#!/usr/bin/env python3
from __future__ import annotations

import os
from pathlib import Path

import pandas as pd
import streamlit as st


APP_TITLE = "OpenLDAP Accounts CSV Editor"


FILES = {
    "Users": {
        "filename": "users.csv",
        "keys": ["uid", "gn", "sn", "mail"],
        "labels": {
            "uid": "UID",
            "gn": "Given Name",
            "sn": "Surname",
            "mail": "Email",
        },
    },
    "Admins": {
        "filename": "admins.csv",
        "keys": ["uid", "gn", "sn", "mail"],
        "labels": {
            "uid": "UID",
            "gn": "Given Name",
            "sn": "Surname",
            "mail": "Email",
        },
    },
    "POSIX Users": {
        "filename": "posix-users.csv",
        "keys": ["uid", "gn", "sn", "mail", "uidNumber", "gidNumber"],
        "labels": {
            "uid": "UID",
            "gn": "Given Name",
            "sn": "Surname",
            "mail": "Email",
            "uidNumber": "POSIX UID",
            "gidNumber": "POSIX GID",
        },
    },
}


def read_csv(path: Path, keys: list[str]) -> pd.DataFrame:
    if not path.exists():
        return pd.DataFrame(columns=keys)

    df = pd.read_csv(
        path,
        header=None,
        names=keys,
        comment="#",
        skip_blank_lines=True,
        dtype=str,
        keep_default_na=False,
        usecols=range(len(keys)),
    )
    return df.apply(lambda col: col.str.strip())


def write_csv(path: Path, keys: list[str], df: pd.DataFrame) -> None:
    path.parent.mkdir(parents=True, exist_ok=True)

    cleaned = df.fillna("").astype(str)
    cleaned = cleaned.apply(lambda col: col.str.strip())
    cleaned = cleaned[cleaned.ne("").any(axis=1)]

    with path.open("w", newline="", encoding="utf-8") as f:
        f.write(f"# {','.join(keys)}\n")
        cleaned.to_csv(f, index=False, header=False)


def render_page(accounts_dir: Path, page_name: str) -> None:
    spec = FILES[page_name]
    csv_path = accounts_dir / spec["filename"]

    st.subheader(page_name)
    st.caption(f"File: {csv_path}")

    df = read_csv(csv_path, spec["keys"])

    column_config = {
        key: st.column_config.TextColumn(label=spec["labels"].get(key, key), width="medium")
        for key in spec["keys"]
    }

    edited = st.data_editor(
        df,
        width="stretch",
        num_rows="dynamic",
        column_config=column_config,
        hide_index=True,
        key=f"editor-{page_name}",
    )

    with st.container(horizontal=True):
        if st.button("Save", type="primary", width=120, key=f"save-{page_name}"):
            write_csv(csv_path, spec["keys"], edited)
            st.success(f"Saved {spec['filename']}")

        if st.button("Reload", width=120, key=f"reload-{page_name}"):
            st.rerun()


def main() -> None:
    st.set_page_config(page_title=APP_TITLE, layout="wide")
    st.title(APP_TITLE)

    default_dir = os.environ.get("OPENLDAP_ACCOUNTS_DIR", "~/app-data/openldap/accounts")

    with st.sidebar:
        st.header("Settings")
        accounts_dir_raw = st.text_input("Accounts directory", value=default_dir)
        page_name = st.radio("Page", list(FILES.keys()))

    accounts_dir = Path(accounts_dir_raw).expanduser()
    st.caption("This editor manages the CSV files used by OpenLDAP bootstrap.")

    if not accounts_dir.exists():
        st.warning(f"Directory does not exist yet: {accounts_dir}")

    render_page(accounts_dir, page_name)


if __name__ == "__main__":
    main()