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#pragma once

#include "languageclient_global.h"

#include <languageserverprotocol/languagefeatures.h>
#include <texteditor/codeassist/completionassistprovider.h>
#include <texteditor/codeassist/iassistprocessor.h>
#include <utils/optional.h>

#include <QPointer>

namespace TextEditor { class IAssistProposal; }

namespace LanguageClient {

class Client;

using ProposalHandler = std::function<void(TextEditor::IAssistProposal *)>;

class LANGUAGECLIENT_EXPORT FunctionHintAssistProvider : public TextEditor::CompletionAssistProvider
{
    Q_OBJECT

public:
    explicit FunctionHintAssistProvider(Client *client);

    TextEditor::IAssistProcessor *createProcessor(const TextEditor::AssistInterface *) const override;
    RunType runType() const override;

    int activationCharSequenceLength() const override;
    bool isActivationCharSequence(const QString &sequence) const override;
    bool isContinuationChar(const QChar &c) const override;

    void setTriggerCharacters(const Utils::optional<QList<QString>> &triggerChars);

    void setProposalHandler(const ProposalHandler &handler) { m_proposalHandler = handler; }

private:
    QList<QString> m_triggerChars;
    ProposalHandler m_proposalHandler;
    int m_activationCharSequenceLength = 0;
    Client *m_client = nullptr; // not owned
};

class LANGUAGECLIENT_EXPORT FunctionHintProcessor : public TextEditor::IAssistProcessor
{
public:
    explicit FunctionHintProcessor(Client *client, const ProposalHandler &proposalHandler);
    TextEditor::IAssistProposal *perform(const TextEditor::AssistInterface *interface) override;
    bool running() override { return m_currentRequest.has_value(); }
    bool needsRestart() const override { return true; }
    void cancel() override;

private:
    void handleSignatureResponse(
        const LanguageServerProtocol::SignatureHelpRequest::Response &response);
    void processProposal(TextEditor::IAssistProposal *proposal);

    QPointer<Client> m_client;
    const ProposalHandler m_proposalHandler;
    Utils::optional<LanguageServerProtocol::MessageId> m_currentRequest;
    int m_pos = -1;
};

} // namespace LanguageClient