import matplotlib as mt
import matplotlib.pyplot as plt

class Graph:
    def __init__(self, key):
        self.key = key
        self.data = None # internal data structure modified and used by self.process and self.draw
    
    # increment dictionary entry by val, initially setting to default if it does not exist
    def inc(self, rel: dict, key, val=1, default=0):
        self.validate(rel, key, default)
        rel[key] += val
    
    # check if key exists in rel. if not init it
    def validate(self, rel: dict, key, default=0):
        if key not in rel:
            rel[key] = default

    # called for every line in the log file. returns any error messages
    def process(self, ip, time, request, size, location, log):
        raise NotImplementedError()
    
    # create and save graph from self.data
    def draw(self, path):
        raise NotImplementedError()

    _COLORS = {}
    # given a set of labels, assign/get a consistent color scheme
    # used to ensure that every label has a consistent color that is persisted across graphs
    def getColors(self, names, category='country'):
        if category not in Graph._COLORS:
            # as func to get infinite cycle
            Graph._COLORS[category] = {'_cycle': iter(mt.cycler(plt.rcParams['axes.prop_cycle'])())}
        
        out = []
        c = Graph._COLORS[category]
        for n in names:
            if n not in c:
                c[n] = next(c['_cycle'])['color']
            out.append(c[n])
        
        return out

    # called at end of program to recycle any memory, if needed
    def close(self):
        pass