var bip39 = require('bip39');
    var HDkey = require('hdkey');
    var createHash = require('create-hash');
    var bs58check = require('bs58check');
    
    exports.seed = async () =>{
      return new Promise(resolve => {
        const mnemonic =  "drive captain sustain winner neutral anchor congress skirt buzz usage orient wood"
        
        //const mnemonic =  bip39.generateMnemonic(); //generates the string above
        const seed =  bip39.mnemonicToSeed(mnemonic); //creates seed buffer
        resolve(seed)
      })
    }

   
    
     exports.key = async (seed) =>{
      return new Promise(resolve => {
    
        const hdkey = HDkey.fromMasterSeed(Buffer.from(seed, 'hex'))
    
        const masterPrivateKey = hdkey.privateExtendedKey
    
         // This key Match iancoleman BIP32 ROOT KEY
        console.log("\x1b[32m%s\x1b[0m",'PRIVATE KEY BIP32 ROOT: ', masterPrivateKey) 
    
        // this line will not give me valid BIP32 EXTENDED PRIVATE KEYS
        //const addrnode = hdkey.derive("m/44'/0'/0'/0/0")
        
        // This one will when I removed the last /0
        const addrnode = hdkey.derive("m/44'/0'/0'/0")
        
        // THESE 2 BIP32 Extended Key are valid on iancoleman's app
        console.log("\x1b[32m%s\x1b[0m",'PRIVATE EXTENDED : ', addrnode.privateExtendedKey)
        const step1 = addrnode.publicExtendedKey
        console.log("\x1b[32m%s\x1b[0m",'PUBLIC EXTENDED : ', step1.toString('hex'))
    
        // Here is what I could understand from the example
    
        //SHA256 of the public key
        const step2 = createHash('sha256').update(step1).digest()
      
        // PIPEDMD-160 of the SHA256 Hash
        const step3 = createHash('rmd160').update(step2).digest()
        
    
        // He we must add the network byte in front of that PIPEDMD result
        // 0x00 for mainnet and 0x6f for testnet
        var step4 = Buffer.allocUnsafe(21)
        step4.writeUInt8(0x00, 0)
        step3.copy(step4,1) 
    
        //step3 now holds the  Network ID +  RIPEMD160 result
        //we hash it twice
        var step5 = createHash('sha256').update(step4).digest()
        var step6 = createHash('sha256').update(step5).digest()
    
    
        //checksum first 4 byte of second hash
        var step7 = step6.slice(0,4)
        console.log("\x1b[32m%s\x1b[0m",'CHECKSUM : ', step7.toString('hex'))
    
       // Adding the checksum to the end of
        var step8 = Buffer.concat([step4, step7]);  
        console.log("\x1b[32m%s\x1b[0m",'Base + CHECKSUM : ', step8.toString('hex'))
        // Return the bitcoins address
        var step9 = bs58check.encode(step8)
    
    
       resolve(step9)
    
        // The address generated by this code;
        // 1WpGHR9UmDm7UiJuFu1H3zE7TmtK187D1yZStMQ
    
        // The address generated with the same mnemonic on iancoleman app;
        // 1HaGGkWmUDTKExFxyXaiGHHPxYNaCefQrj
      })
    }