import os
import subprocess
import sys
from datetime import datetime, timedelta

import requests

LIMIT_COMMITS_30_DAYS = 50
LIMIT_STARS = 200
LIMIT_NLOC = 100000
MARGIN = 0.1
CLONE_DIR = "~/temp/PICable"
EXCLUDED_LANGUAGES = ["CSV", "diff", "INI", "JSON", "Markdown", "reStructuredText", "SVG", "Text", "YAML"]


def get_stars_info(owner, repository, request_headers):
    stars_url = f"https://api.github.com/repos/{owner}/{repository}"
    stars_response = requests.get(stars_url, headers=request_headers)

    if stars_response.status_code != 200:
        return -1

    stars = stars_response.json()["stargazers_count"]
    return stars


def get_commits_last_30_days(owner, repository, request_headers):
    since = (datetime.now() - timedelta(days=30)).isoformat()
    commits_url = f"https://api.github.com/repos/{owner}/{repository}/commits?since={since}"
    commits_response = requests.get(commits_url, headers=request_headers)

    if commits_response.status_code != 200:
        return -1

    if "link" in commits_response.headers:
        page_count = int(
            commits_response.headers["link"].split(", ")[-1].split("; ")[0].split("page=")[1].split(">")[0]
        )

        last_commits_url = f"{commits_url}&page={page_count}"
        last_commits_response = requests.get(last_commits_url, headers=request_headers)

        if last_commits_response.status_code != 200:
            return -1

        return (page_count - 1) * 30 + len(last_commits_response.json())
    return len(commits_response.json())


def get_lines_of_code(owner, repository):
    repository_url = f"https://github.com/{owner}/{repository}.git"
    parent_dir = os.path.expanduser(f"{CLONE_DIR}/{owner}")
    repository_clone_dir = os.path.expanduser(f"{parent_dir}/{repository}")

    try:
        subprocess.run(
            ["git", "clone", "--depth", "1", repository_url, repository_clone_dir],
            check=True,
            stdout=sys.stdout,
            stderr=sys.stderr,
        )
        result = subprocess.run(
            ["cloc", f"--exclude-lang={','.join(EXCLUDED_LANGUAGES)}", repository_clone_dir],
            capture_output=True,
            text=True,
            check=True,
        )
        number_of_lines_of_code = int(result.stdout.split("\n")[-3].split()[-1])
    except Exception:
        return -1
    finally:
        subprocess.run(["rm", "-rf", parent_dir], check=True)
    return number_of_lines_of_code


def is_valid_repository(owner, repository, request_headers):
    repository_url = f"https://api.github.com/repos/{owner}/{repository}"
    repository_response = requests.get(repository_url, headers=request_headers)
    return repository_response.status_code == 200


def PICable(owner, repository, token):
    margin_percentage = round(MARGIN * 100)
    request_headers = {"Authorization": f"token {token}"}
    picable_report = f"Analysis complete for the repository {owner}/{repository}.\n\n"
    repository_url = f"https://www.github.com/{owner}/{repository}"

    if not is_valid_repository(owner, repository, request_headers):
        return f"Invalid repository: {owner}/{repository} :x:"

    stars = get_stars_info(owner, repository, request_headers)
    if stars == -1:
        return "Error fetching stars info. :x:"

    if stars >= LIMIT_STARS:
        picable_report += (
            f"The repository has {stars} stars, which meets the requirement of {LIMIT_STARS}. :white_check_mark:\n"
        )
    elif stars >= LIMIT_STARS * (1 - MARGIN):
        picable_report += f"The repository has {stars} stars, which is close to the requirement of {LIMIT_STARS}, considering a {margin_percentage}% margin. :warning:\n"
    else:
        picable_report += f"The repository has {stars} stars, which is way below the requirement of {LIMIT_STARS}, even if considering a {margin_percentage}% margin. :x:\n"

    commits_30_days = get_commits_last_30_days(owner, repository, request_headers)
    if commits_30_days == -1:
        return "Error fetching commit info. :x:"

    if commits_30_days >= LIMIT_COMMITS_30_DAYS:
        picable_report += f"The repository has {commits_30_days} commits on the default branch in the last 30 days, which meets the requirement of {LIMIT_COMMITS_30_DAYS}. :white_check_mark:\n"
    elif commits_30_days >= LIMIT_COMMITS_30_DAYS * (1 - MARGIN):
        picable_report += f"The repository has {commits_30_days} commits on the default branch in the last 30 days, which is close to the requirement of {LIMIT_COMMITS_30_DAYS}, considering a {margin_percentage}% margin. :warning:\n"
    else:
        picable_report += f"The repository has {commits_30_days} commits on the default branch in the last 30 days, which is way below the requirement of {LIMIT_COMMITS_30_DAYS}, even if considering a {margin_percentage}% margin. :x:\n"

    lines_of_code = get_lines_of_code(owner, repository)
    if lines_of_code == -1:
        return "Error fetching lines of code info. :x:"

    if lines_of_code >= LIMIT_NLOC:
        picable_report += f"The repository has {lines_of_code} lines of code, which meets the requirement of at least {LIMIT_NLOC}. :white_check_mark:\n"
    elif lines_of_code >= LIMIT_NLOC * (1 - MARGIN):
        picable_report += f"The repository has {lines_of_code} lines of code, which is close to the requirement of {LIMIT_NLOC}, considering a {margin_percentage}% margin. :warning:\n"
    else:
        picable_report += f"The repository has {lines_of_code} lines of code, which is way below the requirement of {LIMIT_NLOC}, even if considering a {margin_percentage}% margin. :x:\n"

    picable_report += "\n"

    if (
        stars < LIMIT_STARS * (1 - MARGIN)
        or commits_30_days < LIMIT_COMMITS_30_DAYS * (1 - MARGIN)
        or lines_of_code < LIMIT_NLOC * (1 - MARGIN)
    ):
        picable_report += f"The repository {repository_url} is not PICable. :x:\nThere is at least one requirement which is more than {margin_percentage}% below the requirement.\n"
    elif stars >= LIMIT_STARS and commits_30_days >= LIMIT_COMMITS_30_DAYS and lines_of_code >= LIMIT_NLOC:
        picable_report += f"The repository {repository_url} is PICable. :white_check_mark:\n"
    else:
        picable_report += f"The repository {repository_url} is almost PICable. :warning:\nThere is at least one parameter which is below the requirement, but by less than {margin_percentage}%.\nConsult with a professor before proceeding.\n"

    print("Analysis complete.")
    return picable_report