import os

from flask import Flask, jsonify, render_template, request
from sqlalchemy import func

from models import Sensor, SensorReadout, db


def create_app():
    app = Flask(__name__)

    db_path = os.path.join(os.path.dirname(__file__), "data.db")
    app.config["SQLALCHEMY_DATABASE_URI"] = f"sqlite:///{db_path}"
    app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False

    db.init_app(app)

    @app.route("/sensors")
    def sensors_page():
        return render_template("sensors.html")

    @app.route("/api/docs")
    def api_docs():
        return render_template("docs.html")

    @app.route("/api/sensors")
    def api_sensors():
        sensors = Sensor.query.order_by(Sensor.name).all()
        return jsonify([{"id": s.id, "name": s.name} for s in sensors])

    @app.route("/api/sensors/<int:sensor_id>/types")
    def api_sensor_types(sensor_id):
        types = (
            db.session.query(SensorReadout.type)
            .filter_by(sensor_id=sensor_id)
            .distinct()
            .order_by(SensorReadout.type)
            .all()
        )
        return jsonify([t[0] for t in types])

    @app.route("/api/sensors/<int:sensor_id>/readouts")
    def api_sensor_readouts(sensor_id):
        type_ = request.args.get("type")
        query = SensorReadout.query.filter_by(sensor_id=sensor_id)
        if type_:
            query = query.filter_by(type=type_)
        readouts = query.order_by(SensorReadout.timestamp.desc()).limit(300).all()
        return jsonify(
            [
                {"value": r.value, "timestamp": r.timestamp.isoformat()}
                for r in readouts
            ]
        )

    @app.route("/api/sensors/<int:sensor_id>/readouts/hourly")
    def api_sensor_readouts_hourly(sensor_id):
        type_ = request.args.get("type")
        query = (
            db.session.query(
                func.strftime("%Y-%m-%dT%H:00:00", SensorReadout.timestamp).label("hour"),
                func.avg(SensorReadout.value).label("avg_value"),
            )
            .filter(SensorReadout.sensor_id == sensor_id)
        )
        if type_:
            query = query.filter(SensorReadout.type == type_)
        rows = (
            query.group_by("hour")
            .order_by("hour")
            .all()
        )
        return jsonify(
            [{"timestamp": r.hour, "value": round(r.avg_value, 2)} for r in rows]
        )

    @app.route("/api/sensors", methods=["POST"])
    def api_create_sensor():
        data = request.get_json(silent=True)
        if not data or "name" not in data:
            return jsonify({"error": "name is required"}), 400

        name = data["name"].strip()
        if not name:
            return jsonify({"error": "name cannot be empty"}), 400

        if Sensor.query.filter_by(name=name).first():
            return jsonify({"error": "sensor already exists"}), 409

        sensor = Sensor(name=name)
        db.session.add(sensor)
        db.session.commit()
        return jsonify({"id": sensor.id, "name": sensor.name}), 201

    @app.route("/api/sensors/<int:sensor_id>/readouts", methods=["POST"])
    def api_create_readout(sensor_id):
        sensor = db.session.get(Sensor, sensor_id)
        if not sensor:
            return jsonify({"error": "sensor not found"}), 404

        data = request.get_json(silent=True)
        if not data:
            return jsonify({"error": "request body is required"}), 400

        missing = [f for f in ("type", "value") if f not in data]
        if missing:
            return jsonify({"error": f"missing fields: {', '.join(missing)}"}), 400

        try:
            value = float(data["value"])
        except (TypeError, ValueError):
            return jsonify({"error": "value must be a number"}), 400

        readout = SensorReadout(
            sensor_id=sensor_id,
            type=str(data["type"]).strip(),
            value=value,
        )
        db.session.add(readout)
        db.session.commit()
        return jsonify(
            {
                "id": readout.id,
                "sensor_id": readout.sensor_id,
                "type": readout.type,
                "value": readout.value,
                "timestamp": readout.timestamp.isoformat(),
            }
        ), 201

    return app


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