////////////////////////////////////////////////////////////////////////////////
//
// Copyright 2006 - 2021, Tomas Babej, Paul Beckingham, Federico Hernandez.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//
// https://www.opensource.org/licenses/mit-license.php
//
////////////////////////////////////////////////////////////////////////////////

#include <cmake.h>
// cmake.h include header must come first

#include <Context.h>
#include <ViewTask.h>
#include <format.h>
#include <rules.h>
#include <utf8.h>
#include <util.h>

#include <numeric>

////////////////////////////////////////////////////////////////////////////////
ViewTask::ViewTask()
    : _width(0),
      _left_margin(0),
      _header(0),
      _sort_header(0),
      _odd(0),
      _even(0),
      _intra_padding(1),
      _intra_odd(0),
      _intra_even(0),
      _extra_padding(0),
      _extra_odd(0),
      _extra_even(0),
      _truncate_lines(0),
      _truncate_rows(0),
      _lines(0),
      _rows(0) {}

////////////////////////////////////////////////////////////////////////////////
ViewTask::~ViewTask() {
  for (auto& col : _columns) delete col;

  _columns.clear();
}

////////////////////////////////////////////////////////////////////////////////
//   |<---------- terminal width ---------->|
//
//         +-------+  +-------+  +-------+
//         |header |  |header |  |header |
//   +--+--+-------+--+-------+--+-------+--+
//   |ma|ex|cell   |in|cell   |in|cell   |ex|
//   +--+--+-------+--+-------+--+-------+--+
//   |ma|ex|cell   |in|cell   |in|cell   |ex|
//   +--+--+-------+--+-------+--+-------+--+
//
//   margin        - indentation for the whole table
//   extrapadding  - left and right padding for the whole table
//   intrapadding  - padding between columns
//
//
// Layout Algorithm:
//   - Height is irrelevant
//   - Determine the usable horizontal space for N columns:
//
//       usable = width - ma - (ex * 2) - (in * (N - 1))
//
//   - Look at every column, for every task, and determine the minimum and
//     maximum widths.  The minimum is the length of the largest indivisible
//     word, and the maximum is the full length of the value.
//   - If there is sufficient terminal width to display every task using the
//     maximum width, then do so.
//   - If there is insufficient terminal width to display every task using the
//     minimum width, then there is no layout solution.  Error.
//   - Otherwise there is a need for column wrapping.  Calculate the overage,
//     which is the difference between the sum of the minimum widths and the
//     usable width.
//   - Start by using all the minimum column widths, and distribute the overage
//     among all columns, one character at a time, while the column width is
//     less than the maximum width, and while there is overage remaining.
//
// Note: a possible enhancement is to proportionally distribute the overage
//       according to average data length.
//
// Note: an enhancement to the 'no solution' problem is to simply force-break
//       the larger fields.  If the widest field is W0, and the second widest
//       field is W1, then a solution may be achievable by reducing W0 --> W1.
//
std::string ViewTask::render(std::vector<Task>& data, std::vector<int>& sequence) {
  Timer timer;

  bool const obfuscate = Context::getContext().config.getBoolean("obfuscate");
  bool const print_empty_columns = Context::getContext().config.getBoolean("print.empty.columns");
  std::vector<Column*> nonempty_columns;
  std::vector<bool> nonempty_sort;

  // Determine minimal, ideal column widths.
  std::vector<int> minimal;
  std::vector<int> ideal;

  for (unsigned int i = 0; i < _columns.size(); ++i) {
    // Headers factor in to width calculations.
    unsigned int global_min = 0;
    unsigned int global_ideal = global_min;

    for (unsigned int s = 0; s < sequence.size(); ++s) {
      if ((int)s >= _truncate_lines && _truncate_lines != 0) break;

      if ((int)s >= _truncate_rows && _truncate_rows != 0) break;

      // Determine minimum and ideal width for this column.
      unsigned int min = 0;
      unsigned int ideal = 0;
      _columns[i]->measure(data[sequence[s]], min, ideal);

      if (min > global_min) global_min = min;
      if (ideal > global_ideal) global_ideal = ideal;

      // If a fixed-width column was just measured, there is no point repeating
      // the measurement for all tasks.
      if (_columns[i]->is_fixed_width()) break;
    }

    if (print_empty_columns || global_min != 0) {
      unsigned int label_length = utf8_width(_columns[i]->label());
      if (label_length > global_min) global_min = label_length;
      if (label_length > global_ideal) global_ideal = label_length;
      minimal.push_back(global_min);
      ideal.push_back(global_ideal);
    }

    if (!print_empty_columns) {
      if (global_min != 0)  // Column is nonempty
      {
        nonempty_columns.push_back(_columns[i]);
        nonempty_sort.push_back(_sort[i]);
      } else  // Column is empty, drop it
      {
        // Note: This is safe to do because we set _columns = nonempty_columns
        // after iteration over _columns is finished.
        delete _columns[i];
      }
    }
  }

  if (!print_empty_columns) {
    _columns = nonempty_columns;
    _sort = nonempty_sort;
  }

  int all_extra = _left_margin + (2 * _extra_padding) + ((_columns.size() - 1) * _intra_padding);

  // Sum the widths.
  int sum_minimal = std::accumulate(minimal.begin(), minimal.end(), 0);
  int sum_ideal = std::accumulate(ideal.begin(), ideal.end(), 0);

  // Calculate final column widths.
  int overage = _width - sum_minimal - all_extra;
  Context::getContext().debug(format("ViewTask::render min={1} ideal={2} overage={3} width={4}",
                                     sum_minimal + all_extra, sum_ideal + all_extra, overage,
                                     _width));

  std::vector<int> widths;

  // Ideal case.  Everything fits.
  if (_width == 0 || sum_ideal + all_extra <= _width) {
    widths = ideal;
  }

  // Not enough for minimum. Decrease certain columns.
  else if (overage < 0) {
    // Determine which columns are the longest.
    unsigned int longest = 0;
    unsigned int second_longest = 0;
    for (unsigned int j = 0; j < minimal.size(); j++) {
      if (minimal[j] > minimal[longest]) {
        second_longest = longest;
        longest = j;
      } else if (minimal[j] > minimal[second_longest]) {
        second_longest = j;
      }
    }

    // Case 1: Shortening longest column still keeps it longest. Let it bear
    //         all the shortening.
    widths = minimal;
    if (minimal[longest] + overage >= minimal[second_longest]) widths[longest] += overage;

    // Case 2: Shorten the longest column to second longest length. Try to
    //         split shortening them evenly.
    else {
      int decrease = minimal[second_longest] - minimal[longest];
      widths[longest] += decrease;
      overage = overage - decrease;

      // Attempt to decrease the two longest columns (at most to two characters)
      if (-overage <= widths[longest] + widths[second_longest] - 4) {
        // Compute half of the overage, rounding up
        int half_overage = overage / 2 + overage % 2;

        // Decrease both larges columns by this amount
        widths[longest] += half_overage;
        widths[second_longest] += half_overage;
      } else
        // If reducing two of the longest solumns to 2 characters is not sufficient, then give up.
        Context::getContext().error(format(
            "The report has a minimum width of {1} and does not fit in the available width of {2}.",
            sum_minimal + all_extra, _width));
    }
  }

  // Perfect minimal width.
  else if (overage == 0) {
    widths = minimal;
  }

  // Extra space to share.
  else if (overage > 0) {
    widths = minimal;

    // Spread 'overage' among columns where width[i] < ideal[i]
    bool needed = true;
    while (overage && needed) {
      needed = false;
      for (unsigned int i = 0; i < _columns.size() && overage; ++i) {
        if (widths[i] < ideal[i]) {
          ++widths[i];
          --overage;
          needed = true;
        }
      }
    }
  }

  // Compose column headers.
  unsigned int max_lines = 0;
  std::vector<std::vector<std::string>> headers;
  for (unsigned int c = 0; c < _columns.size(); ++c) {
    headers.emplace_back();
    _columns[c]->renderHeader(headers[c], widths[c], _sort[c] ? _sort_header : _header);

    if (headers[c].size() > max_lines) max_lines = headers[c].size();
  }

  // Render column headers.
  std::string left_margin = std::string(_left_margin, ' ');
  std::string extra = std::string(_extra_padding, ' ');
  std::string intra = std::string(_intra_padding, ' ');

  std::string extra_odd = Context::getContext().color() ? _extra_odd.colorize(extra) : extra;
  std::string extra_even = Context::getContext().color() ? _extra_even.colorize(extra) : extra;
  std::string intra_odd = Context::getContext().color() ? _intra_odd.colorize(intra) : intra;
  std::string intra_even = Context::getContext().color() ? _intra_even.colorize(intra) : intra;

  std::string out;
  _lines = 0;
  for (unsigned int i = 0; i < max_lines; ++i) {
    out += left_margin + extra;

    for (unsigned int c = 0; c < _columns.size(); ++c) {
      if (c) out += intra;

      if (headers[c].size() < max_lines - i)
        out += _header.colorize(std::string(widths[c], ' '));
      else
        out += headers[c][i];
    }

    out += extra;

    // Trim right.
    out.erase(out.find_last_not_of(' ') + 1);
    out += "\n";

    // Stop if the line limit is exceeded.
    if (++_lines >= _truncate_lines && _truncate_lines != 0) {
      Context::getContext().time_render_us += timer.total_us();
      return out;
    }
  }

  // Compose, render columns, in sequence.
  _rows = 0;
  std::vector<std::vector<std::string>> cells;
  for (unsigned int s = 0; s < sequence.size(); ++s) {
    max_lines = 0;

    // Apply color rules to task.
    Color rule_color;
    autoColorize(data[sequence[s]], rule_color);

    // Alternate rows based on |s % 2|
    bool odd = (s % 2) ? true : false;
    Color row_color;
    if (Context::getContext().color()) {
      row_color = odd ? _odd : _even;
      row_color.blend(rule_color);
    }

    for (unsigned int c = 0; c < _columns.size(); ++c) {
      cells.emplace_back();
      _columns[c]->render(cells[c], data[sequence[s]], widths[c], row_color);

      if (cells[c].size() > max_lines) max_lines = cells[c].size();

      if (obfuscate)
        if (_columns[c]->type() == "string")
          for (auto& line : cells[c]) line = obfuscateText(line);
    }

    // Listing breaks are simply blank lines inserted when a column value
    // changes.
    if (s > 0 && _breaks.size() > 0) {
      for (const auto& b : _breaks) {
        if (data[sequence[s - 1]].get(b) != data[sequence[s]].get(b)) {
          out += "\n";
          ++_lines;

          // Only want one \n, regardless of how many values change.
          break;
        }
      }
    }

    for (unsigned int i = 0; i < max_lines; ++i) {
      out += left_margin + (odd ? extra_odd : extra_even);

      for (unsigned int c = 0; c < _columns.size(); ++c) {
        if (c) {
          if (row_color.nontrivial())
            row_color._colorize(out, intra);
          else
            out += (odd ? intra_odd : intra_even);
        }

        if (i < cells[c].size())
          out += cells[c][i];
        else
          row_color._colorize(out, std::string(widths[c], ' '));
      }

      out += (odd ? extra_odd : extra_even);

      // Trim right.
      out.erase(out.find_last_not_of(' ') + 1);
      out += "\n";

      // Stop if the line limit is exceeded.
      if (++_lines >= _truncate_lines && _truncate_lines != 0) {
        Context::getContext().time_render_us += timer.total_us();
        return out;
      }
    }

    cells.clear();

    // Stop if the row limit is exceeded.
    if (++_rows >= _truncate_rows && _truncate_rows != 0) {
      Context::getContext().time_render_us += timer.total_us();
      return out;
    }
  }

  Context::getContext().time_render_us += timer.total_us();
  return out;
}

////////////////////////////////////////////////////////////////////////////////