local mod_gui = require("mod-gui")
local Event = require("__stdlib__/stdlib/event/event")
local Changes = require("__stdlib__/stdlib/event/changes")
local UPGui = require("upgrade-planner/gui")
local UPGuiEvent = require("upgrade-planner/gui-events")
local UPEntityUpgrade = require("upgrade-planner/entity-upgrade")

-----------------------------------------------
-- Initialization
-----------------------------------------------
Changes.register("mod_versions", "upgrade-planner/mod-upgrade")

local function global_init()
  global.current_config = {}
  global["config-tmp"] = {}
  global.storage = {}
  global.storage_index = {}
  global.default_bot = {}
end

local function player_init(player_idx)
  global.default_bot[player_idx] = global.default_bot[player_idx] or false
  global.current_config[player_idx] = global.current_config[player_idx] or {}
  global.storage_index[player_idx] = global.storage_index[player_idx] or 1
  global.storage[player_idx] = global.storage[player_idx] or {}
end

Event.register(Event.core_events.init, function()
  global_init()
  for player_idx, player in pairs(game.players) do
    UPGui.init(player)
    player_init(player_idx)
  end
end)

-- Verify if all items selected for upgrade still exists (e.g. modded items)
local function verify_all_configs()
  local items = game.item_prototypes
  local verify_config = function(config)
    local changed = false
    for k, entry in pairs(config) do
      local to = items[entry.to]
      local from = items[entry.from]
      if not (to and from) then
        log("Deleted invalid config: " .. k .. serpent.line(entry))
        entry[k] = nil
        changed = true
      end
    end
    return changed
  end
  for name, config in pairs(global.current_config) do
    local changed = verify_config(config)
    if changed then
      UPGui.open_frame(game.players[name])
      UPGui.open_frame(game.players[name])
    end
  end
  for _, config in pairs(global["config-tmp"]) do verify_config(config) end
  for _, storage in pairs(global.storage) do
    for _, config in pairs(storage) do verify_config(config) end
  end
end

Event.register(Event.core_events.on_configuration_changed, function(event)
  if not event or not event.mod_changes then return end
  verify_all_configs()
end)

Event.register(defines.events.on_player_joined_game, function(event)
  local player = game.players[event.player_index]
  UPGui.init(player)
  player_init(event.player_index)
end)

Event.register(defines.events.on_pre_player_removed, function(event)
  global.default_bot[event.player_index] = nil
  global.current_config[event.player_index] = nil
  global.storage_index[event.player_index] = nil
  global.storage[event.player_index] = nil
end)

-----------------------------------------------
-- GUI events
-----------------------------------------------

UPGuiEvent.register()

-----------------------------------------------
-- Upgrade handling
-----------------------------------------------
Event.register(defines.events.on_player_selected_area, function(event)
  if global.default_bot[event.player_index] then
    UPEntityUpgrade.upgrade_area_bot(event)
  else
    UPEntityUpgrade.upgrade_area_player(event)
  end
end)
Event.register(defines.events.on_player_alt_selected_area, function(event)
  if global.default_bot[event.player_index] then
    UPEntityUpgrade.upgrade_area_player(event)
  else
    UPEntityUpgrade.upgrade_area_bot(event)
  end
end)

-----------------------------------------------
-- Key bindings
-----------------------------------------------
Event.register("upgrade-planner-hide", function(event)
  local player = game.players[event.player_index]
  local button_flow = mod_gui.get_button_flow(player)
  if button_flow["upgrade_planner_config_button"] then
    button_flow["upgrade_planner_config_button"].visible =
        not button_flow.upgrade_planner_config_button.visible
    return
  end
  local button = button_flow.add {
    type = "sprite-button",
    name = "upgrade_planner_config_button",
    style = mod_gui.button_style,
    sprite = "item/upgrade-builder",
    tooltip = {"upgrade-planner.button-tooltip"},
  }
  button.visible = true
end)

--- Clean up additional upgrade planner items
-- Whenever more than one Upgrade planner is in a player inventory, destroy it.
-- If a planner lands in the trash inventory, destroy it.
Event.register({
  defines.events.on_player_trash_inventory_changed,
  defines.events.on_player_main_inventory_changed,
}, function(event)
  local player = game.players[event.player_index]
  local is_trash = event.name ==
                       defines.events.on_player_trash_inventory_changed
  local inventory

  if is_trash then
    inventory = player.get_inventory(defines.inventory.character_trash)
  elseif is_trash == false then
    inventory = player.get_main_inventory()
  else
    return
  end

  if game.item_prototypes["upgrade-builder"] then
    if is_trash then
      local upgrade_builder = inventory.find_item_stack("upgrade-builder")
      if upgrade_builder then upgrade_builder.clear() end
    else
      local cnt = inventory.get_item_count("upgrade-builder")
      if cnt > 1 then
        inventory.remove {name = "upgrade-builder", count = cnt - 1}
      end
    end
  end
end)

Event.register(defines.events.on_player_dropped_item, function(event)
  local stack = event.entity and event.entity.stack
  if (stack.name == "upgrade-builder") then event.entity.destroy() end
end)