import requests
import csv

# === Configuration ===
ACCESS_TOKEN = "YOUR_ACCESS_TOKEN_HERE"
START_DATETIME = "2025-05-19T00:00:00Z"
END_DATETIME   = "2025-05-26T23:59:59Z"
OUTPUT_FILE    = "calendar.csv"

# === Setup headers ===
headers = {
    "Authorization": f"Bearer {ACCESS_TOKEN}",
    "Prefer": 'outlook.timezone="UTC"'
}

# === Initial API endpoint ===
base_url = "https://graph.microsoft.com/v1.0/me/calendarview"
params = {
    "$select": "subject,start,end",
    "startDateTime": START_DATETIME,
    "endDateTime": END_DATETIME
}

# === Event storage ===
all_events = []

# === Fetch all pages ===
print("Fetching events...")
url = base_url
while url:
    response = requests.get(url, headers=headers, params=params if url == base_url else None)
    if response.status_code != 200:
        print("Failed to fetch events:", response.status_code, response.text)
        break

    data = response.json()
    events = data.get("value", [])
    all_events.extend(events)

    # Get next page link
    url = data.get("@odata.nextLink")

# === Write to CSV ===
print(f"Writing {len(all_events)} events to {OUTPUT_FILE}...")
with open(OUTPUT_FILE, "w", newline="", encoding="utf-8") as f:
    writer = csv.DictWriter(f, fieldnames=["subject", "start", "end"])
    writer.writeheader()
    for e in all_events:
        writer.writerow({
            "subject": e.get("subject", ""),
            "start": e.get("start", {}).get("dateTime", ""),
            "end": e.get("end", {}).get("dateTime", "")
        })

print("Done.")