#include <stdlib.h>
#include <limits.h>
#include <string.h>
#include <unistd.h>

#include <grass/gis.h>
#include <grass/raster.h>
#include <grass/raster.h>
#include <grass/raster3d.h>
#include <grass/btree.h>
#include <grass/glocale.h>
#include <grass/calc.h>

#include "mapcalc.h"
#include "globals.h"
#include "globals3.h"

/****************************************************************************/

static void prepare_region_from_maps(expression **, int, int);
RASTER3D_Region current_region3;

void setup_region(void)
{
    Rast3d_init_defaults();
    Rast3d_get_window(&current_region3);

    rows = current_region3.rows;
    columns = current_region3.cols;
    depths = current_region3.depths;
    calc_init(columns);
}

/****************************************************************************/

typedef struct map {
    const char *name;
    const char *mapset;
    int have_cats;
    int have_colors;
    int min_row, max_row;
    void *handle;
    int fd;
    struct Categories cats;
    struct Colors colors;
    BTREE btree;
} map;

/****************************************************************************/

static map *maps;
static int num_maps;
static int max_maps;

static void **omaps;
static int num_omaps;
static int max_omaps;

static unsigned char *red, *grn, *blu;
static unsigned char *set;

static int min_row = INT_MAX;
static int max_row = -INT_MAX;
static int min_col = INT_MAX;
static int max_col = -INT_MAX;

/****************************************************************************/

static void read_row(void *handle, char *buf, int type, int depth, int row)
{
    int i;

    switch (type) {
    case CELL_TYPE:
        for (i = 0; i < columns; i++) {
            double x;

            Rast3d_get_value(handle, i, row, depth, (char *)&x, DCELL_TYPE);
            if (Rast3d_is_null_value_num(&x, DCELL_TYPE))
                SET_NULL_C(&((CELL *)buf)[i]);
            else
                ((CELL *)buf)[i] = (CELL)x;
        }
        break;
    case FCELL_TYPE:
        for (i = 0; i < columns; i++) {
            float x;

            Rast3d_get_value(handle, i, row, depth, (char *)&x, FCELL_TYPE);
            if (Rast3d_is_null_value_num(&x, FCELL_TYPE))
                SET_NULL_F(&((FCELL *)buf)[i]);
            else
                ((FCELL *)buf)[i] = x;
        }
        break;
    case DCELL_TYPE:
        for (i = 0; i < columns; i++) {
            double x;

            Rast3d_get_value(handle, i, row, depth, (char *)&x, DCELL_TYPE);
            if (Rast3d_is_null_value_num(&x, DCELL_TYPE))
                SET_NULL_D(&((DCELL *)buf)[i]);
            else
                ((DCELL *)buf)[i] = x;
        }
        break;
    }
}

static void write_row(void *handle, const char *buf, int type, int depth,
                      int row)
{
    int i;

    switch (type) {
    case CELL_TYPE:
        for (i = 0; i < columns; i++) {
            double x;

            if (IS_NULL_C(&((CELL *)buf)[i]))
                Rast3d_set_null_value(&x, 1, DCELL_TYPE);
            else
                x = ((CELL *)buf)[i];

            if (Rast3d_put_value(handle, i, row, depth, (char *)&x,
                                 DCELL_TYPE) < 0)
                G_fatal_error(_("Error writing data"));
        }
        break;
    case FCELL_TYPE:
        for (i = 0; i < columns; i++) {
            float x;

            if (IS_NULL_F(&((FCELL *)buf)[i]))
                Rast3d_set_null_value(&x, 1, FCELL_TYPE);
            else
                x = ((FCELL *)buf)[i];

            if (Rast3d_put_value(handle, i, row, depth, (char *)&x,
                                 FCELL_TYPE) < 0)
                G_fatal_error(_("Error writing data"));
        }
        break;
    case DCELL_TYPE:
        for (i = 0; i < columns; i++) {
            double x;

            if (IS_NULL_D(&((DCELL *)buf)[i]))
                Rast3d_set_null_value(&x, 1, DCELL_TYPE);
            else
                x = ((DCELL *)buf)[i];

            if (Rast3d_put_value(handle, i, row, depth, (char *)&x,
                                 DCELL_TYPE) < 0)
                G_fatal_error(_("Error writing data"));
        }
        break;
    }
}

/****************************************************************************/

static int compare_ints(const void *a, const void *b)
{
    return *(const int *)a - *(const int *)b;
}

static void init_colors(map *m)
{
    if (!red)
        red = G_malloc(columns);
    if (!grn)
        grn = G_malloc(columns);
    if (!blu)
        blu = G_malloc(columns);
    if (!set)
        set = G_malloc(columns);

    if (Rast3d_read_colors((char *)m->name, (char *)m->mapset, &m->colors) < 0)
        G_fatal_error(_("Unable to read color file for raster map <%s@%s>"),
                      m->name, m->mapset);

    m->have_colors = 1;
}

static void init_cats(map *m)
{
    if (Rast3d_read_cats((char *)m->name, (char *)m->mapset, &m->cats) < 0)
        G_fatal_error(_("Unable to read category file of raster map <%s@%s>"),
                      m->name, m->mapset);

    if (!btree_create(&m->btree, compare_ints, 1))
        G_fatal_error(_("Unable to create btree for raster map <%s@%s>"),
                      m->name, m->mapset);

    m->have_cats = 1;
}

static void translate_from_colors(map *m, DCELL *rast, CELL *cell, int ncols,
                                  int mod)
{
    int i;

    Rast_lookup_d_colors(rast, red, grn, blu, set, ncols, &m->colors);

    switch (mod) {
    case 'r':
        for (i = 0; i < ncols; i++)
            cell[i] = red[i];
        break;
    case 'g':
        for (i = 0; i < ncols; i++)
            cell[i] = grn[i];
        break;
    case 'b':
        for (i = 0; i < ncols; i++)
            cell[i] = blu[i];
        break;
    case '#': /* grey (backwards compatible) */
        /* old weightings: R=0.177, G=0.813, B=0.011 */
        for (i = 0; i < ncols; i++)
            cell[i] = (181 * red[i] + 833 * grn[i] + 11 * blu[i] + 512) / 1024;
        break;
    case 'y': /* grey (NTSC) */
        /* NTSC weightings: R=0.299, G=0.587, B=0.114 */
        for (i = 0; i < ncols; i++)
            cell[i] = (306 * red[i] + 601 * grn[i] + 117 * blu[i] + 512) / 1024;
        break;
    case 'i': /* grey (equal weight) */
        for (i = 0; i < ncols; i++)
            cell[i] = (red[i] + grn[i] + blu[i]) / 3;
        break;
    case 'M':
    case '@':
    default:
        G_fatal_error(_("Invalid map modifier: '%c'"), mod);
        break;
    }
}

/* convert cell values to double based on the values in the
 * category file.
 *
 * This requires performing sscanf() of the category label
 * and only do it it for new categories. Must maintain
 * some kind of maps of already scanned values.
 *
 * This maps is a hybrid tree, where the data in each node
 * of the tree is an array of, for example, 64 values, and
 * the key of the tree is the category represented by the
 * first index of the data
 *
 * To speed things up a little, use shifts instead of divide or multiply
 * to compute the key and the index
 *
 * This uses the BTREE library to manage the tree itself
 * btree structure must already be initialized
 * pcats structure must already contain category labels
 */

#define SHIFT 6
#define NCATS (1 << SHIFT)

static void translate_from_cats(map *m, CELL *cell, DCELL *xcell, int ncols)
{
    struct Categories *pcats;
    BTREE *btree;
    int i, idx;
    CELL cat, key;
    double vbuf[1 << SHIFT];
    double *values;
    void *ptr;
    char *label;

    btree = &m->btree;
    pcats = &m->cats;

    for (; ncols-- > 0; cell++, xcell++) {
        cat = *cell;
        if (IS_NULL_C(cell)) {
            SET_NULL_D(xcell);
            continue;
        }

        /* compute key as cat/NCATS * NCATS, adjusting down for negatives
         * and idx so that key+idx == cat
         */
        if (cat < 0)
            key = -(((-cat - 1) >> SHIFT) << SHIFT) - NCATS;
        else
            key = (cat >> SHIFT) << SHIFT;
        idx = cat - key;

        /* If key not already in the tree, sscanf() all cats for this key
         * and put them into the tree
         */
        if (!btree_find(btree, &key, &ptr)) {
            values = vbuf;
            int cat = i + key;

            for (i = 0; i < NCATS; i++) {
                if ((label = Rast_get_c_cat((CELL *)&cat, pcats)) == NULL ||
                    sscanf(label, "%lf", values) != 1)
                    SET_NULL_D(values);
                values++;
            }

            values = vbuf;
            btree_update(btree, &key, sizeof(key), vbuf, sizeof(vbuf));
        }
        else
            values = ptr;

        /* and finally lookup the translated value */
        if (IS_NULL_D(&values[idx]))
            SET_NULL_D(xcell);
        else
            *xcell = values[idx];
    }
}

static void setup_map(map *m UNUSED)
{
}

static void read_map(map *m, void *buf, int res_type, int depth, int row,
                     int col)
{
    CELL *ibuf = buf;
    FCELL *fbuf = buf;
    DCELL *dbuf = buf;

    if (row < 0 || row >= rows || depth < 0 || depth >= depths) {
        int i;

        switch (res_type) {
        case CELL_TYPE:
            for (i = 0; i < columns; i++)
                SET_NULL_C(&ibuf[i]);
            break;
        case FCELL_TYPE:
            for (i = 0; i < columns; i++)
                SET_NULL_F(&fbuf[i]);
            break;
        case DCELL_TYPE:
            for (i = 0; i < columns; i++)
                SET_NULL_D(&dbuf[i]);
            break;
        default:
            G_fatal_error(_("Unknown type: %d"), res_type);
            break;
        }

        return;
    }

    read_row(m->handle, buf, res_type, depth, row);

    if (col)
        column_shift(buf, res_type, col);
}

static void close_map(map *m)
{
    if (!m->handle)
        return;

    if (!Rast3d_close(m->handle))
        G_fatal_error(_("Unable to close raster map <%s@%s>"), m->name,
                      m->mapset);

    if (m->have_cats) {
        btree_free(&m->btree);
        Rast_free_cats(&m->cats);
        m->have_cats = 0;
    }

    if (m->have_colors) {
        Rast_free_colors(&m->colors);
        m->have_colors = 0;
    }
}

/****************************************************************************/

int map_type(const char *name, int mod)
{
    const char *mapset;
    char *tmpname;
    int result;

    switch (mod) {
    case 'M':
        tmpname = G_store((char *)name);
        mapset = G_find_raster3d(tmpname, "");
        if (mapset) {
            void *handle;

            setup_region(); /* TODO: setup_region should be called by evaluate()
                               ? */
            handle = Rast3d_open_cell_old(tmpname, mapset, &current_region3,
                                          RASTER3D_TILE_SAME_AS_FILE,
                                          RASTER3D_NO_CACHE);
            result = (Rast3d_file_type_map(handle) == FCELL_TYPE) ? FCELL_TYPE
                                                                  : DCELL_TYPE;
            Rast3d_close(handle);
        }
        else
            result = -1;
        G_free(tmpname);
        return result;
    case '@':
        return DCELL_TYPE;
    case 'r':
    case 'g':
    case 'b':
    case '#':
    case 'y':
    case 'i':
        return CELL_TYPE;
    default:
        G_fatal_error(_("Invalid map modifier: '%c'"), mod);
        return -1;
    }
}

int open_map(const char *name, int mod, int row, int col)
{
    int i;
    const char *mapset;
    char *tmpname;
    int use_cats = 0;
    int use_colors = 0;
    map *m;

    if (row < min_row)
        min_row = row;
    if (row > max_row)
        max_row = row;
    if (col < min_col)
        min_col = col;
    if (col > max_col)
        max_col = col;

    tmpname = G_store((char *)name);
    mapset = G_find_raster3d(tmpname, "");
    G_free(tmpname);

    if (!mapset)
        G_fatal_error("open_map: map [%s] not found", name);

    switch (mod) {
    case 'M':
        break;
    case '@':
        use_cats = 1;
        break;
    case 'r':
    case 'g':
    case 'b':
    case '#':
    case 'y':
    case 'i':
        use_colors = 1;
        break;
    default:
        G_fatal_error(_("Invalid map modifier: '%c'"), mod);
        break;
    }

    for (i = 0; i < num_maps; i++) {
        m = &maps[i];

        if (strcmp(m->name, name) != 0 || strcmp(m->mapset, mapset) != 0)
            continue;

        if (row < m->min_row)
            m->min_row = row;
        if (row > m->max_row)
            m->max_row = row;

        if (use_cats && !m->have_cats)
            init_cats(m);

        if (use_colors && !m->have_colors)
            init_colors(m);

        return i;
    }

    if (num_maps >= max_maps) {
        max_maps += 10;
        maps = G_realloc(maps, max_maps * sizeof(map));
    }

    m = &maps[num_maps];

    m->name = name;
    m->mapset = mapset;
    m->have_cats = 0;
    m->have_colors = 0;
    m->min_row = row;
    m->max_row = row;

    if (use_cats)
        init_cats(m);
    if (use_colors)
        init_colors(m);

    m->handle =
        Rast3d_open_cell_old((char *)name, (char *)mapset, &current_region3,
                             DCELL_TYPE, RASTER3D_USE_CACHE_DEFAULT);

    if (!m->handle)
        G_fatal_error(_("Unable to open raster map <%s>"), name);

    return num_maps++;
}

void setup_maps(void)
{
    int i;

    /* We need to reduce the number of worker threads to one, to
     * avoid that several threads access a single map for reading
     * at the same time. The raster3d library is not thread safe.
     * */
    putenv("WORKERS=0");

    for (i = 0; i < num_maps; i++)
        setup_map(&maps[i]);
}

void get_map_row(int idx, int mod, int depth, int row, int col, void *buf,
                 int res_type)
{
    static CELL *ibuf;
    static DCELL *fbuf;
    map *m = &maps[idx];

    switch (mod) {
    case 'M':
        read_map(m, buf, res_type, depth, row, col);
        break;
    case '@':
        if (!ibuf)
            ibuf = G_malloc(columns * sizeof(CELL));
        read_map(m, ibuf, CELL_TYPE, depth, row, col);
        translate_from_cats(m, ibuf, buf, columns);
        break;
    case 'r':
    case 'g':
    case 'b':
    case '#':
    case 'y':
    case 'i':
        if (!fbuf)
            fbuf = G_malloc(columns * sizeof(DCELL));
        read_map(m, fbuf, DCELL_TYPE, depth, row, col);
        translate_from_colors(m, fbuf, buf, columns, mod);
        break;
    default:
        G_fatal_error(_("Invalid map modifier: '%c'"), mod);
        break;
    }
}

void close_maps(void)
{
    int i;

    for (i = 0; i < num_maps; i++)
        close_map(&maps[i]);

    num_maps = 0;
}

void list_maps(FILE *fp, const char *sep)
{
    int i;

    for (i = 0; i < num_maps; i++) {
        const struct map *m = &maps[i];

        fprintf(fp, "%s%s@%s", i ? sep : "", m->name, m->mapset);
    }
}

/****************************************************************************/

int check_output_map(const char *name)
{
    return !!G_find_raster3d(name, G_mapset());
}

int open_output_map(const char *name, int res_type)
{
    void *handle;

    Rast3d_set_file_type(res_type == FCELL_TYPE ? FCELL_TYPE : DCELL_TYPE);

    handle = Rast3d_open_new_opt_tile_size(
        (char *)name, RASTER3D_USE_CACHE_XYZ, &current_region3,
        res_type == FCELL_TYPE ? FCELL_TYPE : DCELL_TYPE, 32);

    if (!handle)
        G_fatal_error(_("Unable to create raster map <%s>"), name);

    if (num_omaps >= max_omaps) {
        max_omaps += 10;
        omaps = G_realloc(omaps, max_omaps * sizeof(void *));
    }

    omaps[num_omaps] = handle;

    return num_omaps++;
}

void put_map_row(int fd, void *buf, int res_type)
{
    void *handle = omaps[fd];

    write_row(handle, buf, res_type, current_depth, current_row);
}

void close_output_map(int fd)
{
    void *handle = omaps[fd];

    if (!Rast3d_close(handle))
        G_fatal_error(_("Unable to close output raster map"));
}

void unopen_output_map(int fd)
{
    close_output_map(fd);
}

/****************************************************************************/

void copy_cats(const char *dst, int idx)
{
    const map *m = &maps[idx];
    struct Categories cats;

    if (Rast3d_read_cats((char *)m->name, (char *)m->mapset, &cats) < 0)
        return;

    Rast3d_write_cats((char *)dst, &cats);
    Rast_free_cats(&cats);
}

void copy_colors(const char *dst, int idx)
{
    const map *m = &maps[idx];
    struct Colors colr;

    if (Rast3d_read_colors((char *)m->name, (char *)m->mapset, &colr) <= 0)
        return;

    Rast3d_write_colors((char *)dst, G_mapset(), &colr);
    Rast_free_colors(&colr);
}

void copy_history(const char *dst UNUSED, int idx UNUSED)
{
}

void create_history(const char *dst UNUSED, expression *e UNUSED)
{
}

/****************************************************************************/

void prepare_region_from_maps_union(expression **map_list, int num_maps)
{
    prepare_region_from_maps(map_list, 1, num_maps);
}

void prepare_region_from_maps_intersect(expression **map_list, int num_maps)
{
    prepare_region_from_maps(map_list, 2, num_maps);
}

void prepare_region_from_maps(expression **map_list, int type, int num_maps)
{
    /* \brief Setup the computational region from all 3d raster maps
     *
     * This function computes the disjoint union or intersection extent
     * that is covered by all 3d raster maps and sets the smallest
     * resolution that it can find.
     *
     * TODO: Must be implemented
     */

    G_fatal_error("Union or intersection of regions is not implemented");

    int first = 0;
    struct Cell_head window, temp_window;
    int i;
    const char *mapset;

    for (i = 0; i < num_maps; i++) {
        expression *e = map_list[i];

        char rast_name[GNAME_MAX];

        strcpy(rast_name, e->data.map.name);
        mapset = G_find_raster2(rast_name, "");

        if (!mapset)
            G_fatal_error(_("Raster map <%s> not found"), rast_name);

        G_debug(1, "Setting region from raster map: %s@%s", rast_name, mapset);

        Rast_get_cellhd(rast_name, mapset, &temp_window);

        if (!first) {
            window = temp_window;
            first = 1;
        }
        else {
            if (type == 1) {
                /* Union: find the largest extent */
                window.north = (window.north > temp_window.north)
                                   ? window.north
                                   : temp_window.north;
                window.south = (window.south < temp_window.south)
                                   ? window.south
                                   : temp_window.south;
                window.east = (window.east > temp_window.east)
                                  ? window.east
                                  : temp_window.east;
                window.west = (window.west < temp_window.west)
                                  ? window.west
                                  : temp_window.west;
            }
            else {
                /* Intersect: Find the smallest extent */
                window.north = (window.north < temp_window.north)
                                   ? window.north
                                   : temp_window.north;
                window.south = (window.south > temp_window.south)
                                   ? window.south
                                   : temp_window.south;
                window.east = (window.east < temp_window.east)
                                  ? window.east
                                  : temp_window.east;
                window.west = (window.west > temp_window.west)
                                  ? window.west
                                  : temp_window.west;
            }
            /* Find the smallest resolution */
            window.ns_res = (window.ns_res < temp_window.ns_res)
                                ? window.ns_res
                                : temp_window.ns_res;
            window.ew_res = (window.ew_res < temp_window.ew_res)
                                ? window.ew_res
                                : temp_window.ew_res;
        }
    }

    /* Set the region only if a map was found in the expression */
    if (first == 1) {
        G_adjust_Cell_head3(&window, 0, 0, 0);
        G_debug(1, "Region was set to n %g s %g e %g w %g ns_res %g ew_res %g",
                window.north, window.south, window.east, window.west,
                window.ns_res, window.ew_res);
        G_put_window(&window);
    }
}

/****************************************************************************/
