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import { proxy, ref, snapshot, subscribe } from '../vanilla'
/** * proxyWithHistory * * This creates a new proxy with history support. * It includes following properties: * - value: any value (does not have to be an object) * - history: an array holding the history of snapshots * - historyIndex: the history index to the current snapshot * - canUndo: a function to return true if undo is available * - undo: a function to go back history * - canRedo: a function to return true if redo is available * - redo: a function to go forward history * - saveHistory: a function to save history * * [Notes] * Suspense/promise is not supported. * * @example * import { proxyWithHistory } from 'valtio/utils' * const state = proxyWithHistory({ *   count: 1, * }) */export function proxyWithHistory<V>(initialValue: V, skipSubscribe = false) {  const proxyObject = proxy({    value: initialValue,    history: ref({      wip: initialValue, // to avoid infinite loop      snapshots: [] as V[],      index: -1,    }) as { wip: V; snapshots: V[]; index: number },    canUndo: () => proxyObject.history.index > 0,    undo: () => {      if (proxyObject.canUndo()) {        proxyObject.value = proxyObject.history.wip = proxyObject.history          .snapshots[--proxyObject.history.index] as V        // refresh snapshot to use again        proxyObject.history.snapshots[proxyObject.history.index] = snapshot(          proxyObject        ).value as V      }    },    canRedo: () =>      proxyObject.history.index < proxyObject.history.snapshots.length - 1,    redo: () => {      if (proxyObject.canRedo()) {        proxyObject.value = proxyObject.history.wip = proxyObject.history          .snapshots[++proxyObject.history.index] as V        // refresh snapshot to use again        proxyObject.history.snapshots[proxyObject.history.index] = snapshot(          proxyObject        ).value as V      }    },    saveHistory: () => {      proxyObject.history.snapshots.splice(proxyObject.history.index + 1)      proxyObject.history.snapshots.push(snapshot(proxyObject).value as V)      ++proxyObject.history.index    },    subscribe: () =>      subscribe(proxyObject, (ops) => {        if (          ops.every(            (op) =>              op[1][0] === 'value' &&              (op[0] !== 'set' || op[2] !== proxyObject.history.wip)          )        ) {          proxyObject.saveHistory()        }      }),  })  proxyObject.saveHistory()  if (!skipSubscribe) {    proxyObject.subscribe()  }  return proxyObject}