import { AES_GCM_Decrypt, AES_GCM_Encrypt } from "./AES.js";
import { deriveKey } from "./ECDHe.js";
import type { ECDHe_P384_KeyPair, ECDHe_P384_LiteKeyPair, ECDHe_P384_PublicKey, ECDHe_P384_PublicKeyInfo } from "./RawTypes.js";

export type EncryptedItem = {
	ct: Uint8Array;
}

const keySizeBit = 256;

export async function ECDHe_AES_GCM_Encrypt(other: ECDHe_P384_PublicKeyInfo, me: ECDHe_P384_LiteKeyPair | ECDHe_P384_KeyPair, iv: BufferSource, msg: BufferSource, aad?: BufferSource): Promise<ArrayBuffer>;
export async function ECDHe_AES_GCM_Encrypt(other: ECDHe_P384_PublicKey, me: ECDHe_P384_KeyPair, iv: BufferSource, msg: BufferSource, aad?: BufferSource): Promise<ArrayBuffer>;
export async function ECDHe_AES_GCM_Encrypt(other: ECDHe_P384_PublicKeyInfo, me: ECDHe_P384_LiteKeyPair, iv: BufferSource, msg: BufferSource, aad?: BufferSource): Promise<ArrayBuffer>;

export async function ECDHe_AES_GCM_Encrypt(other: ECDHe_P384_PublicKeyInfo | ECDHe_P384_PublicKey, me: ECDHe_P384_KeyPair | ECDHe_P384_LiteKeyPair, iv: BufferSource, msg: BufferSource, aad?: BufferSource): Promise<ArrayBuffer>{
	let key: ArrayBuffer;
	if('publicInfo' in me){
		key = await deriveKey(other, me, keySizeBit);
	}
	else if('publicKey' in other){
		key = await deriveKey(other, me, keySizeBit);
	}
	else{
		throw new Error("Invalid argument: may be trying to do ECDH, not ECDHe.");
	}
	
	return AES_GCM_Encrypt(key, iv, msg, aad);
}

export async function ECDHe_AES_GCM_Decrypt(other: ECDHe_P384_PublicKeyInfo, me: ECDHe_P384_LiteKeyPair | ECDHe_P384_KeyPair, iv: BufferSource, ciphertext: BufferSource, aad?: BufferSource): Promise<ArrayBuffer>;
export async function ECDHe_AES_GCM_Decrypt(other: ECDHe_P384_PublicKey, me: ECDHe_P384_KeyPair, iv: BufferSource, ciphertext: BufferSource, aad?: BufferSource): Promise<ArrayBuffer>;
export async function ECDHe_AES_GCM_Decrypt(other: ECDHe_P384_PublicKeyInfo, me: ECDHe_P384_LiteKeyPair, iv: BufferSource, ciphertext: BufferSource, aad?: BufferSource): Promise<ArrayBuffer>;


export async function ECDHe_AES_GCM_Decrypt(other: ECDHe_P384_PublicKeyInfo | ECDHe_P384_PublicKey, me: ECDHe_P384_KeyPair | ECDHe_P384_LiteKeyPair, iv: BufferSource, ciphertext: BufferSource, aad?: BufferSource): Promise<ArrayBuffer>{
	let key: ArrayBuffer;
	if('publicInfo' in me){
		key = await deriveKey(other, me, keySizeBit);
	}
	else if('publicKey' in other){
		key = await deriveKey(other, me, keySizeBit);
	}
	else{
		throw new Error("Invalid argument: may be trying to do ECDH, not ECDHe.");
	}

	return AES_GCM_Decrypt(key, iv, ciphertext, aad);
}