package snake
package life

// m13 life model: the whole world is one value, like the snake and the match.

/**
 * The whole world. `cells` are the live cells, always kept canonical: sorted row-major (by `y`, then by `x`), each cell
 * at most once, all on the board. `seed` is the unsigned 32-bit seed that `Randomize` draws from; `generation` counts
 * the generations since the board was last cleared or randomized.
 */
final case class LifeState(cells: List[Point], running: Boolean, seed: Long, generation: Int)

/** Everything that can happen to the world, as data. `Toggle` carries the cell that was clicked. */
enum LifeAction:
  case Frame
  case Toggle(cell: Point)
  case TogglePause, Step, Clear, Randomize

object LifeModel:

  // The board, in cells: LW columns, LH rows, LCELL pixels per cell. Below it the page shows a status strip.
  val LW = 40
  val LH = 30

  /** Pixels per cell. */
  val LCELL = 16

  /** Height of the status strip under the board, in pixels. */
  val STRIP = 24

  /** A fresh world: no live cells, paused, the given seed, generation 0. */
  def initialLife(seed: Long): LifeState = LifeState(Nil, running = false, seed, generation = 0)