-- Room management: selection, spawning, transitions
RoomManager = {}
RoomManager.__index = RoomManager

function RoomManager:new(assetLoader)
  self = setmetatable({}, RoomManager)
  self.assetLoader = assetLoader
  self.currentBiomeIdx = 0
  self.currentBiome = nil
  self.roomCount = 0
  self.currentRoomCollision = nil
  self.currentRoomVisual = nil
  self.currentRoomConfig = nil
  return self
end

function RoomManager:getCurrentBiome()
  if self.roomCount % Config.ROOMS_PER_BIOME == 0 then
    self.currentBiomeIdx = self.currentBiomeIdx + 1
    local biomePool = Config.BIOME_SELECT[self.currentBiomeIdx]
    self.currentBiome = Utils.pickRandomKeyFromWeightedTable(biomePool)
  end
  return self.currentBiome
end

function RoomManager:selectNextRoom()
  local currentBiome = self:getCurrentBiome()
  return Utils.pickRandomKeyFromWeightedTable(Config.BIOMES[currentBiome].rooms)
end

function RoomManager:loadRoom(roomName)
  local asset = self.assetLoader:loadRoom(roomName)
  self.currentRoomCollision = asset.imageDataLoader("collision_mask")
  self.currentRoomVisual = RoomVisuals[asset.config.visual or "default"]:new(asset)
  self.currentRoomConfig = asset.config or {}
  self.roomCount = self.roomCount + 1
end

function RoomManager:findPlayerSpawnPosition()
  -- Scan left area columns, find lowest solid pixel in each column
  local spawnAreaMinWidth = 32
  local spawnAreaMinHeight = 32

  for x = 0, Config.ROOM_W do
    for y = Config.ROOM_H - spawnAreaMinWidth, 0, -1 do
      if not self:isSolidAt(x, y) and not self:isSolidAt(x + spawnAreaMinWidth, y) and not self:isSolidAt(x, y - spawnAreaMinHeight) and not self:isSolidAt(x + spawnAreaMinWidth, y - spawnAreaMinHeight) then
        return x, y
      end
    end
  end
  return 0, 0
end

function RoomManager:findFloor(x, y, entityHeight)
  for y = y, Config.ROOM_H - entityHeight do
    if self:isSolidAt(x, y) then
      return x, y - (entityHeight / 2)
    end
  end
  return 0, 0
end

function RoomManager:isSolidAt(x, y)
  if self.currentRoomCollision then
    return Utils.maskIsSolidAt(x, y, self.currentRoomCollision)
  end
  return false
end

return RoomManager