# Writing Rust Smart Contracts on NEAR

## Building Your lib.rs

### Importing Common NEAR Crates

// To conserve gas, efficient serialization is achieved through Borsh (http://borsh.io/)
use near_sdk::borsh::{self, BorshDeserialize, BorshSerialize}; 
use near_sdk::{env, near_bindgen, setup_alloc};
use near_sdk::collections::LookupMap;

// Boilerplate for setting up allocator used in Wasm binary.
setup_alloc!();

#### What is Borsh?

use near_sdk::borsh::{self, BorshDeserialize, BorshSerialize}; 

Serialization protocol to send Info to Store Data on NEAR

#### env, near_bindgen, setup_alloc?

use near_sdk::{env, near_bindgen, setup_alloc};

| Name | Description |
| ------------ | ------------------------------------------------------- |
| setup_alloc | memory optimization |
| near_bindgen | Used to expose state and smart contract methods to user |
| env | Boilerplate for setting up allocator in Wasm binary |

#### Collections in NEAR

use near_sdk::collections::LookupMap;

[Collections](https://docs.rs/near-sdk/2.0.0/near_sdk/collections/index.html) are simply data structures used to optimize data storage on the NEAR blockchain

## Structs and Bindgen

#[near_bindgen]
#[derive(BorshDeserialize, BorshSerialize)]
pub struct MiamiContract {
    records: LookupMap<String, String>,
}

Sturcts are essentially like object in javascript. `key-value` pairs and method `implimentations`

impl Default for MiamiContract {
  fn default() -> Self {
    Self {
      records: LookupMap::new(b"a".to_vec()),
    }
  }
}

`Impl` are essentially used to add methods to a struct.
`Default` is used to initialize a smart contract in place of a custom `init` function. Init functions on Near utilize the `# `

## View and Change Methods on NEAR

- View Methods: Read and Return information from blockchain: No Cost
- Change Methods: Add or modify information to the blockchain: Gas fees are included

#[near_bindgen]
impl MiamiContract {
}

### Change Method Implimentation

    pub fn set_message(&mut self, message: String) {
        let account_id = env::signer_account_id();
        self.records.insert(&account_id, &message);
    }

### View Method Implimentation

    // `match` is similar to `switch` in other languages; here we use it to default to "Hello" if
    // self.records.get(&account_id) is not yet defined.
    // Learn more: https://doc.rust-lang.org/book/ch06-02-match.html#matching-with-optiont
    pub fn get_status(&self, account_id: String) -> Option<String> {
        return self.records.get(&account_id);
    }

## Compiling Rust code

In your `Contract` folder

 cargo build --target wasm32-unknown-unknown --release

## Deploying Smart Contract
To install `near-cli`

npm install -g near-cli

To then `login` run `near login` in your terminal to store a FullAccess Key on your local machine

Create a sub account using

near create-account  activate-miami.blockhead.testnet --masterAccount blockhead.testnet --initialBalance 30

Afterwards run

near deploy --accountId activate-miami.blockhead.testnet --wasmFile miami-contract/target/wasm32-unknown-unknown/debug/miami_contract.wasm

## NEAR Zero to HERO Tutorial
Check out the NEAR NFT Zero to Hero Tutorial!
https://docs.near.org/docs/tutorials/contracts/nfts/introduction

Check out this resource for information about the NEAR SDK!
https://www.near-sdk.io/