#include "components/parser.hpp"
#include "utils/math.hpp"
#include "utils/string.hpp"

LEMONBUDDY_NS

/**
 * Parse input data
 */
void parser::operator()(string data) {
  size_t pos;

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

/**
 * Parse contents in tag blocks, i.e: %{...}
 */
void parser::codeblock(string data) {
  size_t pos;

  while (data.length()) {
    data = string_util::ltrim(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':
        // Ignore tag if it occurs again later in the same block
        if (data.find(" B") == string::npos && g_signals::parser::color_change)
          g_signals::parser::color_change(gc::BG, parse_color(value, m_bar.background));
        break;

      case 'F':
        // Ignore tag if it occurs again later in the same block
        if (data.find(" F") == string::npos && g_signals::parser::color_change)
          g_signals::parser::color_change(gc::FG, parse_color(value, m_bar.foreground));
        break;

      case 'U':
        // Ignore tag if it occurs again later in the same block
        if (data.find(" U") == string::npos && g_signals::parser::color_change) {
          g_signals::parser::color_change(gc::UL, parse_color(value, m_bar.linecolor));
          g_signals::parser::color_change(gc::OL, parse_color(value, m_bar.linecolor));
        }
        break;

      case 'R':
        if (g_signals::parser::color_change) {
          g_signals::parser::color_change(gc::BG, m_bar.foreground);
          g_signals::parser::color_change(gc::FG, m_bar.background);
        }
        break;

      case 'T':
        if (data.find(" T") == string::npos && g_signals::parser::font_change)
          g_signals::parser::font_change(parse_fontindex(value));
        break;

      case 'O':
        if (g_signals::parser::pixel_offset)
          g_signals::parser::pixel_offset(std::atoi(value.c_str()));
        break;

      case 'l':
        if (g_signals::parser::alignment_change)
          g_signals::parser::alignment_change(alignment::LEFT);
        break;

      case 'c':
        if (g_signals::parser::alignment_change)
          g_signals::parser::alignment_change(alignment::CENTER);
        break;

      case 'r':
        if (g_signals::parser::alignment_change)
          g_signals::parser::alignment_change(alignment::RIGHT);
        break;

      case '+':
        if (g_signals::parser::attribute_set)
          g_signals::parser::attribute_set(parse_attr(value[0]));
        break;

      case '-':
        if (g_signals::parser::attribute_unset)
          g_signals::parser::attribute_unset(parse_attr(value[0]));
        break;

      case '!':
        if (g_signals::parser::attribute_toggle)
          g_signals::parser::attribute_toggle(parse_attr(value[0]));
        break;

      case 'A':
        if (isdigit(data[0]) || data[0] == ':') {
          value = parse_action_cmd(data);
          mousebtn btn = parse_action_btn(data);
          m_actions.push_back(static_cast<int>(btn));

          if (g_signals::parser::action_block_open)
            g_signals::parser::action_block_open(btn, value);

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

      default:
        throw unrecognized_token(string{tag});
    }

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

/**
 * Parse text strings
 */
size_t parser::text(string data) {
  uint8_t* utf = (uint8_t*)data.c_str();

  if (g_signals::parser::string_write && utf[0] < 0x80) {
    // grab all consecutive ascii chars
    size_t next_tag = data.find("%{");
    if (next_tag != string::npos) {
      data.erase(next_tag);
    }
    size_t n = 0;
    while (utf[n] != '\0' && utf[++n] < 0x80)
      ;
    g_signals::parser::string_write(data.substr(0, n).c_str(), n);
    return n;
  } else if (utf[0] < 0x80) {
    if (g_signals::parser::ascii_text_write)
      g_signals::parser::ascii_text_write(utf[0]);
    return 1;
  } else if ((utf[0] & 0xe0) == 0xc0) {  // 2 byte utf-8 sequence
    if (g_signals::parser::unicode_text_write)
      g_signals::parser::unicode_text_write((utf[0] & 0x1f) << 6 | (utf[1] & 0x3f));
    return 2;
  } else if ((utf[0] & 0xf0) == 0xe0) {  // 3 byte utf-8 sequence
    if (g_signals::parser::unicode_text_write)
      g_signals::parser::unicode_text_write(
          (utf[0] & 0xf) << 12 | (utf[1] & 0x3f) << 6 | (utf[2] & 0x3f));
    return 3;
  } else if ((utf[0] & 0xf8) == 0xf0) {  // 4 byte utf-8 sequence
    if (g_signals::parser::unicode_text_write)
      g_signals::parser::unicode_text_write(0xfffd);
    return 4;
  } else if ((utf[0] & 0xfc) == 0xf8) {  // 5 byte utf-8 sequence
    if (g_signals::parser::unicode_text_write)
      g_signals::parser::unicode_text_write(0xfffd);
    return 5;
  } else if ((utf[0] & 0xfe) == 0xfc) {  // 6 byte utf-8 sequence
    if (g_signals::parser::unicode_text_write)
      g_signals::parser::unicode_text_write(0xfffd);
    return 6;
  } else {  // invalid utf-8 sequence
    if (g_signals::parser::ascii_text_write)
      g_signals::parser::ascii_text_write(utf[0]);
    return 1;
  }
}

/**
 * TODO: docstring
 */
color parser::parse_color(string s, color fallback) {
  if (s.empty() || s == "-")
    return fallback;
  return color::parse(s, fallback);
}

/**
 * TODO: docstring
 */
int parser::parse_fontindex(string s) {
  if (s.empty() || s == "-")
    return -1;
  char* p = (char*)s.c_str();
  return std::strtoul(p, &p, 10);
}

/**
 * TODO: docstring
 */
attribute parser::parse_attr(const char s) {
  switch (s) {
    case 'o':
      return attribute::o;
      break;
    case 'u':
      return attribute::u;
      break;
  }
  return attribute::NONE;
}

/**
 * TODO: docstring
 */
mousebtn parser::parse_action_btn(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;
}

/**
 * TODO: docstring
 */
string parser::parse_action_cmd(string data) {
  auto start = string_util::find_nth(data, 0, ":", 1);
  auto end = string_util::find_nth(data, 0, ":", 2);
  return string_util::trim(data.substr(start, end), ':');
}

LEMONBUDDY_NS_END