def serve(request: bytes) -> str:
""" Handle the peer request
Parameters:
request - the list containing the request parameters
Returns:
str - the response
"""
command = request[0:4].decode('UTF-8')
if command == "LOGI":
if len(request) != 64:
return "0" * 16
ip = request[4:59].decode('UTF-8')
port = request[59:64].decode('UTF-8')
try:
conn = database.get_connection(db_file)
conn.row_factory = database.sqlite3.Row
except database.Error as e:
print(f'Error: {e}')
return "0" * 16
try:
peer = peer_repository.find_by_ip(conn, ip)
# if the peer didn't already logged in
if peer is None:
session_id = str(uuid.uuid4().hex[:16].upper())
peer = peer_repository.find(conn, session_id)
# while the generated session_id exists
while peer is not None:
session_id = str(uuid.uuid4().hex[:16].upper())
peer = peer_repository.find(conn, session_id)
peer = Peer(session_id, ip, port)
peer.insert(conn)
conn.commit()
conn.close()
except database.Error as e:
conn.close()
print(f'Error: {e}')
return "0" * 16
return "ALGI" + peer.session_id
elif command == "ADDF":
if len(request) != 152:
return "Invalid request. Usage is: ADDF<your_session_id><file_md5><filename>"
session_id = request[4:20].decode('UTF-8')
md5 = request[20:52].decode('UTF-8')
name = request[52:152].decode('UTF-8').lower()
try:
conn = database.get_connection(db_file)
conn.row_factory = database.sqlite3.Row
except database.Error as e:
print(f'Error: {e}')
return "The server has encountered an error while trying to serve the request."
try:
peer = peer_repository.find(conn, session_id)
if peer is None:
conn.close()
return "Unauthorized: your SessionID is invalid"
file = file_repository.find(conn, md5)
if file is None:
file = File(md5, name, 0)
file.insert(conn)
file_repository.add_owner(conn, md5, session_id)
else:
file.file_name = name
file.update(conn)
if not file_repository.peer_has_file(conn, session_id, md5):
file_repository.add_owner(conn, md5, session_id)
num_copies = file_repository.get_copies(conn, md5)
conn.commit()
conn.close()
except database.Error as e:
conn.rollback()
conn.close()
print(f'Error: {e}')
return "The server has encountered an error while trying to serve the request."
return "AADD" + str(num_copies).zfill(3)
elif command == "DELF":
if len(request) != 52:
return "Invalid request. Usage is: DELF<your_session_id><file_md5>"
session_id = request[4:20].decode('UTF-8')
md5 = request[20:52].decode('UTF-8')
try:
conn = database.get_connection(db_file)
conn.row_factory = database.sqlite3.Row
except database.Error as e:
print(f'Error: {e}')
return "The server has encountered an error while trying to serve the request."
try:
peer = peer_repository.find(conn, session_id)
if peer is None:
conn.close()
return "Unauthorized: your SessionID is invalid"
if not file_repository.peer_has_file(conn, session_id, md5):
conn.close()
return "ADEL999"
peer_repository.file_unlink(conn, session_id, md5)
copy = file_repository.get_copies(conn, md5)
if copy == 0:
file = file_repository.find(conn, md5)
file.delete(conn)
conn.commit()
conn.close()
except database.Error as e:
conn.rollback()
conn.close()
print(f'Error: {e}')
return "The server has encountered an error while trying to serve the request."
return "ADEL" + str(copy).zfill(3)
elif command == "FIND":
if len(request) != 40:
return "Invalid command. Usage is: FIND<your_session_id><query_string>"
session_id = request[4:20].decode('UTF-8')
query = request[20:40].decode('UTF-8').lower().lstrip().rstrip()
if query != '*':
query = '%' + query + '%'
try:
conn = database.get_connection(db_file)
conn.row_factory = database.sqlite3.Row
except database.Error as e:
print(f'Error: {e}')
return "The server has encountered an error while trying to serve the request."
try:
peer = peer_repository.find(conn, session_id)
if peer is None:
conn.close()
return "Unauthorized: your SessionID is invalid"
total_file = file_repository.get_files_count_by_querystring(conn, query)
if total_file == 0:
return 'AFIN' + str(total_file).zfill(3)
result = str(total_file).zfill(3)
file_list = file_repository.get_files_with_copy_amount_by_querystring(conn, query)
for file_row in file_list:
file_md5 = file_row['file_md5']
file_name = file_row['file_name']
copies = file_row['copies']
result = result + file_md5 + file_name + str(copies).zfill(3)
peer_list = peer_repository.get_peers_by_file(conn, file_md5)
for peer_row in peer_list:
peer_ip = peer_row['ip']
peer_port = peer_row['port']
result = result + peer_ip + peer_port
conn.commit()
conn.close()
except database.Error as e:
conn.rollback()
conn.close()
print(f'Error: {e}')
return "The server has encountered an error while trying to serve the request."
return "AFIN" + result
elif command == "DREG":
if len(request) != 52:
return "Invalid request. Usage is: DREG<your_session_id><file_md5>"
session_id = request[4:20].decode('UTF-8')
md5 = request[20:52].decode('UTF-8')
try:
conn = database.get_connection(db_file)
conn.row_factory = database.sqlite3.Row
except database.Error as e:
print(f'Error: {e}')
return "The server has encountered an error while trying to serve the request."
try:
peer = peer_repository.find(conn, session_id)
if peer is None:
conn.close()
return "Unauthorized: your SessionID is invalid"
file = file_repository.find(conn, md5)
if file is None:
return "File not found."
file.download_count += 1
file.update(conn)
conn.commit()
conn.close()
except database.Error as e:
conn.rollback()
conn.close()
print(f'Error: {e}')
return "The server has encountered an error while trying to serve the request."
return "ADRE" + str(file.download_count).zfill(5)
elif command == "LOGO":
if len(request) != 20:
return "Invalid request. Usage is: LOGO<your_session_id>"
session_id = request[4:20].decode('UTF-8')
try:
conn = database.get_connection(db_file)
conn.row_factory = database.sqlite3.Row
except database.Error as e:
print(f'Error: {e}')
return "The server has encountered an error while trying to serve the request."
try:
peer = peer_repository.find(conn, session_id)
if peer is None:
conn.close()
return "Unauthorized: your SessionID is invalid"
deleted = file_repository.delete_peer_files(conn, session_id)
peer.delete(conn)
conn.commit()
conn.close()
except database.Error as e:
conn.rollback()
conn.close()
print(f'Error: {e}')
return "The server has encountered an error while trying to serve the request."
return "ALGO" + str(deleted).zfill(3)
else:
return "Command \'" + request.decode('UTF-8') + "\' is invalid, try again."
