_G.requireInjector()

local UI    = require('ui')
local Util  = require('util')

local colors     = _G.colors
local help       = _G.help

UI:configure('Help', ...)

local topics = { }
for _,topic in pairs(help.topics()) do
  if help.lookup(topic) then
    table.insert(topics, { name = topic })
  end
end

local page = UI.Page {
  labelText = UI.Text {
    x = 3, y = 2,
    value = 'Search',
  },
  filter = UI.TextEntry {
    x = 10, y = 2, ex = -3,
    limit = 32,
  },
  grid = UI.ScrollingGrid {
    y = 4,
    values = topics,
    columns = {
      { heading = 'Topic', key = 'name' },
    },
    sortColumn = 'name',
  },
  accelerators = {
    q     = 'quit',
    enter = 'grid_select',
  },
}

local topicPage = UI.Page {
  backgroundColor = colors.black,
  titleBar = UI.TitleBar {
    title = 'text',
    previousPage = true,
  },
  helpText = UI.TextArea {
    backgroundColor = colors.black,
    x = 2, ex = -1, y = 3, ey = -2,
  },
  accelerators = {
    q = 'back',
    backspace = 'back',
  },
}

function topicPage:eventHandler(event)
  if event.type == 'back' then
    UI:setPreviousPage()
  end
  return UI.Page.eventHandler(self, event)
end

function page:eventHandler(event)
  if event.type == 'quit' then
    UI:exitPullEvents()

  elseif event.type == 'grid_select' then
    if self.grid:getSelected() then
      local name = self.grid:getSelected().name
      local f = help.lookup(name)

      topicPage.titleBar.title = name
      topicPage.helpText:setText(Util.readFile(f))

      UI:setPage(topicPage)
    end

  elseif event.type == 'text_change' then
    if #event.text == 0 then
      self.grid.values = topics
    else
      self.grid.values = { }
      for _,f in pairs(topics) do
        if string.find(f.name, event.text) then
          table.insert(self.grid.values, f)
        end
      end
    end
    self.grid:update()
    self.grid:setIndex(1)
    self.grid:draw()
  else
    return UI.Page.eventHandler(self, event)
  end
end

UI:setPage(page)
UI:pullEvents()