#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <math.h>
#include <grass/gis.h>
#include <grass/vector.h>
#include <grass/dbmi.h>
#include <grass/glocale.h>

/* Result code */
#define SP_OK           0 /* Path found */
#define SP_UNREACHABLE  1 /* Node is not reachable */
#define SP_NOPOINT      2 /* Missing point of given category */

#define INPUT_MODE_NODE 1
#define INPUT_MODE_COOR 2

typedef struct { /* category index */
    int cat;     /* line category */
    int line;    /* line number */
} CIDX;

int cmp(const void *, const void *);

int path(struct Map_info *In, struct Map_info *Out, char *filename, int nfield,
         double maxdist, int segments, int tucfield, int use_ttb)
{
    FILE *in_file = NULL;
    int i, nlines, line, npoints, type, cat, id, fcat, tcat, fline, tline,
        fnode, tnode, count;
    int ret, sp, input_mode, unreachable, nopoint, formaterr;
    struct ilist *AList;
    double cost;
    struct line_pnts *Points, *OPoints, *FPoints, *TPoints;
    struct line_cats *Cats;
    CIDX *Cidx, *Citem;
    char buf[2000], dummy[2000];
    double fx, fy, tx, ty;

    /* Attribute table */
    dbString sql;
    dbDriver *driver;
    struct field_info *Fi;

    if (filename) {
        /* open input file */
        if ((in_file = fopen(filename, "r")) == NULL)
            G_fatal_error(_("Unable to open input file <%s>"), filename);
    }

    AList = Vect_new_list();
    Points = Vect_new_line_struct();
    OPoints = Vect_new_line_struct();
    FPoints = Vect_new_line_struct();
    TPoints = Vect_new_line_struct();
    Cats = Vect_new_cats_struct();
    db_init_string(&sql);

    /* Create category index for input points */
    npoints = Vect_get_num_primitives(In, GV_POINT);
    Cidx = (CIDX *)G_malloc(npoints * sizeof(CIDX));

    nlines = Vect_get_num_lines(In);
    count = 0;
    for (line = 1; line <= nlines; line++) {
        type = Vect_read_line(In, NULL, Cats, line);
        if (type != GV_POINT)
            continue;

        Vect_cat_get(Cats, nfield, &cat);

        if (cat < 0)
            continue;

        Cidx[count].cat = cat;
        Cidx[count].line = line;
        count++;
    }

    if (count < npoints)
        G_warning(_("[%d] points without category (nfield: [%d])"),
                  npoints - count, nfield);

    npoints = count;

    qsort((void *)Cidx, npoints, sizeof(CIDX), cmp);

    /* Create table */
    Fi = Vect_default_field_info(Out, 1, NULL, GV_1TABLE);
    Vect_map_add_dblink(Out, 1, NULL, Fi->table, GV_KEY_COLUMN, Fi->database,
                        Fi->driver);

    driver = db_start_driver_open_database(Fi->driver, Fi->database);
    if (driver == NULL)
        G_fatal_error(_("Unable to open database <%s> by driver <%s>"),
                      Fi->database, Fi->driver);
    db_set_error_handler_driver(driver);

    snprintf(buf, sizeof(buf),
             "create table %s ( cat integer, id integer, fcat integer, tcat "
             "integer, "
             "sp integer, cost double precision, fdist double precision, tdist "
             "double precision )",
             Fi->table);

    db_set_string(&sql, buf);
    G_debug(2, "%s", db_get_string(&sql));

    if (db_execute_immediate(driver, &sql) != DB_OK) {
        G_fatal_error(_("Unable to create table: '%s'"), db_get_string(&sql));
    }

    if (db_create_index2(driver, Fi->table, GV_KEY_COLUMN) != DB_OK)
        G_warning(_("Cannot create index"));

    if (db_grant_on_table(driver, Fi->table, DB_PRIV_SELECT,
                          DB_GROUP | DB_PUBLIC) != DB_OK)
        G_fatal_error(_("Cannot grant privileges on table <%s>"), Fi->table);

    db_begin_transaction(driver);

    /* Read stdin, find shortest path, and write connecting line and new
     * database record */
    cat = 0;
    formaterr = nopoint = unreachable = 0;
    while (1) {
        double fdist, tdist;

        if (!filename) {
            if (fgets(buf, sizeof(buf), stdin) == NULL)
                break;
        }
        else {
            if (G_getl2(buf, sizeof(buf) - 1, in_file) == 0)
                break;
        }

        G_chop(buf);

        sp = SP_OK;

        ret = sscanf(buf, "%d %lf %lf %lf %lf %s", &id, &fx, &fy, &tx, &ty,
                     dummy);
        if (ret == 5) {
            input_mode = INPUT_MODE_COOR;
            if (fx == tx && fy == ty) {
                G_warning(_("From and to are identical (id %d)"), id);
                continue;
            }
        }
        else {
            ret = sscanf(buf, "%d %d %d %s", &id, &fcat, &tcat, dummy);
            if (ret != 3) {
                G_warning(_("Wrong input format: %s"), buf);
                formaterr++;
                continue;
            }
            input_mode = INPUT_MODE_NODE;

            /* From */
            Citem = (CIDX *)bsearch((void *)&fcat, Cidx, npoints, sizeof(CIDX),
                                    cmp);
            if (Citem == NULL) {
                G_warning(_("No point with category [%d]"), fcat);
                sp = SP_NOPOINT;
                fline = 0;
                fnode = 0;
                nopoint++;
            }
            else {
                fline = Citem->line;
                type = Vect_read_line(In, Points, NULL, fline);
                fnode = Vect_find_node(In, Points->x[0], Points->y[0],
                                       Points->z[0], 0, 0);
                if (fnode == 0)
                    sp = SP_NOPOINT;
                /* Vect_get_line_nodes(In, fline, &fnode, NULL); */
            }
            G_debug(3, "from: cat = %5d point(line) = %5d node = %5d", fcat,
                    fline, fnode);

            /* To */
            Citem = (CIDX *)bsearch((void *)&tcat, Cidx, npoints, sizeof(CIDX),
                                    cmp);
            if (Citem == NULL) {
                G_warning(_("No point with category [%d]"), tcat);
                sp = SP_NOPOINT;
                tline = 0;
                tnode = 0;
                nopoint++;
            }
            else {
                tline = Citem->line;
                type = Vect_read_line(In, Points, NULL, tline);
                tnode = Vect_find_node(In, Points->x[0], Points->y[0],
                                       Points->z[0], 0, 0);
                if (tnode == 0)
                    sp = SP_NOPOINT;
                /* Vect_get_line_nodes(In, tline, &tnode, NULL); */
            }
            G_debug(3, "to  : cat = %5d point(line) = %5d node = %5d", tcat,
                    tline, tnode);

            if (sp == SP_NOPOINT)
                continue;

            if (fnode == tnode) {
                G_warning(_("From and to are identical (id %d)"), id);
                continue;
            }
        }

        G_debug(3, "mode = %d", input_mode);

        cat++; /* Output category */
        cost = fdist = tdist = 0;

        if (input_mode == INPUT_MODE_NODE) {
            if (use_ttb)
                ret = Vect_net_ttb_shortest_path(In, fnode, 0, tnode, 0,
                                                 tucfield, AList, &cost);
            else
                ret = Vect_net_shortest_path(In, fnode, tnode, AList, &cost);

            if (ret == -1) {
                sp = SP_UNREACHABLE;
                unreachable++;
                G_warning(_("Point with category [%d] is not reachable "
                            "from point with category [%d]"),
                          tcat, fcat);
            }
            else {
                /* Write new line connecting 'from' and 'to' */
                G_debug(3, "Number of arcs = %d, total costs = %f",
                        AList->n_values, cost);

                Vect_reset_cats(Cats);
                Vect_cat_set(Cats, 1, cat);

                if (segments) {
                    for (i = 0; i < AList->n_values; i++) {
                        line = AList->value[i];
                        Vect_read_line(In, Points, NULL, abs(line));

                        if (line > 0) {
                            Vect_write_line(Out, GV_LINE, Points, Cats);
                        }
                        else {
                            Vect_reset_line(OPoints);
                            Vect_append_points(OPoints, Points, GV_BACKWARD);
                            Vect_write_line(Out, GV_LINE, OPoints, Cats);
                        }
                    }
                }
                else {
                    Vect_reset_line(OPoints);

                    for (i = 0; i < AList->n_values; i++) {
                        line = AList->value[i];
                        Vect_read_line(In, Points, NULL, abs(line));
                        if (line > 0)
                            Vect_append_points(OPoints, Points, GV_FORWARD);
                        else
                            Vect_append_points(OPoints, Points, GV_BACKWARD);
                        OPoints->n_points--;
                    }
                    if (AList->n_values > 0 && OPoints->n_points > 0) {
                        OPoints->n_points++;
                        Vect_write_line(Out, GV_LINE, OPoints, Cats);
                    }
                }
            }
        }
        else { /* INPUT_MODE_COOR */
            fcat = tcat = 0;

            if (use_ttb)
                ret = Vect_net_ttb_shortest_path_coor(
                    In, fx, fy, 0.0, tx, ty, 0.0, maxdist, maxdist, tucfield,
                    &cost, OPoints, AList, NULL, FPoints, TPoints, &fdist,
                    &tdist);
            else
                ret = Vect_net_shortest_path_coor(
                    In, fx, fy, 0.0, tx, ty, 0.0, maxdist, maxdist, &cost,
                    OPoints, AList, NULL, FPoints, TPoints, &fdist, &tdist);

            if (ret == 0) {
                sp = SP_UNREACHABLE;
                unreachable++;
                G_warning(_("Point %f,%f is not reachable from "
                            "point %f,%f"),
                          tx, ty, fx, fy);
            }
            else {
                Vect_reset_cats(Cats);
                Vect_cat_set(Cats, 1, cat);

                if (segments) {
                    /* From point to the first node */
                    if (FPoints->n_points > 0)
                        Vect_write_line(Out, GV_LINE, FPoints, Cats);

                    /* On the network */
                    for (i = 0; i < AList->n_values; i++) {
                        line = AList->value[i];

                        Vect_read_line(In, Points, NULL, abs(line));

                        if (line > 0) {
                            Vect_write_line(Out, GV_LINE, Points, Cats);
                        }
                        else {
                            Vect_reset_line(OPoints);
                            Vect_append_points(OPoints, Points, GV_BACKWARD);
                            Vect_write_line(Out, GV_LINE, OPoints, Cats);
                        }
                    }

                    /* From last node to point */
                    if (TPoints->n_points > 0)
                        Vect_write_line(Out, GV_LINE, TPoints, Cats);
                }
                else {
                    if (OPoints->n_points > 0)
                        Vect_write_line(Out, GV_LINE, OPoints, Cats);
                }
            }
        }

        snprintf(buf, sizeof(buf),
                 "insert into %s values ( %d, %d, %d, %d, %d, %f, %f, %f)",
                 Fi->table, cat, id, fcat, tcat, sp, cost, fdist, tdist);
        db_set_string(&sql, buf);
        G_debug(3, "%s", db_get_string(&sql));

        if (db_execute_immediate(driver, &sql) != DB_OK) {
            G_fatal_error(_("Cannot insert new record: %s"),
                          db_get_string(&sql));
        }
    }

    db_commit_transaction(driver);

    db_close_database_shutdown_driver(driver);

    Vect_destroy_list(AList);
    Vect_destroy_line_struct(Points);
    Vect_destroy_line_struct(OPoints);
    Vect_destroy_cats_struct(Cats);

    if (filename)
        fclose(in_file);

    if (formaterr)
        G_warning(_("[%d] input format errors"), formaterr);
    if (nopoint)
        G_warning(_("[%d] points of given category missing"), nopoint);
    if (unreachable)
        G_warning(_("%d destination(s) unreachable (including points out "
                    "of threshold)"),
                  unreachable);

    return 1;
}

int cmp(const void *pa, const void *pb)
{
    CIDX *p1 = (CIDX *)pa;
    CIDX *p2 = (CIDX *)pb;

    if (p1->cat < p2->cat)
        return -1;
    if (p1->cat > p2->cat)
        return 1;
    return 0;
}
