require 'js'
require 'json'
require 'uri'

# 処理中画面の表示/非表示
# @param f [Boolean]
def in_progress(&block)
  @in_progress ||= []
  @in_progress.push true
  JSrb.timeout(0.3) do
    Document.get_element_by_id('in-progress').style.display = 'block' unless @in_progress.empty?
  end
  JSrb.timeout(0) do
    block.call
    @in_progress.shift
    Document.get_element_by_id('in-progress').style.display = 'none' if @in_progress.empty?
  end
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
  Document.get_element_by_id('in-progress').style.display = 'none'
  res = JS.global.fetch('/json/versions.json').await
  unless res.ok
    JS.global.alert("error #{res.status}")
    raise
  end
  json = res.json.await
  @available_versions = JSON.parse(JS.global.JSON.stringify(json))
  main
end

# 開始
def main
  @param_cache = {}
  uri = URI.parse(JS.global.location.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 = Document.get_element_by_id('menu').query_selector_all('li a')
  list.each do |a|
    a.add_event_listener('click') do
      @type = URI.parse(a.href).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.add_event_listener('change'){change_diff}

  plugin = q['plugin'] == 'true'
  e_plugin = plugin_element
  e_plugin.checked = plugin
  e_plugin.add_event_listener('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
  Document.styleSheets[0].cssRules.each do |css|
    if css[:selectorText].to_s == 'tr.same-value'
      css.style.display = only_diff ? 'none' : JS::Null
    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
  Document.get_element_by_id('versions').append_child(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 = Document.create_element(type)
  opts.each do |k, v|
    e[k.to_s] = v
    e.set_attribute(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', className: 'version', type: 'search', list: 'version_list')
  v[:value] = ver if ver
  Document.get_element_by_id('versions').append_child(v)
  v.add_event_listener('keypress') do |e|
    redisplay if e.key == 'Enter'
  end
  v.add_event_listener('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
  Document.get_elements_by_name('version')
end

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

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

# 再表示
def redisplay
  in_progress do
    next if @in_redisplay
    @in_redisplay = true
    set_location
    Document.get_element_by_id('param_table')&.remove
    @versions = []
    version_elements.each_with_index do |v, i|
      ver = v[:value] = v[:value].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.empty?
    display_table
  ensure
    @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)
  JSrb.sleep 0  # switch fiber
  plugin = include_plugins?
  return if @param_cache[[@type, ver, plugin]]

  file = plugin ? 'all.json' : 'base.json'
  res = JS.global.fetch("/json/#{ver}/#{@type}/#{file}").await
  unless res.ok
    JS.global.alert("error #{res.status}")
    raise "error #{res.status}"
  end
  json = res.json.await
  @param_cache[[@type, ver, plugin]] = JSON.parse(JS.global.JSON.stringify(json))
end

# HTML 要素を元に URL を設定する
def set_location
  uri = URI.parse(JS.global.location.to_s)
  uri.path = "/#{@type}/"
  vers = version_elements.map(&:value).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.replace_state('', '', uri.to_s)

  list = Document.get_element_by_id('menu').query_selector_all('li a')
  list.each do |a|
    href = a.href
    a.href = href.sub(/\?.*|\z/, '?'+query) unless query.empty?
    if URI.parse(href).path.start_with? "/#{@type}/"
      a.parent_element[:className] = 'current'
      Document.title = "#{a[:textContent]} / MySQL Parameters"
    else
      a.parent_element[:className] = JS::Null
    end
  end
  JSrb.sleep 0  # switch fiber
end

# パラメータテーブルを表示する
def display_table
  versions = @versions
  plugin = include_plugins?
  table = Document.get_element_by_id('param_table')
  table&.remove
  table = create_element('table', id: 'param_table')
  tr = create_element('tr')
  tr.append_child(create_element('th', textContent: 'Parameter'))
  versions.each do |ver|
    next unless @param_cache[[@type, ver, plugin]]
    th = create_element('th', textContent: ver)
    tr.append_child(th)
  end
  table.append_child(tr)
  cache_keys = versions.map{|v| [@type, v, plugin]}
  params = @param_cache.values_at(*cache_keys).compact.map(&:keys).flatten.sort.uniq
  Document.get_element_by_id('params').append_child(table)
  i = 0
  params.each do |name|
    i += 1
    JSrb.sleep 0 if i % 15 == 0  # switch fiber
    same_value = @param_cache.values_at(*cache_keys).compact.map{_1[name]}.uniq.size == 1
    tr = create_element('tr')
    tr.set_attribute('class', 'same-value') if same_value
    tr.append_child(create_element('td', className: 'parameter-name', textContent: name))
    first = true
    prev = 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', className: 'parameter-value')
      if value
        td[:textContent] = value
        td[:className] = 'parameter-value difference' if !first && prev != value
      else
        td[:className] = 'parameter-value unexist'
      end
      tr.append_child(td)
      prev = value
      first = false
    end
    table.append_child(tr)
  end
end

def include_plugins?
  plugin_element.checked == true
end