refactor: 使用flutter对原先的web项目重构，正在进行中

tmp/js/save.js

@@ -0,0 +1,59 @@
+// 本地存档：通关记录、最佳成绩、自制关卡
+const KEY = 'iwbtc_fan_v1';
+
+const blank = () => ({ cleared: {}, customs: [], audio: true });
+
+export const Save = {
+  data: blank(),
+
+  load() {
+    try {
+      const s = localStorage.getItem(KEY);
+      if (s) this.data = Object.assign(blank(), JSON.parse(s));
+    } catch (e) { this.data = blank(); }
+    return this.data;
+  },
+  flush() {
+    try { localStorage.setItem(KEY, JSON.stringify(this.data)); } catch (e) { }
+  },
+  get(id) { return this.data.cleared[id] || null; },
+  isCleared(id) { return !!this.data.cleared[id]; },
+  /** 记录通关，返回是否刷新纪录 */
+  clear(id, deaths, ms, apples) {
+    const old = this.data.cleared[id];
+    const rec = { deaths, time: ms, apples: apples || 0, at: Date.now() };
+    let better = false;
+    if (!old) { this.data.cleared[id] = rec; better = true; }
+    else {
+      const nd = Math.min(old.deaths, deaths);
+      const nt = Math.min(old.time, ms);
+      better = deaths < old.deaths || ms < old.time;
+      this.data.cleared[id] = { ...old, deaths: nd, time: nt, apples: Math.max(old.apples || 0, apples || 0) };
+    }
+    this.flush();
+    return better;
+  },
+  wipe() { this.data = blank(); this.flush(); },
+
+  customs() { return this.data.customs || []; },
+  addCustom(lv) {
+    this.data.customs = this.data.customs || [];
+    this.data.customs.push(lv);
+    this.flush();
+    return lv;
+  },
+  /** 更新已保存的自制关卡（按 id 就地替换，不新增）；id 不存在则追加 */
+  updateCustom(lv) {
+    this.data.customs = this.data.customs || [];
+    const i = this.data.customs.findIndex(l => l.id === lv.id);
+    if (i >= 0) this.data.customs[i] = lv;
+    else this.data.customs.push(lv);
+    this.flush();
+    return lv;
+  },
+  removeCustom(id) {
+    this.data.customs = (this.data.customs || []).filter(l => l.id !== id);
+    this.flush();
+  },
+  setAudio(on) { this.data.audio = on; this.flush(); },
+};