add modify block command

.gitignore

@@ -6,3 +6,4 @@ build/
 dist/
 blockshell/
 blockshell.egg-info/
+*.csv

add_blocks.sh

@@ -0,0 +1,18 @@
+#!/bin/sh
+
+CMD=""
+PREVIFS=$IFS
+IFS=','
+
+[ $# -ne 1 ] && { echo "Usage: add_blocks <file.csv>"; exit 1; }
+[ ! -f $1 ] && { echo "file $1 not found"; exit 1; }
+
+while read uid mail firstname lastname end
+do
+    CMD="${CMD}dotx $uid $mail $firstname $lastname\n"
+done < $1
+
+# Add blocks to existing blockchain (if it exists) or to a new blockchain
+printf $CMD | blockshell load chain.txt
+
+IFS=$PREVIFS

blockchain/chain.py

@@ -77,6 +77,7 @@ class Block:
         """
         print(Back.RED + "\n[Status] Mining block (" + str(self.index) + ") with PoW ...")
         startTime = time.time()
+        self.hash = ""
 
         while self.hash[:difficulty] != "0"*difficulty:
             self.nonce += 1
@@ -152,3 +153,29 @@ class Blockchain:
             print(Back.RED + "[Error] Creating new blockchain.")
             print(Style.RESET_ALL)
             self.writeBlocks()
+
+    def modifyBlock(self, hash, uid_epita, email_epita, firstname, lastname):
+        """
+            Method to modify existing block
+        """
+        i = 0
+        for i in range(len(self.chain)):
+            eachBlock = self.chain[i]
+            if eachBlock.hash == hash:
+                eachBlock.uid_epita = uid_epita
+                eachBlock.email_epita = email_epita
+                eachBlock.firstname = firstname
+                eachBlock.lastname = lastname
+                eachBlock.createRandomImage()
+                eachBlock.mineBlock(self.difficulty)
+                break
+        if i == len(self.chain) - 1:
+            return False
+        for i in range(i+1, len(self.chain)):
+            eachBlock = self.chain[i]
+            eachBlock.index = i
+            eachBlock.previousHash = self.chain[i-1].hash
+            eachBlock.mineBlock(self.difficulty)
+            self.writeBlocks()
+        return True
+

bscli.py

@@ -25,7 +25,8 @@ SUPPORTED_COMMANDS = [
     'dotx',
     'allblocks',
     'getblock',
-    'help'
+    'help',
+    'modify',
 ]
 
 def printLogo():
@@ -91,6 +92,7 @@ def load(filename, difficulty):
     # Set difficulty of blockchain
     coin.difficulty = difficulty
 
+    printSuccess(f"Blockchain loaded successfully. {len(coin.chain)} blocks loaded.")
     # Start blockshell shell
     startShell()
 
@@ -148,6 +150,16 @@ def help(cmd):
     print("   dotx <uid> <mail> <firstname> <lastname>                    Create new transaction")
     print("   allblocks                                                   Fetch all mined blocks in blockchain")
     print("   getblock <block hash>                                       Fetch information about particular block")
+    print("   modify <block hash> <uid> <mail> <firstname> <lastname>     Modify a particular block keeping blockchain validity")
+
+def modify(args):
+    """
+        Method to modify any block in blockchain.
+    """
+    if coin.modifyBlock(args[0], args[1], args[2], args[3], args[4]):
+        printSuccess("Block modified successfully!")
+    else:
+        throwError("Block modification failed!")
 
 def throwError(msg):
     """