/*
 * Copyright (c) 2010-2013 OTClient <https://github.com/edubart/otclient>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "map.h"
#include "game.h"
#include "localplayer.h"
#include "tile.h"
#include "item.h"
#include "missile.h"
#include "statictext.h"
#include "mapview.h"

#include <framework/core/eventdispatcher.h>
#include <framework/core/application.h>

Map g_map;
TilePtr Map::m_nulltile;

void Map::terminate()
{
    clean();
}

void Map::addMapView(const MapViewPtr& mapView)
{
    m_mapViews.push_back(mapView);
}

void Map::removeMapView(const MapViewPtr& mapView)
{
    auto it = std::find(m_mapViews.begin(), m_mapViews.end(), mapView);
    if(it != m_mapViews.end())
        m_mapViews.erase(it);
}

void Map::notificateTileUpdateToMapViews(const Position& pos)
{
    for(const MapViewPtr& mapView : m_mapViews)
        mapView->onTileUpdate(pos);
}

void Map::clean()
{
    cleanDynamicThings();

    for(int i=0;i<=Otc::MAX_Z;++i)
        m_tileBlocks[i].clear();

    m_waypoints.clear();

    g_towns.clear();
    g_houses.clear();
    g_creatures.clearSpawns();
    m_tilesRect = Rect(65534, 65534, 0, 0);
}

void Map::cleanDynamicThings()
{
    for(const auto& pair : m_knownCreatures) {
        const CreaturePtr& creature = pair.second;
        removeThing(creature);
    }
    m_knownCreatures.clear();

    for(int i=0;i<=Otc::MAX_Z;++i)
        m_floorMissiles[i].clear();

    cleanTexts();
}

void Map::cleanTexts()
{
    m_animatedTexts.clear();
    m_staticTexts.clear();
}

void Map::addThing(const ThingPtr& thing, const Position& pos, int stackPos)
{
    if(!thing)
        return;

    if(thing->isItem() || thing->isCreature() || thing->isEffect()) {
        const TilePtr& tile = getOrCreateTile(pos);
        tile->addThing(thing, stackPos);
    } else {
        if(thing->isMissile()) {
            m_floorMissiles[pos.z].push_back(thing->static_self_cast<Missile>());
            thing->onAppear();
        } else if(thing->isAnimatedText()) {
            AnimatedTextPtr animatedText = thing->static_self_cast<AnimatedText>();
            m_animatedTexts.push_back(animatedText);
        } else if(thing->isStaticText()) {
            StaticTextPtr staticText = thing->static_self_cast<StaticText>();
            bool mustAdd = true;
            for(auto other : m_staticTexts) {
                // try to combine messages
                if(other->getPosition() == pos && other->addMessage(staticText->getName(), staticText->getMessageMode(), staticText->getFirstMessage())) {
                    mustAdd = false;
                    break;
                }
            }

            if(mustAdd) {
                m_staticTexts.push_back(staticText);
                staticText->onAppear();
            }
        }

        thing->setPosition(pos);
        thing->onAppear();
    }

    notificateTileUpdateToMapViews(pos);
}

ThingPtr Map::getThing(const Position& pos, int stackPos)
{
    if(TilePtr tile = getTile(pos))
        return tile->getThing(stackPos);
    return nullptr;
}

bool Map::removeThing(const ThingPtr& thing)
{
    if(!thing)
        return false;

    notificateTileUpdateToMapViews(thing->getPosition());

    if(thing->isMissile()) {
        MissilePtr missile = thing->static_self_cast<Missile>();
        int z = missile->getPosition().z;
        auto it = std::find(m_floorMissiles[z].begin(), m_floorMissiles[z].end(), missile);
        if(it != m_floorMissiles[z].end()) {
            m_floorMissiles[z].erase(it);
            return true;
        }
    } else if(thing->isAnimatedText()) {
        AnimatedTextPtr animatedText = thing->static_self_cast<AnimatedText>();
        auto it = std::find(m_animatedTexts.begin(), m_animatedTexts.end(), animatedText);
        if(it != m_animatedTexts.end()) {
            m_animatedTexts.erase(it);
            return true;
        }
    } else if(thing->isStaticText()) {
        StaticTextPtr staticText = thing->static_self_cast<StaticText>();
        auto it = std::find(m_staticTexts.begin(), m_staticTexts.end(), staticText);
        if(it != m_staticTexts.end()) {
            m_staticTexts.erase(it);
            return true;
        }
    } else if(const TilePtr& tile = thing->getTile())
        return tile->removeThing(thing);

    return false;
}

bool Map::removeThingByPos(const Position& pos, int stackPos)
{
    if(TilePtr tile = getTile(pos))
        return removeThing(tile->getThing(stackPos));
    return false;
}

const TilePtr& Map::createTile(const Position& pos)
{
    if(!pos.isMapPosition())
        return m_nulltile;
    if(pos.x < m_tilesRect.left())
        m_tilesRect.setLeft(pos.x);
    if(pos.y < m_tilesRect.top())
        m_tilesRect.setTop(pos.y);
    if(pos.x > m_tilesRect.right())
        m_tilesRect.setRight(pos.x);
    if(pos.y > m_tilesRect.bottom())
        m_tilesRect.setBottom(pos.y);
    TileBlock& block = m_tileBlocks[pos.z][getBlockIndex(pos)];
    return block.create(pos);
}

template <typename... Items>
const TilePtr& Map::createTileEx(const Position& pos, const Items&... items)
{
    if(!pos.isValid())
        return m_nulltile;
    const TilePtr& tile = getOrCreateTile(pos);
    auto vec = {items...};
    for(auto it : vec)
        addThing(it, pos);

    return tile;
}

const TilePtr& Map::getOrCreateTile(const Position& pos)
{
    if(!pos.isMapPosition())
        return m_nulltile;
    if(pos.x < m_tilesRect.left())
        m_tilesRect.setLeft(pos.x);
    if(pos.y < m_tilesRect.top())
        m_tilesRect.setTop(pos.y);
    if(pos.x > m_tilesRect.right())
        m_tilesRect.setRight(pos.x);
    if(pos.y > m_tilesRect.bottom())
        m_tilesRect.setBottom(pos.y);
    TileBlock& block = m_tileBlocks[pos.z][getBlockIndex(pos)];
    return block.getOrCreate(pos);
}

const TilePtr& Map::getTile(const Position& pos)
{
    if(!pos.isMapPosition())
        return m_nulltile;
    auto it = m_tileBlocks[pos.z].find(getBlockIndex(pos));
    if(it != m_tileBlocks[pos.z].end())
        return it->second.get(pos);
    return m_nulltile;
}

void Map::cleanTile(const Position& pos)
{
    if(!pos.isMapPosition())
        return;
    auto it = m_tileBlocks[pos.z].find(getBlockIndex(pos));
    if(it != m_tileBlocks[pos.z].end()) {
        TileBlock& block = it->second;
        if(const TilePtr& tile = block.get(pos)) {
            tile->clean();
            if(tile->canErase())
                block.remove(pos);

            notificateTileUpdateToMapViews(pos);
        }
    }
}

void Map::addCreature(const CreaturePtr& creature)
{
    m_knownCreatures[creature->getId()] = creature;
}

CreaturePtr Map::getCreatureById(uint32 id)
{
    auto it = m_knownCreatures.find(id);
    if(it == m_knownCreatures.end())
        return nullptr;
    return it->second;
}

void Map::removeCreatureById(uint32 id)
{
    if(id == 0)
        return;

    auto it = m_knownCreatures.find(id);
    if(it != m_knownCreatures.end())
        m_knownCreatures.erase(it);
}

void Map::setCentralPosition(const Position& centralPosition)
{
    m_centralPosition = centralPosition;

    // remove creatures from tiles that we are not aware anymore
    for(const auto& pair : m_knownCreatures) {
        const CreaturePtr& creature = pair.second;
        if(!isAwareOfPosition(creature->getPosition()))
            removeThing(creature);
    }

    // this fixes local player position when the local player is removed from the map,
    // the local player is removed from the map when there are too many creatures on his tile,
    // so there is no enough stackpos to the server send him
    g_dispatcher.addEvent([this] {
        LocalPlayerPtr localPlayer = g_game.getLocalPlayer();
        if(!localPlayer || localPlayer->getPosition() == m_centralPosition)
            return;
        TilePtr tile = localPlayer->getTile();
        if(tile && tile->hasThing(localPlayer))
            return;

        Position oldPos = localPlayer->getPosition();
        Position pos = m_centralPosition;
        if(oldPos != pos) {
            if(!localPlayer->isRemoved())
                localPlayer->onDisappear();
            localPlayer->setPosition(pos);
            localPlayer->onAppear();
            g_logger.debug("forced player position update");
        }
    });

    for(const MapViewPtr& mapView : m_mapViews)
        mapView->onMapCenterChange(centralPosition);
}

std::vector<CreaturePtr> Map::getSpectators(const Position& centerPos, bool multiFloor)
{
    return getSpectatorsInRange(centerPos, multiFloor, (Otc::VISIBLE_X_TILES - 1)/2, (Otc::VISIBLE_Y_TILES - 1)/2);
}

std::vector<CreaturePtr> Map::getSpectatorsInRange(const Position& centerPos, bool multiFloor, int xRange, int yRange)
{
    return getSpectatorsInRangeEx(centerPos, multiFloor, xRange, xRange, yRange, yRange);
}

std::vector<CreaturePtr> Map::getSpectatorsInRangeEx(const Position& centerPos, bool multiFloor, int minXRange, int maxXRange, int minYRange, int maxYRange)
{
    int minZRange = 0;
    int maxZRange = 0;
    std::vector<CreaturePtr> creatures;

    if(multiFloor) {
        minZRange = 0;
        maxZRange = Otc::MAX_Z;
    }

    //TODO: optimize
    //TODO: get creatures from other floors corretly
    //TODO: delivery creatures in distance order

    for(int iz=-minZRange; iz<=maxZRange; ++iz) {
        for(int iy=-minYRange; iy<=maxYRange; ++iy) {
            for(int ix=-minXRange; ix<=maxXRange; ++ix) {
                TilePtr tile = getTile(centerPos.translated(ix,iy,iz));
                if(!tile)
                    continue;

                auto tileCreatures = tile->getCreatures();
                creatures.insert(creatures.end(), tileCreatures.rbegin(), tileCreatures.rend());
            }
        }
    }

    return creatures;
}

bool Map::isLookPossible(const Position& pos)
{
    TilePtr tile = getTile(pos);
    return tile && tile->isLookPossible();
}

bool Map::isCovered(const Position& pos, int firstFloor)
{
    // check for tiles on top of the postion
    Position tilePos = pos;
    while(tilePos.coveredUp() && tilePos.z >= firstFloor) {
        TilePtr tile = getTile(tilePos);
        // the below tile is covered when the above tile has a full ground
        if(tile && tile->isFullGround())
            return true;
    }
    return false;
}

bool Map::isCompletelyCovered(const Position& pos, int firstFloor)
{
    const TilePtr& checkTile = getTile(pos);
    Position tilePos = pos;
    while(tilePos.coveredUp() && tilePos.z >= firstFloor) {
        bool covered = true;
        bool done = false;
        // check in 2x2 range tiles that has no transparent pixels
        for(int x=0;x<2 && !done;++x) {
            for(int y=0;y<2 && !done;++y) {
                const TilePtr& tile = getTile(tilePos.translated(-x, -y));
                if(!tile || !tile->isFullyOpaque()) {
                    covered = false;
                    done = true;
                } else if(x==0 && y==0 && (!checkTile || checkTile->isSingleDimension())) {
                    done = true;
                }
            }
        }
        if(covered)
            return true;
    }
    return false;
}

bool Map::isAwareOfPosition(const Position& pos)
{
    if(pos.z < getFirstAwareFloor() || pos.z > getLastAwareFloor())
        return false;

    Position groundedPos = pos;
    while(groundedPos.z != m_centralPosition.z) {
        if(groundedPos.z > m_centralPosition.z)
            groundedPos.coveredUp();
        else
            groundedPos.coveredDown();
    }
    return m_centralPosition.isInRange(groundedPos, Otc::AWARE_X_LEFT_TILES,
                                                    Otc::AWARE_X_RIGHT_TILES,
                                                    Otc::AWARE_Y_TOP_TILES,
                                                    Otc::AWARE_Y_BOTTOM_TILES);
}

int Map::getFirstAwareFloor()
{
    if(m_centralPosition.z > Otc::SEA_FLOOR)
        return m_centralPosition.z-Otc::AWARE_UNDEGROUND_FLOOR_RANGE;
    else
        return 0;
}

int Map::getLastAwareFloor()
{
    if(m_centralPosition.z > Otc::SEA_FLOOR)
        return std::min(m_centralPosition.z+Otc::AWARE_UNDEGROUND_FLOOR_RANGE, (int)Otc::MAX_Z);
    else
        return Otc::SEA_FLOOR;
}

std::tuple<std::vector<Otc::Direction>, Otc::PathFindResult> Map::findPath(const Position& startPos, const Position& goalPos, int maxSteps, int flags)
{
    // pathfinding using A* search algorithm
    // as described in http://en.wikipedia.org/wiki/A*_search_algorithm

    struct Node {
        Node(const Position& pos) : cost(0), totalCost(0), steps(0), pos(pos), prev(nullptr), dir(Otc::InvalidDirection), evaluated(false) { }
        bool operator<(const Node& other) const { return  totalCost < other.totalCost; }
        float cost;
        float totalCost;
        int steps;
        Position pos;
        Node *prev;
        Otc::Direction dir;
        bool evaluated;
    };

    struct LessNode : std::binary_function<Node*, Node*, bool> {
        bool operator()(Node* a, Node* b) const {
            return b->totalCost < a->totalCost;
        }
    };

    std::tuple<std::vector<Otc::Direction>, Otc::PathFindResult> ret;
    std::vector<Otc::Direction>& dirs = std::get<0>(ret);
    Otc::PathFindResult& result = std::get<1>(ret);

    result = Otc::PathFindResultNoWay;

    if(startPos == goalPos) {
        result = Otc::PathFindResultSamePosition;
        return ret;
    }

    if(startPos.z != goalPos.z) {
        result = Otc::PathFindResultImpossible;
        return ret;
    }

    if(startPos.distance(goalPos) > maxSteps) {
        result = Otc::PathFindResultTooFar;
        return ret;
    }

    std::unordered_map<Position, Node*, PositionHasher> nodes;
    std::priority_queue<Node*, std::vector<Node*>, LessNode> searchList;

    Node *currentNode = new Node(startPos);
    currentNode->pos = startPos;
    nodes[startPos] = currentNode;
    Node *foundNode = nullptr;
    while(currentNode) {
        // too far
        if(currentNode->steps >= maxSteps) {
            result = Otc::PathFindResultTooFar;
            break;
        }

        // path found
        if(currentNode->pos == goalPos && (!foundNode || currentNode->cost < foundNode->cost))
            foundNode = currentNode;

        // cost too high
        if(foundNode && currentNode->totalCost >= foundNode->cost)
            break;

        for(int i=-1;i<=1;++i) {
            for(int j=-1;j<=1;++j) {
                if(i == 0 && j == 0)
                    continue;

                Position neighborPos = currentNode->pos.translated(i, j);
                const TilePtr& tile = getTile(neighborPos);

                float walkFactor = 0;
                if(neighborPos != goalPos) {
                    /*
                      Known Issue with Otc::PathFindAllowNullTiles flag:
                      If you are above ground floor this will attempt to path over null
                      tiles, need to rework this for "fly servers" and blank map click,
                      but it is breaking normal path finding.
                    */
                    if(!(flags & Otc::PathFindAllowNullTiles) && !tile)
                        walkFactor = 1.0f;
                    if(tile) {
                        if(!(flags & Otc::PathFindAllowCreatures) && tile->hasCreature())
                            continue;
                        if(!(flags & Otc::PathFindAllowNonPathable) && !tile->isPathable())
                            continue;
                        if(!(flags & Otc::PathFindAllowNonWalkable) && !tile->isWalkable())
                            continue;
                    }
                }

                Otc::Direction walkDir = currentNode->pos.getDirectionFromPosition(neighborPos);
                if(walkDir >= Otc::NorthEast)
                    walkFactor += 3.0f;
                else
                    walkFactor += 1.0f;

                int groundSpeed = tile ? tile->getGroundSpeed() : 100;
                float cost = currentNode->cost + (groundSpeed * walkFactor) / 100.0f;

                Node *neighborNode;
                if(nodes.find(neighborPos) == nodes.end()) {
                    neighborNode = new Node(neighborPos);
                    nodes[neighborPos] = neighborNode;
                } else {
                    neighborNode = nodes[neighborPos];
                    if(neighborNode->cost < cost)
                        continue;
                }

                neighborNode->prev = currentNode;
                neighborNode->cost = cost;
                neighborNode->steps = currentNode->steps + 1;
                neighborNode->totalCost = neighborNode->cost + neighborPos.distance(goalPos);
                neighborNode->dir = walkDir;
                neighborNode->evaluated = false;
                searchList.push(neighborNode);
            }
        }

        currentNode->evaluated = true;
        currentNode = nullptr;
        while(searchList.size() > 0 && !currentNode) {
            Node *node = searchList.top();
            searchList.pop();

            if(!node->evaluated)
                currentNode = node;
        }
    }

    if(foundNode) {
        currentNode = foundNode;
        while(currentNode) {
            dirs.push_back(currentNode->dir);
            currentNode = currentNode->prev;
        }
        dirs.pop_back();
        std::reverse(dirs.begin(), dirs.end());
        result = Otc::PathFindResultOk;
    }

    for(auto it : nodes)
        delete it.second;

    return ret;
}