options-pricer/frontend/assets/strategy-store.js

/**
 * Strategy basket persistence — localStorage-backed, multi-symbol.
 * Exposed as window.StrategyStore. No modules, no deps.
 *
 * Stored shape (key "optionsPricer:strategy", v2):
 * {
 *   v: 2,
 *   active: "SPY",                     // currently-shown symbol
 *   updatedAt: "2026-05-13T...Z",
 *   baskets: {
 *     "SPY":  { spotSnapshot: 738.18, legs: [ ...legs ] },
 *     "AAPL": { spotSnapshot: 0,      legs: [ ...legs ] }
 *   }
 * }
 * leg = { id, symbol, expiry:"YYYY-MM-DD", type:"call"|"put", strike, side:"long"|"short",
 *         qty, entryPrice, iv, locked:bool, currentMark:number|null }
 *
 * `load()` returns the *active* basket in a flat back-compat shape, plus a
 * `symbols` array of all symbols that currently have legs.
 */
(function () {
  "use strict";

  const KEY = "optionsPricer:strategy";
  const VERSION = 2;
  const MULTIPLIER = 100; // standard equity option contract size

  /** Round a price to 2 decimals (kills float artifacts like 15.000000001). */
  function round2(v) {
    const n = Number(v);
    return Number.isFinite(n) ? Math.round(n * 100) / 100 : 0;
  }

  function emptyDoc() { return { v: VERSION, active: "", updatedAt: null, baskets: {} }; }

  function sanitizeLegs(legs) {
    if (!Array.isArray(legs)) return [];
    return legs
      .filter((l) => l && Number.isFinite(Number(l.strike)) && (l.type === "call" || l.type === "put"))
      .map((l) => ({
        ...l,
        strike: round2(l.strike),
        entryPrice: round2(l.entryPrice),
        currentMark: typeof l.currentMark === "number" ? round2(l.currentMark) : (l.currentMark ?? null),
        locked: l.locked === true,
      }));
  }

  function loadDoc() {
    try {
      const raw = localStorage.getItem(KEY);
      if (!raw) return emptyDoc();
      const obj = JSON.parse(raw);
      if (!obj || typeof obj !== "object") return emptyDoc();

      // migrate v1 (single basket) -> v2
      if (obj.v === 1 && Array.isArray(obj.legs)) {
        const doc = emptyDoc();
        const sym = obj.symbol || "";
        const legs = sanitizeLegs(obj.legs);
        if (sym && legs.length) {
          doc.baskets[sym] = { spotSnapshot: Number(obj.spotSnapshot) || 0, legs };
          doc.active = sym;
        }
        return doc;
      }

      if (obj.v !== VERSION || !obj.baskets || typeof obj.baskets !== "object") return emptyDoc();

      const doc = emptyDoc();
      for (const sym of Object.keys(obj.baskets)) {
        const b = obj.baskets[sym] || {};
        const legs = sanitizeLegs(b.legs);
        if (legs.length) doc.baskets[sym] = { spotSnapshot: Number(b.spotSnapshot) || 0, legs };
      }
      doc.active = obj.active && doc.baskets[obj.active] ? obj.active : (Object.keys(doc.baskets)[0] || "");
      doc.updatedAt = obj.updatedAt || null;
      return doc;
    } catch {
      return emptyDoc();
    }
  }

  function saveDoc(doc) {
    doc.v = VERSION;
    // drop empty baskets
    for (const sym of Object.keys(doc.baskets)) {
      const b = doc.baskets[sym];
      if (!b || !Array.isArray(b.legs) || b.legs.length === 0) delete doc.baskets[sym];
    }
    if (!doc.baskets[doc.active]) doc.active = Object.keys(doc.baskets)[0] || "";
    doc.updatedAt = new Date().toISOString();
    try { localStorage.setItem(KEY, JSON.stringify(doc)); }
    catch (e) { console.warn("[StrategyStore] save failed:", e); }
  }

  // ---- active-basket view (flat, back-compat) -----------------------------
  function load() {
    const doc = loadDoc();
    const sym = doc.active;
    const b = (sym && doc.baskets[sym]) || { spotSnapshot: 0, legs: [] };
    return {
      v: VERSION,
      symbol: sym || "",
      spotSnapshot: b.spotSnapshot || 0,
      updatedAt: doc.updatedAt,
      legs: (b.legs || []).map((l) => ({ ...l })),
      symbols: Object.keys(doc.baskets),
    };
  }

  /** Write a flat {symbol, spotSnapshot, legs} state back into that symbol's basket. */
  function save(state) {
    const doc = loadDoc();
    const sym = state && state.symbol;
    if (sym) {
      const legs = sanitizeLegs(state.legs);
      if (legs.length) {
        doc.baskets[sym] = { spotSnapshot: Number(state.spotSnapshot) || 0, legs };
        doc.active = sym;
      } else {
        delete doc.baskets[sym];
        if (doc.active === sym) doc.active = Object.keys(doc.baskets)[0] || "";
      }
    }
    saveDoc(doc);
    return load();
  }

  /** Clear the ACTIVE basket only. */
  function clear() {
    const doc = loadDoc();
    if (doc.active) {
      delete doc.baskets[doc.active];
      doc.active = Object.keys(doc.baskets)[0] || "";
    }
    saveDoc(doc);
    return load();
  }

  /** Wipe every basket. */
  function clearAll() {
    try { localStorage.removeItem(KEY); } catch {}
    return load();
  }

  function listSymbols() { return Object.keys(loadDoc().baskets); }

  function setActive(symbol) {
    const doc = loadDoc();
    if (!symbol) return load();
    if (!doc.baskets[symbol]) doc.baskets[symbol] = { spotSnapshot: 0, legs: [] };
    doc.active = symbol;
    saveDoc(doc);
    return load();
  }

  function addLeg(leg) {
    const strike = Number(leg && leg.strike);
    if (!Number.isFinite(strike) || strike <= 0) {
      console.warn("[StrategyStore] addLeg: invalid strike", leg);
      return { state: load() };
    }
    const doc = loadDoc();
    const sym = leg.symbol || doc.active || "MANUAL";
    if (!doc.baskets[sym]) doc.baskets[sym] = { spotSnapshot: 0, legs: [] };
    if (typeof leg.spotSnapshot === "number" && leg.spotSnapshot > 0) {
      doc.baskets[sym].spotSnapshot = leg.spotSnapshot;
    }
    doc.baskets[sym].legs.push({
      id: (typeof crypto !== "undefined" && crypto.randomUUID) ? crypto.randomUUID() : "id-" + Date.now() + "-" + Math.random().toString(36).slice(2),
      symbol: sym,
      expiry: leg.expiry,
      type: leg.type,
      strike: round2(strike),
      side: leg.side === "short" ? "short" : "long",
      qty: Math.max(1, Math.round(Number(leg.qty) || 1)),
      entryPrice: round2(leg.entryPrice),
      iv: Number(leg.iv) || 0,
      locked: leg.locked === true,
      currentMark: typeof leg.currentMark === "number" ? round2(leg.currentMark) : null,
    });
    doc.active = sym;
    saveDoc(doc);
    return { state: load() };
  }

  function basketOf(doc, id) {
    for (const sym of Object.keys(doc.baskets)) {
      if (doc.baskets[sym].legs.some((l) => l.id === id)) return sym;
    }
    return null;
  }

  function removeLeg(id) {
    const doc = loadDoc();
    const sym = basketOf(doc, id);
    if (sym) {
      doc.baskets[sym].legs = doc.baskets[sym].legs.filter((l) => l.id !== id);
      if (doc.baskets[sym].legs.length === 0) {
        delete doc.baskets[sym];
        if (doc.active === sym) doc.active = Object.keys(doc.baskets)[0] || "";
      }
    }
    saveDoc(doc);
    return load();
  }

  function updateLeg(id, patch) {
    const doc = loadDoc();
    const sym = basketOf(doc, id);
    if (sym) {
      const leg = doc.baskets[sym].legs.find((l) => l.id === id);
      if (leg) {
        const p = { ...patch };
        if ("entryPrice" in p) p.entryPrice = round2(p.entryPrice);
        if ("currentMark" in p && p.currentMark != null) p.currentMark = round2(p.currentMark);
        if ("strike" in p) p.strike = round2(p.strike);
        Object.assign(leg, p);
      }
    }
    saveDoc(doc);
    return load();
  }

  /** multi-basket: adding a different symbol no longer wipes anything. */
  function mismatch() { return null; }

  /** legs in the active basket. */
  function count() {
    const doc = loadDoc();
    const b = doc.baskets[doc.active];
    return b ? b.legs.length : 0;
  }

  window.StrategyStore = {
    KEY, VERSION, MULTIPLIER,
    empty: () => ({ v: VERSION, symbol: "", spotSnapshot: 0, updatedAt: null, legs: [], symbols: [] }),
    load, save, clear, clearAll, addLeg, removeLeg, updateLeg, mismatch, count, listSymbols, setActive,
  };
})();