"""
Felix Muzny
DS 2000
Lecture 12
October 18, 2024

Data file (all sept 2024 ebike trips starting at Forsyth)
Three columns:
- end station name
- end station latitude (latitude is flatitude)
- end station longitude (longitude is veritcal)

Goals for today’s code:
- read a csv into a list of lists
- how many trips were to "Brigham Circle - Francis St at Huntington"
- where did the BlueBikes riders go from NEU in September?
"""

import matplotlib.pyplot as plt

# to help us read CSVs
import csv


FILENAME = "bluebikes_forsyth.csv"

STATION_OF_INTEREST = "Brigham Circle - Francis St at Huntington Ave"

FORSYTH_LAT = 42.339202
FORSYTH_LONG = -71.090511
STATION_COL = 0
LAT_COL = 1
LONG_COL = 2

def read_csv(filename):
   ''' Function: read_csv
       parameter: filename, a string
       Returns: 2d list of strings, the contents of the file
   '''
   data = []
   with open(filename, "r") as infile:
       csvfile = csv.reader(infile, delimiter=",")
       for row in csvfile:
           data.append(row)
   return data


def get_station(data, station_name, col):
    """
    Get all rows from the data where the station name

    :param data: list of lists of strings
    :param station_name: string station name to search for
    :param col: int column to look in for the station name
    :return: list of ints
    """
    new_rows = []
    for row in data:
        # secret python code:
        # row = next sublist in the data
        # row[col] will be the station name in this row
        if row[col] == station_name:
            new_rows.append(row)
    return new_rows

def plot_locations(data, lat_col, long_col, begin_lat, begin_long):
    """
    Make a scatter plot of all the end locations given by the lat and long
    columns in the data. Plot one point as a special point to differentiate
    it from the others
    :param data: list of lists of strings
    :param lat_col: int column with the latitude information
    :param long_col: int column with the longitude information
    :param begin_lat: int special point's latitude
    :param begin_long: int special point's longitude
    :return: nothing
    """
    # longitudes
    xs = []
    # latitudes
    ys = []
    for row in data:
        xs.append(float(row[long_col]))
        ys.append(float(row[lat_col]))

    plt.plot(xs, ys, "*", color="blue", label="destinations")
    # plot the special point second so it appears second
    plt.plot(begin_long, begin_lat, "s", color="red", label="Forsyth at Huntington")
    plt.xlabel("longitude")
    plt.ylabel("latitude")
    plt.legend()
    plt.savefig("lec12_bluebikes.png")
    plt.show()

def main():
    print("lec 12 - bluebikes")

    data = read_csv(FILENAME)

    print("Number of rows:", len(data))
    print("First row:", data[0])

    # get the rows for the station we care about
    station_rows = get_station(data, STATION_OF_INTEREST, STATION_COL)

    print("Number of trips to", STATION_OF_INTEREST, ":", len(station_rows))

    # if time, let's plot these!
    plot_locations(data, LAT_COL, LONG_COL, FORSYTH_LAT, FORSYTH_LONG)

main()