import requests
import msal
import atexit
import os.path
import urllib.parse
import os

TENANT_ID = '19a6096e-3456-7890-abcd-19taco8cdedd'
CLIENT_ID = '0cd0453d-cdef-xyz1-1234-532burrito98'
CLIENT_SECRET  = '.i.need.tacos-and.queso'
SHAREPOINT_HOST_NAME = 'tacoranch.sharepoint.com'
SITE_NAME = 'python'
TARGET_LIBRARY = 'reports'
UPLOAD_FILE = 'C:\\code\\test files\\LargeExcel.xlsx'
UPLOAD_FILE_NAME = 'LargeExcel.xlsx'
UPLOAD_FILE_DESCRIPTION = 'A large excel file' #not required

AUTHORITY = 'https://login.microsoftonline.com/' + TENANT_ID
ENDPOINT = 'https://graph.microsoft.com/v1.0'

SCOPES = [
    'Files.ReadWrite.All',
    'Sites.ReadWrite.All'
]

cache = msal.SerializableTokenCache()

if os.path.exists('token_cache.bin'):
    cache.deserialize(open('token_cache.bin', 'r').read())

atexit.register(lambda: open('token_cache.bin', 'w').write(cache.serialize()) if cache.has_state_changed else None)

SCOPES = ["https://graph.microsoft.com/.default"]

app = msal.ConfidentialClientApplication(CLIENT_ID, authority=AUTHORITY, client_credential=CLIENT_SECRET, token_cache=cache)

result = None
result = app.acquire_token_silent(SCOPES, account=None)

drive_id = None

if result is None:
    result = app.acquire_token_for_client(SCOPES)

if 'access_token' in result:
    print('Token acquired')
else:
    print(result.get('error'))
    print(result.get('error_description'))
    print(result.get('correlation_id')) 

if 'access_token' in result:
    access_token = result['access_token']
    headers={'Authorization': 'Bearer ' + access_token}

    # get the site id
    result = requests.get(f'{ENDPOINT}/sites/{SHAREPOINT_HOST_NAME}:/sites/{SITE_NAME}', headers=headers)
    result.raise_for_status()
    site_info = result.json()
    site_id = site_info['id']

    # get the drive / library id
    result = requests.get(f'{ENDPOINT}/sites/{site_id}/drives', headers=headers)
    result.raise_for_status()
    drives_info = result.json()
    
    for drive in drives_info['value']:
        if drive['name'] == TARGET_LIBRARY:
            drive_id = drive['id']
            break

    if drive_id is None:
        print(f'No drive named "{TARGET_LIBRARY}" found')

    # upload a large file to
    file_url = urllib.parse.quote(UPLOAD_FILE_NAME)
    result = requests.post(
        f'{ENDPOINT}/drives/{drive_id}/root:/{file_url}:/createUploadSession',
        headers=headers,
        json={
            '@microsoft.graph.conflictBehavior': 'replace',
            'description': UPLOAD_FILE_DESCRIPTION,
            'fileSystemInfo': {'@odata.type': 'microsoft.graph.fileSystemInfo'},
            'name': UPLOAD_FILE_NAME
        }
    )

    result.raise_for_status()
    upload_session = result.json()
    upload_url = upload_session['uploadUrl']

    st = os.stat(UPLOAD_FILE)
    size = st.st_size
    CHUNK_SIZE = 10485760
    chunks = int(size / CHUNK_SIZE) + 1 if size % CHUNK_SIZE > 0 else 0
    with open(UPLOAD_FILE, 'rb') as fd:
        start = 0
        for chunk_num in range(chunks):
            chunk = fd.read(CHUNK_SIZE)
            bytes_read = len(chunk)
            upload_range = f'bytes {start}-{start + bytes_read - 1}/{size}'
            print(f'chunk: {chunk_num} bytes read: {bytes_read} upload range: {upload_range}')
            result = requests.put(
                upload_url,
                headers={
                    'Content-Length': str(bytes_read),
                    'Content-Range': upload_range
                },
                data=chunk
            )
            result.raise_for_status()
            start += bytes_read

else:
    raise Exception('no access token')