'''calc flow direction.
step1. division block.
step2. appoint source.
setp3. calc flow direction.
'''
from relations.src.system_relation import systemdatautils
import networkx as nx

def calc(block_datas,source_datas):
	'''
	calc block flow direction.
	:param project_id:
	:param block_id:
	:return:
	'''
	# get roots
	roots=list(i.source_id for i in source_datas)
	g = nx.Graph()
	for item in block_datas:
		item.direction=None
		g.add_edge(item.id1,item.id2)
	G = g.to_directed()
	# get leaves
	leaves=list(v for v,d in G.out_degree() if d==1)
	G_new=nx.DiGraph()
	try:
		for i in range(len(roots)):
			root=roots[i]
			sign=1 if source_datas[i].is_source else -1
			for leaf in leaves:
				paths = nx.all_simple_paths(G, root, leaf)
				for path in paths:
					# remove contain source path
					if is_path_contain_root(path, roots, root):
						continue
					# set path direction
					for j in range(len(path) - 1):
						G_new.add_edge(path[j], path[j + 1],weight=(j*sign))
			# add source direct to source path.
			for j in range(i + 1, len(roots)):
				next_root=roots[j]
				paths = list(nx.all_simple_paths(G, root, next_root))
				for path in paths:
					if len(path) == 2:
						G_new.add_edge(root, next_root,weight=0)
						G_new.add_edge(next_root, root,weight=0)
	except Exception as ex:
		print(ex)
	for edge in G_new.edges:
		edge_data=G_new.get_edge_data(edge[0],edge[1])
		weight=edge_data["weight"]
		set_edge_direction(block_datas,edge,weight)
	return block_datas

def is_path_contain_root(path, roots, cur_root):
	'''
	judge whether path contain root node except cur_root.
	:param path:
	:param roots:
	:param cur_root:
	:return:
	'''
	result = False
	for root in roots:
		if root == cur_root:
			continue
		result = (root in path)
		if result:
			break
	return result
def set_edge_direction(block_datas,edge,weight):
	'''
	set connected_block direction.
	connector1 to connector2.sign:1
	connector2 to connector1.sign:-1
	both way.sign:0
	un calc.sign:None
	:param block_datas:
	:param edge:
	:return:
	'''
	for block_data in block_datas:
		# connector1 to connector2.sign:1
		if block_data.id1 == edge[0] and block_data.id2 == edge[1]:
			j=1
			block_data.direction=(block_data.direction+j if block_data.direction else j)
			block_data.depth=(weight)
		# connector2 to connector1.sing:-1
		if block_data.id1 == edge[1] and block_data.id2 == edge[0]:
			j = -1
			block_data.direction=(block_data.direction+j if block_data.direction else j)
			block_data.depth = (weight)