tdtp_parada_v2/tpmcqr_service/models/gtfs.py

from tpmcqr_service import db
from sqlalchemy.orm import aliased
from sqlalchemy import any_
from sqlalchemy import func
from geoalchemy2 import Geometry
from zoneinfo import ZoneInfo


class Lineas(db.Model):
    __tablename__   = 'linea'
    __table_args__  = { 'schema': 'public' }

    id_linea            = db.Column(db.String(150), primary_key=True )
    id_operador         = db.Column(db.String(150))
    route_short_name	= db.Column(db.String(150))
    route_long_name     = db.Column(db.String(150))
    route_color			= db.Column(db.String(150))
    route_text_color	= db.Column(db.String(150))
    vigente				= db.Column(db.Boolean)

class QRDev(db.Model):
    __tablename__   = 'dispositivo'
    __table_args__  = { 'schema': 'public' }

    id_dispositivo	    = db.Column(db.String(100), primary_key=True )
    id_paradero         = db.Column(db.String(50))

class Paraderos(db.Model):
    __tablename__   = 'paradero'
    __table_args__  = { 'schema': 'public' }

    id_paradero	    = db.Column(db.String(50), primary_key=True )
    stop_name        = db.Column(db.String(50))
    stop_lat        = db.Column(db.Float)
    stop_lon        = db.Column(db.Float)

class Shapes(db.Model):
    __tablename__   = 'gtfs_shape'
    __table_args__  = { 'schema': 'public' }

    id_gtfs_pk 			= db.Column(db.Integer, primary_key=True )
    id_shape 			= db.Column(db.String(150))
    shape_pt_lat 		= db.Column(db.Float)
    shape_pt_lon		= db.Column(db.Float)
    shape_pt_sequence 	= db.Column(db.Integer)
    shape_dist_traveled = db.Column(db.Float)

class Trips(db.Model):
    __tablename__   = 'gtfs_trips'
    __table_args__  = { 'schema': 'public' }

    id_trip         = db.Column(db.String(150), primary_key=True)
    id_linea        = db.Column(db.String(150))
    id_shape 		= db.Column(db.String(150))
    service_id       = db.Column(db.String(50))


def find_shape_position(shape_id, lat, lng):
    Shape1 = aliased(Shapes)
    Shape2 = aliased(Shapes)

    point = func.ST_SetSRID(func.ST_MakePoint(lng, lat), 4326)  # Create PostGIS point

    segmento = db.session.query(
            Shape1.shape_pt_sequence.label("start_sequence"),
    #            Shape2.shape_pt_sequence.label("end_sequence"),
            Shape1.shape_dist_traveled.label("traveled_start"),
            Shape2.shape_dist_traveled.label("traveled_end"),
            func.ST_Distance(
                func.ST_MakeLine(
                    func.ST_SetSRID(func.ST_MakePoint(Shape1.shape_pt_lon, Shape1.shape_pt_lat), 4326),
                    func.ST_SetSRID(func.ST_MakePoint(Shape2.shape_pt_lon, Shape2.shape_pt_lat), 4326)
                ),
                point
            ).label("distance"),
            func.ST_LineLocatePoint(  # Compute fractional position on the segment
                func.ST_MakeLine(
                    func.ST_SetSRID(func.ST_MakePoint(Shape1.shape_pt_lon, Shape1.shape_pt_lat), 4326),
                    func.ST_SetSRID(func.ST_MakePoint(Shape2.shape_pt_lon, Shape2.shape_pt_lat), 4326)
                ),
                point
            ).label("fraction")
        ).filter(
            Shape1.id_shape == shape_id,
            Shape2.id_shape == shape_id,
            Shape2.shape_pt_sequence == Shape1.shape_pt_sequence + 1  # Ensure correct segment order
        ).order_by("distance").first()

    avanzado = segmento.traveled_start + segmento.fraction * (segmento.traveled_end - segmento.traveled_start)

    return ( segmento.start_sequence, avanzado )