#include "Gwater.h"

CELL split_stream(int row, int col, int new_r[], int new_c[], int ct,
                  CELL basin_num, double stream_length, CELL old_elev)
{
    CELL downdir, old_basin, new_elev, aspect;
    double slope, easting, northing;
    int doit, ctr, updir, splitdir[9];
    int thisdir, leftflag, riteflag;
    int r, c, rr, cc;

    new_elev = 0;

    for (ctr = 1; ctr <= ct; ctr++)
        splitdir[ctr] = drain[row - new_r[ctr] + 1][col - new_c[ctr] + 1];
    updir = splitdir[1];
    downdir = asp[SEG_INDEX(asp_seg, row, col)];
    if (downdir < 0)
        downdir = -downdir;
    riteflag = leftflag = 0;
    for (r = row - 1, rr = 0; rr < 3; r++, rr++) {
        for (c = col - 1, cc = 0; cc < 3; c++, cc++) {
            if (r >= 0 && c >= 0 && r < nrows && c < ncols) {
                if (r == row && c == col)
                    continue;
                aspect = asp[SEG_INDEX(asp_seg, r, c)];
                if (aspect == drain[rr][cc]) {
                    doit = 1;
                    thisdir = updrain[rr][cc];
                    for (ctr = 1; ctr <= ct; ctr++) {
                        if (thisdir == splitdir[ctr]) {
                            doit = 0;
                            ctr = ct;
                        }
                    }
                    if (doit) {
                        thisdir = updrain[rr][cc];
                        switch (haf_basin_side(updir, (int)downdir, thisdir)) {
                        case LEFT:
                            overland_cells(r, c, basin_num, basin_num - 1,
                                           &new_elev);
                            leftflag++;
                            break;
                        case RITE:
                            overland_cells(r, c, basin_num, basin_num,
                                           &new_elev);
                            riteflag++;
                            break;
                        }
                    }
                }
            }
        }
    }
    if (leftflag >= riteflag) {
        haf[SEG_INDEX(haf_seg, row, col)] = basin_num - 1;
    }
    else {
        haf[SEG_INDEX(haf_seg, row, col)] = basin_num;
    }
    old_basin = basin_num;
    if (arm_flag) {
        new_elev = alt[SEG_INDEX(alt_seg, row, col)];
        if ((slope = (new_elev - old_elev) / stream_length) < MIN_SLOPE)
            slope = MIN_SLOPE;
        fprintf(fp, " %f %f\n", slope, stream_length);
    }
    for (r = 1; r <= ct; r++) {
        basin_num += 2;
        if (arm_flag) {
            easting = window.west + (new_c[r] + .5) * window.ew_res;
            northing = window.north - (new_r[r] + .5) * window.ns_res;
            fprintf(fp, "%5d drains into %5d at %3d %3d %.3f %.3f",
                    (int)basin_num, old_basin, new_r[r], new_c[r], easting,
                    northing);
        }
        if (new_r[r] != row && new_c[r] != col)
            basin_num =
                def_basin(new_r[r], new_c[r], basin_num, diag, new_elev);
        else if (new_r[r] != row)
            basin_num = def_basin(new_r[r], new_c[r], basin_num, window.ns_res,
                                  new_elev);
        else
            basin_num = def_basin(new_r[r], new_c[r], basin_num, window.ew_res,
                                  new_elev);
    }
    return (basin_num);
}
