from email.policy import default
import os
import re
import bcrypt
import dotenv
from flask import (
    Flask,
    flash,
    redirect,
    render_template,
    request,
    session,
    url_for,
)
from flask_sqlalchemy import SQLAlchemy
from sqlalchemy.orm import DeclarativeBase
from sqlalchemy.sql import func
from sqlalchemy.exc import IntegrityError


dotenv.load_dotenv()
app = Flask(__name__)
app.secret_key = os.getenv("SECRET_KEY", "whataloadofnonsense")


class Base(DeclarativeBase):
    pass


app.config["SQLALCHEMY_DATABASE_URI"] = (
    f"mysql://root:root@{os.getenv('DB_HOST', "db")}:3306/topperstasks"
)
db = SQLAlchemy(model_class=Base)
db.init_app(app)


class User(db.Model):
    __tablename__ = "users"
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String, unique=True, nullable=False)
    passhash = db.Column(db.String, nullable=False)
    is_admin = db.Column(db.Boolean, default=False)

    tasks = db.relationship("Task", back_populates="user")
    task_assignments = db.relationship("Task_Assignment", back_populates="user")


class Task(db.Model):
    __tablename__ = "tasks"
    id = db.Column(db.Integer, primary_key=True)
    created_datetime = db.Column(db.String, nullable=False, default=func.now())
    tasktext = db.Column(db.String, nullable=False)
    created_by = db.Column(db.Integer, db.ForeignKey(User.id), nullable=False)
    due = db.Column(db.String)
    completed = db.Column(db.Boolean, default=False)
    deleted = db.Column(db.Boolean, default=False)

    user = db.relationship(User, back_populates="tasks")
    task_assignments = db.relationship("Task_Assignment", back_populates="task")


class Task_Assignment(db.Model):
    __tablename__ = "task_assignments"
    id = db.Column(db.Integer, primary_key=True)
    user_id = db.Column(db.Integer, db.ForeignKey(User.id), nullable=False)
    task_id = db.Column(db.Integer, db.ForeignKey(Task.id), nullable=False)

    user = db.relationship(User, back_populates="task_assignments")
    task = db.relationship(Task, back_populates="task_assignments")


@app.route("/")
def home(completed=False):
    if not session.get("userid"):
        return redirect(url_for("login"))

    select = (
        db.select(Task)
        .where(Task.deleted == False)
        .order_by(Task.created_datetime.desc())
    )

    if completed:
        select = select.where(Task.completed == True)
    else:
        select = select.where(Task.completed == False)

    tasks = db.session.execute(select).scalars().all()

    for task in tasks:
        task.assignees = ""

        assignees = (
            db.session.execute(
                db.select(User)
                .join(Task_Assignment)
                .where(Task_Assignment.task_id == task.id)
            )
            .scalars()
            .all()
        )

        for assignee in assignees:
            task.assignees += assignee.username + ", "
        task.assignees = task.assignees[:-2] if task.assignees else "[NONE]"

    users = db.session.execute(db.select(User)).scalars().all()

    return render_template(
        "home.html", tasks=tasks, completed=completed, users=users
    )


@app.route("/completed")
def completed():
    return home(completed=True)


@app.route("/account", methods=["GET", "POST"])
def account():
    if not session.get("userid"):
        return redirect(url_for("login"))

    user = db.session.execute(
        db.select(User).where(User.id == session.get("userid"))
    ).scalar_one_or_none()

    if not user:
        return redirect(url_for("login"))

    if request.method == "POST":
        if newpassword := request.form.get("newpassword"):
            if not bcrypt.checkpw(
                request.form.get("oldpassword").encode(), user.passhash.encode()
            ):
                flash("Incorrect Password", category="warning")
                return redirect(url_for("account"))

            salt = bcrypt.gensalt()
            user.passhash = bcrypt.hashpw(newpassword.encode(), salt)
            db.session.commit()
            flash("Updated Password", category="success")
            return redirect(url_for("account"))

        if username := request.form.get("username"):
            user.username = username
            db.session.commit()
            flash("Updated Username", category="success")
            return redirect(url_for("account"))

        flash("Failed to update", category="warning")
        return redirect(url_for("account"))

    return render_template("account.html", user=user)


@app.route("/login", methods=["GET", "POST"])
def login():
    if request.method == "POST":
        try:
            username = request.form.get("user")
            password = request.form.get("password")

            user: User = db.session.execute(
                db.select(User).where(User.username == username)
            ).scalar_one_or_none()

            if not user:
                flash("Failed to login", category="warning")
                return redirect(url_for("login"))

            if not user.passhash:
                if not password:
                    flash("Can't set a blank password")
                    return redirect(url_for("login"))

                salt = bcrypt.gensalt()
                user.passhash = bcrypt.hashpw(password.encode(), salt)
                db.session.commit()
                flash("Password set succesfully!", category="success")
                return redirect(url_for("login"))

            if bcrypt.checkpw(password.encode(), user.passhash.encode()):
                session["userid"] = user.id
                return redirect(url_for("home"))
            else:
                flash("Failed to login", category="warning")
                return redirect(url_for("login"))
        except:
            flash("Critical Error, contact Peter pls", category="danger")
            return redirect(url_for("login"))

    return render_template("login.html")


@app.route("/addtask", methods=["POST"])
def addtask():
    if not session.get("userid"):
        return redirect(url_for("login"))
    try:
        tasktext = request.form.get("task-text")
        user_id = session.get("userid")

        if not tasktext:
            flash("Invalid task text", category="warning")
            return redirect(url_for("home"))

        if not user_id:
            return redirect(url_for("login"))

        newtask = Task(tasktext=tasktext, created_by=user_id)
        db.session.add(newtask)
        db.session.commit()
    except:
        flash("Critical Error, contact Peter pls", category="danger")
        return redirect(url_for("home"))

    return redirect(url_for("home"))


@app.route("/updatetask", methods=["POST"])
def updatetask():
    if not session.get("userid"):
        return redirect(url_for("login"))
    if "task-id" not in request.form:
        flash("Failed to find task", category="warning")
        return redirect(url_for("home"))

    task = db.session.execute(
        db.select(Task).where(Task.id == request.form.get("task-id"))
    ).scalar_one_or_none()

    if not task:
        flash("Failed to find task", category="warning")
        return redirect(url_for("home"))

    if "due" in request.form:
        due = request.form.get("due")
        if not due:
            flash("Invalid due date", category="warning")
            return redirect(url_for("home"))

        datetime_str = due
        datetime_str = datetime_str.replace("T", " ")
        datetime_str += ":00"
        app.logger.info(datetime_str)
        task.due = datetime_str

    if "assignee" in request.form:
        assignee = request.form.get("assignee")
        if not assignee:
            flash("Invalid assignee", category="warning")
            return redirect(url_for("home"))

        assignment = Task_Assignment(user_id=assignee, task_id=task.id)
        db.session.add(assignment)

    if "completed" in request.form:
        task.completed = not task.completed

    try:
        db.session.commit()
    except IntegrityError as e:
        flash("Database error, what did you just try to do?", category="danger")

    return redirect(url_for("home"))


@app.route("/admin", methods=["GET", "POST"])
def admin():
    if not session.get("userid"):
        return redirect(url_for("login"))
    user = db.session.execute(
        db.select(User).where(User.id == session.get("userid"))
    ).scalar_one_or_none()
    if not user or not user.is_admin:
        flash("You are not an admin!", category="danger")
        return redirect(url_for("home"))

    if request.method == "POST":
        if userid := request.form.get("userid-reset"):
            resetuser = db.session.execute(
                db.select(User).where(User.id == userid)
            ).scalar_one_or_none()
            resetuser.passhash = None
            db.session.commit()
            flash("Reset user's password succesfully", category="success")
            return redirect(url_for("admin"))

        if newusername := request.form.get("username-add"):
            newuser = User()
            newuser.username = newusername
            db.session.add(newuser)
            db.session.commit()
            flash("New user added successfully", category="success")
            return redirect(url_for("admin"))

        if newadminid := request.form.get("userid-admin"):
            newadmin = db.session.execute(
                db.select(User).where(User.id == newadminid)
            ).scalar_one_or_none()

            if newadmin.is_admin:
                flash("User is already an admin", category="warning")
                return redirect(url_for("admin"))

            newadmin.is_admin = True
            db.session.commit()
            flash("User is now an admin", category="success")
            return redirect(url_for("admin"))

    users = db.session.execute(db.select(User)).scalars().all()
    return render_template("admin.html", users=users)


@app.route("/logout", methods=["POST"])
def logout():
    session.pop("userid", None)
    return redirect(url_for("login"))


if __name__ == "__main__":
    app.run(host="0.0.0.0", debug=True)