Adding readme

README.md

@@ -18,8 +18,173 @@ did:bnb can draw from the previous work on EVM-based did methods. The following
 - **Persistence**: DID Documents are stored on-chain and can be retrieved by any client. There is no block or time-limit or the persisted data.
 - **Goverance**: did:bnb Smart Contract is gonvered by BNB Beacon Chain.
 
-## Other EVM based DID methods (for reference)
-- [did:ethr](https://github.com/decentralized-identity/ethr-did-resolver/blob/master/doc/did-method-spec.md)
-- [did:jolo](https://github.com/jolocom/jolo-did-method/blob/master/jolocom-did-method-specification.md)
-- [did:selfkey](https://github.com/SelfKeyFoundation/selfkey-did-ledger/blob/develop/DIDMethodSpecs.md)
-- [did:safe](https://github.com/ceramicnetwork/CIPs/blob/main/CIPs/cip-101.md)
+
+## Creating DIDs
+
+*Any ethereum public key can be a DID.* This means that if you have a public key `0xabc`, then that key
+corresponds to the decentralized identifier `did:bnb:0xabc`.
+
+This DID is called a `generative` DID, because it is generated from a public key, and has no other information associated with it.
+
+Generative DIDs have one authority, which is the public key itself (`0xabc` in this case).
+
+## Updating DIDs
+
+In order to add more authorities, or any other information to the DID it must be initialised on chain, the `initializeDidState` function must be called first.
+
+Once a DID is initialized new verification methods, services and controllers can be added/removed from the DIDs state.
+
+## DID State
+The state of a DID is stored in a mapping `didStates` where the keys are public keys coressponding to didIdentifiers and the values are a struct representing the state of a DID.
+
+ `mapping(address => DidState) private didStates;`
+
+ ```
+ struct DidState {
+        VerificationMethod[] verificationMethods;
+        Service[] services;
+        address[] nativeControllers;
+        string[] externalControllers;
+    }
+ ```
+
+## Contract Functions
+
+### `resolveDidState`
+Returns the state of a given did
+
+Arguments:
+- address: `didIdentifier`
+
+Returns:
+- DidState: `didState`
+
+### `initializeDidState`
+Initalizes a DID with the default state and persist it on-chain.
+
+Arguments:
+- address: `didIdentifier`
+
+### `isGenerativeDidState`
+
+Arguments:
+- address: `didIdentifier`
+
+Returns:
+- bool: `isGenerative`
+
+### `addVerificationMethod`
+Attempts to add a verification method to a DIDs state with the following contraints:
+
+1. Fragments used for naming verification methods must be unique.
+
+2. A verification method cannot be create with the ownership OR protected flags.
+
+Arguments:
+- address: `didIdentifier`
+- VerificationMethod: `verificationMethod`
+
+Event Emitted: `VerificationMethodAdded`
+
+### `removeVerificationMethod`
+Attempts to remove a verification method from a DIDs state with the following contraints:
+
+1. A DID must always have at least 1 verification method with the `CAPABILITY_INVOCATION` flag.
+
+2. A verification method cannot be removed if it has the `PROTECTED` flag.
+
+Arguments:
+- address: `didIdentifier`
+- string: `fragment`
+
+Event Emitted: `VerificationMethodRemoved`
+
+### `updateVerificationMethodFlags`
+Attempts to update a verification methods flags on a DIDs state with the following contraints:
+
+1. If trying to change the `OWNERSHIP_PROOF` or `PROTECTED` flags the keyData must match the message sender.
+
+2. A DID must always have at least 1 verification method with the `CAPABILITY_INVOCATION` flag.
+
+Arguments:
+- address: `didIdentifier`
+- string: `fragment`
+- u16: `flags`
+
+Event Emitted: `VerificationMethodFlagsUpdated`
+
+### `addService`
+Attempts to add a service to a DIDs state with the following contraints:
+
+1. Fragments used for naming verification methods must be unique.
+
+Arguments:
+- address: `didIdentifier`
+- Service: `service`
+
+Event Emitted: `ServiceAdded`
+
+### `removeService`
+Attempts to remove a service from a DIDs state.
+
+Arguments:
+- address: `didIdentifier`
+- string: `fragment`
+
+Event Emitted: `ServiceRemoved`
+
+### `addNativeController`
+Attempts to add a controller to a DIDs state with the following contraints:
+
+1. No duplicate controllers are allowed
+
+Arguments:
+- address: `didIdentifier`
+- address: `nativeController`
+
+Event Emitted: `ControllerAdded`
+
+### `removeNativeController`
+Attempts to remove a controller from a DIDs state.
+
+Arguments:
+- address: `didIdentifier`
+- address: `nativeController`
+
+Event Emitted: `ControllerRemoved`
+
+### `addExternalController`
+Attempts to add a controller to a DIDs state with the following contraints:
+
+1. No duplicate controllers are allowed
+
+Arguments:
+- address: `didIdentifier`
+- string: `controller`
+
+Event Emitted: `ControllerAdded`
+
+### `removeExternalController`
+Attempts to remove a controller from a DIDs state.
+
+Arguments:
+- address: `didIdentifier`
+- string: `controller`
+
+Event Emitted: `ControllerRemoved`
+
+## Deployments
+
+- Testnet: [0x75837371D170Bb8E5b74A968aDe00eDeaf59AD56](https://testnet.bscscan.com/address/0x75837371d170bb8e5b74a968ade00edeaf59ad56#code)
+
+
+## Developer Notes
+
+### Running unit test
+This project uses foundry for writing test. You can run the unit test suite by running:
+
+`forge test`
+
+To run the test and get a test coverage report you can run:
+
+`forge coverage`