#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)));
    }
  }

  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(value, bar.background)});
        break;

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

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

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

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

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

      case 'R':
        m_sig.emit(change_background{parse_color(value, bar.foreground)});
        m_sig.emit(change_foreground{parse_color(value, bar.background)});
        break;

      case 'O':
        m_sig.emit(offset_pixel{static_cast<int16_t>(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

  const uint8_t* utf{reinterpret_cast<const uint8_t*>(&data[0])};

  // clang-format off
  if (utf[0] < 0x80) {
    size_t pos{0};

    // grab consecutive ascii chars
    while (utf[pos] && utf[pos] < 0x80) {
      packet pkt{};
      size_t limit{memory_util::countof(pkt.data)};
      size_t len{0};

      while (len + 1 < limit && utf[pos] && utf[pos] < 0x80) {
        pkt.data[len++] = utf[pos++];
      }

      if (!len) {
        break;
      }

      pkt.length = len;
      m_sig.emit(write_text_string{move(pkt)});
    }

    if (pos > 0) {
      return pos;
    }

  } else if ((utf[0] & 0xe0) == 0xc0) {  // 2 byte utf-8 sequence
    m_sig.emit(write_text_unicode{static_cast<uint16_t>(((utf[0] & 0x1f) << 6) | (utf[1] & 0x3f))});
    return 2;
  } else if ((utf[0] & 0xf0) == 0xe0) {  // 3 byte utf-8 sequence
    m_sig.emit(write_text_unicode{static_cast<uint16_t>(((utf[0] & 0x0f) << 12) | ((utf[1] & 0x3f) << 6) | (utf[2] & 0x3f))});
    return 3;
  } else if ((utf[0] & 0xf8) == 0xf0) {  // 4 byte utf-8 sequence
    // m_sig.emit(write_text_unicode{((utf[0] & 0x07) << 18) | ((utf[1] & 0x3f) << 12) | ((utf[2] & 0x3f) << 6) | (utf[3] & 0x3f)});
    m_sig.emit(write_text_unicode{static_cast<uint16_t>(0xfffd)});
    return 4;
  } else if ((utf[0] & 0xfc) == 0xf8) {  // 5 byte utf-8 sequence
    // m_sig.emit(write_text_unicode{((utf[0] & 0x03) << 24) | ((utf[1] & 0x3f) << 18) | ((utf[2] & 0x3f) << 12) | ((utf[3] & 0x3f) << 6) | (utf[4] & 0x3f)});
    m_sig.emit(write_text_unicode{static_cast<uint16_t>(0xfffd)});
    return 5;
  } else if ((utf[0] & 0xfe) == 0xfc) {  // 6 byte utf-8 sequence
    // m_sig.emit(write_text_unicode{((utf[0] & 0x01) << 30) | ((utf[1] & 0x3f) << 24) | ((utf[2] & 0x3f) << 18) | ((utf[3] & 0x3f) << 12) | ((utf[4] & 0x3f) << 6) | (utf[5] & 0x3f)});
    m_sig.emit(write_text_unicode{static_cast<uint16_t>(0xfffd)});
    return 6;
  }
  // clang-format on

  if (utf[0] < 0x80) {
    m_sig.emit(write_text_ascii{utf[0]});
  }

  return 1;
}

/**
 * Process color hex string and convert it to the correct value
 */
uint32_t parser::parse_color(const string& s, uint32_t fallback) {
  uint32_t color{0};
  if (s.empty() || s[0] == '-' || (color = color_util::parse(s, fallback)) == fallback) {
    return fallback;
  }
  return color_util::premultiply_alpha(color);
}

/**
 * Process font index and convert it to the correct value
 */
uint8_t parser::parse_fontindex(const string& s) {
  if (s.empty() || s[0] == '-') {
    return 0;
  }

  try {
    return std::stoul(s, nullptr, 10);
  } catch (const std::invalid_argument& err) {
    return 0;
  }
}

/**
 * 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