import os
from pathlib import Path
from typing import Dict, List, Optional, Union

import requests
import yaml
from dateutil import parser
from django.conf import settings
from django.http import Http404
from markdown2 import markdown

COMMITS_URL = "https://api.github.com/repos/{owner}/{name}/commits?path={path}&sha={branch}"
BASE_ARTICLES_LOCATION = "pydis_site/apps/content/resources/content/"


def _get_base_path() -> Path:
    """Have extra function for base path getting for testability."""
    return Path(settings.BASE_DIR, "pydis_site", "apps", "content", "resources", "content")


def get_category(category: str) -> Dict[str, str]:
    """Load category information by name from _info.yml."""
    path = _get_base_path().joinpath(category)
    if not path.exists() or not path.is_dir():
        raise Http404("Category not found.")

    return yaml.safe_load(path.joinpath("_info.yml").read_text())


def get_categories() -> Dict[str, Dict]:
    """Get all categories information."""
    base_path = _get_base_path()
    categories = {}

    for name in base_path.iterdir():
        if name.is_dir():
            categories[name.name] = get_category(name.name)

    return categories


def get_articles(category: Optional[str] = None) -> Dict[str, Dict]:
    """Get all root or category articles."""
    if category is None:
        base_dir = _get_base_path()
    else:
        base_dir = _get_base_path().joinpath(category)

    articles = {}

    for item in base_dir.iterdir():
        if item.is_file() and item.name.endswith(".md"):
            md = markdown(item.read_text(), extras=["metadata"])
            articles[os.path.splitext(item.name)[0]] = md.metadata

    return articles


def get_article(article: str, category: Optional[str]) -> Dict[str, Union[str, Dict]]:
    """Get one specific article. When category is specified, get it from there."""
    if category is None:
        base_path = _get_base_path()
    else:
        base_path = _get_base_path().joinpath(category)

        if not base_path.exists() or not base_path.is_dir():
            raise Http404("Category not found.")

    article_path = base_path.joinpath(f"{article}.md")
    if not article_path.exists() or not article_path.is_file():
        raise Http404("Article not found.")

    html = markdown(
        article_path.read_text(),
        extras=[
            "metadata",
            "fenced-code-blocks",
            "header-ids",
            "strike",
            "target-blank-links",
            "tables",
            "task_list"
        ]
    )

    return {"article": str(html), "metadata": html.metadata}


def get_github_information(
        article: str,
        category: Optional[str] = None
) -> Dict[str, Union[List[str], str]]:
    """Get article last modified date and contributors from GitHub."""
    result = requests.get(
        COMMITS_URL.format(
            owner=settings.SITE_REPOSITORY_OWNER,
            name=settings.SITE_REPOSITORY_NAME,
            branch=settings.SITE_REPOSITORY_BRANCH,
            path=f"{BASE_ARTICLES_LOCATION}{f'{category}/' if category else ''}{article}.md"
        )
    )

    if result.status_code == 200:
        data = result.json()
        return {
            "last_modified": parser.isoparse(
                data[0]["commit"]["committer"]["date"]
            ).strftime("%dth %B %Y"),
            "contributors": {
                c["commit"]["committer"]["name"]: c["committer"]["html_url"] for c in data
            }
        }
    else:
        return {
            "last_modified": "N/A",
            "contributors": {}
        }