local Event  = require('event')
local GPS    = require('gps')
local Point  = require('point')
local Socket = require('socket')
local Swarm  = require('core.swarm')
local UI     = require('ui')
local Util   = require('util')

local colors  = _G.colors
local network = _G.network
local os      = _G.os

local swarm = Swarm()
local gpt   = GPS.getPoint() or error('GPS not found')
local pts, blocks

local page = UI.Page {
  mode = UI.Chooser {
    x = 13, y = -1,
    choices = {
      { name = 'No breaking', value = 'digNone'    },
      { name = 'Destructive', value = 'turtleSafe' },
    },
    value = 'digNone',
  },
  grid = UI.ScrollingGrid {
    y = 2, ey = -2,
    columns = {
      { heading = 'Label',  key = 'label'    },
      { heading = 'Dist',   key = 'distance' },
      { heading = 'Status', key = 'status'   },
      { heading = 'Fuel',   key = 'fuel'     },
    },
    sortColumn = 'distance',
    autospace = true,
  },
}

function page.grid:getRowTextColor(row, selected)
  if swarm.pool[row.id] then
    return colors.yellow
  end
  return UI.ScrollingGrid.getRowTextColor(self, row, selected)
end

function page.grid:getDisplayValues(row)
	row = Util.shallowCopy(row)
	if row.fuel then
		row.fuel = row.fuel > 0 and Util.toBytes(row.fuel) or ''
	end
	if row.distance then
		row.distance = Util.round(row.distance, 1)
	end
	return row
end

function page:enable()
  local function update()
    local t = { }
    for _,v in pairs(network) do
      if v.fuel and v.active and v.fuel > 0 and v.distance then
        table.insert(t, v)
      end
    end
    self.grid:setValues(t)
  end

  Event.onInterval(3, function()
    update()
    self.grid:draw()
    self:sync()
  end)

  update()

  UI.Page.enable(self)
end

local function follow(member)
  local turtle = member.turtle
  turtle.reset()
  turtle.set({
    digPolicy = page.mode.value,
    status = 'Following',
  })

  if not turtle.enableGPS(nil, true) then
    error('turtle: No GPS found')
  end

  member.snmp = Socket.connect(member.id, 161)
  member.snmp.co = coroutine.running()

  local pt

  while true do
    while pt and Point.same(gpt, pt) do
      os.sleep(.5)
    end
    pt = Point.copy(gpt)

    local cpt = Point.closest(turtle.getPoint(), pts)

    turtle.abort(false)
    if turtle.pathfind(cpt, { blocks = blocks }) then
      turtle.headTowards(pt)
    end
  end
end

function swarm:onRemove(member, status, message)
  if member.socket then
    pcall(function()
      member.turtle.set({ status = 'idle' })
      member.turtle.abort(true)
    end)
  end
  if member.snmp then
    member.snmp:close()
    member.snmp = nil
  end
  if not status then
    _G._debug(message)
  end
end

function page:eventHandler(event)
  if event.type == 'grid_select' then
    if not swarm.pool[event.selected.id] then
      swarm:add(event.selected.id)
      swarm:run(follow)
    else
      swarm:remove(event.selected.id)
    end
    self.grid:draw()

  elseif event.type == 'choice_change' then
    local script = string.format('turtle.set({ digPolicy = "%s"})', event.value)
    for _, member in pairs(swarm.pool) do
      member.snmp:write({ type = 'scriptEx', args = script })
    end

  else
    return UI.Page.eventHandler(self, event)
  end
  return true
end

Event.addRoutine(function()
  while true do
    local pt = GPS.getPoint()
    if not pts or (pt and not Point.same(pt, gpt)) then
      gpt = pt
      pts = {
        { x = pt.x + 2, z = pt.z,     y = pt.y },
        { x = pt.x - 2, z = pt.z,     y = pt.y },
        { x = pt.x,     z = pt.z + 2, y = pt.y },
        { x = pt.x,     z = pt.z - 2, y = pt.y },
      }
      blocks = { }

      local function addBlocks(tpt)
        table.insert(blocks, tpt)
        local apts = Point.adjacentPoints(tpt)
        for _,apt in pairs(apts) do
          table.insert(blocks, apt)
        end
      end

      -- don't run into player
      addBlocks(pt)
      addBlocks(Point.above(pt))

      for _, member in pairs(swarm.pool) do
        if member.snmp then
          member.snmp:write({ type = 'scriptEx', args = 'turtle.abort(true)' })
        end
      end
    end
    os.sleep(1)
  end
end)

UI:setPage(page)
UI:pullEvents()

swarm:stop()