feat: scaffold mvp shell and content runtime

js/gameplay/session/index.js

@@ -0,0 +1,189 @@
+import { generateBoard, getClickablePieces } from '../difficulty/index.js'
+
+function cloneBoardState(boardState) {
+  return {
+    ...boardState,
+    pieces: boardState.pieces.map((piece) => ({ ...piece })),
+    overlapGraph: Object.fromEntries(
+      Object.entries(boardState.overlapGraph ?? {}).map(([pieceId, blockedIds]) => [pieceId, [...blockedIds]]),
+    ),
+    metrics: { ...(boardState.metrics ?? {}) },
+  }
+}
+
+function getPieceById(boardState, pieceId) {
+  return boardState.pieces.find((piece) => piece.id === pieceId) ?? null
+}
+
+function createSlotEntry(piece) {
+  return {
+    pieceId: piece.id,
+    elementId: piece.elementId,
+  }
+}
+
+function removeMatchedEntries(slot, elementId) {
+  let remaining = 3
+
+  return slot.filter((entry) => {
+    if (entry.elementId === elementId && remaining > 0) {
+      remaining -= 1
+      return false
+    }
+
+    return true
+  })
+}
+
+function getMatchingTriples(slot) {
+  const counts = slot.reduce((map, entry) => {
+    map.set(entry.elementId, (map.get(entry.elementId) ?? 0) + 1)
+    return map
+  }, new Map())
+
+  const matchedElementId = [...counts.entries()].find(([, count]) => count >= 3)?.[0] ?? null
+
+  return matchedElementId
+}
+
+function getStateSnapshot(state, boardState) {
+  return {
+    cityId: state.cityId,
+    levelId: state.levelId,
+    seed: state.seed,
+    status: state.status,
+    slot: [...state.slot],
+    bypass: [...state.bypass],
+    removedPieceIds: [...state.removedPieceIds],
+    boardState,
+  }
+}
+
+export function createGameSession({
+  cityId,
+  levelId,
+  seed,
+  contentSystem,
+  boardState,
+}) {
+  const resolvedBoard = boardState ? cloneBoardState(boardState) : generateBoard({ cityId, levelId, seed, contentSystem })
+  const state = {
+    cityId,
+    levelId,
+    seed: resolvedBoard.seed,
+    status: 'playing',
+    slot: [],
+    bypass: [],
+    removedPieceIds: [],
+  }
+
+  function getState() {
+    return getStateSnapshot(state, resolvedBoard)
+  }
+
+  function isBoardCleared() {
+    return resolvedBoard.pieces.every((piece) => piece.removed) && state.slot.length === 0
+  }
+
+  function getClickable() {
+    return getClickablePieces(resolvedBoard)
+  }
+
+  function pickPiece(pieceId) {
+    if (state.status !== 'playing') {
+      return {
+        status: state.status,
+        state: getState(),
+      }
+    }
+
+    const piece = getPieceById(resolvedBoard, pieceId)
+
+    if (!piece || piece.removed) {
+      return {
+        status: 'invalid',
+        state: getState(),
+      }
+    }
+
+    const clickableIds = new Set(getClickable().map((clickablePiece) => clickablePiece.id))
+    if (!clickableIds.has(pieceId)) {
+      return {
+        status: 'blocked',
+        state: getState(),
+      }
+    }
+
+    piece.removed = true
+    state.slot.push(createSlotEntry(piece))
+
+    const matchedElementId = getMatchingTriples(state.slot)
+    if (matchedElementId) {
+      const matchedIds = state.slot
+        .filter((entry) => entry.elementId === matchedElementId)
+        .slice(0, 3)
+        .map((entry) => entry.pieceId)
+
+      state.slot = removeMatchedEntries(state.slot, matchedElementId)
+      state.removedPieceIds.push(...matchedIds)
+
+      if (isBoardCleared()) {
+        state.status = 'won'
+        return {
+          status: 'won',
+          matchedElementId,
+          matchedIds,
+          state: getState(),
+        }
+      }
+
+      return {
+        status: 'matched',
+        matchedElementId,
+        matchedIds,
+        state: getState(),
+      }
+    }
+
+    if (state.slot.length >= 7) {
+      state.status = 'failed'
+      return {
+        status: 'failed',
+        state: getState(),
+      }
+    }
+
+    return {
+      status: 'picked',
+      state: getState(),
+    }
+  }
+
+  function restart(nextSeed = seed ?? resolvedBoard.seed) {
+    const freshSession = createGameSession({
+      cityId,
+      levelId,
+      seed: nextSeed,
+      contentSystem,
+    })
+
+    return freshSession
+  }
+
+  return {
+    cityId,
+    levelId,
+    seed: resolvedBoard.seed,
+    getBoardState() {
+      return resolvedBoard
+    },
+    getState,
+    getClickablePieces() {
+      return getClickable()
+    },
+    pickPiece,
+    restart,
+  }
+}
+
+export default createGameSession