#include <QJsonArray>
#include <QJsonDocument>
#include "topologyManager.h"
#include "powerEntity.h"

TopologyManager& TopologyManager::instance()
{
    static TopologyManager instance;
    return instance;
}

TopologyManager::TopologyManager(QObject* parent)
    : QObject(parent) {}

TopologyManager::~TopologyManager() {
    clearAllData();
}

void TopologyManager::clearAllData()
{
    // 删除所有连接
    qDeleteAll(m_connections);
    m_connections.clear();
    m_connectionIndex.clear();

    // 删除所有实体（自动删除子对象）
    qDeleteAll(m_entities);
    m_entities.clear();

    m_allTerminals.clear();         //端点由父亲entity释放
}

PowerEntity* TopologyManager::createEntity(EntityType type,const QString& uuid, const QString& name)
{
    PowerEntity* entity = nullptr;
    switch(type) {
    case EntityType::ConfigurationDiagram:
        entity = new ConfigurationDiagram(uuid,name);
        break;
    case EntityType::Grid:
    case EntityType::Zone:
    case EntityType::Station:
        entity = new PowerDivision(type, uuid,name);
    default:
        entity = new PowerComponent(type, uuid,name);
    }

    m_entities.insert(entity->id(), entity);
    emit entityCreated(entity->id());  // 发送信号通知
    return entity;
}

PowerEntity* TopologyManager::findEntity(const QString& id) const
{
    return m_entities.value(id, nullptr);  // 避免异常的安全查询
}

bool TopologyManager::deleteEntity(const QString& id)
{
    if (!m_entities.contains(id)) return false;

    PowerEntity* entity = m_entities[id];

    // 步骤1：删除所有相关连接
    auto relatedConns = getConnectionsFor(id);

    for (auto conn : relatedConns) {
        removeConnection(conn->id());
    }

    // 步骤2：从父节点移除（防止悬空指针）
    if (PowerEntity* parent = entity->parent()) {
        parent->removeChild(entity);
    }

    // 步骤3：递归删除子实体
    auto children = entity->children();
    for (auto child : children) {
        deleteEntity(child->id());  // 递归删除
    }

    // 步骤4：从哈希表移除并释放内存
    m_entities.remove(id);
    delete entity;  // 触发PowerEntity析构函数

    emit entityDeleted(id);
    return true;
}


PowerConnection* TopologyManager::createConnection(const QString& connId,const QString& fromId, const QString& toId)
{
    // 验证有效性
    if (!m_allTerminals.contains(fromId) ||
        !m_allTerminals.contains(toId) ||
        fromId == toId)
    {
        qWarning() << "Invalid connection endpoints";
        return nullptr;
    }

    // 防止重复连接
    foreach (auto conn, m_connections) {
        if (conn->fromTerminalId() == fromId &&
            conn->toTerminalId() == toId)
        {
            return conn;  // 返回已存在的连接
        }
    }

    // 创建新连接
    PowerConnection* conn = new PowerConnection(connId,fromId, toId);
    m_connections[connId] = conn;

    // 更新索引
    m_connectionIndex.insert(fromId, conn);
    m_connectionIndex.insert(toId, conn);

    emit connectionCreated(connId);
    return conn;
}

QList<PowerConnection*> TopologyManager::getConnectionsForTerminal(const QString& terminalId) const
{
    return m_connectionIndex.values(terminalId);
}

void TopologyManager::removeConnection(const QString& connId)
{
    if (!m_connections.contains(connId)) return;

    PowerConnection* conn = m_connections[connId];

    // 更新索引
    m_connectionIndex.remove(conn->fromTerminalId(), conn);
    m_connectionIndex.remove(conn->toTerminalId(), conn);

    // 清理内存
    m_connections.remove(connId);
    delete conn;

    emit connectionRemoved(connId);
}

bool TopologyManager::validateConnection(const QString& fromTermId, const QString& toTermId) const
{
    PowerTerminal* fromTerm = getTerminal(fromTermId);
    PowerTerminal* toTerm = getTerminal(toTermId);

    if (!fromTerm || !toTerm) return false;

    // 类型兼容性检查（示例规则）
    switch(fromTerm->type()) {
    case TerminalType::PowerOutput:
        if (toTerm->type() != TerminalType::PowerInput && toTerm->type() != TerminalType::PowerConnect) return false;
        break;
    case TerminalType::PowerInput:
        if (toTerm->type() != TerminalType::PowerOutput && toTerm->type() != TerminalType::PowerConnect) return false;
        break;
    case TerminalType::PowerConnect:
        break;
    case TerminalType::ControlSignal:
        if (toTerm->type() != TerminalType::ControlSignal) return false;
        break;
    default:
        return false;
    }

    int a  =1;
    // 禁止自连接
    return (fromTerm->parentEntityId() != toTerm->parentEntityId());
}

// 连接查询接口
QList<PowerConnection*> TopologyManager::connectionsFrom(const QString& elementId) const
{
    QList<PowerConnection*> res;
    /*QList<PowerConnection*> lst = m_connectionIndex.values(elementId);
    for(auto &val:lst)
    {
        if(val->fromTerminalId() == elementId)
            res.append(val);
    }*/
    return res;
}

QList<PowerConnection*> TopologyManager::connectionsTo(const QString& elementId) const
{
    QList<PowerConnection*> res;
    /*QList<PowerConnection*> lst = m_connectionIndex.values(elementId);
    for(auto &val:lst)
    {
        if(val->toTerminalId() == elementId)
            res.append(val);
    }*/
    return res;
}

QList<PowerConnection*> TopologyManager::getConnectionsFor(const QString& entityId) const
{
    QList<PowerConnection*> lst;
    QList<PowerTerminal*> lstTerminal = getTerminalsForEntity(entityId);
    for(auto &terminal:lstTerminal)
    {
        PowerConnection* con = getConnectionContainsTerminal(terminal->id());
        if(con)
            lst.append(con);
    }
    return lst;
}

PowerConnection* TopologyManager::connection(const QString& conId) const
{
    return m_connections.value(conId,nullptr);
}

void TopologyManager::saveToDB(const QString& path)
{
    QJsonObject root;

    // 序列化实体（含接线点）
    QJsonArray entities;
    foreach (auto entity, m_entities) {
        QJsonObject entObj = entity->toJson();

        QJsonArray terminalsArray;
        foreach (auto term, entity->terminals()) {
            terminalsArray.append(term->toJson());
        }
        entObj["terminals"] = terminalsArray;

        entities.append(entObj);
    }
    root["entities"] = entities;

    QJsonArray connectionsArray;
    for (auto conn : m_connections)
        connectionsArray.append(conn->toJson());
    root["connections"] = connectionsArray;

    //todo:写入到数据库
}

void TopologyManager::loadFromDB(const QString& path)
{
    //todo::将读到的字为json
    QString strJson;
    QJsonDocument doc = QJsonDocument::fromJson(strJson.toLocal8Bit());
    QJsonObject root = doc.object();

    clearAllData();  // 清除现有数据

    // 阶段1：创建所有实体
    QHash<QString, QStringList> pendingChildren;

    QJsonArray entities = root["entities"].toArray();
    foreach (QJsonValue entVal, entities) {
        QJsonObject entObj = entVal.toObject();

        // 创建实体
        EntityType type = static_cast<EntityType>(entObj["type"].toInt());
        QString id = entObj["id"].toString();
        QString name = entObj["name"].toString();

        PowerEntity* entity = createEntity(type, id, name);

        foreach (auto termJson, entObj["terminals"].toArray()) {
            PowerTerminal* term = PowerTerminal::fromJson(termJson.toObject(), entity);
            m_allTerminals[term->id()] = term;
            m_terminalsByEntity[entity->id()].append(term);
        }

        // 记录待处理的子关系
        pendingChildren[id] = entObj["children"].toVariant().toStringList();
    }

    // 阶段2：建立父子关系
    QHashIterator<QString, QStringList> it(pendingChildren);
    while (it.hasNext()) {
        it.next();
        PowerEntity* parent = getEntity(it.key());
        if (!parent) continue;

        foreach (QString childId, it.value()) {
            if (PowerEntity* child = getEntity(childId)) {
                parent->addChild(child);
            }
        }
    }

    // 阶段3：创建连接
    QJsonArray connections = root["connections"].toArray();
    foreach (QJsonValue connVal, connections) {
        QJsonObject connObj = connVal.toObject();
        createConnection(
            connObj["id"].toString(),
            connObj["from"].toString(),
            connObj["to"].toString()
            );
    }
}

PowerEntity* TopologyManager::getEntity(const QString& id) const
{
    auto it = m_entities.find(id);
    return (it != m_entities.end()) ? it.value() : nullptr;
}

QList<PowerEntity*> TopologyManager::findEntitiesByName(const QString& name) const
{
    QList<PowerEntity*> results;
    foreach (auto entity, m_entities) {
        if (entity->name() == name) {
            results.append(entity);
        }
    }
    return results;
}

PowerTerminal* TopologyManager::createTerminal(const QString& parentEntityId,
                                        TerminalType type,
                                        const QString& name,
                                        const QPointF& relPos,
                                        const QString& uuid) {
    if (!m_entities.contains(parentEntityId)) return nullptr;

    PowerTerminal* term = new PowerTerminal(parentEntityId, type, name, relPos, uuid);
    m_allTerminals[term->id()] = term;
    m_terminalsByEntity[parentEntityId].append(term);

    // 关联到父实体
    if (PowerEntity* parent = getEntity(parentEntityId)) {
        parent->addTerminal(term);
    }

    return term;
}

bool TopologyManager::deleteTerminal(const QString& terminalId) {
    if (!m_allTerminals.contains(terminalId)) return false;

    PowerTerminal* term = m_allTerminals[terminalId];
    QString parentId = term->parentEntityId();

    // 从父实体移除
    if (PowerEntity* parent = getEntity(parentId)) {
        parent->removeTerminal(terminalId);
    }

    // 清理全局存储
    m_terminalsByEntity[parentId].removeAll(term);
    m_allTerminals.remove(terminalId);
    //delete term;      //在parent中已经delete

    return true;
}

PowerTerminal* TopologyManager::getTerminal(const QString& terminalId) const
{
    auto it = m_allTerminals.find(terminalId);
    return (it != m_allTerminals.end()) ? it.value() : nullptr;
}

QList<PowerTerminal*> TopologyManager::getTerminalsForEntity(const QString& entityId) const {
    return m_terminalsByEntity.value(entityId);
}

PowerEntity* TopologyManager::getEntityByTerminal(const QString& terminalId) const
{
    QHash<QString, QList<PowerTerminal*>>::ConstIterator iter;
    for(iter = m_terminalsByEntity.begin();iter != m_terminalsByEntity.end();++iter)
    {
        for(auto &terminal:iter.value())
        {
            if(terminal->id() == terminalId)
            {
                return m_entities[iter.key()];
            }
        }
    }
    return nullptr;
}

PowerConnection* TopologyManager::getConnectionContainsTerminal(const QString& terminalId) const
{
    for(auto &con:m_connections)
    {
        if(con->fromTerminalId() == terminalId || con->toTerminalId() == terminalId)
        {
            return con;
        }
    }
    return nullptr;
}