advanced_npc/relationships.lua

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-- Gift and relationship system
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-- Each NPCs has 2 favorite and 2 disliked items. These items are chosen at spawn
-- time and will be re-chosen when the age changes (from child to adult, for example).
-- The items are chosen from the npc.FAVORITE_ITEMS table, and depends on sex and age.
-- A player, via right-click, or another NPC, can gift an item to a NPC. In the case
-- of the player, the player will give one of the currently wielded item. Gifts can be
-- given only once per some time period, the NPC will reject the given item if still 
-- the period isn't over.
-- If the NPC is neutral on the item (meanining it's neither favorite or disliked), it 
-- is possible it will not accept it, and the relationship the giver has with the NPC
-- will be unchanged.
-- In the other hand, if the item given its a favorite, the relationship points the NPC
-- has with giver will increase by a given amount, depending on favoriteness. Favorite 1
-- will increase the relationship by 2 * npc.ITEM_GIFT_EFFECT, and favorite 2 only by
-- npc.ITEM_GIFT_EFFECT. Similarly, if the item given is a disliked item, the NPC will
-- not take it, and its relationship points with the giver will decrease by 2 or 1 times
-- npc.ITEM_GIFT_EFFECT.

local S = mobs.intllib

npc.relationships = {}

-- Constants
npc.relationships.ITEM_GIFT_EFFECT = 2.5

-- Expected values for these are 720 each respectively
npc.relationships.GIFT_TIMER_INTERVAL = 2
npc.relationships.RELATIONSHIP_DECREASE_TIMER_INTERVAL = 60

npc.relationships.RELATIONSHIP_PHASE = {}
-- Define phases
npc.relationships.RELATIONSHIP_PHASE["phase1"] = {limit = 10}
npc.relationships.RELATIONSHIP_PHASE["phase2"] = {limit = 25}
npc.relationships.RELATIONSHIP_PHASE["phase3"] = {limit = 45}
npc.relationships.RELATIONSHIP_PHASE["phase4"] = {limit = 70}
npc.relationships.RELATIONSHIP_PHASE["phase5"] = {limit = 100}

-- Married NPC dialogue definition
npc.relationships.MARRIED_NPC_DIALOGUE = {
  text = "Hi darling!",
  is_married_dialogue = true,
  responses = {
    [1] = {
      text = "Let's talk!",
      action_type = "function",
      response_id = 1,
      action = function(self, player)
        npc.start_dialogue(self, player, false)
      end
    },
    [2] = {
      text = "Honey, can you wait for me here?",
      action_type = "function",
      response_id = 2,
      action = function(self, player)
        self.order = "stand"
        minetest.chat_send_player(player:get_player_name(), S("Ok dear, I will wait here for you."))
      end
    },
    [3] = {
      text = "Come with me, please!",
      action_type = "function",
      response_id = 3,
      action = function(self, player)
        self.order = "follow"
        minetest.chat_send_player(player:get_player_name(), S("Ok, let's go!"))
      end
    }
  }
}

-- Function to get relationship phase
function npc.relationships.get_relationship_phase_by_points(points)
	if points > npc.relationships.RELATIONSHIP_PHASE["phase5"].limit then
    return "phase6"
  elseif points > npc.relationships.RELATIONSHIP_PHASE["phase4"].limit then
    return "phase5"
  elseif points > npc.relationships.RELATIONSHIP_PHASE["phase3"].limit then
    return "phase4"
  elseif points > npc.relationships.RELATIONSHIP_PHASE["phase2"].limit then
    return "phase3"
  elseif points > npc.relationships.RELATIONSHIP_PHASE["phase1"].limit then
    return "phase2"
  else
    return "phase1"
  end
end

-- Returns the response message for a given item
function npc.relationships.get_response_for_favorite_item(item_name, sex, phase)
  local items = npc.FAVORITE_ITEMS.female
  if sex == npc.MALE then
    items = npc.FAVORITE_ITEMS.male
  end

  for i = 1, #items[phase] do
    if items[phase][i].item == item_name then
      return items[phase][i].response
    end
  end
  return nil
end 

-- Returns the response message for a disliked item
function npc.relationships.get_response_for_disliked_item(item_name, sex)
  local items = npc.DISLIKED_ITEMS.female
  if sex == npc.MALE then
    items = npc.DISLIKED_ITEMS.male
  end

  for i = 1, #items do
  	minetest.log(dump(items[i]))
    if items[i].item == item_name then
    	minetest.log("Returning: "..dump(items[i].response))
      return items[i].response
    end
  end
  return nil
end 

-- Gets the item hint for a favorite item
function npc.relationships.get_hint_for_favorite_item(item_name, sex, phase)
  for i = 1, #npc.FAVORITE_ITEMS[sex][phase] do
    if npc.FAVORITE_ITEMS[sex][phase][i].item == item_name then
      return npc.FAVORITE_ITEMS[sex][phase][i].hint
    end
  end
  return nil
end

-- Gets the item hint for a disliked item
function npc.relationships.get_hint_for_disliked_item(item_name, sex)
  for i = 1, #npc.DISLIKED_ITEMS[sex] do
    if npc.DISLIKED_ITEMS[sex][i].item == item_name then
      return npc.DISLIKED_ITEMS[sex][i].hint
    end
  end
  return nil
end


-- Relationship functions
---------------------------------------------------------------------------------------

-- This function selects two random items from the npc.favorite_items table
-- It checks for sex and phase for choosing the items
function npc.relationships.select_random_favorite_items(sex, phase)
  local result = {}
  local items = {}
  
  -- Filter sex
  if sex == npc.FEMALE then
    items = npc.FAVORITE_ITEMS.female
  else
    items = npc.FAVORITE_ITEMS.male
  end

  -- Select the phase
  items = items[phase]
  
  result.fav1 = items[math.random(1, #items)].item
  result.fav2 = items[math.random(1, #items)].item
  return result
end

-- This function selects two random items from the npc.disliked_items table
-- It checks for sex for choosing the items. They stay the same for all
-- phases
function npc.relationships.select_random_disliked_items(sex)
  local result = {}
  local items = {}
  
  -- Filter sex
  if sex == npc.FEMALE then
    items = npc.DISLIKED_ITEMS.female
  else
    items = npc.DISLIKED_ITEMS.male
  end

  result.dis1 = items[math.random(1, #items)].item
  result.dis2 = items[math.random(1, #items)].item
  return result
end

-- Creates a relationship with a given player or NPC
local function create_relationship(self, clicker_name)
  local count = #self.relationships
  self.relationships[count + 1] = {
    -- Player or NPC name with whom the relationship is with
    name = clicker_name,
    -- Relationship points
    points = 0,
    -- Relationship phase, used for items and for phrases
    phase = "phase1",
    -- How frequent can the NPC receive a gift
    gift_interval = npc.relationships.GIFT_TIMER_INTERVAL,
    -- Current timer count since last gift
    gift_timer_value = 0,
    -- The amount of time without providing gift or talking that will decrease relationship points
    relationship_decrease_interval = npc.relationships.RELATIONSHIP_DECREASE_TIMER_INTERVAL,
    -- Current timer count for relationship decrease
    relationship_decrease_timer_value = 0,
    -- Current timer count since last time player talked to NPC
    talk_timer_value = 0
  }
end

-- Returns a relationship points
local function get_relationship_points(self, clicker_name)
  for i = 1, #self.relationships do
    if self.relationships[i].name == clicker_name then
      return self.relationships[i].points
    end
  end
  return nil
end

-- Updates relationship with given points
local function update_relationship(self, clicker_name, modifier)
  for i = 1, #self.relationships do
    if self.relationships[i].name == clicker_name then
      self.relationships[i].points = self.relationships[i].points + modifier
      local current_phase = self.relationships[i].phase
      self.relationships[i].phase = 
      	npc.relationships.get_relationship_phase_by_points(self.relationships[i].points)
      if current_phase ~= self.relationships[i].phase then
        -- Re-select favorite items per new phase
        self.gift_data.favorite_items = 
          npc.relationships.select_random_favorite_items(self.sex, self.relationships[i].phase)
        -- Re-select dialogues per new
        self.dialogues =
          npc.dialogue.select_random_dialogues_for_npc(self.sex, 
                                                       self.relationships[i].phase,
                                                       self.gift_data.favorite_items,
                                                       self.gift_data.disliked_items)
        return true
      end
      return false
    end
  end
  -- Relationship not found, huge error
  return nil
end

-- Checks if a relationship with given player or NPC exists
local function check_relationship_exists(self, clicker_name)
  for i = 1, #self.relationships do
    if self.relationships[i].name == clicker_name then
      return true
    end
  end
  return false
end

-- Returns the relationship phase given the name of the player
function npc.relationships.get_relationship_phase(self, clicker_name)
  for i = 1, #self.relationships do
    if clicker_name == self.relationships[i].name then
      return self.relationships[i].phase
    end
  end
  return nil
end

-- Checks if NPC can receive gifts
local function check_npc_can_receive_gift(self, clicker_name)
  for i = 1, #self.relationships do
    if self.relationships[i].name == clicker_name then
      -- Checks avoid married NPC to receive from others
      if self.is_married_to == nil 
        or (self.is_married ~= nil and self.is_married_to == clicker_name) then 
        return self.relationships[i].gift_timer_value >= self.relationships[i].gift_interval
      else
        return false
      end
    end
  end
  -- Not found
  return nil
end

-- Checks if relationship can be updated by talking
local function check_relationship_by_talk_timer_ready(self, clicker_name)
  for i = 1, #self.relationships do
    if self.relationships[i].name == clicker_name then
      return self.relationships[i].talk_timer_value >= self.relationships[i].gift_interval
    end
  end
  -- Not found
  return nil
end

-- Resets the gift timer
local function reset_gift_timer(self, clicker_name)
  for i = 1, #self.relationships do
    if self.relationships[i].name == clicker_name then
      self.relationships[i].gift_timer_value = 0
      self.relationships[i].relationship_decrease_timer_value = 0
      return
    end
  end
end

-- Resets the talk timer
local function reset_talk_timer(self, clicker_name)
  for i = 1, #self.relationships do
    if self.relationships[i].name == clicker_name then
      self.relationships[i].talk_timer_value = 0
      return
    end
  end
end

-- Resets the relationshop decrease timer
local function reset_relationship_decrease_timer(self, clicker_name)
  for i = 1, #self.relationships do
    if self.relationships[i].name == clicker_name then
      self.relationships[i].relationship_decrease_timer_value = 0
      return
    end
  end
end

-- Gifts functions
---------------------------------------------------------------------------------------
  
-- Displays message and hearts depending on relationship level
local function show_receive_gift_reaction(self, item_name, modifier, clicker_name, phase_change) 
  local points = get_relationship_points(self, clicker_name)
  
  local pos = self.object:getpos()  
  -- Positive modifier (favorite items) reactions
  if modifier >= 0 then
    local phase = npc.relationships.get_relationship_phase_by_points(points)
    if phase == "phase3" then
      effect({x = pos.x, y = pos.y + 1, z = pos.z}, 2, "heart.png")
    elseif phase == "phase4" then
      effect({x = pos.x, y = pos.y + 1, z = pos.z}, 4, "heart.png")
    elseif phase == "phase5" then
      effect({x = pos.x, y = pos.y + 1, z = pos.z}, 6, "heart.png")
    elseif phase == "phase6" then
      effect({x = pos.x, y = pos.y + 1, z = pos.z}, 8, "heart.png")
    end
    if phase_change then
      local number_code = phase:byte(phase:len()) - 1
      phase = "phase"..string.char(number_code)
    end
    -- Send message
    -- TODO: There might be an error with getting the message...
    minetest.log("Item_name: "..dump(item_name)..", sex: "..dump(self.sex)..", phase: "..dump(phase))
    local message_to_send =
    	npc.relationships.get_response_for_favorite_item(item_name, self.sex, phase)
    minetest.chat_send_player(clicker_name, message_to_send)
  -- Disliked items reactions
  elseif modifier < 0 then
    effect({x = pos.x, y = pos.y + 1, z = pos.z}, 8, "smoke.png")
    minetest.log("Item name: "..item_name..", sex: "..self.sex)
    local message_to_send = npc.relationships.get_response_for_disliked_item(item_name, self.sex)
    minetest.chat_send_player(clicker_name, message_to_send)
  end
  
end

-- Receive gift function; applies relationship points as explained above
-- Also, creates a relationship object if not present
function npc.relationships.receive_gift(self, clicker)  
  -- Return if clicker is not offering an item
  local item = npc.get_entity_wielded_item(clicker)
  if item:get_name() == "" then return false end
  
  -- Get clicker name
  local clicker_name = npc.get_entity_name(clicker)
  
  -- Create relationship if it doesn't exists
  if check_relationship_exists(self, clicker_name) == false then
    create_relationship(self, clicker_name)
  end

  -- If NPC received a gift from this person, then reject any more gifts for now
  if check_npc_can_receive_gift(self, clicker_name) == false then
    minetest.chat_send_player(clicker_name, "Thanks, but I don't need anything for now")
    return false
  end
  
  -- If NPC is ready for marriage, do no accept anything else but the ring,
  -- and that with only a certain chance. The self.owner is to whom is married
  -- this NPC... he he.
  if get_relationship_points(self, clicker_name) >= 
  	npc.relationships.RELATIONSHIP_PHASE["phase5"].limit 
    and self.owner ~= clicker_name
    and item:get_name() ~= "advanced_npc:marriage_ring" then
    minetest.chat_send_player(clicker_name, 
      "Thank you my love, but I think that you have given me")
    minetest.chat_send_player(clicker_name, 
      "enough gifts for now. Maybe we should go a step further")
    -- Reset gift timer
    reset_gift_timer(self, clicker_name)
    return true
  elseif get_relationship_points(self, clicker_name) >= 
  	npc.relationships.RELATIONSHIP_PHASE["phase5"].limit 
    and item:get_name() == "advanced_npc:marriage_ring" then
    -- If the player/entity is offering a marriage ring, then NPC will accept with a 50%
    -- chance to marry the clicker
    local receive_chance = math.random(1, 10)
    -- Receive ring and get married
    if receive_chance < 6 then
      minetest.chat_send_player(clicker_name, 
        "Oh, oh you make me so happy! Yes! I will marry you!")
      -- Get ring
      item:take_item()
      clicker:set_wielded_item(item)
      -- TODO: Implement marriage event
      -- Show marriage reaction
      local pos = self.object:getpos()
      effect({x = pos.x, y = pos.y + 1, z = pos.z}, 20, "heart.png", 4)
      -- Give 100 points, so NPC is really happy on marriage
      update_relationship(self, clicker_name, 100)
      -- This sets the married state, for now. Hehe
      self.owner = clicker_name
    -- Reject ring for now
    else 
      minetest.chat_send_player(clicker_name, 
        "Dear, I feel the same as you. But maybe not yet...")
    
    end
    -- Reset gift timer
    reset_gift_timer(self, clicker_name)
    return true
  end
  -- Marriage gifts: except for disliked items, all product a 0.5 * npc.ITEM_GIFT_EFFECT
  -- Disliked items cause only a -1 point effect
  if get_relationship_points(self, clicker_name) >=
  	npc.relationships.RELATIONSHIP_PHASE["phase5"].limit then
    local modifier = 0.5 * npc.ITEM_GIFT_EFFECT
    -- Check for disliked items
    if item:get_name() == self.gift_data.disliked_items.dis1 
      or item:get_name() == self.gift_data.disliked_items.dis2 then
      modifier = -1
      show_receive_gift_reaction(self, item:get_name(), modifier, clicker_name, false)
    elseif item:get_name() == self.gift_data.favorite_items.fav1 
      or item:get_name() == self.gift_data.favorite_items.fav2 then
      -- Favorite item reaction
      show_receive_gift_reaction(self, item:get_name(), modifier, clicker_name, false)
    else
      -- Neutral item reaction 
      minetest.chat_send_player(clicker_name, "Thank you honey!")
    end
    -- Take item
    item:take_item()
    clicker:set_wielded_item(item)
    -- Update relationship
    update_relationship(self, clicker_name, modifier)
    -- Reset gift timer
    reset_gift_timer(self, clicker_name)
    return true
  end
  
  -- Modifies relationship depending on given item
  local modifier = 0
  local take = true
  local show_reaction = false
  
  if item:get_name() == self.gift_data.favorite_items.fav1 then
    modifier = 2 * npc.relationships.ITEM_GIFT_EFFECT
    show_reaction = true
  elseif item:get_name() == self.gift_data.favorite_items.fav2 then 
    modifier = npc.relationships.ITEM_GIFT_EFFECT
    show_reaction = true
  elseif item:get_name() == self.gift_data.disliked_items.dis1 then
    modifier = (-2) * npc.relationships.ITEM_GIFT_EFFECT
    show_reaction = true
  elseif item:get_name() == self.gift_data.disliked_items.dis2 then 
    modifier = (-1) * npc.relationships.ITEM_GIFT_EFFECT
    show_reaction = true
  else
    -- If item is not a favorite or a dislike, then receive chance
    -- if 70%
      local receive_chance = math.random(1,10)
      if receive_chance < 7 then
        minetest.chat_send_player(clicker_name, "Thanks. I will find some use for this.")
      else
        minetest.chat_send_player(clicker_name, "Thank you, but no, I have no use for this.")
        take = false
      end
      show_reaction = false
  end
  
  -- Update relationship status
  local is_phase_changed = update_relationship(self, clicker_name, modifier)

  -- Show NPC reaction to gift
  if show_reaction == true then
    show_receive_gift_reaction(self, item:get_name(), modifier, clicker_name, is_phase_changed)
  end

  -- Take item if NPC accepted it
  if take == true then
    item:take_item()
    clicker:set_wielded_item(item)
  end
  
  minetest.log(dump(self))
  -- Reset gift timer
  reset_gift_timer(self, clicker_name)
  return true  
end

-- Relationships are slowly increased by talking, increases by +0.2.
-- Talking to married NPC increases relationship by +1 
-- TODO: This needs a timer as the gift timer. NPC will talk anyways
-- but relationship will not increase.
function npc.relationships.dialogue_relationship_update(self, clicker)
  -- Get clicker name
  local clicker_name = npc.get_entity_name(clicker)

  -- Check if relationship can be updated via talk
  if check_relationship_by_talk_timer_ready(self, clicker_name) == false then
    return
  end
  
  -- Create relationship if it doesn't exists
  if check_relationship_exists(self, clicker_name) == false then
    create_relationship(self, clicker_name)
  end

  local modifier = 0.2
  if self.is_married_to ~= nil and clicker_name == self.is_married_to then
    modifier = 1
  end
  -- Update relationship
  update_relationship(self, clicker_name, modifier)

  -- Resert timers
  reset_talk_timer(self, clicker_name)
  reset_relationship_decrease_timer(self, clicker_name)
end