Initial commit: adding ref-exchange contract

.gitignore

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 # Generated by Cargo
 # will have compiled files and executables
-/target/
+**/target/
 
 # Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
 # More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
 Cargo.lock
 
 # These are backup files generated by rustfmt
 **/*.rs.bk
+
+.idea
+

LICENSE

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+Copyright 2019 Ref Finance
+
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+
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+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.

LICENSE-APACHE

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README.md

@@ -1,2 +1,46 @@
-# ref-contracts
-Smart contracts for Ref Finance
+# Ref Finance Contracts
+
+This mono repo contains the source code for the smart contracts of Ref Finance on [NEAR](https://near.org).
+
+## Contracts
+
+| Contract | Reference | Description |
+| - | - | - |
+| [test-token](test-token/src/lib) | - | Test token contract |
+| [ref-exchange](ref-exchange/src/lib) | TODO | Main exchange contract, that allows to deposit and withdraw tokens, exchange them via various pools |
+
+## Development
+
+1. Install `rustup` via https://rustup.rs/
+2. Run the following:
+
+```
+rustup default stable
+rustup target add wasm32-unknown-unknown
+```
+
+### Testing
+
+Contracts have unit tests and also integration tests using NEAR Simulation framework. All together can be run:
+
+```
+cargo test --all
+```
+
+### Compiling
+
+You can build release version by running next scripts inside each contract folder:
+
+```
+./build.sh
+```
+
+### Deploying to TestNet
+
+To deploy to TestNet, you can use next command:
+```
+near dev-deploy
+```
+
+This will output on the contract ID it deployed it.
+

docs.md

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+# Ref Finance
+
+[Ref Finance](https://ref.finance) is the protocol for creating synthetic tokenized assets on NEAR blockchain.
+
+It uses NEAR as collateral and allows to mint any token that has a whitelisted price feed, for example: rUSD, rBTC, rTESLA, rSPBEAR (short S&P500) or rOIL.
+
+The protocol will be governed by an instance of SputnikDAO.
+
+## Approach
+
+There are two main approaches to create synthetic assets:
+- Collateralized Debt Position, where the position is over collateralized and serves to borrow the synthetic asset
+- A fractional reserve approach, selling tokens above the peg value and allowing to trade in below with various incentives.
+
+Ref Finance is taking an approach of fractional reserve that is used to provide liquidity instead of just sitting as collateral, while allowing people to use other lending protocols for CDP-like experience.
+
+*This design leverages Fei Protocol's stabilization mechanics extended to multiple assets.*
+
+Ref Finance maintains internal pools of <collateral, synthetic asset> for each asset. These assets provide liquidity in the form of Uniswap exchange.
+
+Additionally new assets are minted with price above `x%` (configurable parameter) the oracle price. This allows to expand the supply when there is demand.
+
+If the price is below the pool price:
+- For anyone who is buying under the price, additional tokens are minted to reward them based on time-weighted difference with the market price `r * num_blocks * (target_price - current_price) * amount`.
+- If someone is selling more below the oracle price - the slippage increases and extra tokens `(target_price - end_price) ^ 2 * 100 * amount` are burnt.
+
+If that didn't help to bring the price, the pool can be reweighted by burning the extra Ref tokens to bring price to the target price. Condition for reweight to happen if `num_blocks = (target_price - current_price) * 100 / r`.
+
+There is a central contract "Controller" that provides all operations including minting and exchange functionality.
+
+Next functions are available on `Controller`:
+- `add_asset(asset_name, oracle_feed, config)` - adds new assets to available with given oracle feed. Only allowed by `owner`.
+- `set_asset_config(asset_name, config)` - sets config including all the trading parameters for given asset. Only allowed by `owner`.
+- `buy(asset_name, amount_out)` - buy given `amount_out` of `asset_name`, must attach enough $NEAR to cover the trade. This will first buy from the Uniswap formula (rewarding with new minted tokens if the price of liquidity below oracle price) and if the amount brings price above current bonding curve - will buy from bonding curve expanding the supply.
+- `sell(asset_name, amount_in, amount_out)` - (works as callback from `asset_name`) sell `amount_in` of given `asset_name` and expecting at least `amount_out` of $N. This uses Uniswap curve and uses quadratic penalty to disinsentivize large sell orders. Penalty is getting burnt.
+- `trade(asset_name_in, amount_in, asset_name_in, amount_out)` - (works as callback from `asset_name_in`) trade two assets between each other. Uses internal calculations to exchange them to save on the fees.
+- `reweight(asset_name)` - if the internal exchange rate is way below the oracle price for given `asset_name` and ??? - allows to reweight the Uniswap pool to bring it back to the pool.
+- `stage_upgrade(contract)` - Stage upgrade for this contract. Only allowed by `owner`.
+- `upgrade()` - Upgrade to staged contract. Only allowed by `owner`.
+
+Each Ref Token will have it's own contract living under sub-name of the Controller contract. These token contracts provide `owner` ability for Controller to mint / burn assets .
+
+Future features:
+- Allowing to add external capital as LP to the exchange.
+
+# References
+
+- MarkerDAO - https://makerdao.com/whitepaper/
+- Synthetix - https://synthetix.io/
+- Mirror Protocol - https://mirror.finance/
+- Fei Protocol - https://fei.money/static/media/whitepaper.7d5e2986.pdf

ref-exchange/Cargo.toml

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+[package]
+name = "ref-exchange"
+version = "0.1.0"
+authors = ["Illia Polosukhin <[email protected]>"]
+edition = "2018"
+publish = false
+
+[lib]
+crate-type = ["cdylib", "rlib"]
+
+[profile.release]
+codegen-units = 1
+# Tell `rustc` to optimize for small code size.
+opt-level = "z"
+lto = true
+debug = false
+panic = "abort"
+overflow-checks = true
+
+[dependencies]
+near-sdk = { git = "https://github.com/near/near-sdk-rs", rev = "76c4180dc68f01ab5527faa0dd9c6985d900060c" }
+near-contract-standards = { git = "https://github.com/near/near-sdk-rs", rev = "76c4180dc68f01ab5527faa0dd9c6985d900060c" }
+uint = { version = "0.9.0", default-features = false }
+
+[dev-dependencies]
+near-sdk-sim = { git = "https://github.com/near/near-sdk-rs", rev = "76c4180dc68f01ab5527faa0dd9c6985d900060c" }
+test-token = { path = "../test-token" }

ref-exchange/README.md

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+# Multiswap
+
+This is a contract that contains many token swap pools.
+Each pool can have up to 10 tokens and it's own fee %.
+
+## Usage
+
+- deposit funds / withdraw funds of the contract's virtual balance. User can maintain up to 10 distinct tokens on their balance.
+- create a pool with specific set of tokens and a fee, get `pool_id`
+- add liquidity to specific pool from the funds deposited
+- remove liquidity from specific pool back into deposited funds on the contract
+- with funds in the pool, call swap to trade 

ref-exchange/build.sh

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+#!/bin/bash
+set -e
+
+RUSTFLAGS='-C link-arg=-s' cargo +stable build --target wasm32-unknown-unknown --release
+cp target/wasm32-unknown-unknown/release/ref_exchange.wasm ../res/

ref-exchange/neardev/dev-account

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+dev-1614947681178-6795333

ref-exchange/neardev/dev-account.env

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+CONTRACT_NAME=dev-1614947681178-6795333