/* 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 "ListTokenSource.h"

#include "CharStream.h"
#include "CommonToken.h"
#include "Token.h"

using namespace antlr4;

ListTokenSource::ListTokenSource(std::vector<std::unique_ptr<Token>> tokens_)
    : ListTokenSource(std::move(tokens_), "") {}

ListTokenSource::ListTokenSource(
    std::vector<std::unique_ptr<Token>> tokens_, const std::string& sourceName_)
    : tokens(std::move(tokens_)), sourceName(sourceName_) {
    InitializeInstanceFields();
    if (tokens.empty()) {
        throw "tokens cannot be null";
    }

    // Check if there is an eof token and create one if not.
    if (tokens.back()->getType() != Token::EOF) {
        Token* lastToken = tokens.back().get();
        size_t start = INVALID_INDEX;
        size_t previousStop = lastToken->getStopIndex();
        if (previousStop != INVALID_INDEX) {
            start = previousStop + 1;
        }

        size_t stop = std::max(INVALID_INDEX, start - 1);
        tokens.emplace_back((_factory->create({this, getInputStream()}, Token::EOF, "EOF",
            Token::DEFAULT_CHANNEL, start, stop, static_cast<int>(lastToken->getLine()),
            lastToken->getCharPositionInLine())));
    }
}

size_t ListTokenSource::getCharPositionInLine() {
    if (i < tokens.size()) {
        return tokens[i]->getCharPositionInLine();
    }
    return 0;
}

std::unique_ptr<Token> ListTokenSource::nextToken() {
    if (i < tokens.size()) {
        return std::move(tokens[i++]);
    }
    return nullptr;
}

size_t ListTokenSource::getLine() const {
    if (i < tokens.size()) {
        return tokens[i]->getLine();
    }

    return 1;
}

CharStream* ListTokenSource::getInputStream() {
    if (i < tokens.size()) {
        return tokens[i]->getInputStream();
    } else if (!tokens.empty()) {
        return tokens.back()->getInputStream();
    }

    // no input stream information is available
    return nullptr;
}

std::string ListTokenSource::getSourceName() {
    if (sourceName != "") {
        return sourceName;
    }

    CharStream* inputStream = getInputStream();
    if (inputStream != nullptr) {
        return inputStream->getSourceName();
    }

    return "List";
}

TokenFactory<CommonToken>* ListTokenSource::getTokenFactory() {
    return _factory;
}

void ListTokenSource::InitializeInstanceFields() {
    i = 0;
    _factory = CommonTokenFactory::DEFAULT.get();
}
