from flask import Flask, request, abort
import os, requests

from graph import graph_request

TENANT_ID = os.getenv("TENANT_ID")
SITE_PATH = os.getenv("SITE_PATH")
GRAPH_BASE = "https://graph.microsoft.com/v1.0"

WEBHOOK_SECRET = os.getenv("WEBHOOK_SECRET")
if not WEBHOOK_SECRET:
    raise RuntimeError("WEBHOOK_SECRET not set")

# Détection de la taille du fichier /  Upload thresholds   
MAX_SIMPLE_UPLOAD = 4 * 1024 * 1024  # 4 MB
CHUNK_SIZE = 10 * 1024 * 1024        # 10 MB

app = Flask(__name__)


# ─────────────────────────────
# Sécurité webhook MinIO
# ─────────────────────────────  
def verify_minio_webhook(req):
    auth = req.headers.get("Authorization")

    if not auth or not auth.startswith("Bearer "):
        abort(401, "Missing Authorization header")

    token = auth[len("Bearer "):].strip()

    if token != WEBHOOK_SECRET:
        abort(403, "Invalid MinIO webhook token")
        
# ─────────────────────────────
# SharePoint drive
# ─────────────────────────────
def get_drive_id():
    site = graph_request(
        "GET",
        f"{GRAPH_BASE}/sites/{SITE_PATH}"
    )
    drive = graph_request(
        "GET",
        f"{GRAPH_BASE}/sites/{site['id']}/drive"
    )
    return drive["id"]

# INITIALISATION AU DÉMARRAGE
print("Initializing SharePoint drive…")
DRIVE_ID = get_drive_id()
print(f"Drive ID initialized: {DRIVE_ID}")

# ─────────────────────────────
# Upload helpers
# ─────────────────────────────
def create_upload_session(sp_path):
    res = graph_request(
        "POST",
        f"{GRAPH_BASE}/drives/{DRIVE_ID}/root:/{sp_path}:/createUploadSession",
        json={
            "item": {
                "@microsoft.graph.conflictBehavior": "replace"
            }
        }
    )
    return res["uploadUrl"]


def upload_simple(sp_path, data):
    graph_request(
        "PUT",
        f"{GRAPH_BASE}/drives/{DRIVE_ID}/root:/{sp_path}:/content",
        data=data
    )


def upload_chunked(sp_path, file_path):
    upload_url = create_upload_session(sp_path)
    size = os.path.getsize(file_path)

    with open(file_path, "rb") as f:
        start = 0
        while start < size:
            chunk = f.read(CHUNK_SIZE)
            end = start + len(chunk) - 1

            headers = {
                "Content-Length": str(len(chunk)),
                "Content-Range": f"bytes {start}-{end}/{size}"
            }

            r = requests.put(upload_url, headers=headers, data=chunk)
            r.raise_for_status()
            start += len(chunk)


# ─────────────────────────────
# Event handlers
# ─────────────────────────────
def upload_object(key):
    print(f"Uploading {key} to SharePoint", flush=True)

    # 🔴 TODO : ici télécharger le fichier depuis MinIO vers /tmp
    file_path = f"/tmp/{os.path.basename(key)}"

    # (temporaire pour tests)
    with open(file_path, "wb") as f:
        f.write(b"TEST")

    size = os.path.getsize(file_path)

    if size <= MAX_SIMPLE_UPLOAD:
        with open(file_path, "rb") as f:
            upload_simple(key, f.read())
    else:
        upload_chunked(key, file_path)

    os.remove(file_path)


def delete_object(key):
    print(f"Deleting {key} from SharePoint", flush=True)
    graph_request(
        "DELETE",
        f"{GRAPH_BASE}/drives/{DRIVE_ID}/root:/{key}"
    )
# ─────────────────────────────
# Webhook endpoint
# ─────────────────────────────
@app.route("/s3event", methods=["POST"])
def s3_event():
    verify_minio_webhook(request)
    event = request.get_json()
    record = event["Records"][0]
    event_name = record["eventName"]
    key = record["s3"]["object"]["key"]

    if event_name.startswith("s3:ObjectCreated"):
        upload_object(key)
    elif event_name.startswith("s3:ObjectRemoved"):
        delete_object(key)

    return "", 204

if __name__ == "__main__":
    app.run(host="0.0.0.0", port=8080)