#include "parse_context.h"
#include "assert.h"

#include <iostream>
#include <iomanip>
#include <cmath>


ParseContext::ParseContext() {
    applicationDir = std::string();
}

unsigned ParseContext::addFile(const std::string &fileName,
                               const std::string &source) {
    fileMap.emplace_back(fileName, source);
    return fileMap.size();
}

SourceFile &ParseContext::getFile(unsigned fileId) {
    return fileMap[fileId - 1];
}


struct pad {
    char ch;
    int count;

    pad(char ch, int count) : ch(ch), count(count) {}
};

std::ostream &operator<<(std::ostream &stream, const pad &p) {
    for (int i = 0; i < p.count; i++) {
        stream << p.ch;
    }
    return stream;
}

#define ATLAS_ASSERT(x) \
    do {} while(0)

void ParseContext::formatError(const SourceError &sourceError,
                               std::ostream &stream,
                               const std::string &errorOrWarning) {
    ATLAS_ASSERT(sourceError.span.lo.col != 0
                 && sourceError.span.hi.col != 0);

    stream << errorOrWarning << sourceError.message << std::endl;

    Span span = sourceError.span;

    // figure out how much padding is required for line numbers in front of
    // printed source code
    int numberPad = 0;
    while (true) {
        numberPad = std::max(numberPad,
                             static_cast<int>(ceil(log10(span.hi.line))) + 1);
        break;
    }

    span = sourceError.span;

    // print all spans
    while (true) {
        SourceFile sourceFile = getFile(span.lo.fileId);

        // check if the span spans across multiple lines or even files
        bool complex = span.lo.fileId != span.hi.fileId
                       || span.lo.line != span.hi.line;

        stream << pad(' ', numberPad) << " -> " << sourceFile.getFileName()
               << ":" << span.lo.line << ":" << span.lo.col << std::endl;
        stream << pad(' ', numberPad) << " |" << std::endl
               << std::right << std::setw(numberPad) << span.lo.line << " | "
               << sourceFile.getLine(span.lo.line) << std::endl
               << pad(' ', numberPad) << " | ";
        for (unsigned i = 0; i < span.lo.col - 1; i++) {
            stream << ' ';
        }
        if (complex) {
            // just point to the beginning of the span
            stream << '^';
        } else {
            // underline the entire span
            for (unsigned i = 0; i < span.hi.col - span.lo.col; i++) {
                stream << '^';
            }
        }

        stream << std::endl;

        break;
    }

    stream << std::endl;
}


SourceFile::SourceFile(std::string fileName, std::string source)
        : fileName(std::move(fileName)), source(std::move(source)) {
    lineOffsets.push_back(0);
}

const std::string &SourceFile::getFileName() const {
    return fileName;
}

std::string SourceFile::getLine(unsigned line) const {
    auto lineOffset = lineOffsets[line - 1];
    auto nextLF = source.find('\n', lineOffset);
    auto nextCR = source.find('\r', lineOffset);
    auto nl = std::min(nextCR, nextLF);

    return source.substr(lineOffset, nl - lineOffset);
}

void SourceFile::addLineOffset(unsigned offset) {
    lineOffsets.push_back(offset);
}