import math
import os
import uuid

# TODO:
# Add hidden nodes in each cluster above visible nodes connected by hidden edges and attach visible edges to them
# - also see: https://stackoverflow.com/questions/53862417/how-to-set-head-and-tail-position-in-nodes-graphviz
# Solve layering of clusters
# - https://observablehq.com/@gordonsmith/church
# https://candide-guevara.github.io/cs_related/2019/09/10/graphviz-examples.html
# https://forum.graphviz.org/t/set-nodes-from-left-to-right-and-other-from-top-to-bottom-on-the-same-rank/1860



def make_header(config):
    return "graph {\n" + config["graph"] + "\n"

def make_footer():
    return "}\n"

def make_node_line(node, config):
    line = f"{node['id']} [label=\"{node['text']}\"\n"
    if node['hidden']:
        line += config["node"]["hidden"]
    else:
        line += config["node"]["text"]
    return line + "]\n"

def make_link_line(link, config):
    configs = []
    if link['head'] != "":
        configs.append(f"lhead=cluster_{link['head']}")
    if link['hidden']:
        configs.append(config["edge"]["hidden"])
    else:
        configs.append(config["edge"]["default"])
    
    line = f"{link['from']} -- {link['to']}"
    if len(configs) > 0:
        line += " [" + ", ".join(configs) + "]"
    return line + "\n"

def make_block_line(block, config):
    configs = []
    if block['hidden']:
        configs.append(config["subgraph"]["hidden"])
    else:
        configs.append(config["subgraph"]["block"])
    
    config_line = "\n".join(configs)
    
    line = f"subgraph cluster_{block['id']} {{\n{config_line}\nlabel=\"{block['label']}\"\n"
    for node in block["nodes"]:
        line += f"{node}\n"
    #if block['hidden']:
        #line += "{rank=same\nedge [constraint=false]\n"
        #line += f"{block['nodes'][0]} -- {block['nodes'][1]}\n"
        #line += "}"
    return line + "}\n\n"



def add_nodes(nodes, config):
    line = ""
    for node in nodes:
        line += make_node_line(node, config)
    return line

def add_links(links, config):
    line = ""
    for link in links:
        line += make_link_line(link, config)
    return line

def add_blocks(blocks, config):
    line = ""
    for block in blocks:
        line += make_block_line(block, config)
    return line



def get_id():
    return "id" + str(uuid.uuid4().hex)



class Graph:
    def __init__(self):
        self.config = {}

        self.blocks = []
        self.nodes = []
        self.links = []
        self.dot_file = ""
    
    def __str__(self):
        return self.dot_file
    
    def set_config(self, config):
        dot = config.get("dot", {})
        if dot != {}:
            dot["graph"] = dot.get("graph", "")
            dot["subgraph"] = dot.get("subgraph", {})
            dot["subgraph"]["block"] = dot["subgraph"].get("block", "")
            dot["subgraph"]["hidden"] = dot["subgraph"].get("hidden", "")
            dot["node"] = dot.get("node", {})
            dot["node"]["text"] = dot["node"].get("text", "")
            dot["node"]["hidden"] = dot["node"].get("hidden", "")
            dot["edge"] = dot.get("edge", {})
            dot["edge"]["default"] = dot["edge"].get("default", "")
            dot["edge"]["middle"] = dot["edge"].get("middle", "")
            dot["edge"]["hidden"] = dot["edge"].get("hidden", "")
        self.config = dot
    
    def process_blocks(self, data):
        blocks = data.get('blocks', [])
        linker = {}
        
        for block in blocks:
            block_id = get_id()
            
            new_block = {
                "id": block_id,
                "label": block.get("label", ""),
                "nodes": [],
                "hidden": False
            }

            texts_in_block = block.get("texts", [])
            for i, text in enumerate(texts_in_block):
                node_id = get_id()
                
                # Link to middle node
                if i == math.ceil(len(texts_in_block) / 2) - 1:
                    for link in block.get("links", []):
                        if link in linker:
                            """link_node1 = get_id()
                            link_node2 = get_id()

                            self.nodes.append({"id": link_node1, "text": "", "hidden": True})
                            self.nodes.append({"id": link_node2, "text": "", "hidden": True})

                            link_block_id = get_id()
                            self.blocks.append({"id": link_block_id, "label": "", "nodes": [link_node1, link_node2], "hidden": True})

                            self.links.append({"from": linker[link], "to": link_node1, "head": "", "hidden": False})
                            #self.links.append({"from": link_node1, "to": link_node2, "head": "", "hidden": False})
                            self.links.append({"from": link_node2, "to": node_id, "head": block_id, "hidden": False})"""
                            self.links.append({"from": linker[link], "to": node_id, "head": block_id, "hidden": False})
                            del linker[link]
                
                self.nodes.append({"id": node_id, "text": text.get("text", ""), "hidden": False})
                
                new_block["nodes"].append(node_id)

                for link in text.get("links", []):
                    linker[link] = node_id
            
            self.blocks.append(new_block)

    def build_dot(self):
        self.dot_file = make_header(self.config)
        self.dot_file += add_nodes(self.nodes, self.config)
        self.dot_file += add_blocks(self.blocks, self.config)
        self.dot_file += add_links(self.links, self.config)
        self.dot_file += make_footer()
    
    def make_dot(self, format="svg", dot_file="dot.gv", svg_file="graph.svg"):
        if self.dot_file != "":
            with open(dot_file, "w") as f:
                f.write(self.dot_file)
            if format == "svg":
                os.system(f"dot -T{format} {dot_file} -o {svg_file}")