#include "comdellexer.h"
#include "comdelparser.h"
#include "parserutil.h"

#include <iostream>
#include <fstream>
#include <string>
#include <QDir>

std::optional<LibraryNode> loadLibraryFromFile(ParseContext * parseContext,
                                                            const char* name,
                                                            std::ostream& stream)
{
    std::ifstream in(name, std::ios::in | std::ios::binary);
    if( ! in ) {
        stream << "ERROR: cannot open file '" << name
               << "' (file does not exist or is unreadable)" << std::endl;
        return std::nullopt;
    }

    std::string source((std::istreambuf_iterator<char>(in)),
                       std::istreambuf_iterator<char>());
    ComdelLexer lexer(name, source, parseContext);
    LexerResult lexerResult = lexer.tokenize();

    if (lexerResult.errors.size()) {
        for (auto& error : lexerResult.errors) {
            parseContext->formatError(error, stream, "ERROR: ");
        }
        return std::nullopt;  // if lexer has found errors => don't parse
    }

    ComdelParser parser(lexerResult.tokens);
    auto unit = parser.parse();
    if (!unit) {
        for (auto& error : parser.getErrors()) {
            parseContext->formatError(error, stream, "ERROR: ");
        }
        return std::nullopt;
    }

    return *unit;
}


std::optional<SchemaNode> loadSchemaFromFile(ParseContext * parseContext,
                                                            const char* name,
                                                            std::ostream& stream)
{
    std::ifstream in(name, std::ios::in | std::ios::binary);
    if( ! in ) {
        stream << "ERROR: cannot open file '" << name
               << "' (file does not exist or is unreadable)" << std::endl;
        return std::nullopt;
    }

    std::string source((std::istreambuf_iterator<char>(in)),
                       std::istreambuf_iterator<char>());
    ComdelLexer lexer(name, source, parseContext);
    LexerResult lexerResult = lexer.tokenize();

    if (lexerResult.errors.size()) {
        for (auto& error : lexerResult.errors) {
            parseContext->formatError(error, stream, "ERROR: ");
        }
        return std::nullopt;  // if lexer has found errors => don't parse
    }

    ComdelParser parser(lexerResult.tokens);
    auto unit = parser.parseSchema();
    if (!unit) {
        for (auto& error : parser.getErrors()) {
            parseContext->formatError(error, stream, "ERROR: ");
        }
        return std::nullopt;
    }

    if(unit->source) {
        QFileInfo info(name);
        auto filepath = info.absolutePath();
        QDir dir;
        dir.setCurrent(filepath);

        auto libraryPath = dir.absoluteFilePath(QString::fromStdString(unit->source->asString()));

        unit->library = loadLibraryFromFile(parseContext, libraryPath.toUtf8().data(), stream);
        if(unit->library == std::nullopt) {
            return std::nullopt;
        }
    }


    return *unit;
}