import io
import json
import os
from google.oauth2 import service_account
from googleapiclient.discovery import build
from googleapiclient.http import MediaIoBaseDownload, MediaIoBaseUpload
from api.models import Projects


def get_drive_credentials():
    """Get Google Drive credentials from environment."""
    key = os.environ.get('SERVICE_ACCOUNT_KEY')
    if not key:
        key_file_path = os.environ.get('SERVICE_ACCOUNT_KEY_FILE', '/app/service_account_key.json')
        if os.path.exists(key_file_path):
            with open(key_file_path, 'r') as f:
                return json.load(f)
        return None

    return json.loads(key) if isinstance(key, str) else key


def duplicate_punchlist(new_name):
    """
    Duplicates a punchlist template from Google Drive.

    Arguments:
        new_name: str : New filename for the punchlist

    Returns:
        dict : Google Drive file object for the new punchlist
    """
    scopes = ['https://www.googleapis.com/auth/drive']
    key = get_drive_credentials()
    impersonator = os.environ.get('DISPATCH_EMAIL', 'dispatch@example.com')

    creds = service_account.Credentials.from_service_account_info(
        key, scopes=scopes, subject=impersonator
    )
    service = build('drive', 'v3', credentials=creds)

    # Get folder and template IDs from environment
    folder_id = os.environ.get('PUNCHLIST_FOLDER_ID')
    template_id = os.environ.get('PUNCHLIST_TEMPLATE_ID')

    request_body = {
        'name': new_name,
        'parents': [folder_id] if folder_id else [],
    }

    return service.files().copy(fileId=template_id, body=request_body).execute()


def create_pdf_from_punchlist(sheet_id):
    """
    Creates a PDF from a Google Sheet.

    Args:
        sheet_id: str : The ID of the Google Sheet

    Returns:
        str : The file ID of the created PDF, or None on error
    """
    try:
        scopes = ['https://www.googleapis.com/auth/drive']
        key = get_drive_credentials()
        impersonator = os.environ.get('DISPATCH_EMAIL', 'dispatch@example.com')

        creds = service_account.Credentials.from_service_account_info(
            key, scopes=scopes, subject=impersonator
        )
        service = build('drive', 'v3', credentials=creds)

        # Get the original sheet's metadata
        file_metadata = service.files().get(fileId=sheet_id, fields='name,parents').execute()
        sheet_name = file_metadata.get('name')
        parent_folder_id = file_metadata.get('parents', [None])[0]

        pdf_filename = f"{sheet_name}.pdf"

        # Export as PDF
        request = service.files().export_media(fileId=sheet_id, mimeType='application/pdf')
        fh = io.BytesIO()
        downloader = MediaIoBaseDownload(fh, request)
        done = False
        while not done:
            status, done = downloader.next_chunk()

        # Upload PDF to same folder
        file_metadata = {
            'name': pdf_filename,
            'mimeType': 'application/pdf',
        }
        if parent_folder_id:
            file_metadata['parents'] = [parent_folder_id]

        fh.seek(0)
        media = MediaIoBaseUpload(fh, mimetype='application/pdf')
        file = service.files().create(
            body=file_metadata, media_body=media, fields='id'
        ).execute()

        return file.get('id')

    except Exception as e:
        print(f"An error occurred: {e}")
        return None


def store_pdf_as_bytecode(pdf_id, proj_id):
    """
    Retrieves a PDF from Google Drive and stores it in the database.

    Args:
        pdf_id: str : The ID of the PDF file in Google Drive
        proj_id: str : The project ID in the database
    """
    try:
        scopes = ['https://www.googleapis.com/auth/drive']
        key = get_drive_credentials()
        impersonator = os.environ.get('DISPATCH_EMAIL', 'dispatch@example.com')

        creds = service_account.Credentials.from_service_account_info(
            key, scopes=scopes, subject=impersonator
        )
        service = build('drive', 'v3', credentials=creds)

        request = service.files().get_media(fileId=pdf_id)
        fh = io.BytesIO()
        downloader = MediaIoBaseDownload(fh, request)
        done = False
        while not done:
            status, done = downloader.next_chunk()

        pdf_bytes = fh.getvalue()

        project = Projects.objects.get(id=proj_id)
        project.punchlist = pdf_bytes
        project.save()

    except Exception as e:
        print(f"An error occurred: {e}")