Make it possible to load existing solutions on starting

utils/data.py

 import datetime
+import glob
 import json
 import math
 import os
@@ -26,6 +27,14 @@ class Problem(object):
         self.block_groups = list()
 
         self._load_problem(problem_path)
+
+        if not self.solution_path is None:
+            solution_files = glob.glob(f'{self.solution_path}/{self.name}/*.json')
+            for v in solution_files:
+                solution = Solution(solution_file=v)
+                solution_id = solution.get_id()
+                print(f'I: Put a solution: {solution_id}')
+                self.solutions[solution_id] = solution
     
     @property
     def size_str(self):
@@ -336,7 +345,11 @@ class Problem(object):
 
 class Solution(object):
 
-    def __init__(self, data):
+    def __init__(self, data=None, solution_file=None):
+
+        if not solution_file is None:
+            with open(solution_file, 'r') as fp:
+                data = json.load(fp)
 
         self.problem = data['problem']
         self.request_id = data['request_id']
@@ -344,15 +357,21 @@ class Solution(object):
         self.elapsed_time = data['elapsed_time']
         self.solution = data['solution']
         self.status = data['status']
+
         self.size = (None, None)
         self.map = None
         self.block = dict()
 
-        self.timestamp = time.time()
-        self._id = str(uuid.uuid4())
+        if solution_file is None:
+            self.timestamp = time.time()
+            self._id = str(uuid.uuid4())
+            
+        else:
+            self.timestamp = data['timestamp']
+            self._id = data['id']
 
         self._parse_solution()
-    
+
     def _parse_solution(self):
 
         if self.status != 'done':
@@ -429,7 +448,8 @@ class Solution(object):
             'worker': self.worker,
             'elapsed_time': self.elapsed_time,
             'problem': self.problem,
-            'solution': self.solution
+            'solution': self.solution,
+            'status': self.status
         }
     
     def get_d3json(self):