From d429f09e7e3bc8173e765aba8a91f2440c99a324 Mon Sep 17 00:00:00 2001
From: Stefan Hansson <steha708@edu.liu.se>
Date: Thu, 5 Nov 2020 15:10:55 +0100
Subject: Implement finding nearest nodes to start and end positions

---
 algorithms.py | 11 ++++++++++-
 server.py     | 16 +++++++++++++++-
 store.py      | 23 +++++++++++++++++++++++
 3 files changed, 48 insertions(+), 2 deletions(-)

diff --git a/algorithms.py b/algorithms.py
index de954f4..cc8d35f 100644
--- a/algorithms.py
+++ b/algorithms.py
@@ -18,7 +18,16 @@ def length_haversine(p1, p2):
 def get_closest_node_id(nodes, source_node):
     """ Search through all nodes and return the id of the node
     that is closest to 'source_node'. """
-    pass
+    min_node = None
+    min_value = None
+
+    for node_id, node in nodes.items():
+        length = length_haversine(source_node, node)
+        if min_node == None or length < min_value:
+            min_node = node_id
+            min_value = length
+
+    return min_node
 
 
 def find_shortest_path(nodes, source_id, target_id):
diff --git a/server.py b/server.py
index 0710905..e6ff6c2 100644
--- a/server.py
+++ b/server.py
@@ -1,7 +1,8 @@
 import json
 
+import algorithms
 import store
-from lib import run_server, get, read_html
+from lib import run_server, get, post, read_html
 
 
 @get('/')
@@ -17,4 +18,17 @@ def show_area():
     return json.dumps(all)
 
 
+@post('/shortest-path')
+def shortest_path(body):
+    body = json.loads(body)
+    source_id = algorithms.get_closest_node_id(store.nodes, store.Node(-1, body['lat1'], body['lng1']))
+    target_id = algorithms.get_closest_node_id(store.nodes, store.Node(-1, body['lat2'], body['lng2']))
+    print(source_id, target_id)
+    source_node = store.nodes[source_id]
+    target_node = store.nodes[target_id]
+    path = [(source_node.lat, source_node.lng), (target_node.lat, target_node.lng)]
+    response = {'path': path}
+    return json.dumps(response)
+
+
 run_server()
diff --git a/store.py b/store.py
index 3d91f5b..e03ae77 100644
--- a/store.py
+++ b/store.py
@@ -6,22 +6,45 @@ class Node:
         self.id = id
         self.lat = float(lat)
         self.lng = float(lng)
+        self.neighbors = []
+
 
     def coord_tuple(self):
         return self.lat, self.lng
 
 
 parser = None  # Have a global reusable parser object
+nodes = None
+
+
+def add_neighbours(nodes):
+    for way in parser.iter_ways():
+        if 'highway' not in way['tags']:
+            continue
+
+        road = way['road']
+
+        for i in range(len(road) - 1):
+            node1 = road[i]
+            node2 = road[i + 1]
+
+            nodes[node1].neighbors.append(nodes[node2])
+            nodes[node2].neighbors.append(nodes[node1])
+
+    return nodes
 
 
 def extract_osm_nodes(f_name):
     global parser
+    global nodes
     parser = get_default_parser(f_name)
     nodes = dict()
 
     for node in parser.iter_nodes():
         nodes[node['id']] = Node(node['id'], node['lat'], node['lon'])
 
+    add_neighbours(nodes)
+
     return nodes
 
 
-- 
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