#include <cassert>

#include "components/parser.hpp"
#include "components/types.hpp"
#include "events/signal.hpp"
#include "events/signal_emitter.hpp"
#include "settings.hpp"
#include "utils/color.hpp"
#include "utils/factory.hpp"
#include "utils/file.hpp"
#include "utils/math.hpp"
#include "utils/memory.hpp"
#include "utils/string.hpp"

POLYBAR_NS

using namespace signals::parser;

/**
 * Create instance
 */
parser::make_type parser::make() {
  return factory_util::unique<parser>(signal_emitter::make());
}

/**
 * Construct parser instance
 */
parser::parser(signal_emitter& emitter) : m_sig(emitter) {}

/**
 * Process input string
 */
void parser::parse(const bar_settings& bar, string data) {
  while (!data.empty()) {
    size_t pos{string::npos};

    if (data.compare(0, 2, "%{") == 0 && (pos = data.find('}')) != string::npos) {
      codeblock(data.substr(2, pos - 2), bar);
      data.erase(0, pos + 1);
    } else if ((pos = data.find("%{")) != string::npos) {
      data.erase(0, text(data.substr(0, pos)));
    } else {
      data.erase(0, text(data.substr(0)));
    }
  }

  m_fg = std::stack<unsigned int>();
  m_bg = std::stack<unsigned int>();
  m_ul = std::stack<unsigned int>();
  m_ol = std::stack<unsigned int>();
  m_fonts = std::stack<int>();
  m_reversed = 0u;

  if (!m_actions.empty()) {
    throw unclosed_actionblocks(to_string(m_actions.size()) + " unclosed action block(s)");
  }
}

/**
 * Process contents within tag blocks, i.e: %{...}
 */
void parser::codeblock(string&& data, const bar_settings& bar) {
  size_t pos;

  while (data.length()) {
    data = string_util::ltrim(move(data), ' ');

    if (data.empty()) {
      break;
    }

    char tag{data[0]};
    string value;

    // Remove the tag
    data.erase(0, 1);

    if ((pos = data.find_first_of(" }")) != string::npos) {
      value = data.substr(0, pos);
    } else {
      value = data;
    }

    switch (tag) {
      case 'B': {
        m_sig.emit(change_background{parse_color(m_bg, value, bar.background)});
        break;
      }

      case 'F': {
        m_sig.emit(change_foreground{parse_color(m_fg, value, bar.foreground)});
        break;
      }

      case 'T':
        m_sig.emit(change_font{parse_fontindex(value)});
        break;

      case 'U':
        m_sig.emit(change_underline{parse_color(m_ul, value, bar.underline.color)});
        m_sig.emit(change_overline{parse_color(m_ol, value, bar.overline.color)});
        break;

      case 'u':
        m_sig.emit(change_underline{parse_color(m_ul, value, bar.underline.color)});
        break;

      case 'o':
        m_sig.emit(change_overline{parse_color(m_ol, value, bar.overline.color)});
        break;

      case 'R':
        if (++m_reversed % 2) {
          m_sig.emit(change_background{parse_color(m_fg, value, bar.foreground)});
          m_sig.emit(change_foreground{parse_color(m_bg, value, bar.background)});
        } else {
          m_sig.emit(change_foreground{parse_color(m_fg, value, bar.foreground)});
          m_sig.emit(change_background{parse_color(m_bg, value, bar.background)});
        }
        break;

      case 'O':
        m_sig.emit(offset_pixel{static_cast<int>(std::atoi(value.c_str()))});
        break;

      case 'l':
        m_sig.emit(change_alignment{alignment::LEFT});
        break;

      case 'c':
        m_sig.emit(change_alignment{alignment::CENTER});
        break;

      case 'r':
        m_sig.emit(change_alignment{alignment::RIGHT});
        break;

      case '+':
        m_sig.emit(attribute_set{parse_attr(value[0])});
        break;

      case '-':
        m_sig.emit(attribute_unset{parse_attr(value[0])});
        break;

      case '!':
        m_sig.emit(attribute_toggle{parse_attr(value[0])});
        break;

      case 'A':
        if (isdigit(data[0]) || data[0] == ':') {
          value = parse_action_cmd(data.substr(data[0] != ':' ? 1 : 0));
          mousebtn btn = parse_action_btn(data);
          m_actions.push_back(static_cast<int>(btn));
          m_sig.emit(action_begin{action{btn, value}});

          // make sure we strip the correct length (btn+wrapping colons)
          if (value[0] != ':') {
            value += "0";
          }
          value += "::";
        } else if (!m_actions.empty()) {
          m_sig.emit(action_end{parse_action_btn(value)});
          m_actions.pop_back();
        }
        break;

      default:
        throw unrecognized_token("Unrecognized token '" + string{tag} + "'");
    }

    if (!data.empty()) {
      data.erase(0, !value.empty() ? value.length() : 1);
    }
  }
}

/**
 * Process text contents
 */
size_t parser::text(string&& data) {
#ifdef DEBUG_WHITESPACE
  string::size_type p;
  while ((p = data.find(' ')) != string::npos) {
    data.replace(p, 1, "-"s);
  }
#endif

  m_sig.emit(signals::parser::text{forward<string>(data)});
  return data.size();
}

/**
 * Determine color using passed stack and input value
 */
unsigned int parser::parse_color(std::stack<unsigned int>& color_stack, string& value, unsigned int fallback) {
  if (!color_stack.empty() && !value.empty() && value[0] == '-') {
    color_stack.pop();
  }
  auto parsed_value = parse_color_string(value, !color_stack.empty() ? color_stack.top() : fallback);
  if (!value.empty() && value[0] != '-') {
    color_stack.push(parsed_value);
  }
  return parsed_value;
}

/**
 * Process color hex string and convert it to the correct value
 */
unsigned int parser::parse_color_string(const string& s, unsigned int fallback) {
  if (!s.empty() && s[0] != '-') {
    return color_util::parse(s, fallback);
  }
  return fallback;
}

/**
 * Process font index and convert it to the correct value
 */
int parser::parse_fontindex(const string& value) {
  auto font_index = 0;
  auto reset = value.empty() || value[0] == '-';

  if (reset && !m_fonts.empty()) {
    m_fonts.pop();
  } else if (!reset) {
    try {
      font_index = std::stoul(value, nullptr, 10);
      m_fonts.push(font_index);
      return font_index;
    } catch (const std::invalid_argument& err) {
      return font_index;
    }
  }

  if (!m_fonts.empty()) {
    return m_fonts.top();
  } else {
    return font_index;
  }
}

/**
 * Process attribute token and convert it to the correct value
 */
attribute parser::parse_attr(const char attr) {
  switch (attr) {
    case 'o':
      return attribute::OVERLINE;
    case 'u':
      return attribute::UNDERLINE;
    default:
      throw unrecognized_token("Unrecognized attribute '" + string{attr} + "'");
  }
}

/**
 * Process action button token and convert it to the correct value
 */
mousebtn parser::parse_action_btn(const string& data) {
  if (data[0] == ':') {
    return mousebtn::LEFT;
  } else if (isdigit(data[0])) {
    return static_cast<mousebtn>(data[0] - '0');
  } else if (!m_actions.empty()) {
    return static_cast<mousebtn>(m_actions.back());
  } else {
    return mousebtn::NONE;
  }
}

/**
 * Process action command string
 */
string parser::parse_action_cmd(string&& data) {
  if (data[0] != ':') {
    return "";
  }

  size_t end{1};
  while ((end = data.find(':', end)) != string::npos && data[end - 1] == '\\') {
    end++;
  }

  if (end == string::npos) {
    return "";
  }

  return data.substr(1, end - 1);
}

POLYBAR_NS_END