import json

def v_norm(val,center):
    scale_f = 10 / center
    d = center / 2
    print(val-d)
    return (val - d) * scale_f
def process_node(n):
    for x in ['label','center','source','target','x','y']:
        n = n.replace(x,'"%s"' %x)
    return json.loads(n)

def to_dict(node_s):
    node_s = node_s.strip('{}')
    node_s = node_s.strip('[]')
    node_s = node_s.replace('},{','},E,{')
    node_l = node_s.split(',E,')
    return [process_node(n) for n in node_l]

def extract_features(inp):
    # returns tuple of (height,width,node_s,edge_s)
    node_s, edge_s = inp.split('nodes=')[1].split(' edges=')
    edge_s = edge_s.strip(' />')
    height = int(inp.split('height="')[1].split('"')[0])
    width = int(inp.split('width="')[1].split('"')[0])
    return height,width,to_dict(node_s),to_dict(edge_s)

def str_to_latex(inp,directed=False):
    out = '''\\begin{tikzpicture}
    \\tikzset{vertex/.style = {shape=circle,draw,minimum size=1.5em}}\n'''
    height,width,n,e = extract_features(inp)
    for node in n:
        out += '\\node[vertex] (%s) at  (%f,%f) {%s};\n' % \
               (node['label'], v_norm(node['center']['x'],width), v_norm(node['center']['y'],height), node['label'])
    out += '\\path[%s]\n' % ('->' if directed else '-')
    for edge in e:
        s,t = str(edge['source']), str(edge['target'])
        out += '(%s) edge (%s)\n' % (s, t)
    out += '\\end{tikzpicture}'
    return out