#pragma once

#include "defs.h"

#include <yql/essentials/sql/v1/ide/completion/core/input.h>

#include <util/generic/fwd.h>
#include <util/generic/string.h>
#include <util/generic/vector.h>

#include <unordered_set>

namespace NSQLComplete {

// std::vector is used to prevent copying a C3 output
struct TSuggestedToken {
    TTokenId Number;
    std::vector<TTokenId> Following;
};

struct TMatchedRule {
    TRuleId Index;
    TParserCallStack ParserCallStack;
};

struct TC3Candidates {
    TVector<TSuggestedToken> Tokens;
    TVector<TMatchedRule> Rules;
};

class IC3Engine {
public:
    using TPtr = THolder<IC3Engine>;

    // std::unordered_set is used to prevent copying into c3 core
    struct TConfig {
        std::unordered_set<TTokenId> IgnoredTokens;
        std::unordered_set<TRuleId> PreferredRules;
        std::unordered_set<TRuleId> IgnoredRules;
        std::unordered_map<TTokenId, std::unordered_set<TTokenId>> DisabledPreviousByToken;
        std::unordered_map<TTokenId, std::unordered_set<TTokenId>> ForcedPreviousByToken;
    };

    virtual ~IC3Engine() = default;
    virtual TC3Candidates Complete(TStringBuf text, size_t caretTokenIndex) = 0;
};

} // namespace NSQLComplete