Flight Price Tracking API

import os
import sqlite3
import sys
from datetime import UTC, datetime

import requests

API_KEY = os.environ["IGNAV_API_KEY"]
API = "https://ignav.com/api"
if len(sys.argv) != 4:
    raise SystemExit("Usage: python tracker.py ORIGIN DESTINATION YYYY-MM-DD")
ORIGIN, DESTINATION, DEPARTURE_DATE = sys.argv[1:4]
TARGET_PRICE = 300.0
DROP_PERCENT = 10
ROUTE = {
    "origin": ORIGIN,
    "destination": DESTINATION,
    "departure_date": DEPARTURE_DATE,
}

response = requests.post(
    f"{API}/fares/one-way",
    headers={"X-Api-Key": API_KEY},
    json=ROUTE,
    timeout=60,
)
response.raise_for_status()
itineraries = [
    item
    for item in response.json()["itineraries"]
    if item["price"]["status"] == "verified"
]
if not itineraries:
    raise SystemExit("No verified fares")

best = min(itineraries, key=lambda item: float(item["price"]["amount"]))
price = float(best["price"]["amount"])
currency = best["price"]["currency"]
checked_at = datetime.now(UTC).isoformat()

with sqlite3.connect("fares.db") as db:
    db.execute("""CREATE TABLE IF NOT EXISTS fare_checks (
        id INTEGER PRIMARY KEY,
        origin TEXT NOT NULL,
        destination TEXT NOT NULL,
        departure_date TEXT NOT NULL,
        checked_at TEXT NOT NULL,
        price REAL NOT NULL,
        currency TEXT NOT NULL,
        ignav_id TEXT NOT NULL
    )""")
    previous = db.execute(
        """SELECT price FROM fare_checks
           WHERE origin = ? AND destination = ? AND departure_date = ?
           ORDER BY checked_at DESC LIMIT 1""",
        (ORIGIN, DESTINATION, DEPARTURE_DATE),
    ).fetchone()
    db.execute(
        """INSERT INTO fare_checks
           (origin, destination, departure_date, checked_at, price, currency, ignav_id)
           VALUES (?, ?, ?, ?, ?, ?, ?)""",
        (
            ORIGIN,
            DESTINATION,
            DEPARTURE_DATE,
            checked_at,
            price,
            currency,
            best["ignav_id"],
        ),
    )

dropped = (
    previous is not None
    and price <= previous[0] * (1 - DROP_PERCENT / 100)
)
if price <= TARGET_PRICE or dropped:
    booking_response = requests.post(
        f"{API}/fares/booking-links",
        headers={"X-Api-Key": API_KEY},
        json={"ignav_id": best["ignav_id"]},
        timeout=60,
    )
    booking_response.raise_for_status()
    links = [
        link["url"]
        for option in booking_response.json()["booking_options"]
        for link in option["links"]
    ]
    print(f"Alert: {price:.2f} {currency} for {ORIGIN}-{DESTINATION}")
    if links:
        print(f"Book: {links[0]}")