from typing import Any

from app.db.database import get_connection
from app.db.migrations import run_migrations

ROLES = ("admin", "developer", "viewer")


def _table_columns(con, table_name: str) -> set[str]:
    rows = con.execute(f"PRAGMA table_info({table_name})").fetchall()
    return {row["name"] for row in rows}


def list_users() -> list[dict[str, Any]]:
    run_migrations()
    con = get_connection()
    columns = _table_columns(con, "users")
    last_login_select = "last_login_at" if "last_login_at" in columns else "NULL AS last_login_at"

    rows = con.execute(
        f"""
        SELECT
            id,
            username,
            display_name,
            email,
            role,
            COALESCE(is_enabled, 1) AS is_enabled,
            created_at,
            updated_at,
            {last_login_select}
        FROM users
        ORDER BY id
        """
    ).fetchall()

    con.close()
    return [dict(row) for row in rows]


def get_user(user_id: int) -> dict[str, Any] | None:
    run_migrations()
    con = get_connection()
    columns = _table_columns(con, "users")
    last_login_select = "last_login_at" if "last_login_at" in columns else "NULL AS last_login_at"

    row = con.execute(
        f"""
        SELECT
            id,
            username,
            display_name,
            email,
            role,
            COALESCE(is_enabled, 1) AS is_enabled,
            created_at,
            updated_at,
            {last_login_select}
        FROM users
        WHERE id = ?
        """,
        (user_id,),
    ).fetchone()

    con.close()
    return dict(row) if row else None


def count_enabled_admins(excluding_user_id: int | None = None) -> int:
    run_migrations()
    con = get_connection()
    params: list[Any] = []
    exclusion = ""
    if excluding_user_id is not None:
        exclusion = "AND id != ?"
        params.append(excluding_user_id)

    row = con.execute(
        f"""
        SELECT COUNT(*) AS count
        FROM users
        WHERE LOWER(COALESCE(role, '')) = 'admin'
          AND COALESCE(is_enabled, 1) = 1
          {exclusion}
        """,
        params,
    ).fetchone()

    con.close()
    return int(row["count"] or 0)


def update_user_role(user_id: int, role: str) -> None:
    if role not in ROLES:
        raise ValueError("Invalid user role")

    run_migrations()
    con = get_connection()
    con.execute(
        """
        UPDATE users
        SET role = ?,
            updated_at = CURRENT_TIMESTAMP
        WHERE id = ?
        """,
        (role, user_id),
    )
    con.commit()
    con.close()


def set_user_enabled(user_id: int, enabled: bool) -> None:
    run_migrations()
    con = get_connection()
    con.execute(
        """
        UPDATE users
        SET is_enabled = ?,
            updated_at = CURRENT_TIMESTAMP
        WHERE id = ?
        """,
        (1 if enabled else 0, user_id),
    )
    con.commit()
    con.close()