"use strict";

(function (global) {
  const STORAGE_PREFIX = "tarinai_save_slot_v2_";
  const EXPORT_PREFIX = "TN2!";
  const SLOT_COUNT = 9;
  const Snapshot = global.TarinaiSnapshot;
  if (!Snapshot) throw new Error("TarinaiSnapshot is not available for save_system.js");
  const createSnapshot = (...args) => Snapshot.createSnapshot(...args);
  const restoreSnapshot = (...args) => Snapshot.restoreSnapshot(...args);

  const SAVE_TEXT_ALPHABET = (() => {
    let out = "";
    for (let i = 33; i <= 126; i++) {
      const ch = String.fromCharCode(i);
      if (ch === "*" || ch === "'" || ch === "_") continue;
      out += ch;
    }
    return out;
  })();
  const SAVE_TEXT_REVERSE = (() => {
    const map = new Map();
    for (let i = 0; i < SAVE_TEXT_ALPHABET.length; i++) map.set(SAVE_TEXT_ALPHABET[i], i);
    return map;
  })();
  if (SAVE_TEXT_ALPHABET.length !== 91) throw new Error("save alphabet must contain 91 printable ASCII chars");

  function base91Encode(bytes) {
    let b = 0;
    let n = 0;
    let out = "";
    for (const byte of bytes || []) {
      b |= (byte & 255) << n;
      n += 8;
      if (n > 13) {
        let v = b & 8191;
        if (v > 88) {
          b >>= 13;
          n -= 13;
        } else {
          v = b & 16383;
          b >>= 14;
          n -= 14;
        }
        out += SAVE_TEXT_ALPHABET[v % 91] + SAVE_TEXT_ALPHABET[Math.floor(v / 91)];
      }
    }
    if (n) {
      out += SAVE_TEXT_ALPHABET[b % 91];
      if (n > 7 || b > 90) out += SAVE_TEXT_ALPHABET[Math.floor(b / 91)];
    }
    return out;
  }

  function base91Decode(text) {
    const clean = String(text || "").trim();
    let v = -1;
    let b = 0;
    let n = 0;
    const out = [];
    for (const ch of clean) {
      const c = SAVE_TEXT_REVERSE.get(ch);
      if (c == null) continue;
      if (v < 0) {
        v = c;
      } else {
        v += c * 91;
        b |= v << n;
        n += (v & 8191) > 88 ? 13 : 14;
        do {
          out.push(b & 255);
          b >>= 8;
          n -= 8;
        } while (n > 7);
        v = -1;
      }
    }
    if (v >= 0) out.push((b | (v << n)) & 255);
    return new Uint8Array(out);
  }

  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 = "R") {
    if (codec === "D") {
      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());
    }
    return bytes;
  }

  async function encodeSnapshot(snapshot) {
    const compact = snapshot && snapshot.v === 2 ? snapshot : createSnapshot(global.world);
    const json = JSON.stringify(compact);
    const bytes = new TextEncoder().encode(json);
    let codec = "R";
    let packed = bytes;
    try {
      const compressed = await compressBytes(bytes);
      if (compressed.length < bytes.length) {
        codec = "D";
        packed = compressed;
      }
    } catch (error) {
      console.warn("save compression fallback", error);
    }
    return `${EXPORT_PREFIX}${codec}${base91Encode(packed)}`;
  }

  async function decodeSnapshot(text) {
    const raw = String(text || "").trim();
    if (!raw) throw new Error("empty import text");
    if (raw.startsWith("{") || raw.startsWith("[")) {
      const data = JSON.parse(raw);
      if (data?.v !== 2) throw new Error("unsupported save version");
      return data;
    }
    if (!raw.startsWith(EXPORT_PREFIX)) throw new Error("unsupported save text");
    const codec = raw.charAt(EXPORT_PREFIX.length) || "R";
    const payload = raw.slice(EXPORT_PREFIX.length + 1);
    const packed = base91Decode(payload);
    const bytes = await decompressBytes(packed, codec);
    const json = new TextDecoder().decode(bytes);
    const data = JSON.parse(json);
    if (data?.v !== 2) throw new Error("unsupported save version");
    return data;
  }

  function slotKey(slot) { return `${STORAGE_PREFIX}${slot}`; }

  async function saveSlot(slot) {
    const snapshot = createSnapshot(global.world);
    localStorage.setItem(slotKey(slot), JSON.stringify(snapshot));
    return snapshot;
  }

  async function loadSlot(slot) {
    const raw = localStorage.getItem(slotKey(slot));
    if (!raw) throw new Error("empty slot");
    const snapshot = JSON.parse(raw);
    if (snapshot?.v !== 2) throw new Error("unsupported slot version");
    return restoreSnapshot(snapshot, global.world);
  }

  function deleteSlot(slot) { localStorage.removeItem(slotKey(slot)); }

  function readSlot(slot) {
    const raw = localStorage.getItem(slotKey(slot));
    if (!raw) return null;
    try { return JSON.parse(raw); } catch (_) { return null; }
  }

  const htmlEscape = global.TarinaiUIHelpers.htmlEscape;


  function formatSlotSummary(snapshot) {
    if (!snapshot) return "\u7a7a\u304d";
    const m = snapshot.m || [];
    const date = snapshot.c ? new Date(snapshot.c).toLocaleString("ja-JP", { month: "2-digit", day: "2-digit", hour: "2-digit", minute: "2-digit" }) : "\u65e5\u6642\u4e0d\u660e";
    const day = m[0] || 1;
    const population = m[1] || 0;
    const fieldType = m[2] || "\u5ead";
    const timeText = Number.isFinite(m[3]) ? `${Math.floor((m[3] / 10) % 24).toString().padStart(2, "0")}:00` : "";
    return `${date} / ${fieldType} / ${day}\u65e5\u76ee ${timeText} / ${population}\u5339`;
  }

  function ensureDialog() {
    let dialog = document.getElementById("saveDialog");
    if (dialog) return dialog;
    dialog = document.createElement("div");
    dialog.id = "saveDialog";
    dialog.className = "field-dialog hidden";
    dialog.setAttribute("role", "dialog");
    dialog.setAttribute("aria-modal", "true");
    dialog.innerHTML = `
      <div class="field-dialog-panel save-dialog-panel">
        <h2 id="saveDialogTitle">\u30bb\u30fc\u30d6 / \u30ed\u30fc\u30c9</h2>
        <p class="hint save-warning">\u30bb\u30fc\u30d6\u6a5f\u80fd\u306f\u5b9f\u9a13\u4e2d\u3067\u3042\u308a\u3001\u4fdd\u8a3c\u5bfe\u8c61\u5916\u3067\u3059\u3002</p>
        <p class="hint">9\u3064\u306e\u30b9\u30ed\u30c3\u30c8\u306b\u73fe\u5728\u306e\u30b3\u30ed\u30cb\u30fc\u3092\u4fdd\u5b58\u3067\u304d\u307e\u3059\u3002\u30cf\u30c3\u30b7\u30e5\u30c6\u30ad\u30b9\u30c8\u306f\u5225\u7aef\u672b\u3084\u5225\u30d6\u30e9\u30a6\u30b6\u3078\u306e\u79fb\u52d5\u306b\u4f7f\u3048\u307e\u3059\u3002</p>
        <div id="saveSlotList" class="save-slot-list"></div>
        <div class="save-export-panel">
          <div class="save-export-actions">
            <button id="saveExportBtn" class="btn" type="button">\u73fe\u5728\u306e\u72b6\u614b\u3092\u66f8\u304d\u51fa\u3057</button>
            <button id="saveImportBtn" class="btn primary" type="button">\u30cf\u30c3\u30b7\u30e5\u30c6\u30ad\u30b9\u30c8\u3092\u8aad\u307f\u8fbc\u307f</button>
          </div>
          <textarea id="saveHashText" class="save-hash-text" spellcheck="false" placeholder="\u3053\u3053\u306b\u30cf\u30c3\u30b7\u30e5\u30c6\u30ad\u30b9\u30c8\u304c\u8868\u793a\u3055\u308c\u307e\u3059\u3002\u8aad\u307f\u8fbc\u3080\u5834\u5408\u306f\u3053\u3053\u306b\u8cbc\u308a\u4ed8\u3051\u3066\u304f\u3060\u3055\u3044\u3002"></textarea>
        </div>
        <div class="field-dialog-actions">
          <button id="saveCloseBtn" class="btn" type="button">\u9589\u3058\u308b</button>
        </div>
      </div>`;
    document.body.appendChild(dialog);
    return dialog;
  }

  function renderSlotList() {
    const dialog = ensureDialog();
    const list = dialog.querySelector("#saveSlotList");
    if (!list) return;
    list.innerHTML = "";
    for (let i = 1; i <= SLOT_COUNT; i++) {
      const snapshot = readSlot(i);
      const row = document.createElement("div");
      row.className = "save-slot-row";
      row.innerHTML = `
        <div class="save-slot-title">\u30b9\u30ed\u30c3\u30c8 ${i}</div>
        <div class="save-slot-meta">${htmlEscape(formatSlotSummary(snapshot))}</div>
        <div class="save-slot-actions">
          <button class="btn mini" data-save-slot="${i}" type="button">\u4fdd\u5b58</button>
          <button class="btn mini" data-load-slot="${i}" type="button" ${snapshot ? "" : "disabled"}>\u8aad\u8fbc</button>
          <button class="btn mini danger" data-delete-slot="${i}" type="button" ${snapshot ? "" : "disabled"}>\u524a\u9664</button>
        </div>`;
      list.appendChild(row);
    }
  }

  function openDialog() {
    const dialog = ensureDialog();
    renderSlotList();
    dialog.classList.remove("hidden");
  }

  function closeDialog() {
    document.getElementById("saveDialog")?.classList.add("hidden");
  }

  function bindSaveSystem() {
    const btn = document.getElementById("saveBtn") || global.ui?.saveBtn;
    if (!btn || btn.dataset.saveBound === "1") return;
    btn.dataset.saveBound = "1";
    btn.addEventListener("click", () => {
      global.audio?.uiClick?.();
      openDialog();
    });
    const dialog = ensureDialog();
    dialog.addEventListener("click", async (e) => {
      if (e.target === dialog) { closeDialog(); return; }
      const saveBtn = e.target.closest("[data-save-slot]");
      const loadBtn = e.target.closest("[data-load-slot]");
      const deleteBtn = e.target.closest("[data-delete-slot]");
      if (saveBtn) {
        const slot = Number(saveBtn.dataset.saveSlot);
        try {
          await saveSlot(slot);
          renderSlotList();
          global.audio?.notify?.();
          global.showToast?.(`\u30b9\u30ed\u30c3\u30c8${slot}\u306b\u4fdd\u5b58\u3057\u307e\u3057\u305f\u3002`);
        } catch (error) {
          console.warn(error);
          global.showToast?.("\u4fdd\u5b58\u306b\u5931\u6557\u3057\u307e\u3057\u305f\u3002\u7a7a\u304d\u5bb9\u91cf\u3092\u78ba\u8a8d\u3057\u3066\u304f\u3060\u3055\u3044\u3002");
        }
        return;
      }
      if (loadBtn) {
        const slot = Number(loadBtn.dataset.loadSlot);
        if (!global.confirm?.(`\u30b9\u30ed\u30c3\u30c8${slot}\u3092\u8aad\u307f\u8fbc\u307f\u307e\u3059\u3002\u73fe\u5728\u306e\u72b6\u614b\u306f\u4e0a\u66f8\u304d\u3055\u308c\u307e\u3059\u3002`)) return;
        try {
          await loadSlot(slot);
          closeDialog();
          global.audio?.notify?.();
          global.showToast?.(`\u30b9\u30ed\u30c3\u30c8${slot}\u3092\u8aad\u307f\u8fbc\u307f\u307e\u3057\u305f\u3002`);
        } catch (error) {
          console.warn(error);
          global.showToast?.("\u8aad\u307f\u8fbc\u307f\u306b\u5931\u6557\u3057\u307e\u3057\u305f\u3002");
        }
        return;
      }
      if (deleteBtn) {
        const slot = Number(deleteBtn.dataset.deleteSlot);
        if (!global.confirm?.(`\u30b9\u30ed\u30c3\u30c8${slot}\u3092\u524a\u9664\u3057\u307e\u3059\u304b\uff1f`)) return;
        deleteSlot(slot);
        renderSlotList();
        global.audio?.delete?.();
        global.showToast?.(`\u30b9\u30ed\u30c3\u30c8${slot}\u3092\u524a\u9664\u3057\u307e\u3057\u305f\u3002`);
        return;
      }
      if (e.target.closest("#saveCloseBtn")) closeDialog();
      if (e.target.closest("#saveExportBtn")) {
        const area = dialog.querySelector("#saveHashText");
        if (area) {
          area.value = await encodeSnapshot(createSnapshot(global.world));
          area.focus();
          area.select();
        }
        global.showToast?.("\u73fe\u5728\u306e\u72b6\u614b\u3092\u30cf\u30c3\u30b7\u30e5\u30c6\u30ad\u30b9\u30c8\u306b\u66f8\u304d\u51fa\u3057\u307e\u3057\u305f\u3002");
      }
      if (e.target.closest("#saveImportBtn")) {
        const area = dialog.querySelector("#saveHashText");
        const text = area?.value || "";
        if (!text.trim()) { global.showToast?.("\u8aad\u307f\u8fbc\u3080\u30cf\u30c3\u30b7\u30e5\u30c6\u30ad\u30b9\u30c8\u3092\u8cbc\u308a\u4ed8\u3051\u3066\u304f\u3060\u3055\u3044\u3002"); return; }
        if (!global.confirm?.("\u30cf\u30c3\u30b7\u30e5\u30c6\u30ad\u30b9\u30c8\u3092\u8aad\u307f\u8fbc\u307f\u307e\u3059\u3002\u73fe\u5728\u306e\u72b6\u614b\u306f\u4e0a\u66f8\u304d\u3055\u308c\u307e\u3059\u3002")) return;
        try {
          restoreSnapshot(await decodeSnapshot(text), global.world);
          closeDialog();
          global.showToast?.("\u30cf\u30c3\u30b7\u30e5\u30c6\u30ad\u30b9\u30c8\u304b\u3089\u8aad\u307f\u8fbc\u307f\u307e\u3057\u305f\u3002");
        } catch (error) {
          console.warn(error);
          global.showToast?.("\u8aad\u307f\u8fbc\u307f\u306b\u5931\u6557\u3057\u307e\u3057\u305f\u3002\u30c6\u30ad\u30b9\u30c8\u3092\u78ba\u8a8d\u3057\u3066\u304f\u3060\u3055\u3044\u3002");
        }
      }
    });
  }

  global.TarinaiSaveSystem = {
    createSnapshot,
    restoreSnapshot,
    encodeSnapshot,
    decodeSnapshot,
    saveSlot,
    loadSlot,
    deleteSlot,
    readSlot,
    bindSaveSystem,
    openDialog,
  };
})(typeof window !== "undefined" ? window : globalThis);