/* vim: set sw=8: */

/*
 * sheet-merge.c: merged cell support
 *
 * Copyright (C) 2000-2002 Jody Goldberg (jody@gnome.org)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */
#include <gnumeric-config.h>
#include <glib/gi18n.h>
#include "gnumeric.h"
#include "sheet-merge.h"

#include "sheet-object.h"
#include "sheet.h"
#include "sheet-view.h"
#include "sheet-private.h"
#include "ranges.h"
#include "cell.h"
#include "cellspan.h"
#include "sheet-style.h"
#include "mstyle.h"
#include "expr.h"
#include "command-context.h"

static gint
range_row_cmp (GnmRange const *a, GnmRange const *b)
{
	int tmp = b->start.row - a->start.row;
	if (tmp == 0)
		tmp = a->start.col - b->start.col; /* YES I DO MEAN a - b */
	return tmp;
}

/**
 * sheet_merge_add :
 *
 * @sheet : the sheet which will contain the region
 * @src : The region to merge
 * @clear : should the non-corner content of the region be cleared and the
 *          style from the corner applied.
 * @cc : the calling context
 *
 * Add a range to the list of merge targets.  Checks for array spliting returns
 * TRUE if there was an error.  Does not regen spans, redraw or render.
 */
gboolean
sheet_merge_add (Sheet *sheet, GnmRange const *r, gboolean clear,
		 GnmCmdContext *cc)
{
	GSList *test;
	GnmRange  *r_copy;
	GnmCell   *cell;
	GnmStyle *style;
	GnmComment *comment;

	g_return_val_if_fail (IS_SHEET (sheet), TRUE);
	g_return_val_if_fail (range_is_sane (r), TRUE);

	if (sheet_range_splits_array (sheet, r, NULL, cc, _("Merge")))
		return TRUE;

	test = sheet_merge_get_overlap (sheet, r);
	if (test != NULL) {
		if (cc != NULL)
			gnm_cmd_context_error (cc, g_error_new (gnm_error_invalid(), 0,
				_("There is already a merged region that intersects\n%s!%s"),
				sheet->name_unquoted, range_name (r)));
		g_slist_free (test);
		return TRUE;
	}

	if (clear) {
		int i;

		sheet_redraw_range (sheet, r);

		/* Clear the non-corner content */
		if (r->start.col != r->end.col)
			sheet_clear_region (sheet,
					    r->start.col+1, r->start.row,
					    r->end.col, r->end.row,
					    CLEAR_VALUES | CLEAR_COMMENTS | CLEAR_NOCHECKARRAY | CLEAR_NORESPAN,
					    cc);
		if (r->start.row != r->end.row)
			sheet_clear_region (sheet,
					    r->start.col, r->start.row+1,
	    /* yes I mean start.col */	    r->start.col, r->end.row,
					    CLEAR_VALUES | CLEAR_COMMENTS | CLEAR_NOCHECKARRAY | CLEAR_NORESPAN,
					    cc);

		/* Apply the corner style to the entire region */
		style = mstyle_copy (sheet_style_get (sheet, r->start.col,
						      r->start.row));
		for (i = MSTYLE_BORDER_TOP; i <= MSTYLE_BORDER_DIAGONAL; i++)
			mstyle_unset_element (style, i);
		sheet_style_apply_range (sheet, r, style);
		sheet_region_queue_recalc (sheet, r);
	}

	r_copy = range_dup (r);
	g_hash_table_insert (sheet->hash_merged, &r_copy->start, r_copy);

	/* Store in order from bottom to top then LEFT TO RIGHT (by start coord) */
	sheet->list_merged = g_slist_insert_sorted (sheet->list_merged, r_copy,
						    (GCompareFunc)range_row_cmp);

	cell = sheet_cell_get (sheet, r->start.col, r->start.row);
	if (cell != NULL) {
		cell->base.flags |= CELL_IS_MERGED;
		cell_unregister_span (cell);
	}
	sheet_queue_respan (sheet, r->start.row, r->end.row);

	/* Ensure that edit pos is not in the center of a region. */
	SHEET_FOREACH_VIEW (sheet, sv, {
		sv->reposition_selection = TRUE;
		if (range_contains (r, sv->edit_pos.col, sv->edit_pos.row))
			sv_set_edit_pos (sv, &r->start);
	});

	comment = cell_has_comment_pos (sheet, &r->start);
	if (comment != NULL)
		sheet_object_update_bounds (SHEET_OBJECT (comment), NULL);

	sheet_flag_status_update_range (sheet, r);
	if (sheet->cols.max_used < r->end.col) {
		sheet->cols.max_used = r->end.col;
		sheet->priv->resize_scrollbar = TRUE;
	}
	if (sheet->rows.max_used < r->end.row) {
		sheet->rows.max_used = r->end.row;
		sheet->priv->resize_scrollbar = TRUE;
	}
	return FALSE;
}

/**
 * sheet_merge_remove :
 *
 * @sheet : the sheet which will contain the region
 * @range : The region
 * @cc    : the calling context
 *
 * Remove a merged range.
 * returns TRUE if there was an error.
 */
gboolean
sheet_merge_remove (Sheet *sheet, GnmRange const *r, GnmCmdContext *cc)
{
	GnmRange   *r_copy;
	GnmCell    *cell;
	GnmComment *comment;

	g_return_val_if_fail (IS_SHEET (sheet), TRUE);
	g_return_val_if_fail (r != NULL, TRUE);

	r_copy = g_hash_table_lookup (sheet->hash_merged, &r->start);

	g_return_val_if_fail (r_copy != NULL, TRUE);
	g_return_val_if_fail (range_equal (r, r_copy), TRUE);

	g_hash_table_remove (sheet->hash_merged, &r_copy->start);
	sheet->list_merged = g_slist_remove (sheet->list_merged, r_copy);

	cell = sheet_cell_get (sheet, r->start.col, r->start.row);
	if (cell != NULL)
		cell->base.flags &= ~CELL_IS_MERGED;

	comment = cell_has_comment_pos (sheet, &r->start);
	if (comment != NULL)
		sheet_object_update_bounds (SHEET_OBJECT (comment), NULL);

	sheet_flag_status_update_range (sheet, r);
	SHEET_FOREACH_VIEW (sheet, sv, sv->reposition_selection = TRUE;);
	g_free (r_copy);
	return FALSE;
}

/**
 * sheet_merge_get_overlap :
 *
 * Returns a list of the merged regions that overlap the target region.
 * The list is ordered from top to bottom and RIGHT TO LEFT (by start coord).
 * Caller is responsible for freeing the list, but not the content.
 */
GSList *
sheet_merge_get_overlap (Sheet const *sheet, GnmRange const *range)
{
	GSList *ptr, *res = NULL;

	g_return_val_if_fail (IS_SHEET (sheet), NULL);
	g_return_val_if_fail (range != NULL, NULL);

	for (ptr = sheet->list_merged ; ptr != NULL ; ptr = ptr->next) {
		GnmRange * const test = ptr->data;

		if (range_overlap (range, test))
			res = g_slist_prepend (res, test);
	}

	return res;
}

/**
 * sheet_merge_contains_pos :
 *
 * If the GnmCellPos is contained in the a merged region return the range.
 * The GnmRange should NOT be freed.
 */
GnmRange const *
sheet_merge_contains_pos (Sheet const *sheet, GnmCellPos const *pos)
{
	GSList *ptr;

	g_return_val_if_fail (IS_SHEET (sheet), NULL);
	g_return_val_if_fail (pos != NULL, NULL);

	for (ptr = sheet->list_merged ; ptr != NULL ; ptr = ptr->next) {
		GnmRange const * const range = ptr->data;
		if (range_contains (range, pos->col, pos->row))
			return range;
	}
	return NULL;
}

/**
 * sheet_merge_get_adjacent
 * @sheet : The sheet to look in.
 * @pos : the cell to test for adjacent regions.
 * @left : the return for a region on the left
 * @right : the return for a region on the right
 *
 * Returns the nearest regions to either side of @pos.
 */
void
sheet_merge_get_adjacent (Sheet const *sheet, GnmCellPos const *pos,
			  GnmRange const **left, GnmRange const **right)
{
	GSList *ptr;

	g_return_if_fail (IS_SHEET (sheet));
	g_return_if_fail (pos != NULL);

	*left = *right = NULL;
	for (ptr = sheet->list_merged ; ptr != NULL ; ptr = ptr->next) {
		GnmRange const * const test = ptr->data;
		if (test->start.row <= pos->row && pos->row <= test->end.row) {
			int const diff = test->end.col - pos->col;

			g_return_if_fail (diff != 0);

			if (diff < 0) {
				if (*left == NULL || (*left)->end.col < test->end.col)
					*left = test;
			} else {
				if (*right == NULL || (*right)->start.col > test->start.col)
					*right = test;
			}
		}
	}
}

/**
 * sheet_merge_is_corner :
 *
 * @sheet :
 * @pos : cellpos if top left corner
 *
 * Returns a GnmRange pointer if the @pos is the topleft of a merged region.
 * The pointer should NOT be freed by the caller.
 */
GnmRange const *
sheet_merge_is_corner (Sheet const *sheet, GnmCellPos const *pos)
{
	g_return_val_if_fail (IS_SHEET (sheet), NULL);
	g_return_val_if_fail (pos != NULL, NULL);

	return g_hash_table_lookup (sheet->hash_merged, pos);
}

/**
 * sheet_merge_relocate :
 *
 * @rinfo : Descriptor of what is moving.
 *
 * Shifts merged regions that need to move.
 */
void
sheet_merge_relocate (GnmExprRelocateInfo const *ri)
{
	GSList   *ptr, *copy, *to_move = NULL;
	GnmRange	 dest;
	gboolean change_sheets;

	g_return_if_fail (ri != NULL);
	g_return_if_fail (IS_SHEET (ri->origin_sheet));
	g_return_if_fail (IS_SHEET (ri->target_sheet));

	dest = ri->origin;
	range_translate (&dest, ri->col_offset, ri->row_offset);
	change_sheets = (ri->origin_sheet != ri->target_sheet);

	/* Clear the destination range on the target sheet */
	if (change_sheets) {
		copy = g_slist_copy (ri->target_sheet->list_merged);
		for (ptr = copy; ptr != NULL ; ptr = ptr->next) {
			GnmRange const *r = ptr->data;
			if (range_contains (&dest, r->start.col, r->start.row))
				sheet_merge_remove (ri->target_sheet, r, NULL);
		}
		g_slist_free (copy);
	}

	copy = g_slist_copy (ri->origin_sheet->list_merged);
	for (ptr = copy; ptr != NULL ; ptr = ptr->next ) {
		GnmRange const *r = ptr->data;
		if (range_contains (&ri->origin, r->start.col, r->start.row)) {
			GnmRange tmp = *r;

			/* Toss any merges that would be clipped. */
			sheet_merge_remove (ri->origin_sheet, r, NULL);
			if (!range_translate (&tmp, ri->col_offset, ri->row_offset))
				to_move = g_slist_prepend (to_move, range_dup (&tmp));
		} else if (!change_sheets &&
			   range_contains (&dest, r->start.col, r->start.row))
			sheet_merge_remove (ri->origin_sheet, r, NULL);
	}
	g_slist_free (copy);

	/* move the ranges after removing the previous content in case of overlap */
	for (ptr = to_move ; ptr != NULL ; ptr = ptr->next) {
		GnmRange *dest = ptr->data;
		sheet_merge_add (ri->target_sheet, dest, TRUE, NULL);
		g_free (dest);
	}
	g_slist_free (to_move);
}

/**
 * sheet_merge_find_container
 * @sheet : sheet
 * @r     : the range to test
 */
void
sheet_merge_find_container (Sheet const *sheet, GnmRange *target)
{
	gboolean changed;
	GSList *merged, *ptr;

	/* expand to include any merged regions */
	do {
		changed = FALSE;
		merged = sheet_merge_get_overlap (sheet, target);
		for (ptr = merged ; ptr != NULL ; ptr = ptr->next) {
			GnmRange const *r = ptr->data;
			if (target->start.col > r->start.col) {
				target->start.col = r->start.col;
				changed = TRUE;
			}
			if (target->start.row > r->start.row) {
				target->start.row = r->start.row;
				changed = TRUE;
			}
			if (target->end.col < r->end.col) {
				target->end.col = r->end.col;
				changed = TRUE;
			}
			if (target->end.row < r->end.row) {
				target->end.row = r->end.row;
				changed = TRUE;
			}
		}
		g_slist_free (merged);
	} while (changed);

}