#include "chord.h"

extern int grid_size;
extern int transpose;

extern char *notes[];
extern char mesg[];

int do_transpose (char *chord) {

    int i, j;
    int p_chord, p_new_chord;
    int sharp, flat, new_i;
    unsigned char new_chord[MAXTOKEN];

    p_chord = 0;
    p_new_chord = 0;

    while (TRUE) {
        /* Find basic note */
        i = 0;
        while ((i < 7) && (strncmp (chord + p_chord, notes[i], strlen (notes[i]))))
            i++;

        if (i >= 7)
            return (1);

        /* Look for sharp or flat */
        p_chord += strlen (notes[i]);
        flat = (chord[p_chord] == 'b');
        sharp = (chord[p_chord] == '#');
        if (sharp || flat)
            p_chord++;

        /*compute new chord name */

        new_i = i;

        /* moving upscale ... */
        if (transpose > 0)
            for (j = 0; j < transpose; j++)
                if (sharp) {
                    sharp = 0;
                    new_i = (new_i + 1) % 7;
                }
                else if (flat)
                    flat = 0;
                else if ((new_i == 2) || (new_i == 6))
                    new_i = (new_i + 1) % 7;
                else
                    sharp++;

        /* moving downscale ... */
        else
            for (j = 0; j > transpose; j--)
                if (flat) {
                    flat = 0;
                    new_i = (new_i + 6) % 7;
                }
                else if (sharp)
                    sharp = 0;
                else if ((new_i == 3) || (new_i == 0))
                    new_i = (new_i + 6) % 7;
                else
                    flat++;

        sprintf (new_chord + p_new_chord, "%s", notes[new_i]);
        p_new_chord += strlen (notes[new_i]);

        if (sharp)
            sprintf (new_chord + p_new_chord++, "#");
        if (flat)
            sprintf (new_chord + p_new_chord++, "b");

        while ((chord[p_chord] != '/') && (chord[p_chord] != '\0'))
            new_chord[p_new_chord++] = chord[p_chord++];

        if (chord[p_chord] == '\0') {
            new_chord[p_new_chord] = '\0';
            sprintf (mesg, "[%s] becomes [%s]", chord, new_chord);
            debug (mesg);
            strcpy (chord, new_chord);
            return (0);
        } p_chord++;
        new_chord[p_new_chord++] = '/';
    }
}