/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
 * Use of this file is governed by the BSD 3-clause license that
 * can be found in the LICENSE.txt file in the project root.
 */

#include "atn/ArrayPredictionContext.h"

#include "atn/SingletonPredictionContext.h"
#include "support/Arrays.h"

using namespace antlr4::atn;

ArrayPredictionContext::ArrayPredictionContext(Ref<SingletonPredictionContext> const& a)
    : ArrayPredictionContext({a->parent}, {a->returnState}) {}

ArrayPredictionContext::ArrayPredictionContext(
    std::vector<Ref<PredictionContext>> const& parents_, std::vector<size_t> const& returnStates)
    : PredictionContext(calculateHashCode(parents_, returnStates)), parents(parents_),
      returnStates(returnStates) {
    assert(parents.size() > 0);
    assert(returnStates.size() > 0);
}

ArrayPredictionContext::~ArrayPredictionContext() {}

bool ArrayPredictionContext::isEmpty() const {
    // Since EMPTY_RETURN_STATE can only appear in the last position, we don't need to verify that
    // size == 1.
    return returnStates[0] == EMPTY_RETURN_STATE;
}

size_t ArrayPredictionContext::size() const {
    return returnStates.size();
}

Ref<PredictionContext> ArrayPredictionContext::getParent(size_t index) const {
    return parents[index];
}

size_t ArrayPredictionContext::getReturnState(size_t index) const {
    return returnStates[index];
}

bool ArrayPredictionContext::operator==(PredictionContext const& o) const {
    if (this == &o) {
        return true;
    }

    const ArrayPredictionContext* other = dynamic_cast<const ArrayPredictionContext*>(&o);
    if (other == nullptr || hashCode() != other->hashCode()) {
        return false; // can't be same if hash is different
    }

    return antlrcpp::Arrays::equals(returnStates, other->returnStates) &&
           antlrcpp::Arrays::equals(parents, other->parents);
}

std::string ArrayPredictionContext::toString() const {
    if (isEmpty()) {
        return "[]";
    }

    std::stringstream ss;
    ss << "[";
    for (size_t i = 0; i < returnStates.size(); i++) {
        if (i > 0) {
            ss << ", ";
        }
        if (returnStates[i] == EMPTY_RETURN_STATE) {
            ss << "$";
            continue;
        }
        ss << returnStates[i];
        if (parents[i] != nullptr) {
            ss << " " << parents[i]->toString();
        } else {
            ss << "nul";
        }
    }
    ss << "]";
    return ss.str();
}
