cozy-games/packages/mnswpr/adapters/replay-state.js

57 lines
2.2 KiB
JavaScript

// @ts-check
import { MinesweeperRules } from '../core/minesweeper/rules.js'
import { toMove } from './replay-common.js'
/**
* @typedef {import('../core/minesweeper/rules.js').MoveEvent} MnswprMoveEvent
* @typedef {import('../core/minesweeper/board.js').Layout} Layout
* @typedef {{ mine: boolean, adjacent: number, status: 'hidden' | 'flagged' | 'revealed' }} BoardCell
* @typedef {{ rows: number, cols: number, phase: string, revealedSafe: number, cells: BoardCell[][] }} BoardState
*/
/**
* The full-board state reducer for Minesweeper — mnswpr's implementation of the
* replay engine's `StateReducer<MnswprMoveEvent, BoardState>` seam (replay-05).
* Given the ordered slice of move-events played so far, it reconstructs the
* COMPLETE board at that point: every cell's mine/adjacent/status plus the phase.
*
* Like the progress reducer, it takes the board as closure input and replays the
* moves through the pure core rules — so reveals flood, chords open their
* neighbors, and flags toggle — giving an exact reconstruction at any event
* index. Statelessly a function of the slice, so the engine can jump (seek) to
* any position and rebuild the board there.
*
* @param {Layout} layout - the recorded board (as produced by `generateBoard`)
* @returns {(events: { event: MnswprMoveEvent }[]) => BoardState}
*/
export function createStateReducer(layout) {
return function state(events) {
let s = MinesweeperRules.fromLayout(layout)
for (const record of events) {
const move = toMove(record.event)
if (move) s = MinesweeperRules.apply(s, move).state
}
return toBoard(s)
}
}
/**
* Project a core game state into a plain, render-ready 2D board snapshot.
* @param {import('../core/minesweeper/rules.js').State} s
* @returns {BoardState}
*/
function toBoard(s) {
const { rows, cols } = s.config
/** @type {BoardCell[][]} */
const cells = []
for (let r = 0; r < rows; r++) {
/** @type {BoardCell[]} */
const row = []
for (let c = 0; c < cols; c++) {
const cell = s.grid.at(r, c)
row.push({ mine: cell.mine, adjacent: cell.adjacent, status: cell.status })
}
cells.push(row)
}
return { rows, cols, phase: s.phase, revealedSafe: s.revealedSafe, cells }
}