#pragma once

#include "configuration.h"

#include <yql/essentials/sql/v1/ide/completion/core/input.h>
#include <yql/essentials/sql/v1/ide/completion/core/environment.h>
#include <yql/essentials/sql/v1/ide/completion/name/service/ranking/ranking.h>
#include <yql/essentials/sql/v1/ide/completion/name/service/name_service.h>
#include <yql/essentials/sql/v1/lexer/lexer.h>

#include <library/cpp/threading/future/future.h>

#include <util/generic/string.h>
#include <util/generic/vector.h>
#include <util/generic/hash.h>
#include <util/generic/hash_set.h>

namespace NSQLComplete {

struct TCompletedToken {
    TStringBuf Content;
    size_t SourcePosition = 0;
};

enum class ECandidateKind {
    Keyword,
    PragmaName,
    TypeName,
    FunctionName,
    HintName,
    FolderName,
    TableName,
    ClusterName,
    ColumnName,
    BindingName,
    UnknownName,
};

struct TCandidate {
    ECandidateKind Kind;
    TString Content;
    size_t CursorShift = 0;
    TMaybe<TString> Documentation = Nothing();

    friend bool operator==(const TCandidate& lhs, const TCandidate& rhs) = default;

    TString FilterText() const;
};

struct TCompletion {
    TCompletedToken CompletedToken;
    TVector<TCandidate> Candidates;
};

// TODO(YQL-19747): Make it thread-safe.
class ISqlCompletionEngine {
public:
    using TPtr = THolder<ISqlCompletionEngine>;

    virtual ~ISqlCompletionEngine() = default;

    virtual NThreading::TFuture<TCompletion>
    Complete(TCompletionInput input, TEnvironment env = {}) = 0;

    virtual NThreading::TFuture<TCompletion> // TODO(YQL-19747): Migrate YDB CLI to `Complete` method
    CompleteAsync(TCompletionInput input, TEnvironment env = {}) = 0;
};

using TLexerSupplier = std::function<NSQLTranslation::ILexer::TPtr(bool ansi)>;

ISqlCompletionEngine::TPtr MakeSqlCompletionEngine(
    TLexerSupplier lexer,
    INameService::TPtr names,
    TConfiguration configuration = {},
    IRanking::TPtr ranking = nullptr);

} // namespace NSQLComplete