"use strict";

(function (global) {
  const Snapshot = global.TarinaiSnapshot;
  const SaveSchema = global.TarinaiSaveSchema;
  if (!Snapshot) throw new Error("TarinaiSnapshot is not available for save_codec.js");
  if (!SaveSchema) throw new Error("TarinaiSaveSchema is not available for save_codec.js");
  const EXPORT_PREFIX = "\u305f";
  const SAVE_HEADER_CHARS = "\u3089\u308A\u308B";
  const {
    BINARY_SCHEMA_VERSION,
    FIELD_IDS,
  } = SaveSchema;

  const textEncoder = new TextEncoder();
  const textDecoder = new TextDecoder();

  const SAVE_TEXT_BITS = 12;
  const SAVE_TEXT_BASE = 1 << SAVE_TEXT_BITS;
  const SAVE_TEXT_ALPHABET = (() => {
    const chars = [];
    const addRange = (from, to) => {
      for (let code = from; code <= to && chars.length < SAVE_TEXT_BASE; code++) chars.push(String.fromCharCode(code));
    };
    // \u6b63\u898f\u5316\u3067\u5206\u89e3\u3055\u308c\u306b\u304f\u3044\u4eee\u540d\u3068CJK\u7d71\u5408\u6f22\u5b57\u3060\u3051\u3092\u4f7f\u3046\u3002
    addRange(0x3041, 0x3096); // \u3072\u3089\u304c\u306a
    addRange(0x30A1, 0x30FA); // \u30ab\u30bf\u30ab\u30ca
    addRange(0x4E00, 0x9FFF); // \u5e38\u7528\u6f22\u5b57\u3092\u542b\u3080CJK\u7d71\u5408\u6f22\u5b57\u3002\u5fc5\u8981\u6570\u306b\u9054\u3057\u305f\u3089\u505c\u6b62\u3002
    return chars.join("");
  })();
  const SAVE_TEXT_REVERSE = (() => {
    const map = new Map();
    let index = 0;
    for (const ch of SAVE_TEXT_ALPHABET) map.set(ch, index++);
    return map;
  })();
  if ([...SAVE_TEXT_ALPHABET].length !== SAVE_TEXT_BASE) throw new Error("save alphabet must contain 4096 Japanese chars");

  function jp4096Encode(bytes) {
    const source = bytes instanceof Uint8Array ? bytes : new Uint8Array(bytes || []);
    let b = 0;
    let n = 0;
    let out = "";
    for (const byte of source) {
      b |= (byte & 255) << n;
      n += 8;
      while (n >= SAVE_TEXT_BITS) {
        out += SAVE_TEXT_ALPHABET[b & (SAVE_TEXT_BASE - 1)];
        b >>= SAVE_TEXT_BITS;
        n -= SAVE_TEXT_BITS;
      }
    }
    if (n > 0) out += SAVE_TEXT_ALPHABET[b & (SAVE_TEXT_BASE - 1)];
    return out;
  }

  function jp4096Decode(text, remainder = 0) {
    let b = 0;
    let n = 0;
    const out = [];
    for (const ch of String(text || "").trim()) {
      const value = SAVE_TEXT_REVERSE.get(ch);
      if (value == null) continue;
      b |= value << n;
      n += SAVE_TEXT_BITS;
      while (n >= 8) {
        out.push(b & 255);
        b >>= 8;
        n -= 8;
      }
    }
    if ((Number(remainder) || 0) === 2 && out.length) out.pop();
    return new Uint8Array(out);
  }

  function saveHeader(byteLength = 0) {
    const remainder = ((Number(byteLength) || 0) % 3 + 3) % 3;
    return SAVE_HEADER_CHARS.charAt(remainder);
  }
  function parseSaveHeader(ch = "") {
    const remainder = SAVE_HEADER_CHARS.indexOf(String(ch || "").charAt(0));
    if (remainder < 0) throw new Error("unsupported Japanese save header");
    return { remainder };
  }

  function toSafeUInt(value = 0) {
    const n = Math.floor(Number(value) || 0);
    return Number.isFinite(n) && n > 0 ? Math.min(n, Number.MAX_SAFE_INTEGER) : 0;
  }
  function toSafeInt(value = 0) {
    const n = Math.round(Number(value) || 0);
    return Number.isFinite(n) ? Math.max(Number.MIN_SAFE_INTEGER, Math.min(Number.MAX_SAFE_INTEGER, n)) : 0;
  }
  function zigzagEncode(value = 0) {
    const n = toSafeInt(value);
    return n < 0 ? (-n * 2 - 1) : (n * 2);
  }
  function zigzagDecode(value = 0) {
    const n = toSafeUInt(value);
    return (n % 2) ? -((n + 1) / 2) : (n / 2);
  }

  class BinaryWriter {
    constructor() { this.bytes = []; }
    u(value = 0) {
      let n = toSafeUInt(value);
      while (n >= 128) {
        this.bytes.push((n % 128) | 128);
        n = Math.floor(n / 128);
      }
      this.bytes.push(n & 127);
    }
    s(value = 0) { this.u(zigzagEncode(value)); }
    b(value = 0) { this.bytes.push((Number(value) || 0) & 255); }
    str(value = "") {
      const bytes = textEncoder.encode(String(value || ""));
      this.u(bytes.length);
      for (const byte of bytes) this.bytes.push(byte);
    }
    out() { return new Uint8Array(this.bytes); }
  }

  class BinaryReader {
    constructor(bytes = []) { this.bytes = bytes instanceof Uint8Array ? bytes : new Uint8Array(bytes || []); this.pos = 0; }
    ensure(count = 1) {
      if (this.pos + count > this.bytes.length) throw new Error("truncated binary save");
    }
    u() {
      let n = 0;
      let mul = 1;
      for (let i = 0; i < 10; i++) {
        this.ensure(1);
        const byte = this.bytes[this.pos++];
        n += (byte & 127) * mul;
        if (!(byte & 128)) return n;
        mul *= 128;
      }
      throw new Error("invalid varuint in binary save");
    }
    s() { return zigzagDecode(this.u()); }
    b() { this.ensure(1); return this.bytes[this.pos++]; }
    str() {
      const len = this.u();
      this.ensure(len);
      const slice = this.bytes.subarray(this.pos, this.pos + len);
      this.pos += len;
      return textDecoder.decode(slice);
    }
  }

  let activeStringWriteMap = null;
  let activeStringReadList = null;
  function utf8Length(value = "") {
    return textEncoder.encode(String(value || "")).length;
  }
  function collectStringCounts(snapshot) {
    const counts = new Map();
    const add = value => {
      const s = String(value || "");
      if (s.length < 2 || utf8Length(s) < 4) return;
      counts.set(s, (counts.get(s) || 0) + 1);
    };
    add(snapshot?.w?.[8]);
    for (const row of snapshot?.t || []) add(row?.[1]);
    for (const row of snapshot?.i || []) {
      const extra = row?.[4];
      if (extra && (Array.isArray(extra) ? extra.length : Object.keys(extra || {}).length)) add(JSON.stringify(extra));
    }
    return [...counts.entries()]
      .filter(([, count]) => count > 1)
      .sort((a, b) => (b[0].length * b[1]) - (a[0].length * a[1]))
      .map(([value]) => value)
      .slice(0, 63);
  }
  function writeStringTable(writer, snapshot) {
    const list = collectStringCounts(snapshot);
    writer.u(list.length);
    activeStringWriteMap = list.length ? new Map(list.map((value, i) => [value, i])) : null;
    for (const value of list) writer.str(value);
  }
  function readStringTable(reader) {
    const count = reader.u();
    const list = [];
    for (let i = 0; i < count; i++) list.push(reader.str());
    activeStringReadList = list.length ? list : null;
  }
  function writeSaveString(writer, value = "") {
    const s = String(value || "");
    if (!activeStringWriteMap) return writer.str(s);
    const index = activeStringWriteMap.get(s);
    if (index == null) {
      writer.u(0);
      writer.str(s);
    } else {
      writer.u(index + 1);
    }
  }
  function readSaveString(reader) {
    if (!activeStringReadList) return reader.str();
    const index = reader.u();
    if (!index) return reader.str();
    return activeStringReadList[index - 1] || "";
  }

  function clampToBits(value = 0, bits = 8) {
    const max = (2 ** Math.max(0, bits)) - 1;
    return Math.max(0, Math.min(max, toSafeUInt(value)));
  }
  function writeBitFields(writer, values = [], bits = []) {
    let acc = 0;
    let accBits = 0;
    for (let i = 0; i < bits.length; i++) {
      const width = Math.max(0, Number(bits[i]) || 0);
      if (!width) continue;
      let value = clampToBits(values?.[i] || 0, width);
      let left = width;
      while (left > 0) {
        const room = 8 - accBits;
        const take = Math.min(room, left);
        const mask = (1 << take) - 1;
        acc |= (value & mask) << accBits;
        accBits += take;
        value = Math.floor(value / (2 ** take));
        left -= take;
        if (accBits === 8) {
          writer.b(acc);
          acc = 0;
          accBits = 0;
        }
      }
    }
    if (accBits > 0) writer.b(acc);
  }
  function readBitFields(reader, bits = []) {
    const out = [];
    let acc = 0;
    let accBits = 0;
    for (const rawWidth of bits) {
      const width = Math.max(0, Number(rawWidth) || 0);
      let value = 0;
      let shift = 0;
      let left = width;
      while (left > 0) {
        if (accBits === 0) { acc = reader.b(); accBits = 8; }
        const take = Math.min(accBits, left);
        const mask = (1 << take) - 1;
        value += (acc & mask) * (2 ** shift);
        acc = Math.floor(acc / (2 ** take));
        accBits -= take;
        shift += take;
        left -= take;
      }
      out.push(value);
    }
    return out;
  }
  function writeQuantizedBitFields(writer, values = [], count = 0, bits = 6, step = 1) {
    const list = [];
    for (let i = 0; i < count; i++) list.push(Math.round((Number(values?.[i]) || 0) / Math.max(1, step)));
    writeBitFields(writer, list, Array.from({ length: count }, () => bits));
  }
  function readQuantizedBitFields(reader, count = 0, bits = 6, step = 1) {
    return readBitFields(reader, Array.from({ length: count }, () => bits)).map(v => v * Math.max(1, step));
  }

      function writeFixedPacked(writer, arr = [], count = 0, bits = 8, step = 1) {
    writeQuantizedBitFields(writer, arr, count, bits, step);
  }
  function readFixedPacked(reader, count = 0, bits = 8, step = 1) {
    return readQuantizedBitFields(reader, count, bits, step);
  }
  function writeFixedDiffPacked(writer, base = [], current = [], count = 0, bits = 8) {
    let mask = 0;
    const values = [];
    const widths = [];
    for (let i = 0; i < count; i++) {
      if (valuesDiffer(current?.[i], base?.[i])) {
        mask |= (1 << i);
        values.push(current?.[i] || 0);
        widths.push(bits);
      }
    }
    writeBitFields(writer, [mask], [count]);
    if (widths.length) writeBitFields(writer, values, widths);
  }
  function readFixedDiffPacked(reader, base = [], count = 0, bits = 8) {
    const [mask] = readBitFields(reader, [count]);
    const out = Array.from({ length: count }, (_, i) => base?.[i] || 0);
    const changed = [];
    for (let i = 0; i < count; i++) if (mask & (1 << i)) changed.push(i);
    const values = changed.length ? readBitFields(reader, changed.map(() => bits)) : [];
    changed.forEach((index, i) => { out[index] = values[i]; });
    return out;
  }
  function writeIndexList(writer, arr = []) {
    const list = Array.isArray(arr) ? arr : [];
    writer.u(list.length);
    for (const idx of list) writer.u(idx || 0);
  }
  function readIndexList(reader) {
    const count = reader.u();
    const out = [];
    for (let i = 0; i < count; i++) out.push(reader.u());
    return out;
  }

  function valuesDiffer(a, b) { return (Number(a) || 0) !== (Number(b) || 0); }
  function arrayHasValues(arr = [], defaults = []) {
    for (let i = 0; i < Math.max(arr?.length || 0, defaults.length); i++) {
      if (valuesDiffer(arr?.[i], defaults?.[i] || 0)) return true;
    }
    return false;
  }
  function writeTimers(writer, timers = []) {
    const defaults = [0, 0, 0, 0, 0, 0, 0, 0, 100];
    let mask = 0;
    for (let i = 0; i < defaults.length; i++) if (valuesDiffer(timers?.[i], defaults[i])) mask |= (1 << i);
    writeBitFields(writer, [mask], [defaults.length]);
    for (let i = 0; i < defaults.length; i++) if (mask & (1 << i)) writer.s(timers[i] || 0);
  }
  function readTimers(reader) {
    const defaults = [0, 0, 0, 0, 0, 0, 0, 0, 100];
    const out = defaults.slice();
    const [mask] = readBitFields(reader, [defaults.length]);
    for (let i = 0; i < defaults.length; i++) if (mask & (1 << i)) out[i] = reader.s();
    return out;
  }
  function writeModes(writer, modes = []) {
    writeBitFields(writer, [modes?.[0] || 0, modes?.[1] || 0, modes?.[2] || 0], [2, 2, 1]);
  }
  function readModes(reader) {
    return readBitFields(reader, [2, 2, 1]);
  }
  function defaultNeedsFromVitals(hunger = 0, energy = 0, sleepPressure = 0) {
    const food = Math.max(0, Math.min(100, Math.round(Number(hunger) || 0)));
    const sleep = Math.max(0, Math.min(100, Math.round(Math.max(Number(sleepPressure) || 0, 100 - (Number(energy) || 0)))));
    return [food, sleep, 0, 0, 0, 0];
  }
  function writeRelationships(writer, rows = []) {
    const list = Array.isArray(rows) ? rows : [];
    writer.u(list.length);
    for (const row of list) {
      writer.u(row?.[0] || 0);
      writer.s(row?.[1] || 0);
      writer.s(row?.[2] || 0);
      writer.u(row?.[3] || 0);
    }
  }
  function readRelationships(reader) {
    const count = reader.u();
    const out = [];
    for (let i = 0; i < count; i++) out.push([reader.u(), reader.s(), reader.s(), reader.u()]);
    return out;
  }

  function writeWorld(writer, w = []) {
    writeBitFields(writer, [w[0] || 0, w[1] || 0, w[2] || 0, w[4] || 0], [2, 3, 4, 3]);
    writer.u(w[3] || 0); // worldTick10
    let mask = 0;
    if (valuesDiffer(w[5], -9990)) mask |= 1;
    if (valuesDiffer(w[6], 1)) mask |= 2;
    if (valuesDiffer(w[7], 0)) mask |= 4;
    if (valuesDiffer(w[9], 0)) mask |= 8;
    if (valuesDiffer(w[10], 0)) mask |= 16;
    if (valuesDiffer(w[11], 0)) mask |= 32;
    writeBitFields(writer, [mask], [6]);
    if (mask & 1) writer.s(w[5] || 0); // lastBirthAt10 can be negative
    if (mask & 2) writer.u(w[6] || 1); // generation
    if (mask & 4) writer.u(w[7] || 0); // dead count
    writeSaveString(writer, w[8] || ""); // worldSeed
    if (mask & 8) writer.u(w[9] || 0); // birthSerial
    if (mask & 16) writer.u(w[10] || 0); // tarinai population limit
    if (mask & 32) writer.u(w[11] || 0); // object limit
  }
  function readWorld(reader) {
    const [field, ground, mood, weather] = readBitFields(reader, [2, 3, 4, 3]);
    const tick = reader.u();
    const [mask] = readBitFields(reader, [6]);
    const lastBirthAt = (mask & 1) ? reader.s() : -9990;
    const generation = (mask & 2) ? reader.u() : 1;
    const deadCount = (mask & 4) ? reader.u() : 0;
    const seed = readSaveString(reader);
    const birthSerial = (mask & 8) ? reader.u() : 0;
    const tarinaiPopulationLimit = (mask & 16) ? reader.u() : 0;
    const objectLimit = (mask & 32) ? reader.u() : 0;
    return [field, ground, mood, tick, weather, lastBirthAt, generation, deadCount, seed, birthSerial, tarinaiPopulationLimit, objectLimit];
  }

  function seedPersonalityArray(seed = "", flags = 0) {
    // \u305a\u3093\u3061\u3069\u308c\u3044\u306f\u8a95\u751f\u6642\u6027\u683c\u3082\u5168\u8ef8 -1 \u306a\u306e\u3067\u3001\u5dee\u5206\u57fa\u6e96\u30820\u56fa\u5b9a\u306b\u3059\u308b\u3002
    if ((Number(flags) || 0) & (1 << 5)) return [0, 0, 0, 0];
    return global.TarinaiSeedFactory.personalityArray(seed) || [100, 100, 100, 100];
  }
  function seedGeneticsArray(seed = "", flags = 0) {
    const zunchiSlave = Boolean((Number(flags) || 0) & ((1 << 5) | (1 << 6)));
    const genetics = global.TarinaiSeedFactory?.birthProfile?.(seed, { isZunchiSlave: zunchiSlave, zunchiSlaveLocked: zunchiSlave })?.genetics || {};
    return [
      Math.round((Number(genetics.lifeSpanMul) || 1) * 100),
      Math.round((Number(genetics.attackMul) || 1) * 100),
      Math.round((Number(genetics.speedMul) || 1) * 100),
      Math.round((Number(genetics.sizeMul) || 1) * 100),
      Math.round((Number(genetics.temperatureOffset) || 0) * 10),
    ];
  }
  function writeSignedDiffList(writer, base = [], current = [], count = 0) {
    let mask = 0;
    for (let i = 0; i < count; i++) if (valuesDiffer(current?.[i], base?.[i])) mask |= (1 << i);
    writeBitFields(writer, [mask], [count]);
    for (let i = 0; i < count; i++) if (mask & (1 << i)) writer.s((current?.[i] || 0) - (base?.[i] || 0));
  }
  function readSignedDiffList(reader, base = [], count = 0) {
    const [mask] = readBitFields(reader, [count]);
    const out = Array.from({ length: count }, (_, i) => base?.[i] || 0);
    for (let i = 0; i < count; i++) if (mask & (1 << i)) out[i] = (base?.[i] || 0) + reader.s();
    return out;
  }

  function writeTarinai(writer, row = [], coordState = null) {
    const pinIdx = row[15] ?? -1;
    const nestIdx = row[16] ?? -1;
    const stateId = row[17]?.[0] || 0;
    const stateTarget = row[17]?.[1] ?? -1;
    const genetics = Array.isArray(row[18]) ? row[18] : [];
    const fightStats = Array.isArray(row[19]) ? row[19] : [];
    const birthSeed = row[1] || "";
    const flags = row[0] || 0;
    writeBitFields(writer, [row[0] || 0], [10]);
    writeSaveString(writer, birthSeed);
    const x = toSafeInt(row[2] || 0);
    const y = toSafeInt(row[3] || 0);
    const age = toSafeInt(row[4] || 0);
    const generation = toSafeInt(row[5] || 1);
    writer.s(x - (coordState?.x || 0));
    writer.s(y - (coordState?.y || 0));
    writer.s(age - (coordState?.age || 0));
    writer.s(generation - (coordState?.generation || 1));
    if (coordState) { coordState.x = x; coordState.y = y; coordState.age = age; coordState.generation = generation; }
    writeBitFields(writer, [row[6] || 0, row[7] || 0, row[8] || 0], [8, 8, 8]);
    const defaultPersonality = seedPersonalityArray(birthSeed, flags);
    const defaultTimers = [0, 0, 0, 0, 0, 0, 0, 0, 100];
    let bodyMask = 0;
    if (arrayHasValues(row[10], defaultPersonality)) bodyMask |= 1;
    if ((row[11] || []).length) bodyMask |= 2;
    if ((row[12] || []).length) bodyMask |= 4;
    if (arrayHasValues(row[13], defaultTimers)) bodyMask |= 8;
    if (arrayHasValues(row[14], [0, 0, 0])) bodyMask |= 16;
    writeBitFields(writer, [bodyMask], [5]);
    if (bodyMask & 1) writeFixedDiffPacked(writer, defaultPersonality, row[10], 4, 8);
    if (bodyMask & 2) writeIndexList(writer, row[11]);
    if (bodyMask & 4) writeRelationships(writer, row[12]);
    if (bodyMask & 8) writeTimers(writer, row[13]);
    if (bodyMask & 16) writeModes(writer, row[14]);
    let tailMask = 0;
    if (pinIdx >= 0) tailMask |= 1;
    if (nestIdx >= 0) tailMask |= 2;
    if (stateId || stateTarget >= 0) tailMask |= 4;
    if (arrayHasValues(genetics, seedGeneticsArray(birthSeed, flags))) tailMask |= 8;
    if (arrayHasValues(fightStats, [0, 0, 0])) tailMask |= 16;
    writeBitFields(writer, [tailMask], [5]);
    if (tailMask & 1) writer.u(pinIdx);
    if (tailMask & 2) writer.u(nestIdx);
    if (tailMask & 4) { writeBitFields(writer, [stateId], [1]); writer.s(stateTarget); }
    if (tailMask & 8) writeSignedDiffList(writer, seedGeneticsArray(birthSeed, flags), genetics, 5);
    if (tailMask & 16) writeSignedDiffList(writer, [0, 0, 0], fightStats, 3);
  }
  function readTarinai(reader, coordState = null) {
    const flags = readBitFields(reader, [10])[0];
    const birthSeed = readSaveString(reader);
    const x = (coordState?.x || 0) + reader.s();
    const y = (coordState?.y || 0) + reader.s();
    const age = (coordState?.age || 0) + reader.s();
    const generation = (coordState?.generation || 1) + reader.s();
    if (coordState) { coordState.x = x; coordState.y = y; coordState.age = age; coordState.generation = generation; }
    const [hunger, energy, sleepPressure] = readBitFields(reader, [8, 8, 8]);
    const [bodyMask] = readBitFields(reader, [5]);
    const needs = defaultNeedsFromVitals(hunger, energy, sleepPressure);
    const current = (bodyMask & 1) ? readFixedDiffPacked(reader, seedPersonalityArray(birthSeed, flags), 4, 8) : seedPersonalityArray(birthSeed, flags);
    const parents = (bodyMask & 2) ? readIndexList(reader) : [];
    const relationships = (bodyMask & 4) ? readRelationships(reader) : [];
    const timers = (bodyMask & 8) ? readTimers(reader) : [0, 0, 0, 0, 0, 0, 0, 0, 100];
    const modes = (bodyMask & 16) ? readModes(reader) : [0, 0, 0];
    const [tailMask] = readBitFields(reader, [5]);
    const pinIdx = (tailMask & 1) ? reader.u() : -1;
    const nestIdx = (tailMask & 2) ? reader.u() : -1;
    const stateInfo = (tailMask & 4) ? [readBitFields(reader, [1])[0], reader.s()] : [0, -1];
    const genetics = (tailMask & 8) ? readSignedDiffList(reader, seedGeneticsArray(birthSeed, flags), 5) : [];
    const fightStats = (tailMask & 16) ? readSignedDiffList(reader, [0, 0, 0], 3) : [];
    return [flags, birthSeed, x, y, age, generation, hunger, energy, sleepPressure, needs, current, parents, relationships, timers, modes, pinIdx, nestIdx, stateInfo, genetics, fightStats];
  }

  function writeCurrentItemExtra(writer, extra = []) {
    const value = extra == null ? [] : extra;
    writeSaveString(writer, JSON.stringify(value));
  }
  function readCurrentItemExtra(reader) {
    try {
      const parsed = JSON.parse(readSaveString(reader) || "[]");
      return (Array.isArray(parsed) || (parsed && typeof parsed === "object")) ? parsed : [];
    } catch (_) {
      return [];
    }
  }

  function itemCoordKey(row = []) {
    const x = Math.max(0, Math.min(65535, toSafeUInt(row[1] || 0)));
    const y = Math.max(0, Math.min(65535, toSafeUInt(row[2] || 0)));
    return mortonKey(x, y);
  }
  function mortonKey(x = 0, y = 0) {
    let out = 0;
    for (let i = 0; i < 16; i++) out += (((x >> i) & 1) * (2 ** (2 * i))) + (((y >> i) & 1) * (2 ** (2 * i + 1)));
    return out;
  }
  function writeItemPayload(writer, row = [], typeId = 0, coordState = null) {
    const x = toSafeInt(row[1] || 0);
    const y = toSafeInt(row[2] || 0);
    writer.s(x - (coordState?.x || 0));
    writer.s(y - (coordState?.y || 0));
    if (coordState) { coordState.x = x; coordState.y = y; }
    writer.s(row[3] || 0);
    writeCurrentItemExtra(writer, row[4] || []);
  }
  function readItemPayload(reader, typeId = 0, coordState = null) {
    const x = (coordState?.x || 0) + reader.s();
    const y = (coordState?.y || 0) + reader.s();
    if (coordState) { coordState.x = x; coordState.y = y; }
    const amount = reader.s();
    const extra = readCurrentItemExtra(reader);
    return [typeId, x, y, amount, extra];
  }
  function itemBlocksFromRows(rows = []) {
    const groups = new Map();
    for (const row of rows || []) {
      const typeId = row?.[0] || 0;
      if (!groups.has(typeId)) groups.set(typeId, []);
      groups.get(typeId).push(row);
    }
    const blocks = [];
    for (const [typeId, list] of [...groups.entries()].sort((a, b) => a[0] - b[0])) {
      list.sort((a, b) => itemCoordKey(a) - itemCoordKey(b) || (a[1] || 0) - (b[1] || 0) || (a[2] || 0) - (b[2] || 0));
      blocks.push([typeId, list]);
    }
    return blocks;
  }
  function writeItemBlocks(writer, rows = []) {
    const blocks = itemBlocksFromRows(rows);
    writer.u(blocks.length);
    for (const [typeId, list] of blocks) {
      writer.u(typeId);
      writer.u(list.length);
      const coordState = { x: 0, y: 0 };
      for (const row of list) writeItemPayload(writer, row, typeId, coordState);
    }
  }
  function readItemBlocks(reader) {
    const blockCount = reader.u();
    const items = [];
    for (let b = 0; b < blockCount; b++) {
      const typeId = reader.u();
      const count = reader.u();
      const coordState = { x: 0, y: 0 };
      for (let i = 0; i < count; i++) items.push(readItemPayload(reader, typeId, coordState));
    }
    return items;
  }

  function fieldValue(index = 0) { return FIELD_IDS[Number(index) | 0] || "garden"; }
  function summaryFromPayload(w = [], tarinaiCount = 0) {
    const config = typeof CONFIG !== "undefined" ? CONFIG : (global.CONFIG || {});
    const dayLength = Math.max(1, Number(config.dayLength || 120));
    const totalTime = (Number(w[3]) || 0) / 10;
    const day = Math.max(1, Math.floor(totalTime / dayLength) + 1);
    return [day, tarinaiCount, fieldValue(w[0])];
  }

  function encodeBinarySnapshot(snapshot) {
    if (!snapshot || snapshot.v !== Snapshot.version || snapshot.a !== "tj1") throw new Error("snapshot version mismatch");
    const writer = new BinaryWriter();
    activeStringWriteMap = null;
    try {
      writer.b(BINARY_SCHEMA_VERSION);
      writer.u(Snapshot.version);
      writeStringTable(writer, snapshot);
      writeWorld(writer, snapshot.w || []);
      const tarinaiRows = Array.isArray(snapshot.t) ? snapshot.t : [];
      writer.u(tarinaiRows.length);
      const tarCoordState = { x: 0, y: 0, age: 0, generation: 1 };
      for (const row of tarinaiRows) writeTarinai(writer, row || [], tarCoordState);
      const itemRows = Array.isArray(snapshot.i) ? snapshot.i : [];
      writeItemBlocks(writer, itemRows);
      return writer.out();
    } finally {
      activeStringWriteMap = null;
    }
  }

  function decodeBinarySnapshot(bytes) {
    const reader = new BinaryReader(bytes);
    activeStringReadList = null;
    try {
      const schema = reader.b();
      if (schema !== BINARY_SCHEMA_VERSION) throw new Error("unsupported binary save schema");
      const snapshotVersion = reader.u();
      if (snapshotVersion !== Snapshot.version) throw new Error("unsupported binary save version");
      readStringTable(reader);
      const w = readWorld(reader);
      const tCount = reader.u();
      const t = [];
      const tarCoordState = { x: 0, y: 0, age: 0, generation: 1 };
      for (let i = 0; i < tCount; i++) t.push(readTarinai(reader, tarCoordState));
      const items = readItemBlocks(reader);
      if (reader.pos !== reader.bytes.length) throw new Error("trailing bytes in binary save");
      return { v: Snapshot.version, a: "tj1", m: summaryFromPayload(w, t.length), w, t, i: items };
    } finally {
      activeStringReadList = null;
    }
  }

  async function encodeSnapshot(snapshot) {
    const bytes = encodeBinarySnapshot(snapshot);
    return `${EXPORT_PREFIX}${saveHeader(bytes.length)}${jp4096Encode(bytes)}`;
  }

  async function decodeSnapshot(text) {
    const raw = String(text || "").trim();
    if (!raw.startsWith(EXPORT_PREFIX)) throw new Error("unsupported Japanese save text");
    const header = parseSaveHeader(raw.charAt(EXPORT_PREFIX.length));
    const payload = raw.slice(EXPORT_PREFIX.length + 1);
    return decodeBinarySnapshot(jp4096Decode(payload, header.remainder));
  }

  global.TarinaiSaveCodec = {
    encodeSnapshot,
    decodeSnapshot,
  };
})(typeof window !== "undefined" ? window : globalThis);