# flower-farm-math 🌷

**The open-source math behind [Stemwise](https://getstemwise.com).** Three pure,
zero-dependency functions for the numbers a small flower farm or farmer-florist
runs by hand every week:

- **`weddingStems()`** — turn an arrangement list into a real stem count, with a buy-in buffer and a focal/filler/greenery recipe split.
- **`csaPricing()`** — costs-up pricing for a bouquet CSA: per-bouquet cost, the price at your target margin, full-season member price, season P&L, and a margin comparison.
- **`reconcile()`** — the bloom→sales bridge: compare the stems you'll **cut** against the stems you've **promised**, by variety, and get the shortfall to **buy in** and the surplus to **push to market**.

No dependencies. Works in Node and the browser. MIT licensed.

**▶️ [Try the live demo + docs →](https://saschaheyer.github.io/flower-farm-math/)** — run all three functions in your browser, no install.

> This is the same client-side math our free tools run in the browser — extracted,
> tested, and documented so other growers (and the people who build tools for them)
> can use it. The hosted product — accounts, bloom plans, CSA management, and the
> live weekly reconcile across your whole season — lives at **[getstemwise.com](https://getstemwise.com)**.

## Install

```bash
npm install flower-farm-math
```

Or use the CLI without installing:

```bash
npx flower-farm-math wedding examples/wedding.json
```

## Why this exists

Every flower-farm tool sits on one side of a gap. **Growing-side** tools (crop
planners) know your beds but not who you've sold to. **Selling-side** tools
(florist proposal software) assume you *buy* every stem wholesale and have no
idea what's blooming in your field. Nobody bridges the two — so the farmer-florist
does it by hand every Sunday night across three spreadsheets:

> *"Did I overcommit my dahlias this week? What do I have to buy in? What surplus
> can I dump at market?"*

`reconcile()` is that Sunday-night math as a pure function. The rest of this
package is the supporting arithmetic (wedding stem counts, CSA pricing) that the
free [Stemwise tools](https://getstemwise.com) are built on.

## Usage

### Wedding stem count

```js
import { weddingStems } from 'flower-farm-math';

const r = weddingStems([
  { type: 'bridal-bouquet', qty: 1 },
  { type: 'bridesmaid-bouquet', qty: 4 },
  { type: 'boutonniere', qty: 6 },
  { type: 'corsage', qty: 2 },
  { type: 'low-centerpiece', qty: 10 },
  { type: 'ceremony-arch', qty: 1 },
  { type: 'cake-flowers', qty: 1 },
]);

console.log(r.total);    // 671  (before buffer)
console.log(r.buffered); // 752  (with a 12% buy-in buffer)
console.log(r.roles);    // { focal: 226, secondary: 188, filler: 150, greenery: 188 }
```

Pass `{ stems }` on any row to override the default, or `{ buffer, roleSplit }`
as a second argument. Known arrangement types and their florist-standard stem
counts are in [`src/arrangements.js`](src/arrangements.js).

### CSA pricing

```js
import { csaPricing } from 'flower-farm-math';

const r = csaPricing({ shares: 30, weeks: 16, stems: 20, costPerStem: 0.35, margin: 50 });

console.log(r.unitCost);     // 9.6   ($/bouquet: flowers + packaging + labor)
console.log(r.pricePerWeek); // 19.2  (price that yields a 50% margin)
console.log(r.seasonPrice);  // 307.2 (what a member pays for the season)
console.log(r.totalProfit);  // 4608  (across 30 shares × 16 weeks)
console.log(r.tiers);        // 40 / 50 / 60% margin comparison
```

### Weekly reconciliation (the bloom→sales bridge)

```js
import { reconcile } from 'flower-farm-math';

const r = reconcile({
  availability: [                                  // what you'll cut this week
    { name: 'Dahlia', variety: 'Café au Lait', stems: 120 },
    { name: 'Zinnia', variety: 'Benary Giant', stems: 200 },
  ],
  demand: [                                        // what you've already promised
    { name: 'Dahlia', variety: 'Café au Lait', stems: 180 },
  ],
  csa: { shares: 12, stemsPerShare: 20 },          // bouquets built from leftover surplus
});

console.log(r.shortfalls);     // [{ name: 'Dahlia', variety: 'Café au Lait', buyIn: 60, ... }]
console.log(r.surplusPool);    // 200
console.log(r.marketLeftover); // ...stems left after the CSA is built
```

## CLI

```text
$ npx flower-farm-math csa examples/csa.json
Per-bouquet cost: $9.60 (flowers $7.00 + pack $0.60 + labor $2.00)
Price / week @ 50% margin: $19.20  (profit $9.60)
Full-season member price: $307.20  (16 weeks)
Season gross: $9,216   Season profit: $4,608  (30 shares)
Margin comparison:
  40% → $16.00/wk · $256/season · $3,072 profit
  50% → $19.20/wk · $307/season · $4,608 profit
  60% → $24.00/wk · $384/season · $6,912 profit

$ npx flower-farm-math reconcile examples/reconcile.json
BUY IN — short 60 stems across 1 variety:
  −60  Dahlia / Café au Lait
Surplus pool: 250 stems
CSA: 12 shares need 240 stems → covered, 10 stems left for market
```

Commands: `wedding`, `csa`, `reconcile`, `types`. Each reads JSON from a file or
stdin. Examples are in [`examples/`](examples).

## API

| Function | Input | Returns |
|---|---|---|
| `weddingStems(pieces, opts?)` | arrangement rows (`type` or custom `stems`, `qty`) | `{ total, buffered, roles, lines, arrangements }` |
| `csaPricing(input?)` | `{ shares, weeks, stems, costPerStem, packaging, laborMinutes, laborRate, margin }` | `{ unitCost, pricePerWeek, seasonPrice, grossRevenue, totalProfit, tiers, ... }` |
| `reconcile({ availability, demand, csa })` | stems by variety on each side | `{ shortfalls, surpluses, surplusPool, marketLeftover, csaShort, rows }` |
| `priceAtMargin(cost, marginPct)` | a cost and a target margin | the price that yields that margin |
| `ARRANGEMENTS` | — | reference table of stem counts per arrangement type |

## The hosted app

`flower-farm-math` gives you the formulas. **[Stemwise](https://getstemwise.com)**
gives you the whole workflow: a season-long bloom plan, weddings & market &
wholesale & CSA in one place, and the **weekly reconciliation running live across
all of it** — so the buy-in list and the market surplus write themselves.

- 🌐 **App & free tools:** https://getstemwise.com
- 🧮 **Wedding Flower Calculator** (free): https://getstemwise.com/tools/wedding-flower-calculator.html
- 🌸 **CSA Pricing Calculator** (free): https://getstemwise.com/tools/csa-pricing-calculator.html
- ▶️ **Live demo** (no signup): https://getstemwise.com/app.html

## Tests

```bash
npm test   # node --test — 9 passing
```

## License

MIT © 2026 Stemwise (Wren Calloway). Use it, fork it, build on it.