-- vim: set sw=2:
-- Set Vim’s shiftwidth to 2 instead of 4 because the functions in this file
-- are deeply nested and there are some long lines. 2 instead of 4 gives a tiny
-- bit more space for each indentation level.

local alter_health = hunger_ng.functions.alter_health
local alter_hunger = hunger_ng.functions.alter_hunger
local base_interval = hunger_ng.settings.timers.basal_metabolism
local costs_base = hunger_ng.costs.base
local costs_movement = hunger_ng.costs.movement
local effect_heal = hunger_ng.attributes.effect_heal
local effect_hunger = hunger_ng.attributes.effect_hunger
local effect_starve = hunger_ng.attributes.effect_starve
local get_data = hunger_ng.functions.get_data
local heal_above = hunger_ng.effects.heal.above
local heal_amount = hunger_ng.effects.heal.amount
local heal_interval = hunger_ng.settings.timers.heal
local hunger_attribute = hunger_ng.attributes.hunger_value
local hunger_bar_id = hunger_ng.attributes.hunger_bar_id
local hunger_disabled_attribute = hunger_ng.attributes.hunger_disabled
local move_interval = hunger_ng.settings.timers.movement
local starve_amount = hunger_ng.effects.starve.amount
local starve_below = hunger_ng.effects.starve.below
local starve_die = hunger_ng.effects.starve.die
local starve_interval = hunger_ng.settings.timers.starve
local use_hunger_bar = hunger_ng.settings.hunger_bar.use

-- Localize Luanti
is_yes = core.is_yes
get_connected_players = core.get_connected_players

-- Initiate globalstep timers
local base_timer = 0
local heal_timer = 0
local move_timer = 0
local starve_timer = 0


core.register_globalstep(function(dtime)

  -- Do not run if there are no satiating food items registered
  if hunger_ng.food_items.satiating == 0 then return end

  -- Raise timer values if needed
  if costs_base ~= 0 then base_timer = base_timer + dtime end
  if heal_amount ~= 0 then heal_timer = heal_timer + dtime end
  if costs_movement ~= 0 then move_timer = move_timer + dtime end
  if starve_amount ~= 0 then starve_timer = starve_timer + dtime end

  -- Reset timers if needed
  if costs_base ~= 0 and base_timer >= base_interval then base_timer = 0 end
  if heal_amount ~= 0 and heal_timer >= heal_interval then heal_timer = 0 end
  if costs_movement ~= 0 and move_timer >= move_interval then move_timer=0 end
  if starve_amount~=0 and starve_timer>=starve_interval then starve_timer=0 end

  -- Iterate over all players
  --
  -- If the value and the timer for the corresponding attribute are not zero
  -- (value) and zero (timer) then the alteration of that attribute is executed.
  for _,player in ipairs(get_connected_players()) do
    if player:is_player() then
      local playername = player:get_player_name()
      local hp_max = player:get_properties().hp_max
      local e_heal = get_data(playername, effect_heal, true) == 'enabled'
      local e_hunger = get_data(playername, effect_hunger, true) == 'enabled'
      local e_starve = get_data(playername, effect_starve, true) == 'enabled'

      -- Basal metabolism costs
      if costs_base ~= 0 and base_timer == 0 and e_hunger then
        alter_hunger(player:get_player_name(), -costs_base, 'base')
      end

      -- Heal player if possible and needed
      if heal_amount ~= 0 and heal_timer == 0 then
        local hunger = get_data(playername, hunger_attribute)
        local health = player:get_hp()
        local awash = player:get_breath() < player:get_properties().breath_max
        local can_heal = hunger >= heal_above and not awash
        local needs_health = health < hp_max
        if can_heal and needs_health and e_heal then
          alter_health(playername, heal_amount, 'healing')
        end
      end

      -- Alter hunger based on movement costs
      if costs_movement ~= 0 and move_timer == 0 then
        local move = player:get_player_control()
        local moving = move.up or move.down or move.left or move.right
        if moving and e_hunger then
          alter_hunger(playername, -costs_movement, 'movement')
        end
      end

      -- Starve player if starvation requirements are fulfilled
      if starve_amount ~= 0 and starve_timer == 0 then
        local hunger = get_data(playername, hunger_attribute)
        local health = player:get_hp()
        local starves = hunger < starve_below
        local playername = player:get_player_name()
        if starves and e_starve then
          if health == 1 and not starve_die then return end
          alter_health(playername, -starve_amount, 'starving')
        end
      end

    end -- is player
  end -- players iteration

end)


-- Show/hide hunger bar on player breath status or functionality status
if use_hunger_bar then
  core.register_globalstep(function(dtime)
    for _,player in ipairs(get_connected_players()) do
      if player:is_player() then
        local player_name = player:get_player_name()
        local bar_id = get_data(player_name, hunger_bar_id)
        local awash = player:get_breath() < player:get_properties().breath_max
        local disabled = get_data(player_name, hunger_disabled_attribute)
        local no_food = hunger_ng.food_items.satiating == 0
        if awash or is_yes(disabled) or no_food then
          player:hud_change(bar_id, 'text', '')
        else
          player:hud_change(bar_id, 'text', hunger_ng.hunger_bar_image)
        end
      end
    end
  end)
end