import hashlib
from datetime import date, datetime, time, timedelta

from flask import Blueprint, redirect, render_template, request, url_for

from .database import get_db

bp = Blueprint("public", __name__)

VOTE_COOKIE_NAME = "wyr_daily_vote"


def get_todays_question():
    db = get_db()
    today = date.today().isoformat()

    return db.execute(
        """
        SELECT id, question, option_a, option_b, date
        FROM questions
        WHERE date = ?
        LIMIT 1
        """,
        (today,),
    ).fetchone()


def get_question_version(question):
    parts = (
        str(question["id"]),
        question["date"],
        question["question"],
        question["option_a"],
        question["option_b"],
    )
    fingerprint = "\x1f".join(parts)

    return hashlib.sha256(fingerprint.encode()).hexdigest()


def get_vote_cookie_value(question):
    return f"{question['date']}:{question['id']}:{get_question_version(question)}"


def get_seconds_until_tomorrow():
    now = datetime.now()
    tomorrow = datetime.combine(date.today() + timedelta(days=1), time.min)

    return max(1, int((tomorrow - now).total_seconds()))


def has_voted_for_question(question):
    return request.cookies.get(VOTE_COOKIE_NAME) == get_vote_cookie_value(question)


def set_vote_cookie(response, question):
    response.set_cookie(
        VOTE_COOKIE_NAME,
        get_vote_cookie_value(question),
        max_age=get_seconds_until_tomorrow(),
        httponly=True,
        samesite="Lax",
    )

    return response


@bp.route("/")
def home():
    question = get_todays_question()

    return render_template(
        "public/index.html",
        question=question,
    )


@bp.route("/vote", methods=["POST"])
def vote():
    qid = request.form.get("qid")
    selected_vote = request.form.get("vote")

    if not qid or selected_vote not in {"A", "B"}:
        return redirect(url_for("public.home"))

    db = get_db()
    question = get_todays_question()

    if question is None or str(question["id"]) != str(qid):
        return redirect(url_for("public.home"))

    if has_voted_for_question(question):
        return redirect(url_for("public.results"))

    db.execute(
        """
        INSERT INTO votes (question_id, vote, voter_hash)
        VALUES (?, ?, ?)
        """,
        (qid, selected_vote, "cookie"),
    )
    db.commit()

    response = redirect(url_for("public.results"))
    return set_vote_cookie(response, question)


@bp.route("/results")
def results():
    question = get_todays_question()

    if question is None:
        return render_template(
            "public/results.html",
            question=None,
            votes_a=0,
            votes_b=0,
            percent_a=0,
            percent_b=0,
            total=0,
        )

    db = get_db()

    votes_a = db.execute(
        """
        SELECT COUNT(*)
        FROM votes
        WHERE question_id = ?
        AND vote = 'A'
        """,
        (question["id"],),
    ).fetchone()[0]

    votes_b = db.execute(
        """
        SELECT COUNT(*)
        FROM votes
        WHERE question_id = ?
        AND vote = 'B'
        """,
        (question["id"],),
    ).fetchone()[0]

    total = votes_a + votes_b

    if total == 0:
        percent_a = 0
        percent_b = 0
    else:
        percent_a = round(votes_a / total * 100)
        percent_b = round(votes_b / total * 100)

    return render_template(
        "public/results.html",
        question=question,
        votes_a=votes_a,
        votes_b=votes_b,
        percent_a=percent_a,
        percent_b=percent_b,
        total=total,
    )