require 'js'

# 処理中画面の表示/非表示
# @param f [Boolean]
def in_progress(&block)
  @in_progress ||= []
  @in_progress.push true
  JS.document.getElementById('in-progress').style.display = 'block' unless @in_progress.empty?
  block.call
  @in_progress.shift
  JS.document.getElementById('in-progress').style.display = 'none' if @in_progress.empty?
end

# バージョンファイルを読み終わってから main を呼ぶ
def start
  JS.document.getElementById('in-progress').style.display = 'none'
  JS.global.fetch('/json/versions.json') {|res|
    unless res.ok
      JS.global.alert("error #{res.status}")
      raise
    end
    json = res.json.await
    @available_versions = json.to_a
    main
  }
end

# 開始
def main
  @param_cache = {}
  uri = URI.parse(JS.document.location.href.to_s)
  q = URI.decode_www_form(uri.query.to_s).to_h
  @type = q['type'] || uri.path.sub('index.html', '').split('/').compact.reject(&:empty?).last || 'mysqld'

  list = JS.document.getElementById('menu').querySelectorAll('li a').to_a
  list.each do |a|
    a.addEventListener('click') do
      @type = URI.parse(a.href.to_s).path.split('/')[1]
      redisplay
    end
  end

  vers = q['vers'].to_s.split(',')
  diff = q['diff'] == 'true'
  e_diff = diff_element
  e_diff.checked = diff
  e_diff.addEventListener('change'){change_diff}

  plugin = q['plugin'] == 'true'
  e_plugin = plugin_element
  e_plugin.checked = plugin
  e_plugin.addEventListener('change'){redisplay}

  create_version_list
  vers.each{|ver| add_input(ver.strip)}
  add_input
  change_diff
  redisplay
end

# 差分表示切り替え
def change_diff
  only_diff = diff_element.checked == true
  JS.document.styleSheets[0].cssRules.to_a.each do |css|
    if css[:selectorText] == 'tr.same-value'
      css.style.display = only_diff ? 'none' : nil
    end
  end
  set_location
end

# バージョンリストの datalist 要素作成
def create_version_list
  version_list = create_element('datalist', id: 'version_list')
  @available_versions.each do |v|
    o = create_element('option', value: v, text: v)
    version_list.appendChild(o)
  end
  JS.document.getElementById('versions').appendChild(version_list)
end

# HTML要素作成
# @param type [String] 要素名
# @param opts [Hash] 要素の属性
def create_element(type, **opts)
  e = JS.document.createElement(type)
  opts.each do |k, v|
    e.setAttribute(k.to_s, v)
  end
  e
end

# バージョン入力用の input 要素を作成
# @param ver [String] バージョン
def add_input(ver=nil)
  v = create_element('input', name: 'version', class: 'version', type: 'search', list: 'version_list')
  v.value = ver if ver
  JS.document.getElementById('versions').appendChild(v)
  v.addEventListener('keypress') do |e|
    redisplay if e.key == 'Enter'
  end
  v.addEventListener('change') do
    redisplay
  end
end

# バージョン入力用要素一覧を返す
# @return [Array<JS::Object>]
def version_elements
  JS.document.getElementsByName('version').to_a
end

# 「Difference Only」要素
# @return [Array<JS::Object>]
def diff_element
  JS.document.getElementById('only_difference')
end

# 「Include plugins」要素
# @return [Array<JS::Object>]
def plugin_element
  JS.document.getElementById('include_plugins')
end

# 再表示
def redisplay
  in_progress do
    JS.global[:sleepTime] = 0
    next if @in_redisplay
    @in_redisplay = true
    set_location
    JS.document.getElementById('param_table')&.remove
    @versions = []
    version_elements.each_with_index do |v, i|
      ver = v.value = v.value.to_s.strip
      if ver.empty?
        v.remove if i < version_elements.size - 1
        next
      end
      unless @available_versions.include?(ver)
        ver = @available_versions.select{_1.start_with?(ver+'.')}.first
      end
      unless ver
        v[:className] = 'invalid-version'
        next
      end
      v[:className] = ''
      read_params(ver)
      @versions.push ver
    end
    add_input if version_elements.empty? || !version_elements.last.value.to_s.empty?
    display_table
  ensure
    if $tableonly
      JS.global[:sleepTime] = 2000
    else
      JS.global[:sleepTime] = 300
    end
    @in_redisplay = false
  end
end

# バージョン ver のパラメータ JSON ファイルを読み込む
# @param ver [String] バージョン
def read_params(ver)
  plugin = include_plugins?
  return if @param_cache[[@type, ver, plugin]]

  file = plugin ? 'all.json' : 'base.json'
  JS.global.fetch("/json/#{ver}/#{@type}/#{file}") {|res|
    unless res.ok == true
      JS.global.alert("error #{res.status}")
      raise "error #{res.status}"
    end
    json = res.json.await
    data = JS.global[:Object].keys(json).to_a.map {|key|
      [key, json[key].to_s]
    }.to_h
    @param_cache[[@type, ver, plugin]] = data
  }
end

# HTML 要素を元に URL を設定する
def set_location
  uri = URI.parse(JS.global.location.href.to_s)
  uri.path = "/#{@type}/"
  vers = version_elements.to_a.map{it.value.to_s}.reject(&:empty?).join(',')
  diff = diff_element.checked == true
  plugin = plugin_element.checked == true
  q = URI.decode_www_form(uri.query.to_s).to_h
  q.reject!{|k,| ['type', 'vers', 'diff', 'plugin'].include? k}
  q['vers'] = vers unless vers.empty?
  q['diff'] = 'true' if diff
  q['plugin'] = 'true' if plugin
  query = URI.encode_www_form(q).gsub('%2C', ',')
  uri.query = query.empty? ? nil : query
  JS.global.window.history.replaceState('', '', uri.to_s)

  list = JS.document.getElementById('menu').querySelectorAll('li a').to_a
  list.each do |a|
    href = a.href.to_s
    a.href = href.to_s.sub(/\?.*|\z/, '?'+query) unless query.empty?
    if URI.parse(href).path.start_with? "/#{@type}/"
      a.parentElement[:className] = 'current'
      JS.document.title = "#{a[:textContent]} / MySQL Parameters"
    else
      a.parentElement[:className] = nil
    end
  end
end

# パラメータテーブルを表示する
def display_table
  versions = @versions
  plugin = include_plugins?
  table = JS.document.getElementById('param_table')
  table&.remove
  table = create_element('table', id: 'param_table')
  tr = create_element('tr')
  tr.appendChild(create_element('th').tap{it[:textContent] = 'Parameter'})
  versions.each do |ver|
    next unless @param_cache[[@type, ver, plugin]]
    th = create_element('th')
    th[:textContent] = ver
    tr.appendChild(th)
  end
  table.appendChild(tr)
  cache_keys = versions.map{|v| [@type, v, plugin]}
  params = @param_cache.values_at(*cache_keys).compact.map(&:keys).flatten.sort.uniq
  JS.document.getElementById('params').appendChild(table)
  i = 0
  params.each do |name|
    i += 1
    same_value = @param_cache.values_at(*cache_keys).compact.map{_1[name]}.uniq.size == 1
    tr = create_element('tr')
    tr.setAttribute('class', 'same-value') if same_value
    td = create_element('td', class: 'parameter-name')
    href = manual_link(@type, name)
    if href
      a = create_element('a', href:, rel: 'noreferrer noopenner', target: '_blank').tap{it[:textContent] = name}
      td.appendChild(a)
    else
      td[:textContent] = name
    end
    tr.appendChild(td)
    first = true
    prev = prev_td = nil
    values = []
    versions.each do |ver|
      next unless @param_cache[[@type, ver, plugin]]
      value = @param_cache[[@type, ver, plugin]][name]
      values.push value
      td = create_element('td', class: 'parameter-value')
      build_value(prev_td, td, prev, value, first)
      tr.appendChild(td)
      prev_td = td
      prev = value
      first = false
    end
    table.appendChild(tr)
  end
end

def build_value(prev_td, td, prev, value, first)
  if value
    if !first && prev != value
      td[:className] = 'parameter-value difference'
      if prev && value.chomp =~ /\n/
        prev_lines = prev.lines
        hprev_lines = prev_td.innerHTML.to_s.lines
        xprev_lines = prev.gsub(' ', '').lines
        value_lines = value.lines
        xvalue_lines = value.gsub(' ', '').lines

        require_relative 'diff-lcs/diff-lcs'
        Diff::LCS.diff(xprev_lines, xvalue_lines).flatten(1).each do |d|
          if d.action == '+'
            value_lines[d.position] = "<span class='add'>#{escape value_lines[d.position]}</span>"
          elsif d.action == '-'
            hprev_lines[d.position] = "<span class='del'>#{escape prev_lines[d.position]}</span>"
          end
        end
        prev_td.innerHTML = hprev_lines.join
        td.innerHTML = value_lines.join
      else
        td[:textContent] = value
      end
    else
      td[:textContent] = value
    end
  else
    td[:className] = 'parameter-value unexist'
  end
end

def include_plugins?
  plugin_element.checked == true
end

ESCAPE = {
  '<' => '&lt;',
  '>' => '&gt;',
  '&' => '&ampt;',
}

def escape(s)
  s.gsub(/[<>&]/){ESCAPE[_1]}
end

def manual_link(type, name)
  ver = nil
  @versions.sort.reverse.each do |v|
    if @param_cache[[type, v, false]][name]
      ver = v
      break
    end
  end
  return nil unless ver

  ver = ver.split('.')[0,2].join('.')
  case type
  when 'mysqld'
    name = name.gsub('-', '_')
    "https://dev.mysql.com/doc/refman/9.7/en/server-option-variable-reference.html#:~:text=#{name}"
    # "https://dev.mysql.com/doc/refman/#{ver}/en/server-options.html#option_mysqld_#{name}"
  when 'mysql'
    "https://dev.mysql.com/doc/refman/#{ver}/en/mysql-command-options.html#:~:text=%2D%2D#{name}"
  when 'variable', 'status'
    "https://dev.mysql.com/doc/refman/9.7/en/server-option-variable-reference.html#:~:text=#{name}"
    # "https://dev.mysql.com/doc/refman/#{ver}/en/dynamic-system-variables.html#:~:text=#{name}"
    # "https://dev.mysql.com/doc/refman/#{ver}/en/server-status-variables.html#statvar_#{name}"
    # case name
    # when /^innodb/
    #   "https://dev.mysql.com/doc/refman/#{ver}/en/innodb-parameters.html#sysvar_#{name}"
    # else
    #   "https://dev.mysql.com/doc/refman/#{ver}/en/server-system-variables.html#sysvar_#{name}"
    # end
  when 'privilege'
    "https://dev.mysql.com/doc/refman/#{ver}/en/privileges-provided.html#:~:text=#{name}"
  when 'function'
    name = name.strip.gsub(/[^a-zA-Z0-9_-]/){'%'+it.ord.to_s(16)}
    "https://dev.mysql.com/doc/refman/#{ver}/en/built-in-function-reference.html#:~:text=#{name.strip}"
  when 'ischema'
    "https://dev.mysql.com/doc/refman/#{ver}/en/information-schema-table-reference.html#:~:text=#{name.split('.')[0]}"
  when 'pschema'
    "https://dev.mysql.com/doc/refman/#{ver}/en/performance-schema-table-reference.html#:~:text=#{name.split('.')[0]}"
  else
    nil
  end
end