import requests
import sys
import subprocess
import ops_cache
import copy
import tempfile

# TODO: Cache results
# TODO: Properly render outgouing links

# @ops_cache()
def gen(headline_id, graph):
    reference_node = headline_id

    g = copy.deepcopy(graph)
    centered_graph = { reference_node: g[reference_node] }
    del g[reference_node]
    new_nodes = True

    in_emacs_tree = {
        reference_node: set(),
    }

    while new_nodes:
        new_nodes = False
        removed = set()
        for k, v in g.items():
            for link in v["links"]:
                if link["target"].startswith("id:"):
                    link["target"] = link["target"][3:]
                if link['target'] in centered_graph and link.get('relation') == 'in':
                    centered_graph[k] = v

                    for l in v["links"]:
                        if l.get('relation') == 'in':
                            t = l['target']
                            if t.startswith("id:"):
                                t = t[3:]

                            if '[' in t:
                                # Special case, to be handled on org_rw
                                continue

                            if t not in in_emacs_tree:
                                in_emacs_tree[t] = set()
                            in_emacs_tree[t].add(k)

                    v['links'] = [
                        l for l in v["links"]
                        if l.get('relation') != 'in'
                    ]


                    removed.add(k)
                    new_nodes = True
                    break
        for k in removed:
            del g[k]

    in_emacs = set(centered_graph.keys())

    # One more round for the rest, not requiring "in"
    for k, v in g.items():
        for link in v["links"]:
            if link["target"].startswith("id:"):
                link["target"] = link["target"][3:]
            if link['target'] in in_emacs:
                centered_graph[k] = v
                removed.add(k)

    g = centered_graph

    with tempfile.NamedTemporaryFile(suffix='.dot', mode='wt') as f:
        f.write('digraph {\n')
        f.write('maxiter=1000\n')
        f.write('splines=curved\n')
        # f.write('splines=spline\n') # Not supported with edges to cluster
        f.write('node[shape=rect]\n')

        def draw_subgraph(node_id):
            f.write("subgraph cluster_{} {{\n".format(node_id.replace("-", "_")))
            f.write('URL="./{}.node.html"\n'.format(node_id))

            f.write("label=\"{}\"\n".format(g[node_id]['title'].replace("\"", "'")))
            f.write("\n")

            # print("T: {}".format(in_emacs_tree), file=sys.stderr)
            for k in in_emacs_tree[node_id]:
                v = g[k]
                print("_" + k.replace("-", "_") + "[label=\"" + v["title"].replace("\"", "'") + "\", URL=\"" + k + ".node.html\"];", file=f)

                if k in in_emacs_tree:
                    draw_subgraph(k)

            f.write("\n}")

        draw_subgraph(reference_node)

        for k, v in g.items():
            if k not in in_emacs:
                print("_" + k.replace("-", "_") + "[label=\"" + v["title"].replace("\"", "'") + "\", URL=\"" + k + ".node.html\"];", file=f)

        for k, v in g.items():
            for link in v["links"]:
                if link["target"].startswith("id:"):
                    link["target"] = link["target"][3:]

                if '[' in link['target']:
                    # Special case, to be handled on org_rw
                    continue
                if link['target'] not in g:
                    # Irrelevant
                    continue
                if link['target'] in in_emacs_tree:
                    t = 'cluster_{}'.format(link['target'].replace("-", "_"))
                else:
                    t = "_" + link["target"].replace("-", "_")
                print("_" + k.replace("-", "_") + "->" + t, file=f)

        f.write('}\n')
        f.close()

        with tempfile.NamedTemporaryFile(suffix='.svg') as fsvg:
            subprocess.call("fdp graph.dot -Tsvg -o '{}'".format(fsvg.name), shell=True)
            fsvg.seek(0)
            return fsvg.read().decode()