import streamlit as st

from backend.adapters.snowflake import get_current_user_name, get_session, resolve_env
from backend.actions.bulk_delete import (
    bulk_delete_emails_from_csv,
    parse_emails_from_csv,
)
from backend.permissions import require_access

session = get_session()
require_access(session, "BULK_DELETE")

st.title("Bulk Delete")

st.markdown(
    """
Upload a CSV file containing a list of emails to be deleted.
The CSV must have a header row; the first column will be used as the email column.

Total of 100 000 emails are supported in one upload. NB! - all activities will be logged!
"""
)

uploaded_file = st.file_uploader("Choose a CSV file", type=["csv"])

if uploaded_file is not None:
    emails, errors = parse_emails_from_csv(uploaded_file)
    uploaded_file.seek(0)
    if errors:
        st.error(
            f"CSV has {len(errors)} validation error(s). Fix all errors before deleting."
        )
        st.dataframe({"Validation Errors": errors}, width="content")
    else:
        st.info(f"{len(emails):,} email(s) will be submitted for deletion.")

if st.button("Bulk Delete"):
    if uploaded_file is None:
        st.warning("Please upload a CSV file first.")
    else:
        session = get_session()

        user = get_current_user_name(session)

        schema = resolve_env(session)

        result = bulk_delete_emails_from_csv(session, uploaded_file, user, schema)

        if result.errors:
            st.error(
                f"Upload rejected — {len(result.errors)} validation error(s). "
                "Fix all errors and re-upload."
            )
            st.dataframe(
                {"Validation Errors": result.errors},
                width="content",
            )
        else:
            st.success(
                f"Successfully queued {result.inserted_count} email(s) for deletion."
            )