#define MPP_ENCODER
#include "mppdec.h"
#include <ctype.h>


typedef struct {
    unsigned char  Artist [512];
    unsigned char  Title  [512];
    unsigned char  Album  [512];
    unsigned char  Year   [  5];
    unsigned int   Number;
} taginfo_t;


static int
xdigit ( char c )
{
    if ( (unsigned int )(c-'0') < 10 )
        return c-'0';
    if ( (unsigned int )(c-'A') < 6 )
        return c-'A'+10;
    return -1;
}


static void
percent ( char* p )
{
    char* q = p;

    for (; *p; ) {
        if ( p[0] == '%'  &&  xdigit(p[1]) >= 0  &&  xdigit(p[2]) >= 0 )
            *q++ = 16*xdigit(p[1]) + xdigit(p[2]), p += 3;
        else if (p[0] == '_')
            *q++ = ' ', p++;
        else
            *q++ = *p++;
    }
    *q = '\0';
}


static char*
separator ( char* s )
{
    while (*s) {
        if ( s[0] == PATH_SEP ) {
            s[0] = '\0';
            return s+1;
        }
        if ( (s[0]==' ' || s[0]=='_') && s[1]=='-' && s[2]=='-' && (s[3]==' ' || s[3]=='_') ) {
            s[0] = '\0';
            return s+4;
        }
        s++;
    }
    return NULL;
}


static int
IsIndexType1 ( const char* s )
{
    if ( s[0]=='[' && isdigit(s[1])  && isdigit(s[2]) && s[3]==']' && (s[4]==' ' || s[4]=='_') )
        return 10*s[1]+s[2]-11*'0';
    if ( 0 == strcmp (s, "[00]") )
        return 0;
    return -1;
}


static int
IsIndexType2 ( const char* s )
{
    if ( isdigit(s[0])  && isdigit(s[1]) && s[2] == '\0' )
        return 10*s[0]+s[1]-11*'0';
    return -1;
}

typedef int (*idxfn) (const char*);

int
ParseName ( const char* filename, taginfo_t* const T )
{
    unsigned char*  Components    [64];
    idxfn           fn             [2] = { IsIndexType1, IsIndexType2 };
    int             Ci                 = 0;
    char            Path [PATHLEN_MAX] = "";
    char            Name [PATHLEN_MAX];
    char*           p;
    int             i;
    int             j;
#if DRIVE_SEP != '\0'
    char            Drive           = '@';
#endif


#if DRIVE_SEP != '\0'
    // drive specified?
    if ( isalpha (filename[0])  &&  filename[1] == DRIVE_SEP ) {
        Drive = filename[0];
        filename += 2;
    }
#endif

    if ( filename[0] != PATH_SEP ) {
        // no absolute path, so get the current folder for this drive
        p = Path;
#if DRIVE_SEP != '\0'
# if defined _WIN32
        _getdcwd  ( Drive & 0x1F, Path, sizeof Path );
# else
        getcurdir ( Drive & 0x1F, Path );
# endif
        if ( isalpha (p[0])  &&  p[1] == DRIVE_SEP )
            p += 2;
#else
        getcwd ( Path, sizeof Path );
#endif
        // parse the current folder
        while ( p != NULL  &&  *p != '\0' ) {
            Components [Ci++] = p;
            p = separator ( p );
        }
    }

    // parse the filename
    strcpy ( Name, filename );
    p = Name;
    while ( p != NULL  &&  *p != '\0' ) {
        Components [Ci++] = p;
        p = separator ( p );
    }

    // remove ".", ".." and names from file formats
    for ( i = j = 0; i < Ci; i++ )
        if      ( 0 == strcmp (Components [i], ""   ) )
            ;
        else if ( 0 == strcmp (Components [i], "."  ) )
            ;
        else if ( 0 == strcmp (Components [i], "wav") )
            ;
        else if ( 0 == strcmp (Components [i], "pac") )
            ;
        else if ( 0 == strcmp (Components [i], "mpc") )
            ;
        else if ( 0 == strcmp (Components [i], "mpp") )
            ;
        else if ( 0 == strcmp (Components [i], "mp+") )
            ;
        else if ( 0 == strcmp (Components [i], "mp3") )
            ;
        else if ( 0 == strcmp (Components [i], ".." ) )
            j -= j ? 1 : 0;
        else
             Components [j++] = Components [i];
    Ci = j;

    // remove file extension
    p = strrchr ( Components [Ci-1], '.');
    if ( p != NULL )
        *p = '\0';

    // Merging of (CD 1), (CD 1/7), (CD 1/12) is still missing
    // Decoding of %XX and "_" is still missing

    T->Year  [0] = '\0';
    T->Artist[0] = '\0';
    T->Album [0] = '\0';
    T->Title [0] = '\0';
    T->Number    = -1;

    if ( fn[0] ( Components [Ci-1]) >= 0 ) {
        strcpy ( T->Album , Components [Ci-2] );
        strcpy ( T->Artist, Components [Ci-3] );
        strcpy ( T->Title , strlen (Components [Ci-1]) >= 5  ?  Components [Ci-1]+5  :  (unsigned char*)"" );
        T->Number = fn[0] ( Components [Ci-1]);
        goto okay;
    }
    if ( fn[0] ( Components [Ci-2]) >= 0 ) {
        strcpy ( T->Album , Components [Ci-3] );
        strcpy ( T->Artist, Components [Ci-2]+5 );
        strcpy ( T->Title , Components [Ci-1] );
        T->Number = fn[0] ( Components [Ci-2]);
        goto okay;
    }


    if ( fn[1] ( Components [Ci-1]) == 0 ) {
        strcpy ( T->Album , Components [Ci-2] );
        strcpy ( T->Artist, Components [Ci-3] );
        strcpy ( T->Title , ""                );
        T->Number = 0;
        goto okay;
    }
    if ( fn[1] ( Components [Ci-2]) >= 0 ) {
        strcpy ( T->Album , Components [Ci-3] );
        strcpy ( T->Artist, Components [Ci-4] );
        strcpy ( T->Title , Components [Ci-1] );
        T->Number = fn[1] ( Components [Ci-2]);
        goto okay;
    }
    if ( fn[1] ( Components [Ci-3]) >= 0 ) {
        strcpy ( T->Album , Components [Ci-4] );
        strcpy ( T->Artist, Components [Ci-2] );
        strcpy ( T->Title , Components [Ci-1] );
        T->Number = fn[1] ( Components [Ci-3]);
        goto okay;
    }

    for ( i = 0; i < Ci; i++)
        printf ( "'%s' ", Components [i] );
    printf ( "\n" );
    return 1;

okay:
    T->Year[0] = '\0';
    if ( strlen (T->Album) >= 8 ) {
        p = T->Album + strlen (T->Album) - 7;
        if (p[0] == ' ' && p[1]=='(' && p[6]=='1') {
            i = atoi (p+2);
            if ( i >= 1900 && i <= 2019 ) {
                sprintf (T->Year, "%4u", i);
                p[0] = '\0';
            }
        }
    }
    percent (T->Album);
    percent (T->Artist);
    percent (T->Title);
    return 0;
}


int
main ( int argc, char** argv )
{
    taginfo_t     T;
    const char*   extentions [] = { ".mpc", ".mp+", ".mpp", ".wav", ".ape", ".pac", NULL };

    mysetargv ( &argc, &argv, extentions );

    while ( *++argv ) {
        fprintf ( stderr, "%s\n", *argv );
        ParseName (*argv, &T);
        printf ( "%-40.40s %-40.40s %4.4s [%02d] %s\n", T.Artist, T.Album, T.Year, T.Number, T.Title );
    }

    return 0;
}