"""
This blueprint deals with everything under /api/projects/.

Used environment variables:
    GITEA_URL: The URL (either intenral or external) to the Gitea instance to pull data from.
    GITEA_TOKEN: The API token for the crawler user. Only requires repository.read.
"""

from urllib.parse import urlencode, urlparse, urlunparse, ParseResult
from io import BytesIO
import logging
import string
import os

import requests
import flask
import magic

log = logging.getLogger('blueprints.projects')

class Blueprint(flask.Blueprint):
    """
    Holds the required data for this blueprint to work.
    Automatically gets the UID for the logged in user,
    and gives access to a simple constructURL() function
    to make API calls without specifying the token each time.
    """

    def __init__(self, *args, **kwargs):
        self._baseURL = urlparse(os.getenv('GITEA_URL'))
        self._apiKey = os.getenv('GITEA_TOKEN')
        self.giteaUID = None

        try:
            r = requests.get(self.constructURL('/api/v1/user'), timeout=5)

            if r.ok:
                self.giteaUID = r.json().get('id')
            else:
                log.error('Cannot get Gitea user ID. This blueprint will not work.')
        except requests.exceptions.ConnectionError:
            log.error('Failed to connect to Gitea server. This blueprint will not work.')

        super().__init__(*args, **kwargs)

    def constructURL(self, apiPath: str, query: dict=None) -> str:
        """
        Construcs an API url from the path and queries.
        """

        if query is None:
            query = {}

        query.update({'token': self._apiKey})

        newURL = ParseResult(scheme=self._baseURL.scheme, netloc=self._baseURL.netloc,
                             path=apiPath, params='', query=urlencode(query), fragment='')
        return urlunparse(newURL)

projectsBP = Blueprint('projectsAPI', __name__)

def generateStrippedProjectData(data: dict) -> dict:
    """
    Generates the stripped down project data that the front-end expects.
    """

    # ----- Languages -----
    # Get the languages path and request it
    path = urlparse(data['languages_url']).path
    r = requests.get(projectsBP.constructURL(path), timeout=5)
    languages = r.json()
    # Convert all languages from bytes to percentages
    languages = {lang: size / sum(languages.values()) for lang, size in languages.items()}

    # ----- Image -----
    if not data.get('avatar_url', '') == '':
        # Get the avatar URL
        avatarUrl = urlparse(data['avatar_url'])
        # Parse the URL to get just the hash
        imgHash = avatarUrl.path.split('/')[-1:][0]
        # Create an API path for that image
        imgPath = f'/api/projects/img/{imgHash}'
    else:
        imgPath = None

    # ----- Git URL -----
    if not data.get('private'):
        gitUrl = data.get('html_url')
    else:
        gitUrl = None

    newData = {}
    newData.update({'name': data.get('name')})
    newData.update({'desc': data.get('description')})
    newData.update({'issues': data.get('open_issues_count')})
    newData.update({'langs': languages})
    newData.update({'gitUrl': gitUrl})
    newData.update({'imgPath': imgPath})
    return newData

@projectsBP.route('/api/projects', strict_slashes=False)
def projectsList():
    """
    Returns a filtered list of Gitea projects.
    """

    # Request for all Gitea projects that the crawler account is a contributor in
    r = requests.get(projectsBP.constructURL('/api/v1/repos/search',
                     {'exclusive': False, 'uid': projectsBP.giteaUID}), timeout=5)
    if r.ok:
        # Filter down every repo with generateStrippedProjectData()
        projects = [generateStrippedProjectData(data) for data in r.json().get('data')]
        return projects
    else:
        flask.abort(500)

@projectsBP.route('/api/projects/img/<imgHash>', strict_slashes=False)
def img(imgHash: str):
    """
    Forwards images from Gitea's /repo-avatars.
    """

    # Filter the hash
    imgHash = ''.join([c for c in imgHash if c in string.ascii_lowercase+string.digits])
    # Make the request the Gitea
    r = requests.get(projectsBP.constructURL(f'/repo-avatars/{imgHash}'), timeout=5)
    # Get the MIME type
    mime = magic.from_buffer(BytesIO(r.content).read(128), mime=True)
    # Send the image
    content = BytesIO(r.content)
    return flask.send_file(content, mime)