// Copyright (c) Athena Dev Teams - Licensed under GNU GPL
// For more information, see LICENCE in the main folder

#include "../common/cbasetypes.h"
#include "../common/db.h"  // ARR_FIND
#include "../common/showmsg.h"  // ShowWarning
#include "../common/socket.h"  // RBUF*
#include "../common/strlib.h"  // safestrncpy
#include "atcommand.h"  // msg_txt
#include "battle.h"  // battle_config.*
#include "buyingstore.h"  // struct s_buyingstore
#include "clif.h"  // clif_buyingstore_*
#include "log.h"  // log_pick_pc, log_zeny
#include "pc.h"  // struct map_session_data


/// constants (client-side restrictions)
#define BUYINGSTORE_MAX_PRICE 99990000
#define BUYINGSTORE_MAX_AMOUNT 9999


/// failure constants for clif functions
enum e_buyingstore_failure
{
	BUYINGSTORE_CREATE               = 1,  // "Failed to open buying store."
	BUYINGSTORE_CREATE_OVERWEIGHT    = 2,  // "Total amount of then possessed items exceeds the weight limit by %d. Please re-enter."
	BUYINGSTORE_TRADE_BUYER_ZENY     = 3,  // "All items within the buy limit were purchased."
	BUYINGSTORE_TRADE_BUYER_NO_ITEMS = 4,  // "All items were purchased."
	BUYINGSTORE_TRADE_SELLER_FAILED  = 5,  // "The deal has failed."
	BUYINGSTORE_TRADE_SELLER_COUNT   = 6,  // "The trade failed, because the entered amount of item %s is higher, than the buyer is willing to buy."
	BUYINGSTORE_TRADE_SELLER_ZENY    = 7,  // "The trade failed, because the buyer is lacking required balance."
	BUYINGSTORE_CREATE_NO_INFO       = 8,  // "No sale (purchase) information available."
};


static unsigned int buyingstore_nextid = 0;


/// Returns unique buying store id
static unsigned int buyingstore_getuid(void)
{
	return buyingstore_nextid++;
}


bool buyingstore_setup(struct map_session_data* sd, unsigned char slots)
{
	if( !battle_config.feature_buying_store || sd->vender_id || sd->state.buyingstore || sd->state.trading || slots == 0 )
	{
		return false;
	}

	if( slots > MAX_BUYINGSTORE_SLOTS )
	{
		ShowWarning("buyingstore_setup: Requested %d slots, but server supports only %d slots.\n", (int)slots, MAX_BUYINGSTORE_SLOTS);
		slots = MAX_BUYINGSTORE_SLOTS;
	}

	sd->buyingstore.slots = slots;
	clif_buyingstore_open(sd);

	return true;
}


void buyingstore_create(struct map_session_data* sd, int zenylimit, unsigned char result, const char* storename, const uint8* itemlist, unsigned int count)
{
	unsigned int i, weight, listidx;
	struct item_data* id;

	if( !result || count == 0 )
	{// canceled, or no items
		return;
	}

	if( !battle_config.feature_buying_store || pc_istrading(sd) || sd->buyingstore.slots == 0 || count > sd->buyingstore.slots || zenylimit <= 0 || zenylimit > sd->status.zeny || !storename[0] )
	{// disabled or invalid input
		sd->buyingstore.slots = 0;
		clif_buyingstore_open_failed(sd, BUYINGSTORE_CREATE, 0);
		return;
	}

	if( !pc_can_give_items(pc_isGM(sd)) )
	{// custom: GM is not allowed to buy (give zeny)
		sd->buyingstore.slots = 0;
		clif_displaymessage(sd->fd, msg_txt(246));
		clif_buyingstore_open_failed(sd, BUYINGSTORE_CREATE, 0);
		return;
	}

	weight = sd->weight;

	// check item list
	for( i = 0; i < count; i++ )
	{// itemlist: <name id>.W <amount>.W <price>.L
		unsigned short nameid, amount;
		int price, idx;

		nameid = RBUFW(itemlist,i*8+0);
		amount = RBUFW(itemlist,i*8+2);
		price  = RBUFL(itemlist,i*8+4);

		if( ( id = itemdb_exists(nameid) ) == NULL || amount == 0 )
		{// invalid input
			break;
		}

		if( price <= 0 || price > BUYINGSTORE_MAX_PRICE )
		{// invalid price: unlike vending, items cannot be bought at 0 Zeny
			break;
		}

		if( !id->flag.buyingstore || !itemdb_cantrade_sub(id, pc_isGM(sd), pc_isGM(sd)) || ( idx = pc_search_inventory(sd, nameid) ) == -1 )
		{// restrictions: allowed, no character-bound items and at least one must be owned
			break;
		}

		if( sd->status.inventory[idx].amount+amount > BUYINGSTORE_MAX_AMOUNT )
		{// too many items of same kind
			break;
		}

		if( i )
		{// duplicate check. as the client does this too, only malicious intent should be caught here
			ARR_FIND( 0, i, listidx, sd->buyingstore.items[i].nameid == nameid );
			if( listidx != i )
			{// duplicate
				ShowWarning("buyingstore_create: Found duplicate item on buying list (nameid=%hu, amount=%hu, account_id=%d, char_id=%d).\n", nameid, amount, sd->status.account_id, sd->status.char_id);
				break;
			}
		}

		weight+= id->weight*amount;
		sd->buyingstore.items[i].nameid = nameid;
		sd->buyingstore.items[i].amount = amount;
		sd->buyingstore.items[i].price  = price;
	}

	if( i != count )
	{// invalid item/amount/price
		sd->buyingstore.slots = 0;
		clif_buyingstore_open_failed(sd, BUYINGSTORE_CREATE, 0);
		return;
	}

	if( (sd->max_weight*90)/100 < weight )
	{// not able to carry all wanted items without getting overweight (90%)
		sd->buyingstore.slots = 0;
		clif_buyingstore_open_failed(sd, BUYINGSTORE_CREATE_OVERWEIGHT, weight);
		return;
	}

	// success
	sd->state.buyingstore = true;
	sd->buyer_id = buyingstore_getuid();
	sd->buyingstore.zenylimit = zenylimit;
	sd->buyingstore.slots = i;  // store actual amount of items
	safestrncpy(sd->message, storename, sizeof(sd->message));
	clif_buyingstore_myitemlist(sd);
	clif_buyingstore_entry(sd);
}


void buyingstore_close(struct map_session_data* sd)
{
	if( sd->state.buyingstore )
	{
		// invalidate data
		sd->state.buyingstore = false;
		memset(&sd->buyingstore, 0, sizeof(sd->buyingstore));

		// notify other players
		clif_buyingstore_disappear_entry(sd);
	}
}


void buyingstore_open(struct map_session_data* sd, int account_id)
{
	struct map_session_data* pl_sd;

	if( !battle_config.feature_buying_store || pc_istrading(sd) )
	{// not allowed to sell
		return;
	}

	if( !pc_can_give_items(pc_isGM(sd)) )
	{// custom: GM is not allowed to sell
		clif_displaymessage(sd->fd, msg_txt(246));
		return;
	}

	if( ( pl_sd = map_id2sd(account_id) ) == NULL || !pl_sd->state.buyingstore )
	{// not online or not buying
		return;
	}

	// success
	clif_buyingstore_itemlist(sd, pl_sd);
}


void buyingstore_trade(struct map_session_data* sd, int account_id, unsigned int buyer_id, const uint8* itemlist, unsigned int count)
{
	short blankslots[MAX_SLOTS];  // used when checking whether or not an item's card slots are blank
	int zeny = 0;
	unsigned int i, weight, listidx, k;
	struct map_session_data* pl_sd;

	if( count == 0 )
	{// nothing to do
		return;
	}

	if( !battle_config.feature_buying_store || pc_istrading(sd) )
	{// not allowed to sell
		clif_buyingstore_trade_failed_seller(sd, BUYINGSTORE_TRADE_SELLER_FAILED, 0);
		return;
	}

	if( !pc_can_give_items(pc_isGM(sd)) )
	{// custom: GM is not allowed to sell
		clif_displaymessage(sd->fd, msg_txt(246));
		clif_buyingstore_trade_failed_seller(sd, BUYINGSTORE_TRADE_SELLER_FAILED, 0);
		return;
	}

	if( ( pl_sd = map_id2sd(account_id) ) == NULL || !pl_sd->state.buyingstore || pl_sd->buyer_id != buyer_id )
	{// not online, not buying or not same store
		clif_buyingstore_trade_failed_seller(sd, BUYINGSTORE_TRADE_SELLER_FAILED, 0);
		return;
	}

	if( pl_sd->status.zeny < pl_sd->buyingstore.zenylimit )
	{// buyer lost zeny in the mean time? fix the limit
		pl_sd->buyingstore.zenylimit = pl_sd->status.zeny;
	}
	weight = pl_sd->weight;
	memset(blankslots, 0, sizeof(blankslots));

	// check item list
	for( i = 0; i < count; i++ )
	{// itemlist: <index>.W <name id>.W <amount>.W
		unsigned short nameid, amount;
		int index;

		index  = RBUFW(itemlist,i*6+0)-2;
		nameid = RBUFW(itemlist,i*6+2);
		amount = RBUFW(itemlist,i*6+4);

		if( i )
		{// duplicate check. as the client does this too, only malicious intent should be caught here
			ARR_FIND( 0, i, k, RBUFW(itemlist,k*6+0)-2 == index );
			if( k != i )
			{// duplicate
				ShowWarning("buyingstore_trade: Found duplicate item on selling list (prevnameid=%hu, prevamount=%hu, nameid=%hu, amount=%hu, account_id=%d, char_id=%d).\n",
					RBUFW(itemlist,k*6+2), RBUFW(itemlist,k*6+4), nameid, amount, sd->status.account_id, sd->status.char_id);
				clif_buyingstore_trade_failed_seller(sd, BUYINGSTORE_TRADE_SELLER_FAILED, nameid);
				return;
			}
		}

		if( index < 0 || index >= ARRAYLENGTH(sd->status.inventory) || sd->inventory_data[index] == NULL || sd->status.inventory[index].nameid != nameid || sd->status.inventory[index].amount < amount )
		{// invalid input
			clif_buyingstore_trade_failed_seller(sd, BUYINGSTORE_TRADE_SELLER_FAILED, nameid);
			return;
		}

		if( sd->status.inventory[index].expire_time || !itemdb_cantrade(&sd->status.inventory[index], pc_isGM(sd), pc_isGM(pl_sd)) || memcmp(sd->status.inventory[index].card, blankslots, sizeof(blankslots)) )
		{// non-tradable item
			clif_buyingstore_trade_failed_seller(sd, BUYINGSTORE_TRADE_SELLER_FAILED, nameid);
			return;
		}

		ARR_FIND( 0, pl_sd->buyingstore.slots, listidx, pl_sd->buyingstore.items[listidx].nameid == nameid );
		if( listidx == pl_sd->buyingstore.slots || pl_sd->buyingstore.items[listidx].amount == 0 )
		{// there is no such item or the buyer has already bought all of them
			clif_buyingstore_trade_failed_seller(sd, BUYINGSTORE_TRADE_SELLER_FAILED, nameid);
			return;
		}

		if( pl_sd->buyingstore.items[listidx].amount < amount )
		{// buyer does not need that much of the item
			clif_buyingstore_trade_failed_seller(sd, BUYINGSTORE_TRADE_SELLER_COUNT, nameid);
			return;
		}

		if( pc_checkadditem(pl_sd, nameid, amount) == ADDITEM_OVERAMOUNT )
		{// buyer does not have enough space for this item
			clif_buyingstore_trade_failed_seller(sd, BUYINGSTORE_TRADE_SELLER_FAILED, nameid);
			return;
		}

		if( amount*(unsigned int)sd->inventory_data[index]->weight > pl_sd->max_weight-weight )
		{// normally this is not supposed to happen, as the total weight is
		 // checked upon creation, but the buyer could have gained items
			clif_buyingstore_trade_failed_seller(sd, BUYINGSTORE_TRADE_SELLER_FAILED, nameid);
			return;
		}
		weight+= amount*sd->inventory_data[index]->weight;

		if( amount*pl_sd->buyingstore.items[listidx].price > pl_sd->buyingstore.zenylimit-zeny )
		{// buyer does not have enough zeny
			clif_buyingstore_trade_failed_seller(sd, BUYINGSTORE_TRADE_SELLER_ZENY, nameid);
			return;
		}
		zeny+= amount*pl_sd->buyingstore.items[listidx].price;
	}

	// process item list
	for( i = 0; i < count; i++ )
	{// itemlist: <index>.W <name id>.W <amount>.W
		unsigned short nameid, amount;
		int index;

		index  = RBUFW(itemlist,i*6+0)-2;
		nameid = RBUFW(itemlist,i*6+2);
		amount = RBUFW(itemlist,i*6+4);

		ARR_FIND( 0, pl_sd->buyingstore.slots, listidx, pl_sd->buyingstore.items[listidx].nameid == nameid );
		zeny = amount*pl_sd->buyingstore.items[listidx].price;

		// log
		if( log_config.enable_logs&LOG_BUYING_STORE )
		{
			log_pick_pc(sd, "B", nameid, -((int)amount), &sd->status.inventory[index]);
			log_pick_pc(pl_sd, "B", nameid, amount, &sd->status.inventory[index]);
		}
		if( log_config.zeny )
			log_zeny(sd, "B", pl_sd, zeny);

		// move item
		pc_additem(pl_sd, &sd->status.inventory[index], amount);
		pc_delitem(sd, index, amount, 1, 0);
		pl_sd->buyingstore.items[listidx].amount-= amount;

		// pay up
		pc_payzeny(pl_sd, zeny);
		pc_getzeny(sd, zeny);
		pl_sd->buyingstore.zenylimit-= zeny;

		// notify clients
		clif_buyingstore_delete_item(sd, index, amount, pl_sd->buyingstore.items[listidx].price);
		clif_buyingstore_update_item(pl_sd, nameid, amount);
	}

	// check whether or not there is still something to buy
	ARR_FIND( 0, pl_sd->buyingstore.slots, i, pl_sd->buyingstore.items[i].amount != 0 );
	if( i == pl_sd->buyingstore.slots )
	{// everything was bought
		clif_buyingstore_trade_failed_buyer(pl_sd, BUYINGSTORE_TRADE_BUYER_NO_ITEMS);
		buyingstore_close(pl_sd);
	}
	else if( pl_sd->buyingstore.zenylimit == 0 )
	{// zeny limit reached
		clif_buyingstore_trade_failed_buyer(pl_sd, BUYINGSTORE_TRADE_BUYER_ZENY);
		buyingstore_close(pl_sd);
	}
}