from __future__ import annotations

import os
from datetime import date, datetime
from pathlib import Path

from flask import Flask, flash, redirect, render_template, request, send_from_directory, url_for
from flask_login import LoginManager, UserMixin, current_user, login_required, login_user, logout_user
from flask_sqlalchemy import SQLAlchemy
from sqlalchemy import func, select
from werkzeug.security import check_password_hash, generate_password_hash

from reporting.report_builder import build_validation_report

db = SQLAlchemy()
login_manager = LoginManager()
BASE_DIR = Path(__file__).resolve().parent
GENERATED_DIR = BASE_DIR / "generated"
GENERATED_DIR.mkdir(exist_ok=True)


class User(UserMixin, db.Model):
    __tablename__ = "users"
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(100), unique=True, nullable=False)
    password_hash = db.Column(db.String(255), nullable=False)

    def set_password(self, password):
        self.password_hash = generate_password_hash(password)

    def check_password(self, password):
        return check_password_hash(self.password_hash, password)


class Customer(db.Model):
    __tablename__ = "customers"
    id = db.Column(db.Integer, primary_key=True)
    practice_name = db.Column(db.String(180), nullable=False)
    operator_name = db.Column(db.String(180), nullable=False)
    contact_person = db.Column(db.String(180))
    hygiene_contact = db.Column(db.String(180))
    street = db.Column(db.String(180))
    postal_code = db.Column(db.String(20))
    city = db.Column(db.String(120))
    email = db.Column(db.String(180))
    phone = db.Column(db.String(80))

    @property
    def address(self):
        return ", ".join(x for x in [
            self.street or "",
            f"{self.postal_code or ''} {self.city or ''}".strip()
        ] if x)


class Device(db.Model):
    __tablename__ = "devices"
    id = db.Column(db.Integer, primary_key=True)
    customer_id = db.Column(db.Integer, db.ForeignKey("customers.id"), nullable=False)
    manufacturer = db.Column(db.String(120), nullable=False)
    model = db.Column(db.String(120), nullable=False)
    serial_number = db.Column(db.String(120), unique=True, nullable=False)
    year_built = db.Column(db.String(20))
    commissioning_date = db.Column(db.Date)
    chamber_volume = db.Column(db.String(50))
    steam_generation = db.Column(db.String(180))
    water_supply = db.Column(db.String(180))
    documentation = db.Column(db.String(180))
    supplier = db.Column(db.String(180))
    customer = db.relationship("Customer", backref="devices")


class Equipment(db.Model):
    __tablename__ = "equipment"
    id = db.Column(db.Integer, primary_key=True)
    designation = db.Column(db.String(150), nullable=False)
    manufacturer = db.Column(db.String(120))
    model = db.Column(db.String(120))
    serial_number = db.Column(db.String(120), unique=True, nullable=False)
    measurement_range = db.Column(db.String(150))
    calibration_date = db.Column(db.Date)
    calibration_due = db.Column(db.Date)
    equipment_type = db.Column(db.String(80))


class Validation(db.Model):
    __tablename__ = "validations"
    id = db.Column(db.Integer, primary_key=True)
    report_number = db.Column(db.String(60), unique=True, nullable=False)
    customer_id = db.Column(db.Integer, db.ForeignKey("customers.id"), nullable=False)
    device_id = db.Column(db.Integer, db.ForeignKey("devices.id"), nullable=False)
    validation_type = db.Column(db.String(60), nullable=False)
    project = db.Column(db.String(120), nullable=False)
    test_date = db.Column(db.Date, nullable=False)
    test_location = db.Column(db.String(120), nullable=False)
    examiner = db.Column(db.String(150), nullable=False)
    participants = db.Column(db.String(255))
    status = db.Column(db.String(30), default="Entwurf", nullable=False)
    result = db.Column(db.String(30), default="Bestanden", nullable=False)
    room_temperature = db.Column(db.String(20))
    room_humidity = db.Column(db.String(20))
    vacuum_leak_rate = db.Column(db.String(30))
    next_validation = db.Column(db.Date)
    recommendations = db.Column(db.Text)
    notes = db.Column(db.Text)
    customer = db.relationship("Customer")
    device = db.relationship("Device")


@login_manager.user_loader
def load_user(user_id):
    try:
        return db.session.get(User, int(user_id))
    except Exception:
        return None


def parse_date(value):
    if not value:
        return None
    try:
        return datetime.strptime(value, "%Y-%m-%d").date()
    except ValueError:
        return None


def next_report_number():
    count = db.session.scalar(select(func.count()).select_from(Validation)) or 0
    return f"VAL-{datetime.now().year}-{count + 1:04d}"


def seed_demo_data():
    if db.session.scalar(select(func.count()).select_from(Customer)):
        return

    customer = Customer(
        practice_name="Urologische Praxis Muster",
        operator_name="Dr. Max Mustermann",
        contact_person="Dr. Max Mustermann",
        hygiene_contact="Frau Beispiel",
        street="Musterstraße 5",
        postal_code="90459",
        city="Nürnberg",
        email="praxis@example.de",
        phone="0911 123456",
    )
    db.session.add(customer)
    db.session.flush()

    device = Device(
        customer_id=customer.id,
        manufacturer="Euronda",
        model="E10.7",
        serial_number="DEMO-EXN250688",
        year_built="2025",
        commissioning_date=date(2025, 12, 5),
        chamber_volume="23 Liter",
        steam_generation="Eigendampferzeugung",
        water_supply="Automatische Versorgung über Aquafilter",
        documentation="Interne CF-Card, Ausgabe am PC möglich",
        supplier="Medizintechnik Muster",
    )
    db.session.add(device)

    equipment = [
        Equipment(designation="Temperatur Datenlogger 1", manufacturer="Ebro", model="EBI 11 T235", serial_number="15102807", measurement_range="0 °C bis +150 °C", calibration_date=date(2025,1,17), calibration_due=date(2027,1,17), equipment_type="Temperatur"),
        Equipment(designation="Temperatur Datenlogger 2", manufacturer="Ebro", model="EBI 11 T240", serial_number="15211066", measurement_range="0 °C bis +150 °C", calibration_date=date(2025,1,17), calibration_due=date(2027,1,17), equipment_type="Temperatur"),
        Equipment(designation="Temperatur Datenlogger 3", manufacturer="Ebro", model="EBI 11 T240", serial_number="15102538", measurement_range="0 °C bis +150 °C", calibration_date=date(2025,1,17), calibration_due=date(2027,1,17), equipment_type="Temperatur"),
        Equipment(designation="Temperatur Datenlogger 4", manufacturer="Ebro", model="EBI 11 T240", serial_number="15211067", measurement_range="0 °C bis +150 °C", calibration_date=date(2025,1,17), calibration_due=date(2027,1,17), equipment_type="Temperatur"),
        Equipment(designation="Temperatur Datenlogger 5", manufacturer="Ebro", model="EBI 11 T240", serial_number="15125738", measurement_range="0 °C bis +150 °C", calibration_date=date(2025,1,17), calibration_due=date(2027,1,17), equipment_type="Temperatur"),
        Equipment(designation="Drucklogger", manufacturer="Ebro", model="EBI 11 P111", serial_number="15092368", measurement_range="-100 mbar bis 4 bar abs.", calibration_date=date(2025,1,17), calibration_due=date(2027,1,17), equipment_type="Druck"),
    ]
    db.session.add_all(equipment)
    db.session.flush()

    validation = Validation(
        report_number="VAL-DEMO-0001",
        customer_id=customer.id,
        device_id=device.id,
        validation_type="Erstvalidierung",
        project="Erst-Validierung",
        test_date=date(2025, 12, 5),
        test_location="Nürnberg",
        examiner="Andreas Schubert",
        participants="Frau Beispiel, Dr. Max Mustermann",
        status="Entwurf",
        result="Bestanden",
        room_temperature="21 °C",
        room_humidity="41 %",
        vacuum_leak_rate="0,2 mbar/min",
        next_validation=date(2027, 11, 1),
        recommendations="Auflagen und Empfehlungen werden im Kapitel 4.2 dokumentiert.",
        notes="V2-Vorschau: Winlog-Messwerte, Originalbilder, Zertifikate und Logo werden später dynamisch ersetzt.",
    )
    db.session.add(validation)
    db.session.commit()


def create_app():
    app = Flask(__name__)
    app.config.update(
        SECRET_KEY=os.getenv("SECRET_KEY", "validation-v2-local-secret"),
        SQLALCHEMY_DATABASE_URI=os.getenv("DATABASE_URL", "sqlite:///validation-v2.db"),
        SQLALCHEMY_TRACK_MODIFICATIONS=False,
    )
    db.init_app(app)
    login_manager.init_app(app)
    login_manager.login_view = "login"

    @app.route("/register", methods=["GET", "POST"])
    def register():
        if current_user.is_authenticated:
            return redirect(url_for("dashboard"))
        if request.method == "POST":
            username = (request.form.get("username") or "").strip()
            password = request.form.get("password") or ""
            repeat = request.form.get("password_repeat") or ""
            if len(username) < 3 or len(password) < 6 or password != repeat:
                flash("Bitte gültige Zugangsdaten eingeben.", "error")
            elif db.session.scalar(select(User).where(func.lower(User.username) == username.lower())):
                flash("Benutzername bereits vergeben.", "error")
            else:
                user = User(username=username)
                user.set_password(password)
                db.session.add(user)
                db.session.commit()
                return redirect(url_for("login"))
        return render_template("register.html")

    @app.route("/login", methods=["GET", "POST"])
    def login():
        if current_user.is_authenticated:
            return redirect(url_for("dashboard"))
        if request.method == "POST":
            username = (request.form.get("username") or "").strip()
            user = db.session.scalar(select(User).where(func.lower(User.username) == username.lower()))
            if user and user.check_password(request.form.get("password") or ""):
                login_user(user)
                return redirect(url_for("dashboard"))
            flash("Anmeldung fehlgeschlagen.", "error")
        return render_template("login.html")

    @app.route("/logout", methods=["POST"])
    @login_required
    def logout():
        logout_user()
        return redirect(url_for("login"))

    @app.route("/")
    @login_required
    def dashboard():
        validations = list(db.session.scalars(select(Validation).order_by(Validation.id.desc())))
        return render_template("dashboard.html", validations=validations)

    @app.route("/validations/<int:item_id>/report")
    @login_required
    def report(item_id):
        validation = db.session.get(Validation, item_id)
        if not validation:
            return "Nicht gefunden", 404
        equipment = list(db.session.scalars(select(Equipment).order_by(Equipment.id)))
        filename = build_validation_report(validation, equipment, GENERATED_DIR)
        return send_from_directory(GENERATED_DIR, filename, as_attachment=True)

    with app.app_context():
        db.create_all()
        seed_demo_data()

    return app


app = create_app()