from datetime import datetime, timezone

from sqlalchemy.orm import Session

from .dlt_constants import DLT_DOCUMENT_TYPES, PE_TM_CHAIN_BINDING_ID
from .models import DltApplication, DltDocument, UserAccount


def ensure_dlt_application(db: Session, user: UserAccount) -> DltApplication:
    if user.dlt_application:
        return user.dlt_application
    application = DltApplication(user_id=user.id, status="not_started")
    db.add(application)
    db.flush()
    for document_type in DLT_DOCUMENT_TYPES:
        db.add(DltDocument(application_id=application.id, document_type=document_type, status="missing"))
    db.commit()
    db.refresh(application)
    return application


def serialize_dlt(application: DltApplication) -> dict:
    documents = sorted(application.documents, key=lambda doc: doc.document_type)
    all_approved = bool(documents) and all(doc.status == "approved" for doc in documents)
    return {
        "id": str(application.id),
        "status": "approved" if all_approved and application.status != "not_started" else application.status,
        "completed": all_approved,
        "submitted_at": application.submitted_at,
        "approved_at": application.approved_at,
        "pe_tm_chain_binding_id": PE_TM_CHAIN_BINDING_ID,
        "documents": [
            {
                "id": str(doc.id),
                "document_type": doc.document_type,
                "original_filename": doc.original_filename,
                "status": doc.status,
                "review_note": doc.review_note,
                "uploaded_at": doc.uploaded_at,
                "reviewed_at": doc.reviewed_at,
            }
            for doc in documents
        ],
    }


def refresh_dlt_application_status(application: DltApplication) -> None:
    documents = application.documents
    if not documents:
        return
    if all(doc.status == "approved" for doc in documents):
        application.status = "approved"
        application.approved_at = datetime.now(timezone.utc)
    elif any(doc.status == "rejected" for doc in documents):
        application.status = "rejected"
    elif application.submitted_at:
        application.status = "submitted"