DEMI-PROJECT-PACKAGE
í      {"files":[{"hash":"sha256:e735a66356f32246d2ce9d6712e52afc007ab97df2026ec5ce7bba75b6dc8b32","path":"README.md","size":222},{"hash":"sha256:032544b502f419d6f5e927f0867957b2a5339d103fc0658caa6b65af5802d72d","path":"scripts/demi/gameplay/interactions.lua","size":1362},{"hash":"sha256:9ff07e9d6969d84480f771090bc96e082d9f1d34fdd15ebf9078be12ab809bf7","path":"scripts/demi/gameplay/pickups.lua","size":857},{"hash":"sha256:88e05d010b5e739f9227e052c17f7c28e02ad9043fc5a5637a40dbe1c3e9be2c","path":"tests/interactions_test.lua","size":1230}],"format_version":1,"manifest":{"dependencies":{"demi.gameplay.core":"^1.0.0"},"engine":"^0.1.0","exported_events":["interaction_selected","pickup_collected"],"files":["README.md","scripts/demi/gameplay/interactions.lua","scripts/demi/gameplay/pickups.lua","tests/interactions_test.lua"],"format_version":1,"name":"demi.gameplay.interactions","public_modules":["demi.gameplay.interactions","demi.gameplay.pickups"],"version":"1.0.0"},"package_type":"DemiProjectPackage"}# demi.gameplay.interactions

Deterministic interaction candidate selection and single-use pickup collection.
The game supplies distance and enabled state, then decides what a confirmed
interaction or collected item does.
local Interactions = {}
Interactions.__index = Interactions

function Interactions.new(events)
  return setmetatable({ events = assert(events), candidates = {} }, Interactions)
end

function Interactions:set(id, values)
  assert(type(id) == "string")
  values = values or {}
  self.candidates[id] = { id = id, priority = values.priority or 0,
    distance = values.distance or math.huge, enabled = values.enabled ~= false,
    prompt = values.prompt, payload = values.payload }
end

function Interactions:remove(id) self.candidates[id] = nil end

function Interactions:best(max_distance)
  local result
  for _, value in pairs(self.candidates) do
    if value.enabled and value.distance <= (max_distance or math.huge) and
      (not result or value.priority > result.priority or
       value.priority == result.priority and value.distance < result.distance or
       value.priority == result.priority and value.distance == result.distance and value.id < result.id) then
      result = value
    end
  end
  return result
end

function Interactions:confirm(max_distance)
  local selected = self:best(max_distance)
  if not selected or not self.candidates[selected.id] or not selected.enabled then return false end
  self.events:emit("interaction_selected", { entity = selected.id, payload = selected.payload })
  return true, selected.id
end

return Interactions
local Pickups = {}
Pickups.__index = Pickups

function Pickups.new(events)
  return setmetatable({ events = assert(events), entries = {} }, Pickups)
end

function Pickups:add(id, values)
  assert(type(id) == "string")
  values = values or {}
  self.entries[id] = {
    id = id,
    item = values.item,
    count = values.count or 1,
    enabled = values.enabled ~= false,
    payload = values.payload,
  }
end

function Pickups:remove(id)
  self.entries[id] = nil
end

function Pickups:collect(id, collector)
  local pickup = self.entries[id]
  if not pickup or not pickup.enabled then return false end
  pickup.enabled = false
  self.entries[id] = nil
  self.events:emit("pickup_collected", {
    pickup = id,
    collector = collector,
    item = pickup.item,
    count = pickup.count,
    payload = pickup.payload,
  })
  return true
end

return Pickups
local Events = require("demi.gameplay.events")
local Interactions = require("demi.gameplay.interactions")

Test.case("ties use priority distance then stable id", function()
  local interactions = Interactions.new(Events.new())
  interactions:set("b", { priority = 2, distance = 4 })
  interactions:set("a", { priority = 2, distance = 4 })
  interactions:set("near-low", { priority = 1, distance = 1 })
  Test.equal(interactions:best(5).id, "a")
end)

Test.case("disabled candidate cannot be confirmed", function()
  local interactions = Interactions.new(Events.new())
  interactions:set("door", { enabled = false, distance = 0 })
  Test.equal(interactions:confirm(1), false)
end)

Test.case("pickup collection is single use", function()
  local Events = require("demi.gameplay.events")
  local Pickups = require("demi.gameplay.pickups")
  local events, collected = Events.new(), 0
  events:on("pickup_collected", function(value)
    collected = collected + value.count
  end)
  local pickups = Pickups.new(events)
  pickups:add("coin-1", { item = "coin", count = 3 })
  Test.equal(pickups:collect("coin-1", "player"), true)
  Test.equal(pickups:collect("coin-1", "player"), false)
  events:flush()
  Test.equal(collected, 3)
end)