Err( p_this, "stale interface subscribers" );
    }

    /* Flush the queue */
    if( !p_this->p_libvlc->msg_bank.b_configured )
    {
        msg_Flush( p_this );
    }
    else
    {
        FlushMsg( &p_this->p_libvlc->msg_bank );
    }

#ifdef UNDER_CE
    CloseHandle( p_this->p_libvlc->msg_bank.logfile );
#endif

    /* Destroy lock */
    vlc_mutex_destroy( &p_this->p_libvlc->msg_bank.lock );
}

/*****************************************************************************
 * msg_Subscribe: subscribe to the message queue.
 *****************************************************************************/
msg_subscription_t *__msg_Subscribe( vlc_object_t *p_this )
{
    msg_bank_t *p_bank = &p_this->p_libvlc->msg_bank;
    msg_subscription_t *p_sub = malloc( sizeof( msg_subscription_t ) );

    vlc_mutex_lock( &p_bank->lock );

    /* Add subscription to the list */
    INSERT_ELEM( p_bank->pp_sub, p_bank->i_sub, p_bank->i_sub, p_sub );

    p_sub->i_start = p_bank->i_start;
    p_sub->pi_stop = &p_bank->i_stop;

    p_sub->p_msg   = p_bank->msg;
    p_sub->p_lock  = &p_bank->lock;

    vlc_mutex_unlock( &p_bank->lock );

    return p_sub;
}

/*****************************************************************************
 * msg_Unsubscribe: unsubscribe from the message queue.
 *****************************************************************************/
void __msg_Unsubscribe( vlc_object_t *p_this, msg_subscription_t *p_sub )
{
    msg_bank_t *p_bank = &p_this->p_libvlc->msg_bank;
    int i_index;

    vlc_mutex_lock( &p_bank->lock );

    /* Sanity check */
    if( !p_bank->i_sub )
    {
        msg_Err( p_this, "no subscriber in the list" );
        return;
    }

    /* Look for the appropriate subscription */
    for( i_index = 0; i_index < p_bank->i_sub; i_index++ )
    {
        if( p_bank->pp_sub[ i_index ] == p_sub )
        {
            break;
        }
    }

    if( p_bank->pp_sub[ i_index ] != p_sub )
    {
        msg_Err( p_this, "subscriber not found" );
        vlc_mutex_unlock( &p_bank->lock );
        return;
    }

    /* Remove this subscription */
    REMOVE_ELEM( p_bank->pp_sub, p_bank->i_sub, i_index );

    vlc_mutex_unlock( &p_bank->lock );
}

/*****************************************************************************
 * __msg_*: print a message
 *****************************************************************************
 * These functions queue a message for later printing.
 *****************************************************************************/
void __msg_Generic( vlc_object_t *p_this, int i_type, const char *psz_module,
                    const char *psz_format, ... )
{
    va_list args;

    va_start( args, psz_format );
    QueueMsg( p_this, i_type, psz_module, psz_format, args );
    va_end( args );
}

/* Generic functions used when variadic macros are not available. */
#define DECLARE_MSG_FN( FN_NAME, FN_TYPE ) \
    void FN_NAME( void *p_this, const char *psz_format, ... ) \
    { \
        va_list args; \
        va_start( args, psz_format ); \
        QueueMsg( (vlc_object_t *)p_this, FN_TYPE, "unknown", \
                  psz_format, args ); \
        va_end( args ); \
    } \
    struct _

DECLARE_MSG_FN( __msg_Info, VLC_MSG_INFO );
DECLARE_MSG_FN( __msg_Err,  VLC_MSG_ERR );
DECLARE_MSG_FN( __msg_Warn, VLC_MSG_WARN );
DECLARE_MSG_FN( __msg_Dbg,  VLC_MSG_DBG );

/*****************************************************************************
 * QueueMsg: add a message to a queue
 *****************************************************************************
 * This function provides basic functionnalities to other msg_* functions.
 * It adds a message to a queue (after having printed all stored messages if it
 * is full). If the message can't be converted to string in memory, it issues
 * a warning.
 *****************************************************************************/
static void QueueMsg( vlc_object_t *p_this, int i_type, const char *psz_module,
                      const char *psz_format, va_list args )
{
    msg_bank_t * p_bank = &p_this->p_libvlc->msg_bank;       /* message bank */
    char *       psz_str = NULL;                 /* formatted message string */
    msg_item_t * p_item = NULL;                        /* pointer to message */
    msg_item_t   item;                    /* message in case of a full queue */

#if !defined(HAVE_VASPRINTF) || defined(SYS_DARWIN)
    int          i_size = strlen(psz_format) + INTF_MAX_MSG_SIZE;
#endif

    /*
     * Convert message to string
     */
#if defined(HAVE_VASPRINTF) && !defined(SYS_DARWIN)
    vasprintf( &psz_str, psz_format, args );
#else
    psz_str = (char*) malloc( i_size * sizeof(char) );
#endif

    if( psz_str == NULL )
    {
#ifdef HAVE_ERRNO_H
        fprintf( stderr, "main warning: can't store message (%s): ",
                 strerror(errno) );
#else
        fprintf( stderr, "main warning: can't store message: " );
#endif
        vfprintf( stderr, psz_format, args );
        fprintf( stderr, "\n" );
        return;
    }

#if !defined(HAVE_VASPRINTF) || defined(SYS_DARWIN)
    vsnprintf( psz_str, i_size, psz_format, args );
    psz_str[ i_size - 1 ] = 0; /* Just in case */
#endif

    /* Put message in queue */
    vlc_mutex_lock( &p_bank->lock );

    /* Check there is room in the queue for our message */
    if( p_bank->b_overflow )
    {
        FlushMsg( p_bank );

        if( ((p_bank->i_stop - p_bank->i_start + 1) % VLC_MSG_QSIZE) == 0 )
        {
            /* Still in overflow mode, print from a dummy item */
            p_item = &item;
        }
        else
        {
            /* Pheeew, at last, there is room in the queue! */
            p_bank->b_overflow = VLC_FALSE;
        }
    }
    else if( ((p_bank->i_stop - p_bank->i_start + 2) % VLC_MSG_QSIZE) == 0 )
    {
        FlushMsg( p_bank );

        if( ((p_bank->i_stop - p_bank->i_start + 2) % VLC_MSG_QSIZE) == 0 )
        {
            p_bank->b_overflow = VLC_TRUE;

            /* Put the overflow message in the queue */
            p_item = p_bank->msg + p_bank->i_stop;
            p_bank->i_stop = (p_bank->i_stop + 1) % VLC_MSG_QSIZE;

            p_item->i_type =        VLC_MSG_ERR;
            p_item->i_object_id =   p_this->i_object_id;
            p_item->i_object_type = p_this->i_object_type;
            p_item->psz_module =    strdup( "message" );
            p_item->psz_msg =       strdup( "message queue overflowed" );

            PrintMsg( p_this, p_item );

            /* We print from a dummy item */
            p_item = &item;
        }
    }

    if( !p_bank->b_overflow )
    {
        /* Put the message in the queue */
        p_item = p_bank->msg + p_bank->i_stop;
        p_bank->i_stop = (p_bank->i_stop + 1) % VLC_MSG_QSIZE;
    }

    /* Fill message information fields */
    p_item->i_type =        i_type;
    p_item->i_object_id =   p_this->i_object_id;
    p_item->i_object_type = p_this->i_object_type;
    p_item->psz_module =    strdup( psz_module );
    p_item->psz_msg =       psz_str;

    PrintMsg( p_this, p_item );

    if( p_bank->b_overflow )
    {
        free( p_item->psz_module );
        free( p_item->psz_msg );
    }

    vlc_mutex_unlock( &p_bank->lock );
}

/* following functions are local */

/*****************************************************************************
 * FlushMsg
 *****************************************************************************
 * Print all messages remaining in queue. MESSAGE QUEUE MUST BE LOCKED, since
 * this function does not check the lock.
 *****************************************************************************/
static void FlushMsg ( msg_bank_t *p_bank )
{
    int i_index, i_start, i_stop;

    /* Only flush the queue if it has been properly configured */
    if( !p_bank->b_configured )
    {
        return;
    }

    /* Get the maximum message index that can be freed */
    i_stop = p_bank->i_stop;

    /* Check until which value we can free messages */
    for( i_index = 0; i_index < p_bank->i_sub; i_index++ )
    {
        i_start = p_bank->pp_sub[ i_index ]->i_start;

        /* If this subscriber is late, we don't free messages before
         * his i_start value, otherwise he'll miss messages */
        if(   ( i_start < i_stop
               && (p_bank->i_stop <= i_start || i_stop <= p_bank->i_stop) )
           || ( i_stop < i_start
               && (i_stop <= p_bank->i_stop && p_bank->i_stop <= i_start) ) )
        {
            i_stop = i_start;
        }
    }

    /* Free message data */
    for( i_index = p_bank->i_start;
         i_index != i_stop;
         i_index = (i_index+1) % VLC_MSG_QSIZE )
    {
        free( p_bank->msg[i_index].psz_msg );
        free( p_bank->msg[i_index].psz_module );
    }

    /* Update the new start value */
    p_bank->i_start = i_index;
}

/*****************************************************************************
 * PrintMsg: output a message item to stderr
 *****************************************************************************
 * Print a message to stderr, with colour formatting if needed.
 *****************************************************************************/
static void PrintMsg ( vlc_object_t * p_this, msg_item_t * p_item )
{
#   define COL(x)  "\033[" #x ";1m"
#   define RED     COL(31)
#   define GREEN   COL(32)
#   define YELLOW  COL(33)
#   define WHITE   COL(37)
#   define GRAY    "\033[0m"

#ifdef UNDER_CE
    int i_dummy;
#endif
    static const char * ppsz_type[4] = { "", " error", " warning", " debug" };
    static const char *ppsz_color[4] = { WHITE, RED, YELLOW, GRAY };
    char *psz_object = "private";
    int i_type = p_item->i_type;

    switch( i_type )
    {
        case VLC_MSG_ERR:
            if( p_this->p_libvlc->i_verbose < 0 ) return;
            break;
        case VLC_MSG_INFO:
            if( p_this->p_libvlc->i_verbose < 0 ) return;
            break;
        case VLC_MSG_WARN:
            if( p_this->p_libvlc->i_verbose < 1 ) return;
            break;
        case VLC_MSG_DBG:
            if( p_this->p_libvlc->i_verbose < 2 ) return;
            break;
    }

    switch( p_item->i_object_type )
    {
        case VLC_OBJECT_ROOT: psz_object = "root"; break;
        case VLC_OBJECT_VLC: psz_object = "vlc"; break;
        case VLC_OBJECT_MODULE: psz_object = "module"; break;
        case VLC_OBJECT_INTF: psz_object = "interface"; break;
        case VLC_OBJECT_PLAYLIST: psz_object = "playlist"; break;
        case VLC_OBJECT_ITEM: psz_object = "item"; break;
        case VLC_OBJECT_INPUT: psz_object = "input"; break;
        case VLC_OBJECT_DECODER: psz_object = "decoder"; break;
        case VLC_OBJECT_VOUT: psz_object = "video output"; break;
        case VLC_OBJECT_AOUT: psz_object = "audio output"; break;
        case VLC_OBJECT_SOUT: psz_object = "stream output"; break;
    }

#ifdef UNDER_CE
#   define CE_WRITE(str) WriteFile( p_this->p_libvlc->msg_bank.logfile, \
                                    str, strlen(str), &i_dummy, NULL );
    CE_WRITE( p_item->psz_module );
    CE_WRITE( " " );
    CE_WRITE( psz_object );
    CE_WRITE( ppsz_type[i_type] );
    CE_WRITE( ": " );
    CE_WRITE( p_item->psz_msg );
    CE_WRITE( "\r\n" );
    FlushFileBuffers( p_this->p_libvlc->msg_bank.logfile );

#else
    /* Send the message to stderr */
    if( p_this->p_libvlc->b_color )
    {
        fprintf( stderr, "[" GREEN "%.8i" GRAY "] %s %s%s: %s%s" GRAY "\n",
                         p_item->i_object_id, p_item->psz_module, psz_object,
                         ppsz_type[i_type], ppsz_color[i_type],
                         p_item->psz_msg );
    }
    else
    {
        fprintf( stderr, "[%.8i] %s %s%s: %s\n", p_item->i_object_id,
                         p_item->psz_module, psz_object, ppsz_type[i_type],
                         p_item->psz_msg );
    }

#   if defined(WIN32)
    fflush( stderr );
#   endif
#endif
}
