-- In the Factorio source code, 200 is defined as the maximum viewable distance.
-- The map editor is 3x that, hence, 600.
local overlay_size = 600

--- @param player LuaPlayer
local function create_overlay(player)
  local opacity = player.mod_settings["pvo-overlay-opacity"].value --[[@as double]]
  storage.overlays[player.index] = rendering.draw_sprite({
    sprite = "pvo-black",
    tint = { a = opacity },
    render_layer = "148", -- One below "Pipe visualization" (149)
    target = player.position,
    surface = player.surface,
    players = { player },
    x_scale = overlay_size,
    y_scale = overlay_size,
    only_in_alt_mode = true,
  })
end

--- @param player LuaPlayer
--- @return boolean
local function should_have_overlay(player)
  local cursor_stack = player.cursor_stack
  local cursor_ghost = player.cursor_ghost
  --- @type LuaEntityPrototype?
  local entity
  if cursor_stack and cursor_stack.valid_for_read then
    entity = cursor_stack.prototype.place_result
  elseif cursor_ghost and cursor_ghost.name then
    entity = cursor_ghost.name.place_result
  end
  return entity and entity.show_fluid_visualization_when_in_cursor or false
end

script.on_init(function()
  --- @type table<uint, LuaRenderObject>
  storage.overlays = {}
end)

script.on_event(defines.events.on_player_changed_position, function(e)
  if not storage.overlays then
    return
  end
  local overlay = storage.overlays[e.player_index]
  if overlay then
    overlay.target = game.get_player(e.player_index).position
  end
end)

script.on_event(defines.events.on_player_changed_surface, function(e)
  if not storage.overlays then
    return
  end
  local overlay = storage.overlays[e.player_index]
  if not overlay or not overlay.valid then
    return
  end
  overlay.destroy()
  storage.overlays[e.player_index] = nil
  local player = game.get_player(e.player_index)
  --- @cast player -?
  if should_have_overlay(player) then
    create_overlay(player)
  end
end)

script.on_event(defines.events.on_player_cursor_stack_changed, function(e)
  if not storage.overlays then
    return
  end

  local player = game.get_player(e.player_index)
  --- @cast player -?

  local should_have_overlay = should_have_overlay(player)
  local overlay = storage.overlays[e.player_index]

  if overlay and overlay.valid then
    if not should_have_overlay then
      overlay.destroy()
      storage.overlays[e.player_index] = nil
    end
    return
  end

  if should_have_overlay then
    create_overlay(player)
  end
end)