/* $Id$ */

#include "stdafx.h"
#include "openttd.h"
#include "table/strings.h"
#include "functions.h"
#include "player.h"
#include "signs.h"
#include "saveload.h"
#include "command.h"
#include "variables.h"

static Sign *_new_sign;

enum {
	/* Max signs: 64000 (4 * 16000) */
	SIGN_POOL_BLOCK_SIZE_BITS = 2,       /* In bits, so (1 << 2) == 4 */
	SIGN_POOL_MAX_BLOCKS      = 16000,
};

/**
 * Called if a new block is added to the sign-pool
 */
static void SignPoolNewBlock(uint start_item)
{
	Sign *si;

	/* We don't use FOR_ALL here, because FOR_ALL skips invalid items.
	 * TODO - This is just a temporary stage, this will be removed. */
	for (si = GetSign(start_item); si != NULL; si = (si->index + 1 < GetSignPoolSize()) ? GetSign(si->index + 1) : NULL) si->index = start_item++;
}

/* Initialize the sign-pool */
MemoryPool _sign_pool = { "Signs", SIGN_POOL_MAX_BLOCKS, SIGN_POOL_BLOCK_SIZE_BITS, sizeof(Sign), &SignPoolNewBlock, NULL, 0, 0, NULL };

/**
 *
 * Update the coordinate of one sign
 *
 */
static void UpdateSignVirtCoords(Sign *si)
{
	Point pt = RemapCoords(si->x, si->y, si->z);
	SetDParam(0, si->str);
	UpdateViewportSignPos(&si->sign, pt.x, pt.y - 6, STR_2806);
}

/**
 *
 * Update the coordinates of all signs
 *
 */
void UpdateAllSignVirtCoords(void)
{
	Sign *si;

	FOR_ALL_SIGNS(si) UpdateSignVirtCoords(si);

}

/**
 *
 * Marks the region of a sign as dirty
 *
 * @param si Pointer to the Sign
 */
static void MarkSignDirty(Sign *si)
{
	MarkAllViewportsDirty(
		si->sign.left - 6,
		si->sign.top  - 3,
		si->sign.left + si->sign.width_1 * 4 + 12,
		si->sign.top  + 45);
}

/**
 *
 * Allocates a new sign
 *
 * @return The pointer to the new sign, or NULL if there is no more free space
 */
static Sign *AllocateSign(void)
{
	Sign *si;

	/* We don't use FOR_ALL here, because FOR_ALL skips invalid items.
	 * TODO - This is just a temporary stage, this will be removed. */
	for (si = GetSign(0); si != NULL; si = (si->index + 1 < GetSignPoolSize()) ? GetSign(si->index + 1) : NULL) {
		if (!IsValidSign(si)) {
			uint index = si->index;

			memset(si, 0, sizeof(Sign));
			si->index = index;

			return si;
		}
	}

	/* Check if we can add a block to the pool */
	if (AddBlockToPool(&_sign_pool))
		return AllocateSign();

	return NULL;
}

void DestroySign(Sign *si)
{
	DeleteName(si->str);
}

/**
 * Place a sign at the given coordinates. Ownership of sign has
 * no effect whatsoever except for the colour the sign gets for easy recognition,
 * but everybody is able to rename/remove it.
 * @param tile tile to place sign at
 * @param p1 unused
 * @param p2 unused
 */
int32 CmdPlaceSign(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
{
	Sign *si;

	/* Try to locate a new sign */
	si = AllocateSign();
	if (si == NULL) return_cmd_error(STR_2808_TOO_MANY_SIGNS);

	/* When we execute, really make the sign */
	if (flags & DC_EXEC) {
		int x = TileX(tile) * TILE_SIZE;
		int y = TileY(tile) * TILE_SIZE;

		si->str = STR_280A_SIGN;
		si->x = x;
		si->y = y;
		si->owner = _current_player; // owner of the sign; just eyecandy
		si->z = GetSlopeZ(x,y);
		UpdateSignVirtCoords(si);
		MarkSignDirty(si);
		InvalidateWindow(WC_SIGN_LIST, 0);
		_sign_sort_dirty = true;
		_new_sign = si;
	}

	return 0;
}

/** Rename a sign. If the new name of the sign is empty, we assume
 * the user wanted to delete it. So delete it. Ownership of signs
 * has no meaning/effect whatsoever except for eyecandy
 * @param tile unused
 * @param p1 index of the sign to be renamed/removed
 * @param p2 unused
 */
int32 CmdRenameSign(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
{
	if (!IsValidSignID(p1)) return CMD_ERROR;

	/* If _cmd_text 0 means the new text for the sign is non-empty.
	 * So rename the sign. If it is empty, it has no name, so delete it */
	if (_cmd_text[0] != '\0') {
		/* Create the name */
		StringID str = AllocateName(_cmd_text, 0);
		if (str == 0) return CMD_ERROR;

		if (flags & DC_EXEC) {
			Sign *si = GetSign(p1);

			/* Delete the old name */
			DeleteName(si->str);
			/* Assign the new one */
			si->str = str;
			si->owner = _current_player;

			/* Update; mark sign dirty twice, because it can either becom longer, or shorter */
			MarkSignDirty(si);
			UpdateSignVirtCoords(si);
			MarkSignDirty(si);
			InvalidateWindow(WC_SIGN_LIST, 0);
			_sign_sort_dirty = true;
		} else {
			/* Free the name, because we did not assign it yet */
			DeleteName(str);
		}
	} else { /* Delete sign */
		if (flags & DC_EXEC) {
			Sign *si = GetSign(p1);

			MarkSignDirty(si);
			DeleteSign(si);

			InvalidateWindow(WC_SIGN_LIST, 0);
			_sign_sort_dirty = true;
		}
	}

	return 0;
}

/**
 *
 * Callback function that is called after a sign is placed
 *
 */
void CcPlaceSign(bool success, TileIndex tile, uint32 p1, uint32 p2)
{
	if (success) {
		ShowRenameSignWindow(_new_sign);
		ResetObjectToPlace();
	}
}

/**
 *
 * PlaceProc function, called when someone pressed the button if the
 *  sign-tool is selected
 *
 */
void PlaceProc_Sign(TileIndex tile)
{
	DoCommandP(tile, 0, 0, CcPlaceSign, CMD_PLACE_SIGN | CMD_MSG(STR_2809_CAN_T_PLACE_SIGN_HERE));
}

/**
 *
 * Initialize the signs
 *
 */
void InitializeSigns(void)
{
	CleanPool(&_sign_pool);
	AddBlockToPool(&_sign_pool);
}

static const SaveLoad _sign_desc[] = {
      SLE_VAR(Sign, str,   SLE_UINT16),
  SLE_CONDVAR(Sign, x,     SLE_FILE_I16 | SLE_VAR_I32, 0, 4),
  SLE_CONDVAR(Sign, y,     SLE_FILE_I16 | SLE_VAR_I32, 0, 4),
  SLE_CONDVAR(Sign, x,     SLE_INT32,                  5, SL_MAX_VERSION),
  SLE_CONDVAR(Sign, y,     SLE_INT32,                  5, SL_MAX_VERSION),
  SLE_CONDVAR(Sign, owner, SLE_UINT8,                  6, SL_MAX_VERSION),
      SLE_VAR(Sign, z,     SLE_UINT8),
	SLE_END()
};

/**
 *
 * Save all signs
 *
 */
static void Save_SIGN(void)
{
	Sign *si;

	FOR_ALL_SIGNS(si) {
		SlSetArrayIndex(si->index);
		SlObject(si, _sign_desc);
	}
}

/**
 *
 * Load all signs
 *
 */
static void Load_SIGN(void)
{
	int index;
	while ((index = SlIterateArray()) != -1) {
		Sign *si;

		if (!AddBlockIfNeeded(&_sign_pool, index))
			error("Signs: failed loading savegame: too many signs");

		si = GetSign(index);
		SlObject(si, _sign_desc);
	}

	_sign_sort_dirty = true;
}

const ChunkHandler _sign_chunk_handlers[] = {
	{ 'SIGN', Save_SIGN, Load_SIGN, CH_ARRAY | CH_LAST},
};