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

#include "../common/cbasetypes.h"
#include "../common/socket.h"
#include "../common/malloc.h"
#include "../common/nullpo.h"
#include "../common/showmsg.h"
#include "../common/strlib.h"

#include "map.h"
#include "pc.h"
#include "party.h"
#include "quest.h"
#include "chrif.h"

#include <stdlib.h>

/**
 * Searches a quest by ID.
 * @param quest_id : ID to lookup
 * @return Quest entry (equals to &quest_dummy if the ID is invalid)
 */
struct quest_db *quest_db(int quest_id)
{
  if( quest_id < 0 || quest_id > MAX_QUEST_DB || quest_db_data[quest_id] == NULL )
    return &quest_dummy;

  return quest_db_data[quest_id];
}

/**
 * Sends quest info to the player on login.
 * @param sd : Player's data
 * @return 0 in case of success, nonzero otherwise (i.e. the player has no quests)
 */
int quest_pc_login(TBL_PC *sd)
{
	int i;

	if( sd->avail_quests == 0 )
		return 1;

	clif_quest_send_list(sd);
	clif_quest_send_mission(sd);

	//@TODO[Haru]: Is this necessary? Does quest_send_mission not take care of this?
	for( i = 0; i < sd->avail_quests; i++ )
		clif_quest_update_objective(sd, &sd->quest_log[i]);

	return 0;
}

/**
 * Adds a quest to the player's list.
 * New quest will be added as Q_ACTIVE.
 * @param sd : Player's data
 * @param quest_id : ID of the quest to add.
 * @return 0 in case of success, nonzero otherwise
 */
int quest_add(TBL_PC *sd, int quest_id)
{
	int n;
	struct quest_db *qi = quest_db(quest_id);

	if( qi == &quest_dummy ) {
		ShowError("quest_add: quest %d not found in DB.\n", quest_id);
		return -1;
	}

	if( quest_check(sd, quest_id, HAVEQUEST) >= 0 ) {
		ShowError("quest_add: Character %d already has quest %d.\n", sd->status.char_id, quest_id);
		return -1;
	}

	n = sd->avail_quests; //Insertion point

	sd->num_quests++;
	sd->avail_quests++;
	RECREATE(sd->quest_log, struct quest, sd->num_quests);

	//The character has some completed quests, make room before them so that they will stay at the end of the array
	if( sd->avail_quests != sd->num_quests )
		memmove(&sd->quest_log[n + 1], &sd->quest_log[n], sizeof(struct quest) * (sd->num_quests-sd->avail_quests));

	memset(&sd->quest_log[n], 0, sizeof(struct quest));

	sd->quest_log[n].quest_id = qi->id;
	if( qi->time )
		sd->quest_log[n].time = (unsigned int)(time(NULL) + qi->time);
	sd->quest_log[n].state = Q_ACTIVE;

	sd->save_quest = true;

	clif_quest_add(sd, &sd->quest_log[n]);
	clif_quest_update_objective(sd, &sd->quest_log[n]);

	if( save_settings&CHARSAVE_QUEST )
		chrif_save(sd,0);

	return 0;
}

/**
 * Replaces a quest in a player's list with another one.
 * @param sd : Player's data
 * @param qid1 : Current quest to replace
 * @param qid2 : New quest to add
 * @return 0 in case of success, nonzero otherwise
 */
int quest_change(TBL_PC *sd, int qid1, int qid2)
{
	int i;
	struct quest_db *qi = quest_db(qid2);

	if( qi == &quest_dummy ) {
		ShowError("quest_change: quest %d not found in DB.\n", qid2);
		return -1;
	}

	if( quest_check(sd, qid2, HAVEQUEST) >= 0 ) {
		ShowError("quest_change: Character %d already has quest %d.\n", sd->status.char_id, qid2);
		return -1;
	}

	if( quest_check(sd, qid1, HAVEQUEST) < 0 ) {
		ShowError("quest_change: Character %d doesn't have quest %d.\n", sd->status.char_id, qid1);
		return -1;
	}

	ARR_FIND(0, sd->avail_quests, i, sd->quest_log[i].quest_id == qid1);
	if( i == sd->avail_quests ) {
		ShowError("quest_change: Character %d has completed quest %d.\n", sd->status.char_id, qid1);
		return -1;
	}

	memset(&sd->quest_log[i], 0, sizeof(struct quest));
	sd->quest_log[i].quest_id = qi->id;

	if( qi->time )
		sd->quest_log[i].time = (unsigned int)(time(NULL) + qi->time);

	sd->quest_log[i].state = Q_ACTIVE;

	sd->save_quest = true;

	clif_quest_delete(sd, qid1);
	clif_quest_add(sd, &sd->quest_log[i]);
	clif_quest_update_objective(sd, &sd->quest_log[i]);

	if( save_settings&CHARSAVE_QUEST )
		chrif_save(sd,0);

	return 0;
}

/**
 * Removes a quest from a player's list
 * @param sd : Player's data
 * @param quest_id : ID of the quest to remove
 * @return 0 in case of success, nonzero otherwise
 */
int quest_delete(TBL_PC *sd, int quest_id)
{
	int i;

	//Search for quest
	ARR_FIND(0, sd->num_quests, i, sd->quest_log[i].quest_id == quest_id);
	if( i == sd->num_quests ) {
		ShowError("quest_delete: Character %d doesn't have quest %d.\n", sd->status.char_id, quest_id);
		return -1;
	}

	if( sd->quest_log[i].state != Q_COMPLETE )
		sd->avail_quests--;

	if( i < --sd->num_quests ) //Compact the array
		memmove(&sd->quest_log[i], &sd->quest_log[i + 1], sizeof(struct quest) * (sd->num_quests - i));

	if( sd->num_quests == 0 ) {
		aFree(sd->quest_log);
		sd->quest_log = NULL;
	} else
		RECREATE(sd->quest_log, struct quest, sd->num_quests);

	sd->save_quest = true;

	clif_quest_delete(sd, quest_id);

	if( save_settings&CHARSAVE_QUEST )
		chrif_save(sd,0);

	return 0;
}

/**
 * Map iterator subroutine to update quest objectives for a party after killing a monster.
 * @see map_foreachinrange
 * @param ap : Argument list, expecting:
 *   int Party ID
 *   int Mob ID
 */
int quest_update_objective_sub(struct block_list *bl, va_list ap)
{
	struct map_session_data *sd;
	int mob, party;

	nullpo_ret(bl);
	nullpo_ret(sd = (struct map_session_data *)bl);

	party = va_arg(ap,int);
	mob = va_arg(ap,int);

	if( !sd->avail_quests )
		return 0;
	if( sd->status.party_id != party )
		return 0;

	quest_update_objective(sd, mob);

	return 1;
}

/**
 * Updates the quest objectives for a character after killing a monster.
 * @param sd : Character's data
 * @param mob_id : Monster ID
 */
void quest_update_objective(TBL_PC *sd, int mob)
{
	int i, j;

	for( i = 0; i < sd->avail_quests; i++ ) {
		struct quest_db *qi = NULL;

		if( sd->quest_log[i].state != Q_ACTIVE ) // Skip inactive quests
			continue;

		qi = quest_db(sd->quest_log[i].quest_id);

		for( j = 0; j < qi->num_objectives; j++ ) {
			if( qi->mob[j] == mob && sd->quest_log[i].count[j] < qi->count[j] )  {
				sd->quest_log[i].count[j]++;
				sd->save_quest = true;
				clif_quest_update_objective(sd, &sd->quest_log[i]);
			}
		}
	}
}

/**
 * Updates a quest's state.
 * Only status of active and inactive quests can be updated. Completed quests can't (for now).
 * @param sd : Character's data
 * @param quest_id : Quest ID to update
 * @param qs : New quest state
 * @return 0 in case of success, nonzero otherwise
 * @author [Inkfish]
 */
int quest_update_status(TBL_PC *sd, int quest_id, enum quest_state status)
{
	int i;

	ARR_FIND(0, sd->avail_quests, i, sd->quest_log[i].quest_id == quest_id);
	if( i == sd->avail_quests ) {
		ShowError("quest_update_status: Character %d doesn't have quest %d.\n", sd->status.char_id, quest_id);
		return -1;
	}

	sd->quest_log[i].state = status;
	sd->save_quest = true;

	if( status < Q_COMPLETE ) {
		clif_quest_update_status(sd, quest_id, status == Q_ACTIVE);
		return 0;
	}

	// The quest is complete, so it needs to be moved to the completed quests block at the end of the array.
	if( i < (--sd->avail_quests) ) {
		struct quest tmp_quest;

		memcpy(&tmp_quest, &sd->quest_log[i], sizeof(struct quest));
		memcpy(&sd->quest_log[i], &sd->quest_log[sd->avail_quests], sizeof(struct quest));
		memcpy(&sd->quest_log[sd->avail_quests], &tmp_quest, sizeof(struct quest));
	}

	clif_quest_delete(sd, quest_id);

	if( save_settings&CHARSAVE_QUEST )
		chrif_save(sd,0);

	return 0;
}

/**
 * Queries quest information for a character.
 * @param sd : Character's data
 * @param quest_id : Quest ID
 * @param type : Check type
 * @return -1 if the quest was not found, otherwise it depends on the type:
 *   HAVEQUEST: The quest's state
 *   PLAYTIME:  2 if the quest's timeout has expired
 *              1 if the quest was completed
 *              0 otherwise
 *   HUNTING:   2 if the quest has not been marked as completed yet, and its objectives have been fulfilled
 *              1 if the quest's timeout has expired
 *              0 otherwise
 */
int quest_check(TBL_PC *sd, int quest_id, enum quest_check_type type)
{
	int i;

	ARR_FIND(0, sd->num_quests, i, sd->quest_log[i].quest_id == quest_id);
	if( i == sd->num_quests )
		return -1;

	switch( type ) {
		case HAVEQUEST:
			return sd->quest_log[i].state;
		case PLAYTIME:
			return (sd->quest_log[i].time < (unsigned int)time(NULL) ? 2 : sd->quest_log[i].state == Q_COMPLETE ? 1 : 0);
		case HUNTING:
			if( sd->quest_log[i].state == Q_INACTIVE || sd->quest_log[i].state == Q_ACTIVE ) {
				int j;
				struct quest_db *qi = quest_db(sd->quest_log[i].quest_id);

				ARR_FIND(0, MAX_QUEST_OBJECTIVES, j, sd->quest_log[i].count[j] < qi->count[j]);
				if( j == MAX_QUEST_OBJECTIVES )
					return 2;
				if( sd->quest_log[i].time < (unsigned int)time(NULL) )
					return 1;
			}
			return 0;
		default:
			ShowError("quest_check_quest: Unknown parameter %d",type);
			break;
	}

	return -1;
}

/**
 * Loads quests from the quest db.
 * @return Number of loaded quests, or -1 if the file couldn't be read.
 */
int quest_read_db(void)
{
	const char* dbsubpath[] = {
		"",
		DBIMPORT"/",
	};
	int f;

	for (f = 0; f < ARRAYLENGTH(dbsubpath); f++) {
		FILE *fp;
		char line[1024];
		int i, count = 0;
		char *str[20], *p, *np;
		char filename[256];
		struct quest_db entry;

		sprintf(filename, "%s/%s%s", db_path, dbsubpath[f], "quest_db.txt");
		if( (fp = fopen(filename, "r")) == NULL ) {
			if (f == 0)
				ShowError("Can't read %s\n", filename);

			return -1;
		}

		while( fgets(line, sizeof(line), fp) ) {
			if( line[0] == '/' && line[1] == '/' )
				continue;

			memset(str, 0, sizeof(str));

			for( i = 0, p = line; i < 8; i++ ) {
				if( (np = strchr(p, ',')) != NULL ) {
					str[i] = p;
					*np = 0;
					p = np + 1;
				} else if( str[0] == NULL )
					break;
				else {
					ShowError("quest_read_db: Insufficient columns in line %s\n", line);
					continue;
				}
			}

			if( str[0] == NULL )
				continue;

			memset(&entry, 0, sizeof(entry));

			entry.id = atoi(str[0]);

			if( entry.id < 0 || entry.id >= MAX_QUEST_DB ) {
				ShowError("quest_read_db: Invalid quest ID '%d' in line '%s' (min: 0, max: %d.)\n", entry.id, line, MAX_QUEST_DB);
				continue;
			}

			entry.time = atoi(str[1]);

			for( i = 0; i < MAX_QUEST_OBJECTIVES; i++ ) {
				entry.mob[i] = atoi(str[2 * i + 2]);
				entry.count[i] = atoi(str[2 * i + 3]);

				if( !entry.mob[i] || !entry.count[i] )
					break;
			}

			entry.num_objectives = i;

			if( quest_db_data[entry.id] == NULL )
				quest_db_data[entry.id] = aMalloc(sizeof(struct quest_db));

			memcpy(quest_db_data[entry.id], &entry, sizeof(struct quest_db));
			count++;
		}

		fclose(fp);
		ShowStatus("Done reading '"CL_WHITE"%d"CL_RESET"' entries in '"CL_WHITE"%s"CL_RESET"'.\n", count, filename);
	}

	return 0;
}

/**
 * Map iterator to ensures a player has no invalid quest log entries.
 * Any entries that are no longer in the db are removed.
 * @see map_foreachpc
 * @param sd : Character's data
 * @param ap : Ignored
 */
int quest_reload_check_sub(struct map_session_data *sd, va_list ap)
{
	int i, j;

	nullpo_ret(sd);

	j = 0;
	for( i = 0; i < sd->num_quests; i++ ) {
		struct quest_db *qi = quest_db(sd->quest_log[i].quest_id);

		if( qi == &quest_dummy ) { //Remove no longer existing entries
			if( sd->quest_log[i].state != Q_COMPLETE ) //And inform the client if necessary
				clif_quest_delete(sd, sd->quest_log[i].quest_id);
			continue;
		}

		if( i != j ) {
			//Move entries if there's a gap to fill
			memcpy(&sd->quest_log[j], &sd->quest_log[i], sizeof(struct quest));
		}

		j++;
	}

	sd->num_quests = j;
	ARR_FIND(0, sd->num_quests, i, sd->quest_log[i].state == Q_COMPLETE);
	sd->avail_quests = i;

	return 1;
}

/**
 * Clears the quest database for shutdown or reload.
 */
void quest_clear_db(void)
{
	int i;

	for( i = 0; i < MAX_QUEST_DB; i++ ) {
		if( quest_db_data[i] ) {
			aFree(quest_db_data[i]);
			quest_db_data[i] = NULL;
		}
	}
}

/**
 * Initializes the quest interface.
 */
void do_init_quest(void)
{
	quest_read_db();
}

/**
 * Finalizes the quest interface before shutdown.
 */
void do_final_quest(void)
{
	memset(&quest_dummy, 0, sizeof(quest_dummy));

	quest_clear_db();
}

/**
 * Reloads the quest database.
 */
void do_reload_quest(void)
{
	memset(&quest_dummy, 0, sizeof(quest_dummy));

	quest_clear_db();

	quest_read_db();

	//Update quest data for players, to ensure no entries about removed quests are left over.
	map_foreachpc(&quest_reload_check_sub);
}