"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\u308a";
  const RAW_CODEC = "\u751f";
  const DEFLATE_CODEC = "\u7e2e";
  const {
    BINARY_SCHEMA_VERSION,
    FIELD_IDS,
    STRUCTURE_TYPE_IDS,
    SERVING_FOOD_TYPE_IDS,
    PIN_TYPE_IDS,
    ROTATABLE_ITEM_TYPE_IDS,
    JSON_EXTRA_ITEM_TYPE_IDS,
  } = SaveSchema;

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

  const SAVE_TEXT_BITS = 11;
  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 2048 Japanese chars");

  function writeVaruintToArray(out, value = 0) {
    let n = toSafeUInt(value);
    while (n >= 128) {
      out.push((n % 128) | 128);
      n = Math.floor(n / 128);
    }
    out.push(n & 127);
  }
  function readVaruintFromArray(bytes, start = 0) {
    let n = 0;
    let mul = 1;
    for (let i = 0; i < 10; i++) {
      const byte = bytes[start + i];
      if (byte == null) throw new Error("truncated Japanese save length");
      n += (byte & 127) * mul;
      if (!(byte & 128)) return { value: n, next: start + i + 1 };
      mul *= 128;
    }
    throw new Error("invalid Japanese save length");
  }

  function jp2048Encode(bytes) {
    const source = bytes instanceof Uint8Array ? bytes : new Uint8Array(bytes || []);
    const packet = [];
    writeVaruintToArray(packet, source.length);
    for (const byte of source) packet.push(byte & 255);
    let b = 0;
    let n = 0;
    let out = "";
    for (const byte of packet) {
      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 jp2048Decode(text) {
    let b = 0;
    let n = 0;
    const packet = [];
    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) {
        packet.push(b & 255);
        b >>= 8;
        n -= 8;
      }
    }
    const { value: length, next } = readVaruintFromArray(packet, 0);
    if (packet.length < next + length) throw new Error("truncated Japanese save payload");
    return new Uint8Array(packet.slice(next, next + length));
  }

  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);
    }
  }

  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));
  }

  async function compressBytes(bytes) {
    if (typeof CompressionStream === "function") {
      const stream = new Blob([bytes]).stream().pipeThrough(new CompressionStream("deflate-raw"));
      return new Uint8Array(await new Response(stream).arrayBuffer());
    }
    return bytes;
  }
  async function decompressBytes(bytes, codec) {
    if (codec === DEFLATE_CODEC) {
      if (typeof DecompressionStream !== "function") throw new Error("deflate decoder is not available in this browser");
      const stream = new Blob([bytes]).stream().pipeThrough(new DecompressionStream("deflate-raw"));
      return new Uint8Array(await new Response(stream).arrayBuffer());
    }
    if (codec !== RAW_CODEC) throw new Error("unsupported Japanese save codec");
    return bytes;
  }

      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 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 commonItemAmountNeeded(typeId) {
    if (STRUCTURE_TYPE_IDS.has(typeId)) return false;
    if (SERVING_FOOD_TYPE_IDS.has(typeId)) return false;
    return true;
  }
  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
    writer.s(w[5] || 0); // lastBirthAt10 can be negative
    writer.u(w[6] || 1); // generation
    writer.u(w[7] || 0); // dead count
    writer.str(w[8] || ""); // worldSeed
    writer.u(w[9] || 0); // birthSerial
  }
  function readWorld(reader) {
    const [field, ground, mood, weather] = readBitFields(reader, [2, 3, 4, 3]);
    return [field, ground, mood, reader.u(), weather, reader.s(), reader.u(), reader.u(), reader.str(), reader.u()];
  }

  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 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] || "";
    writeBitFields(writer, [row[0] || 0], [10]);
    writer.str(birthSeed);
    const x = toSafeInt(row[2] || 0);
    const y = toSafeInt(row[3] || 0);
    writer.s(x - (coordState?.x || 0));
    writer.s(y - (coordState?.y || 0));
    if (coordState) { coordState.x = x; coordState.y = y; }
    writer.u(row[4] || 0);
    writer.u(row[5] || 1);
    writeBitFields(writer, [row[6] || 0, row[7] || 0, row[8] || 0], [8, 8, 8]);
    writeFixedPacked(writer, row[9], 6, 6, 2);
    writeFixedDiffPacked(writer, seedPersonalityArray(birthSeed, row[0] || 0), row[10], 4, 8);
    writeIndexList(writer, row[11]);
    writeRelationships(writer, row[12]);
    writeTimers(writer, row[13]);
    writeModes(writer, row[14]);
    let tailMask = 0;
    if (pinIdx >= 0) tailMask |= 1;
    if (nestIdx >= 0) tailMask |= 2;
    if (stateId || stateTarget >= 0) tailMask |= 4;
    if (genetics.length) tailMask |= 8;
    if (fightStats.length) 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) for (let i = 0; i < 5; i++) writer.s(genetics[i] ?? (i === 4 ? 0 : 100));
    if (tailMask & 16) { writer.u(fightStats[0] || 0); writer.u(fightStats[1] || 0); writer.s(fightStats[2] || 0); }
  }
  function readTarinai(reader, coordState = null) {
    const flags = readBitFields(reader, [10])[0];
    const birthSeed = reader.str();
    const x = (coordState?.x || 0) + reader.s();
    const y = (coordState?.y || 0) + reader.s();
    if (coordState) { coordState.x = x; coordState.y = y; }
    const age = reader.u();
    const generation = reader.u();
    const [hunger, energy, sleepPressure] = readBitFields(reader, [8, 8, 8]);
    const needs = readFixedPacked(reader, 6, 6, 2);
    const current = readFixedDiffPacked(reader, seedPersonalityArray(birthSeed, flags), 4, 8);
    const parents = readIndexList(reader);
    const relationships = readRelationships(reader);
    const timers = readTimers(reader);
    const modes = readModes(reader);
    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) ? [reader.s(), reader.s(), reader.s(), reader.s(), reader.s()] : [];
    const fightStats = (tailMask & 16) ? [reader.u(), reader.u(), reader.s()] : [];
    return [flags, birthSeed, x, y, age, generation, hunger, energy, sleepPressure, needs, current, parents, relationships, timers, modes, pinIdx, nestIdx, stateInfo, genetics, fightStats];
  }

  function writeItemExtra(writer, typeId, extra = []) {
    if (STRUCTURE_TYPE_IDS.has(typeId)) {
      writer.s(extra[0] || 0); writer.s(extra[1] || 0); writer.s(extra[2] ?? -1); writer.s(extra[3] ?? -1); writer.u(extra[4] || 0); writer.s(extra[5] ?? -1);
    } else if (typeId === 0) { // grass
      writer.s(extra[0] || 0); writer.s(extra[1] || 0); writer.s(extra[2] || 0); writer.u(extra[3] || 0);
    } else if (typeId === 1) { // zunchi
      writer.u(extra[0] || 0); writer.s(extra[1] || 0); writer.s(extra[2] || 0);
    } else if (typeId === 22) { // signboard
      writer.str(extra[0] || "");
    } else if (typeId === 6) { // duplicator
      writer.s(extra[0] ?? -1);
    } else if (typeId === 42) { // robot_cleaner
      writer.u(Math.max(0, Math.min(0x3f, Number(extra[0] ?? 3) | 0)));
      writer.u(extra[1] ? 1 : 0);
    } else if (JSON_EXTRA_ITEM_TYPE_IDS.has(typeId)) {
      writer.str(JSON.stringify(extra || []));
    } else if (typeId === 21) { // ball
      writer.s(extra[0] || 0); writer.s(extra[1] || 0);
    } else if (typeId === 23) { // ant_nest
      writer.s(extra[0] || 0); writer.s(extra[1] || 0);
    } else if (typeId === 24) { // ant_corpse
      writer.s(extra[0] || 0);
    } else if (typeId === 25) { // firecracker
      writer.s(extra[0] || 0);
    } else if (PIN_TYPE_IDS.has(typeId)) {
      writer.u(extra[0] || 0); writer.s(extra[1] ?? -1); writer.s(extra[2] || 0); writer.s(extra[3] || 0); writer.s(extra[4] || 0);
    } else if (ROTATABLE_ITEM_TYPE_IDS.has(typeId)) {
      writer.s(extra[0] || 0); writer.u(extra[1] || 0);
    } else if (SERVING_FOOD_TYPE_IDS.has(typeId)) {
      writer.s(extra[0] || 0); writer.s(extra[1] || 0);
    }
  }
  function readItemExtra(reader, typeId) {
    if (STRUCTURE_TYPE_IDS.has(typeId)) return [reader.s(), reader.s(), reader.s(), reader.s(), reader.u(), reader.s()];
    if (typeId === 0) return [reader.s(), reader.s(), reader.s(), reader.u()];
    if (typeId === 1) return [reader.u(), reader.s(), reader.s()];
    if (typeId === 22) return [reader.str()];
    if (typeId === 6) return [reader.s()];
    if (typeId === 42) return [reader.u(), reader.u()];
    if (JSON_EXTRA_ITEM_TYPE_IDS.has(typeId)) {
      try {
        const parsed = JSON.parse(reader.str() || "[]");
        return (Array.isArray(parsed) || (parsed && typeof parsed === "object")) ? parsed : [];
      } catch (_) {
        return [];
      }
    }
    if (typeId === 21) return [reader.s(), reader.s()];
    if (typeId === 23) return [reader.s(), reader.s()];
    if (typeId === 24) return [reader.s()];
    if (typeId === 25) return [reader.s()];
    if (PIN_TYPE_IDS.has(typeId)) return [reader.u(), reader.s(), reader.s(), reader.s(), reader.s()];
    if (ROTATABLE_ITEM_TYPE_IDS.has(typeId)) return [reader.s(), reader.u()];
    if (SERVING_FOOD_TYPE_IDS.has(typeId)) return [reader.s(), reader.s()];
    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; }
    if (commonItemAmountNeeded(typeId)) writer.s(row[3] || 0);
    writeItemExtra(writer, typeId, 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 = commonItemAmountNeeded(typeId) ? reader.s() : 0;
    const extra = readItemExtra(reader, typeId);
    let restoredAmount = amount;
    if (STRUCTURE_TYPE_IDS.has(typeId)) restoredAmount = extra[0] || 0;
    else if (SERVING_FOOD_TYPE_IDS.has(typeId)) restoredAmount = extra[0] || 0;
    return [typeId, x, y, restoredAmount, 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();
    writer.b(BINARY_SCHEMA_VERSION);
    writer.u(Snapshot.version);
    writeWorld(writer, snapshot.w || []);
    const tarinaiRows = Array.isArray(snapshot.t) ? snapshot.t : [];
    writer.u(tarinaiRows.length);
    const tarCoordState = { x: 0, y: 0 };
    for (const row of tarinaiRows) writeTarinai(writer, row || [], tarCoordState);
    const itemRows = Array.isArray(snapshot.i) ? snapshot.i : [];
    writeItemBlocks(writer, itemRows);
    return writer.out();
  }

  function decodeBinarySnapshot(bytes) {
    const reader = new BinaryReader(bytes);
    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");
    const w = readWorld(reader);
    const tCount = reader.u();
    const t = [];
    const tarCoordState = { x: 0, y: 0 };
    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 };
  }

  async function packBytesForSave(bytes) {
    let codec = RAW_CODEC;
    let packed = bytes;
    try {
      const compressed = await compressBytes(bytes);
      if (compressed.length < bytes.length) { codec = DEFLATE_CODEC; packed = compressed; }
    } catch (error) { console.warn("save compression fallback", error); }
    return { codec, packed };
  }

  async function encodeSnapshot(snapshot) {
    const bytes = encodeBinarySnapshot(snapshot);
    const { codec, packed } = await packBytesForSave(bytes);
    return `${EXPORT_PREFIX}${codec}${jp2048Encode(packed)}`;
  }

  async function decodeSnapshot(text) {
    const raw = String(text || "").trim();
    if (!raw.startsWith(EXPORT_PREFIX)) throw new Error("unsupported Japanese save text");
    const codec = raw.charAt(EXPORT_PREFIX.length) || RAW_CODEC;
    const payload = raw.slice(EXPORT_PREFIX.length + 1);
    const packed = jp2048Decode(payload);
    const bytes = await decompressBytes(packed, codec);
    return decodeBinarySnapshot(bytes);
  }

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