import requests
import datetime
from matplotlib import pyplot as plt

PULLS_URL = "https://api.github.com/repos/{owner}/{repo}/pulls"


class TooManyRequests(Exception):
    pass


class RepoPulls:
    def __init__(self, owner, repo, user=None, token=None):
        self.owner = owner
        self.repo = repo
        self.url = PULLS_URL.format(owner=self.owner, repo=self.repo)
        self.auth = None
        if user and token:
            self.auth = requests.auth.HTTPBasicAuth(user, token)
        self._pulls = {"open": None, "close": None}

    def get_pulls(self, state="open", verbose=True):
        assert state in self._pulls
        if self._pulls[state] is None:
            pulls = []
            with requests.Session() as session:
                if self.auth:
                    session.auth = self.auth
                cur_page = 1
                while True:
                    if verbose:
                        print("Requesting page {}...".format(cur_page))
                    req = session.get(
                        self.url,
                        params={"state": state, "page": cur_page, "per_page": 100},
                    )
                    if req.status_code in (403, 429):
                        raise TooManyRequests(
                            "GitHub doesn't want to hear from us anymore :c"
                        )
                    cur_pulls = req.json()
                    if len(cur_pulls) == 0:
                        break
                    cur_page += 1
                    pulls += cur_pulls

            self._pulls[state] = pulls

        return self._pulls[state]

    def get_open_ages(self):
        pulls = self.get_pulls("open")
        created_dates = [
            datetime.date.fromisoformat(pull["created_at"][:10]) for pull in pulls
        ]
        today = datetime.date.today()
        ages = [(today - created_on).days for created_on in created_dates]

        return ages

    def plot_ages(self, *args, show=False, **kwargs):
        ages = self.get_open_ages()
        plt.hist(ages, *args, **kwargs)
        if show:
            plt.show()