from datetime import date

from flask import Flask, render_template, redirect, url_for, request, flash, jsonify
from flask_login import (
    LoginManager,
    login_user,
    logout_user,
    login_required,
    current_user,
)

from config import Config
from models import db, User, Trip, Stop, VERKEHRSMITTEL_OPTIONEN
from stops_import import normalize_name, register_cli

login_manager = LoginManager()
login_manager.login_view = "login"


def create_app():
    app = Flask(__name__)
    app.config.from_object(Config)

    db.init_app(app)
    login_manager.init_app(app)

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

    @app.context_processor
    def inject_settings():
        return {"show_map": app.config["SHOW_MAP"]}

    register_routes(app)
    register_cli(app)
    return app


@login_manager.user_loader
def load_user(user_id):
    return User.query.get(int(user_id))


def register_routes(app):
    @app.route("/")
    def index():
        if current_user.is_authenticated:
            return redirect(url_for("dashboard"))
        return redirect(url_for("login"))

    @app.route("/register", methods=["GET", "POST"])
    def register():
        if request.method == "POST":
            username = request.form["username"].strip()
            email = request.form["email"].strip().lower()
            password = request.form["password"]

            if User.query.filter(
                (User.username == username) | (User.email == email)
            ).first():
                flash("Benutzername oder E-Mail bereits vergeben.", "error")
                return redirect(url_for("register"))

            user = User(username=username, email=email)
            user.set_password(password)
            db.session.add(user)
            db.session.commit()

            login_user(user)
            return redirect(url_for("dashboard"))

        return render_template("register.html")

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

            user = User.query.filter_by(username=username).first()
            if user is None or not user.check_password(password):
                flash("Login fehlgeschlagen. Bitte prüfe deine Daten.", "error")
                return redirect(url_for("login"))

            login_user(user)
            return redirect(url_for("dashboard"))

        return render_template("login.html")

    @app.route("/logout")
    @login_required
    def logout():
        logout_user()
        return redirect(url_for("login"))

    @app.route("/dashboard")
    @login_required
    def dashboard():
        fahrten = (
            Trip.query.filter_by(user_id=current_user.id)
            .order_by(Trip.trip_date.desc())
            .all()
        )
        return render_template("dashboard.html", fahrten=fahrten)

    @app.route("/api/stops")
    @login_required
    def api_stops():
        """Autocomplete for the origin/destination fields."""
        query = request.args.get("q", "").strip()
        if len(query) < 2:
            return jsonify([])

        needle = normalize_name(query).replace("\\", "\\\\")
        needle = needle.replace("%", r"\%").replace("_", r"\_")
        order = (db.func.length(Stop.name), Stop.name)

        results = (
            Stop.query.filter(Stop.name_normalized.like(needle + "%", escape="\\"))
            .order_by(*order)
            .limit(8)
            .all()
        )
        if len(results) < 8:
            seen = {stop.id for stop in results}
            for stop in (
                Stop.query.filter(
                    Stop.name_normalized.like("%" + needle + "%", escape="\\")
                )
                .order_by(*order)
                .limit(20)
                .all()
            ):
                if stop.id not in seen:
                    results.append(stop)
                if len(results) >= 8:
                    break

        return jsonify(
            [
                {
                    "id": stop.id,
                    "name": stop.name,
                    "type": stop.stop_type,
                    "municipality": stop.municipality,
                    "lat": stop.latitude,
                    "lon": stop.longitude,
                }
                for stop in results
            ]
        )

    def _line_sort_key(ref):
        head = ""
        i = 0
        while i < len(ref) and not ref[i].isdigit():
            head += ref[i]
            i += 1
        num = ref[i:]
        digits = ""
        while num and num[0].isdigit():
            digits += num[0]
            num = num[1:]
        return (head.lower(), int(digits) if digits else -1, num.lower())

    @app.route("/api/lines")
    @login_required
    def api_lines():
        """Line suggestions for the "Linie" field, scoped to the chosen stops."""
        def stop_lines(param):
            stop = db.session.get(Stop, int(param)) if (param or "").isdigit() else None
            return set(stop.line_list()) if stop else set()

        origin = stop_lines(request.args.get("origin_stop_id"))
        destination = stop_lines(request.args.get("destination_stop_id"))
        candidates = origin | destination
        if not candidates:
            return jsonify([])

        needle = request.args.get("q", "").strip().lower()
        both = origin & destination
        refs = sorted(
            (r for r in candidates if not needle or r.lower().startswith(needle)),
            key=lambda r: (r not in both, _line_sort_key(r)),
        )
        return jsonify(
            [{"ref": r, "both": r in both} for r in refs[:20]]
        )

    def parse_trip_date(raw_value):
        raw_value = (raw_value or "").strip()
        try:
            return date.fromisoformat(raw_value) if raw_value else date.today()
        except ValueError:
            return date.today()

    def resolve_stop_id(raw_id):
        """Return a valid Stop.id for a submitted value, or None (free text)."""
        if not raw_id:
            return None
        try:
            stop = db.session.get(Stop, int(raw_id))
        except (TypeError, ValueError):
            return None
        return stop.id if stop is not None else None

    def fill_trip_from_form(fahrt):
        fahrt.transport_mode = request.form["transport_mode"]
        fahrt.line = request.form.get("line", "").strip()
        fahrt.course = request.form.get("course", "").strip()
        fahrt.origin = request.form["origin"].strip()
        fahrt.origin_stop_id = resolve_stop_id(request.form.get("origin_stop_id"))
        fahrt.destination = request.form["destination"].strip()
        fahrt.destination_stop_id = resolve_stop_id(
            request.form.get("destination_stop_id")
        )
        fahrt.trip_date = parse_trip_date(request.form.get("trip_date"))
        fahrt.rating = int(request.form["rating"])
        fahrt.comment = request.form.get("comment", "").strip()

    @app.route("/fahrt/neu", methods=["GET", "POST"])
    @login_required
    def neue_fahrt():
        if request.method == "POST":
            fahrt = Trip(user_id=current_user.id)
            fill_trip_from_form(fahrt)
            db.session.add(fahrt)
            db.session.commit()
            flash("Fahrt gespeichert.", "success")
            return redirect(url_for("dashboard"))

        return render_template(
            "add_entry.html",
            verkehrsmittel_optionen=VERKEHRSMITTEL_OPTIONEN,
            heute=date.today().isoformat(),
            fahrt=None,
        )

    @app.route("/fahrt/<int:fahrt_id>/bearbeiten", methods=["GET", "POST"])
    @login_required
    def fahrt_bearbeiten(fahrt_id):
        fahrt = Trip.query.get_or_404(fahrt_id)
        if fahrt.user_id != current_user.id:
            flash("Nicht erlaubt.", "error")
            return redirect(url_for("dashboard"))

        if request.method == "POST":
            fill_trip_from_form(fahrt)
            db.session.commit()
            flash("Fahrt aktualisiert.", "success")
            return redirect(url_for("dashboard"))

        return render_template(
            "add_entry.html",
            verkehrsmittel_optionen=VERKEHRSMITTEL_OPTIONEN,
            heute=fahrt.trip_date.isoformat(),
            fahrt=fahrt,
        )

    @app.route("/fahrt/<int:fahrt_id>/loeschen", methods=["POST"])
    @login_required
    def fahrt_loeschen(fahrt_id):
        fahrt = Trip.query.get_or_404(fahrt_id)
        if fahrt.user_id != current_user.id:
            flash("Nicht erlaubt.", "error")
            return redirect(url_for("dashboard"))
        db.session.delete(fahrt)
        db.session.commit()
        flash("Fahrt gelöscht.", "success")
        return redirect(url_for("dashboard"))


app = create_app()

if __name__ == "__main__":
    app.run(host="0.0.0.0", port=5000, debug=True)