dsp-blockchain/linked_data.py

import time
import pprint
from datetime import datetime

class Chain():
    
    def __init__(self):
        
        # initialize the mock blockchain
        self.blockchain = []
        self.current_block = Block()
    
    # add old block to chain and create new block
    def new_block(self):
        self.blockchain.append(self.current_block)
        self.current_block = Block()
        pass
    
    # create new contract
    def new_contract(self,client, contractor, deadline, discription, name, price, people, initiator):
        
        n_contracts = 0
        for block in self.blockchain + [self.current_block]:
            for item in block.block:
                if item['type'] == 'init':
                    n_contracts += 1

        # set discriptors of contract
        contract = {'id':n_contracts,
                    'type':'init',
                    'date of initiation':get_t(),
                    'initiated by': initiator,
                    'data': {'client':client,
                            'contractor':contractor,
                            'discription':discription,
                            'name':name,
                            'people': people},
                    'terms' : {'deadline': deadline,
                               'accepted': False,
                               'progress': '0%',
                               'price':price,
                               'Sign time': 'not yet signed',
                               'comments':{}
                              }
                   }
        
        # add as transaction
        self.current_block.add(contract)
        
        # If block to big, get new
        if self.current_block.size() > 10:
            self.new_block()
    
    # add updates to the contract
    def update_contract(self, iden, attr, value, by, comment=None):
        
        # check if transaction adds or modifies
        self.current_contract_state(iden)
        if attr in self.state['data'] or attr in self.state['terms']:
            t = 'modify'
        else: t = 'update'
                
        # add new or updated info to block
        update = {'id':iden,
                'update id':len(self.get_updates(iden)),   
                'updated':attr,
                'type':t,
                'last update':get_t(),
                'updated by':by,
                'accepted': False,
                'change':{attr:value}}
        
        # check if comment is passed and add it if necassary
        if comment:
            update['comment'] = comment
        
        # add transaction
        self.current_block.add(update)
        
        # check if new block is needed
        if self.current_block.size() > 10:
            self.new_block()
     
    # accept updates
    def accept_update(self, iden, update_id, awnser, by, comment=None):
        update = {
            'id':iden,
            'update id':update_id,
            'accept':awnser,
            'type':'accept',
            'last update':get_t(),
            'accepted by': by
        }
        if comment:
            update['comment'] = comment
            
        self.current_block.add(update)
        
        # check if new block is needed
        if self.current_block.size() > 10:
            self.new_block()
    
    # get current state of the contract
    def current_contract_state(self, iden):
        # set up contract state
        self.state = {'id':iden,
                'data':{},
                'terms':{}
                }
        
        b = []
        
        # loop over all blocks in the chain
        for block in self.blockchain:
            b += block.block 
        
        # retreive all the data
        transactions = b + self.current_block.block
        
        # save not yet approved updates
        updates = {}
        
        # loop over all transaction in block
        for item in transactions:
            
            # save data about our project
            if item['id'] == iden:

                # set state to inital contract state
                if item['type'] == 'init':
                    self.state = item
                    continue

                # if update is not accept update, save it to updates dict
                if item['type'] != 'accept':
                    
                    # comments are always accepted
                    if item['updated'] != 'comments':
                        updates[item['update id']] = item
                        continue
                
                # if accepted is true, retrieve update form dict and add to contract state
                elif item['accept'] == True:
                    item = updates[item['update id']]
                
                # set attr to whatever has been updated
                attr = item['updated']
                
                # check if the update was removal
                if item['type'] == 'remove':
                    
                    # delete item in the right part of the dict
                    try:
                        if attr in self.state['data']:
                            del self.state['data'][attr]
                        else:
                            del self.state['terms'][attr]
                    except:
                        pass
                
                if item['type'] == 'update':
                    self.state['terms'][attr] = item['change'][attr]
                
                # check if updated attr is data or terms
                elif attr in self.state['data']:
                    self.state['data'][attr] = item['change'][attr]
                    
                elif attr in self.state['terms']:
   
                    # special case for comments
                    if attr == 'comments' and item['type'] not in ['remove', 'init']:
                        
                        k = list(item['change'][attr].keys())[0]
                        self.state['terms'][attr][k] = item['change'][attr][k]
                    
                    # case for normal updates
                    else:    
                        self.state['terms'][attr] = item['change'][attr]
                        
                # special cases for last update and date of initiation
                elif 'last update' in item:
                    self.state['last update'] = item['last update']
    
    # get updates based on contract, atribute updated or accept state
    def get_updates(self, iden=None, attr=None, accepted=None):
        updates = []
        
        # get all blocks and loop over transactions
        for block in self.blockchain + [self.current_block]:
            for item in block.block:
                
                # if attr is '' get updates for all attributes
                if attr == None:
                    
                    # if iden is None, get updates for all contracts
                    # updates for all contracts and attrs
                    if iden == None:
                        if item['type'] != 'init':
                            updates.append(item)
                    
                    # updates for specific contracts from all attr
                    else:
                        if item['type'] != 'init' and item['id'] == iden:
                            updates.append(item)
                else:
                    
                    # updates for specific attrs from all contract
                    if iden == None:
                        if item['type'] != 'init' and item['updated'] == attr:
                            updates.append(item)
                    # updates for specific contract and specific attr
                    else:
                        if item['type'] != 'init' and item['updated'] == attr and item['id'] == iden:
                            updates.append(item)
        return updates
    
    # add transaction to remove items
    def remove_item(self, iden, attr):
        
        # add transaction to remove item
        self.current_block.add({'id':iden, 
                                'updated':attr ,
                                'type':'remove',
                                'last update':get_t(), 
                                'accept':False,
                                'update id':len(self.get_updates(iden))})
        
        if self.current_block.size() > 10:
            self.new_block()
    
    # add comments to
    def add_comment(self, iden, body, author):
        
        # get all updates for comments
        comment_updates = []
        for block in self.blockchain + [self.current_block]:
            for item in block.block:
                if 'updated' in item:
                    if item['updated'] == 'comments' and item['id'] == iden:
                        comment_updates.append(item)
           
        # create transaction
        to_add = {'id':iden,
                'updated':'comments',
                'accept':True,
                'type':'modify',
                'last update':get_t(),
                'change':{'comments':{len(comment_updates):{'author':author,
                                                           'body': body, 
                                                           'time': get_t(),
                                                           'contract':iden}}}}
        self.current_block.add(to_add)       
        if self.current_block.size() > 10:
            self.new_block()
    
    # retrieve comments based on author and contract
    def retrieve_comments(self, iden=None, author = None):
        comment = []
        
        # check every block in the chain
        for block in self.blockchain + [self.current_block]:
            for item in block.block:
                
                # if transaction is of type init, skip it
                if item['type'] == 'init' or item['type'] == 'accept':
                    continue
                    
                # check if the update is a comment               
                if item['updated'] == 'comments':
                    
                    #filters for contract and author
                    # no contract or author filter
                    if iden == None and author == None:
                        comment.append(item['change']['comments'])

                    # filter by contract
                    elif iden != None and author == None:
                        if item['id'] == iden:
                            comment.append(item['change']['comments'])
                            
                    # filter by author
                    elif iden == None and author != None:
                        if list(item['change']['comments'].values())[0]['author'] == author:
                            comment.append(item['terms']['comments'])
                    
                    # filter by author and contract
                    elif iden != None and author != None:
                        if item['id'] == iden and list(item['change']['comments'].values())[0]['author'] == author:
                            comment.append(item['change']['comments'])
        return comment
    
    # get updates for a contract that have to be accepted or are already accepted
    def retrieve_updates(self, iden, accepted=None):
    
        updates = {}
        # get all updates for a contract
        all_updates = self.get_updates(iden = iden, accepted = accepted)
        
        for item in all_updates:
            if item['type'] != 'accept' and item['updated'] != 'comments':
                updates[item['update id']] = item
            else:
                try:
                    updates[item['update id']]['accepted'] = item['accept']
                except:
                    pass
        
        if accepted == None:
            return updates 
        
        return [updates[x] for x in list(updates.keys()) if updates[x]['accepted'] == accepted]
        
    def __str__(self):
        print(self.current_block)
        return ''
    

    def populate(self):
        # create contracts
        people = ['astrix', 'obelix']
        self.new_contract('some company', 'semmtech', 'two weeks', 'a sample project', 'project', 10000, people, 'astrix')
        people = ['samson', 'gert']
        self.new_contract('The organization', 'not semmtech', '31-12-2021', 'a real project', 'r project', 10000, people, 'samson')
        people = ['doctor bright', '05-12']
        self.new_contract('The foundation', 'scp-096', '31-12-2021', 'to contain 096', 'containment', 'at all costs', people, '05-2')

        # updates for contract 0
        self.update_contract(0, 'deadline', '1 month', 'obelix')
        self.accept_update(0, 0, True, 'astrix')
        self.update_contract(0, 'progress', '50%', 'astrix' ,'we done with 50 %')
        self.update_contract(0, 'discription', 'A project sample', 'obelix')
        self.update_contract(0, 'progress', '75%', 'astrix')
        self.add_comment(0, 'I like the progress', 'astrix')


        # updates for contract 1
        self.update_contract(1, 'accepted', True, 'gert')
        self.update_contract(1, 'Sign time', get_t(), 'gert')
        self.update_contract(1, 'name', 'actual project', 'samson')
        self.update_contract(1, 'price', 16969, 'gert')
        self.remove_item(1, 'comments')

        # updates for contract 2
        self.add_comment(2, 'needs to be terminated', 'doctor bright')
        self.add_comment(2, 'doctor bright is wrong', '05-12')
        self.add_comment(2, 'no im right 05-12 is defo wrong', 'doctor bright')
        self.update_contract(2, 'test term', 'works', '05-2')

        # # show current state of contract 0
        # self.current_contract_state(0)
        # pprint.pprint(self.state)
        # print('\n\n\n')

        # # show current state of contract 1
        # self.current_contract_state(1)
        # pprint.pprint(self.state)
        # print('\n\n\n')

        # show current state of contract 2
        self.current_contract_state(2)
        pprint.pprint(self.state)
    
class Block():
    
    # init block
    def __init__(self):
        self.block = []
    
    # add new transactions
    def add(self, contract):
        self.block.append(contract)
    
    # get size of block
    def size(self):
        return len(self.block)
    
    def __str__(self):
        pprint.pprint(self.block)
        return ''

# get date/time in readable format
def get_t():
    return datetime.utcfromtimestamp(time.time()).strftime('%Y-%m-%d %H:%M:%S')

# format a dictionary to be readable in a string
def format_dict(d):

    # define string to return
    return_string = ''

    # loop over all key value pairs
    for k in list(d.keys()):

        # if value is a dict, call format dict again
        if type(d[k]) == dict:
            print('geweest')
            return_string += k  + format_dict(d[k])

        # if list, join list with ', '
        elif type(d[k]) == list:
            return_string += k + ', '.join(d[k])

        # stings can just be added without further processing
        else: 
            return_string += k  + str(d[k])

        # and an enter after every  value
        return_string += '\n'
    return return_string + '\n'