geovisualisierung/projects/project-3/backend/db_init.py

import csv
import json
import logging
import sqlite3
from dataclasses import dataclass
from datetime import datetime

import requests

DB_NAME = "bike-data.db"

logFormatter = logging.Formatter("%(asctime)-15s [%(levelname)8s] [%(threadName)s] - %(message)s")
LOG = logging.getLogger()
LOG.setLevel(logging.DEBUG)

fileHandler = logging.FileHandler("db_init.log")
fileHandler.setFormatter(logFormatter)
LOG.addHandler(fileHandler)

consoleHandler = logging.StreamHandler()
consoleHandler.setFormatter(logFormatter)
LOG.addHandler(consoleHandler)


@dataclass
class ApiExportFile:
    path: str
    download_url: str
    etag: str


def get_online_files_list(subdir_filter=None, file_extension_filter=None):
    import urllib.parse
    import xml.etree.ElementTree

    base_uri = "https://s3-eu-west-1.amazonaws.com/cycling.data.tfl.gov.uk/"
    xml_data = xml.etree.ElementTree.fromstringlist(requests.get(base_uri).text)
    entries = []

    for child in xml_data.findall('{http://s3.amazonaws.com/doc/2006-03-01/}Contents'):
        key = child.find('{http://s3.amazonaws.com/doc/2006-03-01/}Key').text
        etag = child.find('{http://s3.amazonaws.com/doc/2006-03-01/}ETag').text
        if key.endswith('/'):
            continue

        download_url = base_uri + urllib.parse.quote_plus(key, safe="/")
        entries.append(
            ApiExportFile(key, download_url, etag)
        )

    if subdir_filter:
        entries = list(filter(lambda el: el.path.startswith(subdir_filter), entries))

    if file_extension_filter:
        entries = list(filter(lambda el: el.path.endswith(file_extension_filter), entries))

    return entries


def init_database():
    LOG.info("Try to create tables")
    conn = sqlite3.connect(DB_NAME, timeout=300)
    conn.execute("""CREATE TABLE IF NOT EXISTS usage_stats(
            rental_id INTEGER PRIMARY KEY,
            duration INTEGER,
            bike_id INTEGER,
            end_date INTEGER,
            end_station_id INTEGER,
            end_station_name TEXT,
            start_date INTEGER,
            start_station_id INTEGER,
            start_station_name TEXT
        )""")
    conn.execute("CREATE TABLE IF NOT EXISTS read_files(file_path TEXT, etag TEXT PRIMARY KEY)")
    conn.execute("""CREATE TABLE IF NOT EXISTS bike_points(
            id TEXT PRIMARY KEY, 
            common_name TEXT,
            lat REAL,
            lon REAL,
            id_num INTEGER
        )""")
    conn.execute("""CREATE TABLE IF NOT EXISTS accidents(
            id INTEGER PRIMARY KEY,
            lat REAL,
            lon REAL,
            location TEXT,
            date TEXT,
            severity TEXT
        )""")
    conn.commit()
    conn.close()
    LOG.info("Tables created")


def create_indexes():
    LOG.info("Try to create indexes")
    conn = sqlite3.connect(DB_NAME, timeout=300)
    LOG.info("Starting to build index: idx_date_of_start_date")
    conn.execute("""CREATE INDEX IF NOT EXISTS idx_date_of_start_date 
            ON usage_stats (date(start_date, 'unixepoch'))""")
    conn.commit()
    LOG.info("Created index: idx_date_of_start_date")
    LOG.info("Starting to build index: idx_end_station_id_date_of_start_date")
    conn.execute("""CREATE INDEX IF NOT EXISTS "idx_end_station_id_date_of_start_date" 
            ON "usage_stats" ("end_station_id" ASC, date(start_date, 'unixepoch'))""")
    conn.commit()
    LOG.info("Created index: idx_end_station_id_date_of_start_date")
    LOG.info("Starting to build index: idx_start_station_id_date_of_start_date")
    conn.execute("""CREATE INDEX IF NOT EXISTS "idx_start_station_id_date_of_start_date" 
            ON "usage_stats" ("start_station_id"	ASC, date("start_date", 'unixepoch'))""")
    conn.commit()
    LOG.info("Created index: idx_start_station_id_date_of_start_date")
    conn.close()
    LOG.info("Indexes created")


def create_dashboard_table():
    LOG.info("Creating dashboard table")
    conn = sqlite3.connect(DB_NAME, timeout=300)
    conn.execute("DROP TABLE IF EXISTS dashboard")
    conn.execute("""CREATE TABLE dashboard AS SELECT
                                b.id_num as id,
                                max(date(u.start_date, 'unixepoch')) AS max_end_date, 
                                min(date(u.start_date, 'unixepoch')) AS max_start_date
                            FROM usage_stats u
                            JOIN bike_points b ON u.start_station_id = b.id_num
                            GROUP BY b.id_num""")
    conn.commit()
    LOG.info("Created dashboard table")


def import_bikepoints():
    LOG.info("Importing bikepoints")
    conn = sqlite3.connect(DB_NAME, timeout=300)
    points = json.loads(requests.get("https://api.tfl.gov.uk/BikePoint").text)
    points = list(map(lambda p: (p['id'], p['commonName'], p['lat'], p['lon'], int(p['id'][11:])), points))

    LOG.info(f"Writing {len(points)} bikepoints to DB")
    conn.executemany("INSERT OR IGNORE INTO bike_points VALUES (?, ?, ?, ?, ?)", points)
    conn.commit()
    conn.close()
    LOG.info("Bikepoints imported")


def import_accidents(year):
    LOG.info("Importing accidents")
    conn = sqlite3.connect(DB_NAME, timeout=300)

    def filter_pedal_cycles(accident):
        for vehicle in accident['vehicles']:
            if vehicle['type'] == "PedalCycle":
                return True
        return False

    accidents = requests.get(f"https://api.tfl.gov.uk/AccidentStats/{year}").text
    accidents = json.loads(accidents)
    accidents = list(filter(filter_pedal_cycles, accidents))
    accidents = list(map(lambda a: (a['id'], a['lat'], a['lon'], a['location'], a['date'], a['severity']), accidents))

    LOG.info(f"Writing {len(accidents)} bike accidents to DB")
    conn.executemany("INSERT OR IGNORE INTO accidents VALUES (?, ?, ?, ?, ?, ?)", accidents)
    conn.commit()
    conn.close()
    LOG.info("Accidents importet")


def import_usage_stats_file(export_file: ApiExportFile):
    conn = sqlite3.connect(DB_NAME, timeout=300)

    rows = conn.execute("SELECT * FROM read_files WHERE etag LIKE ?", (export_file.etag,)).fetchall()
    if len(rows) != 0:
        LOG.warning(f"Skipping import of {export_file.path}")
        return

    LOG.info(f"DOWNLOADING... {export_file.download_url}")
    content = requests.get(export_file.download_url).content.decode("UTF-8")

    LOG.info(f"Parsing {export_file.path}")
    entries = list(csv.reader(content.splitlines()))[1:]
    mapped = []
    for entry in entries:
        try:
            mapped.append((
                # Rental Id
                int(entry[0]),
                # Duration oder Duration_Seconds
                int(entry[1] or "-1"),
                # Bike Id
                int(entry[2] or "-1"),
                # End Date
                int(datetime.strptime(entry[3][:16], "%d/%m/%Y %H:%M").timestamp()) if entry[3] else -1,
                # EndStation Id
                int(entry[4] or "-1"),
                # EndStation Name
                entry[5].strip(),
                # Start Date
                int(datetime.strptime(entry[6][:16], "%d/%m/%Y %H:%M").timestamp()) if entry[6] else -1,
                # StartStation Id
                int(entry[7]),
                # StartStation Name
                entry[8].strip()
            ))
        except ValueError as e:
            LOG.error(f"Value Error {e} on line {entry}")
            return
        except KeyError as e:
            LOG.error(f"Key Error {e} on line {entry}")
            return
    LOG.info(f"Writing {len(mapped)} entries to DB")
    conn.executemany("INSERT OR IGNORE INTO usage_stats VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)", mapped)
    conn.execute("INSERT OR IGNORE INTO read_files VALUES (?, ?)", (export_file.path, export_file.etag))
    conn.commit()
    conn.close()
    LOG.info(f"Finished import of {export_file.path}")


def main():
    # General DB init
    init_database()

    count_pre = sqlite3.connect(DB_NAME, timeout=300).execute("SELECT count(*) FROM usage_stats").fetchone()[0]

    # Download and import opendata from S3 bucket
    all_files = get_online_files_list(subdir_filter="usage-stats", file_extension_filter=".csv")
    for file in all_files:
        import_usage_stats_file(file)

    count_after = sqlite3.connect(DB_NAME, timeout=300).execute("SELECT count(*) FROM usage_stats").fetchone()[0]

    # Create search-index for faster querying
    create_indexes()
    # Import Bikepoints
    import_bikepoints()
    # Import bike accidents
    import_accidents(2019)

    if count_after - count_pre > 0:
        create_dashboard_table()


if __name__ == "__main__":
    main()