/*
    This file is part of TON Blockchain Library.

    TON Blockchain Library is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 2 of the License, or
    (at your option) any later version.

    TON Blockchain Library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with TON Blockchain Library.  If not, see <http://www.gnu.org/licenses/>.

    Copyright 2017-2019 Telegram Systems LLP
*/
#include "srcread.h"

namespace src {

/*
 *
 *   SOURCE FILE READER
 *
 */

std::ostream& operator<<(std::ostream& os, const FileDescr* fdescr) {
  return os << (fdescr ? (fdescr->is_stdin ? "stdin" : fdescr->filename) : "unknown-location");
}

std::ostream& operator<<(std::ostream& os, const Fatal& fatal) {
  return os << fatal.get_msg();
}

void SrcLocation::show(std::ostream& os) const {
  os << fdescr;
  if (line_no > 0) {
    os << ':' << line_no;
    if (line_pos >= 0) {
      os << ':' << (line_pos + 1);
    }
  }
}

bool SrcLocation::show_context(std::ostream& os) const {
  if (text.empty() || line_pos < 0 || (unsigned)line_pos > text.size()) {
    return false;
  }
  bool skip_left = (line_pos > 200), skip_right = (line_pos + 200u < text.size());
  const char* start = skip_left ? text.c_str() + line_pos - 100 : text.c_str();
  const char* end = skip_right ? text.c_str() + line_pos + 100 : text.c_str() + text.size();
  const char* here = text.c_str() + line_pos;
  os << "  ";
  if (skip_left) {
    os << "... ";
  }
  for (const char* ptr = start; ptr < end; ptr++) {
    os << (char)*ptr;
  }
  if (skip_right) {
    os << " ...";
  }
  os << std::endl;
  os << "  ";
  if (skip_left) {
    os << "... ";
  }
  for (const char* ptr = start; ptr < here; ptr++) {
    char c = *ptr;
    os << (c == 9 || c == 10 ? c : ' ');
  }
  os << '^' << std::endl;
  return true;
}

std::ostream& operator<<(std::ostream& os, const SrcLocation& loc) {
  loc.show(os);
  return os;
}

void SrcLocation::show_gen_error(std::ostream& os, std::string message, std::string err_type) const {
  show(os);
  if (!err_type.empty()) {
    os << ": " << err_type;
  }
  os << ": " << message << std::endl;
  show_context(os);
}

std::ostream& operator<<(std::ostream& os, const Error& error) {
  error.show(os);
  return os;
}

void ParseError::show(std::ostream& os) const {
  os << where << ": error: " << message << std::endl;
  where.show_context(os);
}

SourceReader::SourceReader(std::istream* _is, const FileDescr* _fdescr)
    : ifs(_is), loc(_fdescr), eof(false), cur_line_len(0), start(0), cur(0), end(0) {
  load_line();
}

void SourceReader::set_eof() {
  if (!eof) {
    eof = true;
    start = cur = end = 0;
  }
}

int SourceReader::skip_spc() {
  if (!cur) {
    return 0;
  }
  const char* ptr = cur;
  int res = 0;
  while (*ptr == ' ' || *ptr == 9) {
    ++ptr;
    ++res;
  }
  set_ptr(ptr);
  return res;
}

bool SourceReader::seek_eof() {
  while (seek_eoln()) {
    if (!load_line()) {
      return true;
    }
  }
  return false;
}

const char* SourceReader::set_ptr(const char* ptr) {
  if (ptr != cur) {
    if (ptr < cur || ptr > end) {
      error("parsing position went outside of line");
    }
    loc.line_pos = (int)(ptr - start);
    cur = ptr;
  }
  return ptr;
}

bool SourceReader::load_line() {
  if (eof) {
    return false;
  }
  if (ifs->eof()) {
    set_eof();
    return false;
  }
  ++loc.line_no;
  loc.line_pos = -1;
  std::getline(*ifs, cur_line);
  if (ifs->fail()) {
    set_eof();
    if (!ifs->eof()) {
      error("cannot read line from source stream");
    }
    return false;
  }
  std::size_t len = cur_line.size();
  if (len > 0xffffff) {
    set_eof();
    error("line too long");
    return false;
  }
  loc.text = cur_line;
  cur_line_len = (int)len;
  loc.line_pos = 0;
  cur = start = cur_line.c_str();
  end = start + cur_line_len;
  return true;
}

}  // namespace src