local event = require("__flib__.event")
local migration = require("__flib__.migration")

local constants = require("constants")

local cursor = require("scripts.cursor")
local global_data = require("scripts.global-data")
local migrations = require("scripts.migrations")
local player_data = require("scripts.player-data")
local remote_interface = require("scripts.remote-interface")

-- -----------------------------------------------------------------------------
-- EVENT HANDLERS

-- BOOTSTRAP

event.on_init(function()
  global_data.init()
  for i, player in pairs(game.players) do
    player_data.init(i, player)
    player_data.refresh(player, global.players[i])
  end
end)

event.on_configuration_changed(function(e)
  if migration.on_config_changed(e, migrations) then
    global_data.build_global_registry()
    for i, player in pairs(game.players) do
      player_data.update_personal_overrides(player, global.players[i])
    end
  end
end)

-- ENTITY

event.on_entity_destroyed(function(e)
  -- proxies are all we care about and they always have unit numbers
  if e.unit_number then
    local proxies = global.proxies
    local target_unit_number = proxies.by_proxy[e.unit_number]
    if target_unit_number then
      proxies.by_proxy[e.unit_number] = nil
      proxies.by_target[target_unit_number] = nil
    end
  end
end)

-- INPUTS

event.register(constants.item_scroll_input_names, function(e)
  local _, _, direction = string.find(e.input_name, "^cen-%-scroll%-(%a*)$")
  cursor.scroll(e.player_index, direction)
end)

event.register("cen-recall-last-item", function(e)
  local player = game.get_player(e.player_index)
  local player_table = global.players[e.player_index]
  if player_table.last_item
    and not cursor.set_stack(player, player.cursor_stack, player_table, player_table.last_item)
  then
    player.print{"cen-message.unable-to-recall"}
  end
end)

event.register("cen-transfer-stack-from-network", function(e)
  local player = game.get_player(e.player_index)
  local selected = player.selected
  local item = cursor.check_stack(player.cursor_stack, player.cursor_ghost)
  if selected and selected.force == player.force and item then
    cursor.create_proxy(player, selected, item)
  end
end)

-- PLAYER

event.on_player_created(function(e)
  local player = game.get_player(e.player_index)
  player_data.init(e.player_index, player)
  local player_table = global.players[e.player_index]
  player_data.refresh(player, player_table)
end)

event.on_player_removed(function(e)
  global.players[e.player_index] = nil
end)

event.on_put_item(function(e)
  global.players[e.player_index].flags.building = true
end)

event.on_player_cursor_stack_changed(function(e)
  local player = game.get_player(e.player_index)
  local player_table = global.players[e.player_index]

  -- check `building` flag
  -- only proceed if it is true
  if player_table.flags.building then
    -- reset the flag
    player_table.flags.building = false

    local cursor_stack = player.cursor_stack
    local current_item = cursor_stack and cursor_stack.valid_for_read and cursor_stack.name

    if current_item then
      player_table.last_item = current_item
    elseif
      player_table.settings.ghost_cursor_transitions
      and not player.cursor_ghost
    then
      local last_item = player_table.last_item
      if last_item then
        player_data.ensure_valid_inventory(player, player_table)
        if player_table.main_inventory.get_item_count(last_item) == 0 then
          local entity = game.item_prototypes[last_item].place_result
          if entity then
            cursor.set_stack(player, cursor_stack, player_table, last_item)
          end
        end
      end
    end
  end
end)

event.on_player_main_inventory_changed(function(e)
  local player = game.get_player(e.player_index)
  local player_table = global.players[e.player_index]

  if player_table.settings.ghost_cursor_transitions then
    local cursor_ghost = player.cursor_ghost

    if cursor_ghost then
      player_data.ensure_valid_inventory(player, player_table)
      local main_inventory = player_table.main_inventory
      if main_inventory.get_item_count(cursor_ghost.name) > 0 then
        cursor.set_stack(player, player.cursor_stack, player_table, cursor_ghost.name)
      end
    end
  end
end)

-- SETTINGS

event.on_runtime_mod_setting_changed(function(e)
  if string.sub(e.setting, 1, 4) == "cen-" and e.setting_type == "runtime-per-user" then
    local player = game.get_player(e.player_index)
    local player_table = global.players[e.player_index]
    player_data.update_settings(player, player_table)
    if e.setting == "cen-personal-registry-overrides" then
      player_data.update_personal_overrides(player, player_table)
    end
  end
end)

-- -----------------------------------------------------------------------------
-- REMOTE INTERFACE

remote.add_interface("CursorEnhancements", remote_interface)