"use strict";
var __defProp = Object.defineProperty;
var __getOwnPropDesc = Object.getOwnPropertyDescriptor;
var __getOwnPropNames = Object.getOwnPropertyNames;
var __hasOwnProp = Object.prototype.hasOwnProperty;
var __defNormalProp = (obj, key, value) => key in obj ? __defProp(obj, key, { enumerable: true, configurable: true, writable: true, value }) : obj[key] = value;
var __export = (target, all) => {
  for (var name in all)
    __defProp(target, name, { get: all[name], enumerable: true });
};
var __copyProps = (to, from, except, desc) => {
  if (from && typeof from === "object" || typeof from === "function") {
    for (let key of __getOwnPropNames(from))
      if (!__hasOwnProp.call(to, key) && key !== except)
        __defProp(to, key, { get: () => from[key], enumerable: !(desc = __getOwnPropDesc(from, key)) || desc.enumerable });
  }
  return to;
};
var __toCommonJS = (mod) => __copyProps(__defProp({}, "__esModule", { value: true }), mod);
var __publicField = (obj, key, value) => {
  __defNormalProp(obj, typeof key !== "symbol" ? key + "" : key, value);
  return value;
};

// src/index.ts
var src_exports = {};
__export(src_exports, {
  assertCacheEntry: () => assertCacheEntry,
  cachified: () => cachified,
  createBatch: () => createBatch,
  createCacheEntry: () => createCacheEntry,
  default: () => cachified,
  mergeReporters: () => mergeReporters,
  shouldRefresh: () => shouldRefresh,
  softPurge: () => softPurge,
  staleWhileRevalidate: () => staleWhileRevalidate,
  totalTtl: () => totalTtl,
  verboseReporter: () => verboseReporter
});
module.exports = __toCommonJS(src_exports);

// src/common.ts
var HANDLE = Symbol();
var MIGRATED = Symbol();
function createContext({ fallbackToCache, checkValue: checkValue2, ...options }, reporter) {
  const ttl = options.ttl ?? Infinity;
  const staleWhileRevalidate2 = options.swr ?? options.staleWhileRevalidate ?? 0;
  const checkValueCompat = typeof checkValue2 === "function" ? checkValue2 : typeof checkValue2 === "object" ? (value, migrate) => checkValue2.parseAsync(value).then((v) => migrate(v, false)) : () => true;
  const contextWithoutReport = {
    checkValue: checkValueCompat,
    ttl,
    staleWhileRevalidate: staleWhileRevalidate2,
    fallbackToCache: fallbackToCache === false ? 0 : fallbackToCache === true || fallbackToCache === void 0 ? Infinity : fallbackToCache,
    staleRefreshTimeout: 0,
    forceFresh: false,
    ...options,
    metadata: createCacheMetaData({ ttl, swr: staleWhileRevalidate2 }),
    waitUntil: options.waitUntil ?? (() => {
    })
  };
  const report = reporter?.(contextWithoutReport) || (() => {
  });
  return {
    ...contextWithoutReport,
    report
  };
}
function staleWhileRevalidate(metadata) {
  return (typeof metadata.swr === "undefined" ? metadata.swv : metadata.swr) || null;
}
function totalTtl(metadata) {
  if (!metadata) {
    return 0;
  }
  if (metadata.ttl === null) {
    return Infinity;
  }
  return (metadata.ttl || 0) + (staleWhileRevalidate(metadata) || 0);
}
function createCacheMetaData({
  ttl = null,
  swr = 0,
  createdTime = Date.now()
} = {}) {
  return {
    ttl: ttl === Infinity ? null : ttl,
    swr: swr === Infinity ? null : swr,
    createdTime
  };
}
function createCacheEntry(value, metadata) {
  return {
    value,
    metadata: createCacheMetaData(metadata)
  };
}

// src/reporter.ts
var defaultFormatDuration = (ms) => `${Math.round(ms)}ms`;
function formatCacheTime(metadata, formatDuration) {
  const swr = staleWhileRevalidate(metadata);
  if (metadata.ttl == null || swr == null) {
    return `forever${metadata.ttl != null ? ` (revalidation after ${formatDuration(metadata.ttl)})` : ""}`;
  }
  return `${formatDuration(metadata.ttl)} + ${formatDuration(swr)} stale`;
}
function verboseReporter({
  formatDuration = defaultFormatDuration,
  logger = console,
  performance = globalThis.performance || Date
} = {}) {
  return ({ key, fallbackToCache, forceFresh, metadata, cache }) => {
    const cacheName = cache.name || cache.toString().toString().replace(/^\[object (.*?)]$/, "$1");
    let cached;
    let freshValue;
    let getFreshValueStartTs;
    let refreshValueStartTS;
    return (event) => {
      switch (event.name) {
        case "getCachedValueRead":
          cached = event.entry;
          break;
        case "checkCachedValueError":
          logger.warn(
            `check failed for cached value of ${key}
Reason: ${event.reason}.
Deleting the cache key and trying to get a fresh value.`,
            cached
          );
          break;
        case "getCachedValueError":
          logger.error(
            `error with cache at ${key}. Deleting the cache key and trying to get a fresh value.`,
            event.error
          );
          break;
        case "getFreshValueError":
          logger.error(
            `getting a fresh value for ${key} failed`,
            { fallbackToCache, forceFresh },
            event.error
          );
          break;
        case "getFreshValueStart":
          getFreshValueStartTs = performance.now();
          break;
        case "writeFreshValueSuccess": {
          const totalTime = performance.now() - getFreshValueStartTs;
          if (event.written) {
            logger.log(
              `Updated the cache value for ${key}.`,
              `Getting a fresh value for this took ${formatDuration(
                totalTime
              )}.`,
              `Caching for ${formatCacheTime(
                metadata,
                formatDuration
              )} in ${cacheName}.`
            );
          } else {
            logger.log(
              `Not updating the cache value for ${key}.`,
              `Getting a fresh value for this took ${formatDuration(
                totalTime
              )}.`,
              `Thereby exceeding caching time of ${formatCacheTime(
                metadata,
                formatDuration
              )}`
            );
          }
          break;
        }
        case "writeFreshValueError":
          logger.error(`error setting cache: ${key}`, event.error);
          break;
        case "getFreshValueSuccess":
          freshValue = event.value;
          break;
        case "checkFreshValueError":
          logger.error(
            `check failed for fresh value of ${key}
Reason: ${event.reason}.`,
            freshValue
          );
          break;
        case "refreshValueStart":
          refreshValueStartTS = performance.now();
          break;
        case "refreshValueSuccess":
          logger.log(
            `Background refresh for ${key} successful.`,
            `Getting a fresh value for this took ${formatDuration(
              performance.now() - refreshValueStartTS
            )}.`,
            `Caching for ${formatCacheTime(
              metadata,
              formatDuration
            )} in ${cacheName}.`
          );
          break;
        case "refreshValueError":
          logger.log(`Background refresh for ${key} failed.`, event.error);
          break;
      }
    };
  };
}
function mergeReporters(...reporters) {
  return (context) => {
    const reporter = reporters.map((r) => r?.(context));
    return (event) => {
      reporter.forEach((r) => r?.(event));
    };
  };
}

// src/createBatch.ts
function createBatch(getFreshValues, autoSubmit = true) {
  const requests = [];
  let count = 0;
  let submitted = false;
  const submission = new Deferred();
  const checkSubmission = () => {
    if (submitted) {
      throw new Error("Can not add to batch after submission");
    }
  };
  const submit = async () => {
    if (count !== 0) {
      autoSubmit = true;
      return submission.promise;
    }
    checkSubmission();
    submitted = true;
    if (requests.length === 0) {
      submission.resolve();
      return;
    }
    try {
      const results = await Promise.resolve(
        getFreshValues(requests.map(([param]) => param))
      );
      results.forEach((value, index) => requests[index][1](value));
      submission.resolve();
    } catch (err) {
      requests.forEach(([_, __, rej]) => rej(err));
      submission.resolve();
    }
  };
  const trySubmitting = () => {
    count--;
    if (autoSubmit === false) {
      return;
    }
    submit();
  };
  return {
    ...autoSubmit === false ? { submit } : {},
    add(param, onValue) {
      checkSubmission();
      count++;
      let handled = false;
      return Object.assign(
        (context) => {
          return new Promise((res, rej) => {
            requests.push([
              param,
              (value) => {
                onValue?.({ ...context, value });
                res(value);
              },
              rej
            ]);
            if (!handled) {
              handled = true;
              trySubmitting();
            }
          });
        },
        {
          [HANDLE]: () => {
            if (!handled) {
              handled = true;
              trySubmitting();
            }
          }
        }
      );
    }
  };
}
var Deferred = class {
  constructor() {
    __publicField(this, "promise");
    // @ts-ignore
    __publicField(this, "resolve");
    // @ts-ignore
    __publicField(this, "reject");
    this.promise = new Promise((res, rej) => {
      this.resolve = res;
      this.reject = rej;
    });
  }
};

// src/assertCacheEntry.ts
function logKey(key) {
  return key ? `for ${key} ` : "";
}
function assertCacheEntry(entry, key) {
  if (!isRecord(entry)) {
    throw new Error(
      `Cache entry ${logKey(
        key
      )}is not a cache entry object, it's a ${typeof entry}`
    );
  }
  if (!isRecord(entry.metadata) || typeof entry.metadata.createdTime !== "number" || entry.metadata.ttl != null && typeof entry.metadata.ttl !== "number" || entry.metadata.swr != null && typeof entry.metadata.swr !== "number") {
    throw new Error(
      `Cache entry ${logKey(key)}does not have valid metadata property`
    );
  }
  if (!("value" in entry)) {
    throw new Error(
      `Cache entry for ${logKey(key)}does not have a value property`
    );
  }
}
function isRecord(entry) {
  return typeof entry === "object" && entry !== null && !Array.isArray(entry);
}

// src/shouldRefresh.ts
function shouldRefresh(metadata) {
  if (metadata.ttl !== null) {
    const valid = metadata.createdTime + (metadata.ttl || 0);
    const stale = valid + (staleWhileRevalidate(metadata) || 0);
    const now = Date.now();
    if (now <= valid) {
      return false;
    }
    if (now <= stale) {
      return "stale";
    }
    return "now";
  }
  return false;
}

// src/checkValue.ts
async function checkValue(context, value) {
  try {
    const checkResponse = await context.checkValue(
      value,
      (value2, updateCache = true) => ({
        [MIGRATED]: updateCache,
        value: value2
      })
    );
    if (typeof checkResponse === "string") {
      return { success: false, reason: checkResponse };
    }
    if (checkResponse == null || checkResponse === true) {
      return {
        success: true,
        value,
        migrated: false
      };
    }
    if (checkResponse && typeof checkResponse[MIGRATED] === "boolean") {
      return {
        success: true,
        migrated: checkResponse[MIGRATED],
        value: checkResponse.value
      };
    }
    return { success: false, reason: "unknown" };
  } catch (err) {
    return {
      success: false,
      reason: err
    };
  }
}

// src/getCachedValue.ts
var CACHE_EMPTY = Symbol();
async function getCacheEntry({ key, cache }, report) {
  report({ name: "getCachedValueStart" });
  const cached = await cache.get(key);
  report({ name: "getCachedValueRead", entry: cached });
  if (cached) {
    assertCacheEntry(cached, key);
    return cached;
  }
  return CACHE_EMPTY;
}
async function getCachedValue(context, report, hasPendingValue) {
  const {
    key,
    cache,
    staleWhileRevalidate: staleWhileRevalidate2,
    staleRefreshTimeout,
    metadata,
    getFreshValue: { [HANDLE]: handle }
  } = context;
  try {
    const cached = await getCacheEntry(context, report);
    if (cached === CACHE_EMPTY) {
      report({ name: "getCachedValueEmpty" });
      return CACHE_EMPTY;
    }
    const refresh = shouldRefresh(cached.metadata);
    const staleRefresh = refresh === "stale" || refresh === "now" && staleWhileRevalidate2 === Infinity;
    if (refresh === "now") {
      report({ name: "getCachedValueOutdated", ...cached });
    }
    if (staleRefresh) {
      context.waitUntil(
        Promise.resolve().then(async () => {
          await sleep(staleRefreshTimeout);
          report({ name: "refreshValueStart" });
          await cachified({
            ...context,
            getFreshValue({ metadata: metadata2 }) {
              return context.getFreshValue({ metadata: metadata2, background: true });
            },
            forceFresh: true,
            fallbackToCache: false
          }).then((value) => {
            report({ name: "refreshValueSuccess", value });
          }).catch((error) => {
            report({ name: "refreshValueError", error });
          });
        })
      );
    }
    if (!refresh || staleRefresh) {
      const valueCheck = await checkValue(context, cached.value);
      if (valueCheck.success) {
        report({
          name: "getCachedValueSuccess",
          value: valueCheck.value,
          migrated: valueCheck.migrated
        });
        if (!staleRefresh) {
          handle?.();
        }
        if (valueCheck.migrated) {
          context.waitUntil(
            Promise.resolve().then(async () => {
              try {
                await sleep(0);
                const cached2 = await context.cache.get(context.key);
                if (cached2 && cached2.metadata.createdTime === metadata.createdTime && !hasPendingValue()) {
                  await context.cache.set(context.key, {
                    ...cached2,
                    value: valueCheck.value
                  });
                }
              } catch (err) {
              }
            })
          );
        }
        return valueCheck.value;
      } else {
        report({ name: "checkCachedValueErrorObj", reason: valueCheck.reason });
        report({
          name: "checkCachedValueError",
          reason: valueCheck.reason instanceof Error ? valueCheck.reason.message : String(valueCheck.reason)
        });
        await cache.delete(key);
      }
    }
  } catch (error) {
    report({ name: "getCachedValueError", error });
    await cache.delete(key);
  }
  return CACHE_EMPTY;
}
function sleep(ms) {
  return new Promise((resolve) => setTimeout(resolve, ms));
}

// src/getFreshValue.ts
async function getFreshValue(context, metadata, report) {
  const { fallbackToCache, key, getFreshValue: getFreshValue2, forceFresh, cache } = context;
  let value;
  try {
    report({ name: "getFreshValueStart" });
    const freshValue = await getFreshValue2({
      metadata: context.metadata,
      background: false
    });
    value = freshValue;
    report({ name: "getFreshValueSuccess", value: freshValue });
  } catch (error) {
    report({ name: "getFreshValueError", error });
    if (forceFresh && fallbackToCache > 0) {
      const entry = await getCacheEntry(context, report);
      if (entry === CACHE_EMPTY || entry.metadata.createdTime + fallbackToCache < Date.now()) {
        throw error;
      }
      value = entry.value;
      report({ name: "getFreshValueCacheFallback", value });
    } else {
      throw error;
    }
  }
  const valueCheck = await checkValue(context, value);
  if (!valueCheck.success) {
    report({ name: "checkFreshValueErrorObj", reason: valueCheck.reason });
    report({
      name: "checkFreshValueError",
      reason: valueCheck.reason instanceof Error ? valueCheck.reason.message : String(valueCheck.reason)
    });
    throw new Error(`check failed for fresh value of ${key}`, {
      cause: valueCheck.reason
    });
  }
  try {
    const write = shouldRefresh(metadata) !== "now";
    if (write) {
      await cache.set(key, createCacheEntry(value, metadata));
    }
    report({
      name: "writeFreshValueSuccess",
      metadata,
      migrated: valueCheck.migrated,
      written: write
    });
  } catch (error) {
    report({ name: "writeFreshValueError", error });
  }
  return valueCheck.value;
}

// src/cachified.ts
var pendingValuesByCache = /* @__PURE__ */ new WeakMap();
async function cachified(options, reporter) {
  const context = createContext(options, reporter);
  const { key, cache, forceFresh, report, metadata } = context;
  if (!pendingValuesByCache.has(cache)) {
    pendingValuesByCache.set(cache, /* @__PURE__ */ new Map());
  }
  const pendingValues = pendingValuesByCache.get(cache);
  const hasPendingValue = () => {
    return pendingValues.has(key);
  };
  const cachedValue = !forceFresh ? await getCachedValue(context, report, hasPendingValue) : CACHE_EMPTY;
  if (cachedValue !== CACHE_EMPTY) {
    report({ name: "done", value: cachedValue });
    return cachedValue;
  }
  if (pendingValues.has(key)) {
    const { value: pendingRefreshValue, metadata: metadata2 } = pendingValues.get(key);
    if (!shouldRefresh(metadata2)) {
      report({ name: "getFreshValueHookPending" });
      const value2 = await pendingRefreshValue;
      report({ name: "done", value: value2 });
      return value2;
    }
  }
  let resolveFromFuture;
  const freshValue = Promise.race([
    // try to get a fresh value
    getFreshValue(context, metadata, report),
    // or when a future call is faster, we'll take it's value
    // this happens when getting value of first call takes longer then ttl + second response
    new Promise((r) => {
      resolveFromFuture = r;
    })
  ]).finally(() => {
    pendingValues.delete(key);
  });
  if (pendingValues.has(key)) {
    const { resolve } = pendingValues.get(key);
    freshValue.then((value2) => resolve(value2));
  }
  pendingValues.set(key, {
    metadata,
    value: freshValue,
    // here we receive a fresh value from a future call
    resolve: resolveFromFuture
  });
  const value = await freshValue;
  report({ name: "done", value });
  return value;
}

// src/softPurge.ts
async function softPurge({
  cache,
  key,
  ...swrOverwrites
}) {
  const swrOverwrite = swrOverwrites.swr ?? swrOverwrites.staleWhileRevalidate;
  const entry = await getCacheEntry({ cache, key }, () => {
  });
  if (entry === CACHE_EMPTY || shouldRefresh(entry.metadata)) {
    return;
  }
  const ttl = entry.metadata.ttl || Infinity;
  const swr = staleWhileRevalidate(entry.metadata) || 0;
  const lt = Date.now() - entry.metadata.createdTime;
  await cache.set(
    key,
    createCacheEntry(entry.value, {
      ttl: 0,
      swr: swrOverwrite === void 0 ? ttl + swr : swrOverwrite + lt,
      createdTime: entry.metadata.createdTime
    })
  );
}
//# sourceMappingURL=index.cjs.map