# 🧮 pricing_kit
A flexible and extensible Rust library for calculating and managing product pricing, markups, commissions, and currency conversions.
## ✨ Features
- Define a **base (buy) price** and calculate **sell prices** based on:
- Flat amount markups
- Percentage markups
- Commissions in other currencies
- Support for **multi-currency** operations using exchange rates, ensuring **financial precision** with `Decimal` types.
- Support for **adjustments** such as:
- **Tax** calculations with percentage-based rates
- **Discounts** based on percentage
- **Fixed fees** with customizable currencies
- Clean and extensible API design, ready for future enhancements.
---
## ⚡ Quick Start
```rust
use pricing_kit::{Currency, CurrencyConverter, PricingDetail, MarkupType, dec, ToPrimitive};
fn main() {
let usd = Currency::new("USD", "American Dollar");
let idr = Currency::new("IDR", "Indonesian Rupiah");
let mut converter = CurrencyConverter::new();
converter.add_exchange_rate(&usd, dec!(1.0));
converter.add_exchange_rate(&idr, dec!(16500.0));
let mut pricing = PricingDetail::new(dec!(100.0), usd.clone(), idr.clone());
pricing.markup = Some(MarkupType::Amount {
value: dec!(3500),
currency: idr.clone(),
});
pricing.apply_markup(&converter).expect("Failed to apply markup");
println!("Pricing after markup:\n{:#?}", pricing);
// Manual calculation for comparative purpose:
// 1. Buy price: 100.0 USD
// 2. Markup: Amount 3500 IDR → converted to USD = 3500 / 16500 = ~0.21212121 USD
// 3. Converted buy price: 100 + 0.21212121 = ~100.21212121 USD
// 4. Exchange rate USD → IDR = 16500
// 5. Final sell price: 100.21212121 * 16500 = 1_653_500.0 IDR
if let Some(total_f64) = pricing.sell_price.to_f64() {
println!("Total sell price as f64: {}", total_f64);
}
}
```
---
## ⚡ Adjustment Feature Example
```rust
use pricing_kit::{Currency, CurrencyConverter, PricingDetail, MarkupType, dec, PriceAdjustment, ToPrimitive};
fn main() {
let usd = Currency::new("USD", "American Dollar");
let idr = Currency::new("IDR", "Indonesian Rupiah");
let mut converter = CurrencyConverter::new();
converter.add_exchange_rate(&usd, dec!(1.0));
converter.add_exchange_rate(&idr, dec!(16500.0));
let mut pricing = PricingDetail::new(dec!(100.0), usd.clone(), idr.clone());
pricing.markup = Some(MarkupType::Percentage(dec!(20.0)));
pricing.apply_markup(&converter).expect("Failed to apply markup");
let adjustments = vec![
PriceAdjustment::Tax {
name: "Tax 11%".into(),
percentage: dec!(11.0),
},
PriceAdjustment::Discount {
name: "Discount".into(),
percentage: dec!(5.0),
},
PriceAdjustment::Fixed {
name: "Promo New Year".to_string(),
amount: dec!(10.0),
currency: pricing.sell_currency.clone(),
}
];
pricing.apply_adjustments(&adjustments, &converter).expect("Failed to apply adjustments");
println!("Adjustment Pricing:\n{:#?}", pricing);
// Manual calculation for comparative purpose:
// 1. Buy price in USD: 100.0
// 2. Markup 20% -> 100 * 0.2 = 20 USD
// 3. Converted buy price: 100 + 20 = 120 USD
// 4. Sell price in IDR: 120 * 16500 = 1_980_000 IDR
// Adjustments:
// + Tax 11% of 1_980_000 = 217_800 -> 2_197_800
// - Discount 5% of 2_197_800 = 109_890 -> 2_087_910
// + Fixed amount 10 IDR -> final = 2_087_920.0 IDR
if let Some(total_f64) = pricing.sell_price.to_f64() {
println!("Total sell price as f64: {}", total_f64);
}
}
```
---
## 🎯 Crate Goals
This crate is designed to be:
- Easy to use for common e-commerce and fintech pricing scenarios.
- **Accurate**, currency-aware, and reliable in financial calculations through explicit `Decimal` usage.
- Ready for dynamic adjustments such as tax, discount, and fixed fees.
- Extensible for future features like tiered pricing, tax rules, and promotions.
---
## ♻️ Re-exports for Convenience
For ease of use and to ensure robust financial calculations, `pricing_kit` **re-exports** the following types and macros from the `rust_decimal` ecosystem:
- `Decimal` (from the `rust_decimal` crate): Used for all currency amounts and exchange rates to ensure arbitrary precision arithmetic and avoid floating-point inaccuracies.
- `dec!` macro (from the `rust_decimal_macros` crate): A convenient macro for creating `Decimal` literals in your code.
This means you can use `pricing_kit::Decimal` and `pricing_kit::dec!` directly without needing to explicitly import them from their original crates, although you still need to declare `rust_decimal` and `rust_decimal_macros` in your `Cargo.toml`.
```toml
[dependencies]
rust_decimal = "1.37.2"
rust_decimal_macros = "1.37.1"
```
---
## 📖 License
This project is licensed under the Apache-2.0 license. [LICENSE](http://www.apache.org/licenses/LICENSE-2.0.txt)
---
## 🧑 Author
Jerry Maheswara <jerrymaheswara@gmail.com>
---
## ❤️ Built with Love in Rust
This project is built with ❤️ using **Rust** — a systems programming language that is safe, fast, and concurrent. Rust is the perfect choice for building reliable and efficient applications.
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## 👋 Contributing
Pull requests, issues, and feedback are welcome!
If you find this crate useful, give it a ⭐ and share it with others in the Rust community.
---