"""One-shot SQL Server (Navision) query: connect, run a SELECT, print rows.

Composes the registry functions `mssql_connect` and `mssql_query` so a single
`fn run run_mssql_query ...` opens a connection, runs one parameterized SELECT,
closes the connection, and prints the rows as JSON or CSV. Built to make
iterating over Navision queries a one-command loop instead of a manual
copy-paste round trip.
"""

from __future__ import annotations

import os
import sys

sys.path.insert(0, os.path.join(os.path.dirname(__file__), ".."))

from infra.mssql_connect import mssql_connect
from infra.mssql_query import mssql_query


def run_mssql_query(host: str, database: str, user: str, password: str,
                    sql: str, params=None, port: int = 1433,
                    max_rows: int | None = None, login_timeout: int = 15,
                    query_timeout: int = 30) -> dict:
    """Open a SQL Server connection, run one SELECT, close, return the rows.

    Thin impure composition of `mssql_connect` + `mssql_query`. The connection
    is always closed (try/finally), even on error. Credentials are supplied by
    the caller (read from `pass`/env) and never hardcoded.

    Args:
        host: SQL Server host or IP. From WSL2 use the Windows LAN IP, not
            "localhost".
        database: Database name to connect to.
        user: SQL Server login user.
        password: Password for the login user. Pass it from `pass`/env, never a
            string literal in code.
        sql: The SELECT statement, using pymssql placeholders `%s` (positional)
            or `%(name)s` (named) for any bound values.
        params: Tuple/list for positional placeholders, dict for named
            placeholders, or None. Bound safely by the driver (no injection).
        port: TCP port of the SQL Server instance. Defaults to 1433.
        max_rows: If a positive int, only the first `max_rows` rows are
            returned. If None, all rows are returned.
        login_timeout: Seconds allowed for the connect/login phase. Defaults to
            15. Keeps an unreachable host from hanging.
        query_timeout: Seconds allowed for the query. Defaults to 30.

    Returns:
        The dict returned by `mssql_query`: {"columns": [...], "rows": [...],
        "row_count": int}.

    Raises:
        RuntimeError: If the connection or the query fails. The original
            exception (from `mssql_connect` / `mssql_query`) is chained.
    """
    conn = mssql_connect(
        host, database, user, password,
        port=port, login_timeout=login_timeout, query_timeout=query_timeout,
    )
    try:
        return mssql_query(conn, sql, params=params, max_rows=max_rows)
    finally:
        try:
            conn.close()
        except Exception:  # pragma: no cover - close errors are non-fatal here
            pass


def _to_csv(result: dict) -> str:
    """Render a query result dict as CSV text (header + rows)."""
    import csv
    import io

    buf = io.StringIO()
    writer = csv.writer(buf)
    columns = result.get("columns", [])
    writer.writerow(columns)
    for row in result.get("rows", []):
        writer.writerow([row.get(col) for col in columns])
    return buf.getvalue()


if __name__ == "__main__":
    import argparse
    import json

    parser = argparse.ArgumentParser(
        description=(
            "Ejecuta una SELECT contra un SQL Server (Navision) e imprime las "
            "filas. Compone mssql_connect + mssql_query."
        )
    )
    parser.add_argument("--host", required=True, help="Host/IP del SQL Server (IP LAN de Windows desde WSL2).")
    parser.add_argument("--database", required=True, help="Nombre de la base de datos.")
    parser.add_argument("--user", required=True, help="Usuario de login.")
    parser.add_argument(
        "--password-env", default="MSSQL_PASSWORD",
        help="Variable de entorno de la que leer la contrasena (default MSSQL_PASSWORD). "
             "Uso recomendado: MSSQL_PASSWORD=$(pass navision/password) fn run run_mssql_query ...",
    )
    parser.add_argument(
        "--password", default="",
        help="Contrasena literal (DESACONSEJADO: visible en la lista de procesos). "
             "Prefiere --password-env.",
    )
    parser.add_argument("--sql", required=True, help="Sentencia SELECT (placeholders %%s o %%(nombre)s).")
    parser.add_argument(
        "--param", action="append", default=None, dest="params",
        help="Parametro posicional para los placeholders %%s. Repetible y en orden.",
    )
    parser.add_argument("--port", type=int, default=1433, help="Puerto TCP. Default 1433.")
    parser.add_argument("--max-rows", type=int, default=None, help="Limite de filas devueltas.")
    parser.add_argument("--login-timeout", type=int, default=15, help="Timeout de login en segundos.")
    parser.add_argument("--query-timeout", type=int, default=30, help="Timeout de query en segundos.")
    parser.add_argument(
        "--format", choices=["json", "csv"], default="json", dest="fmt",
        help="Formato de salida. Default json.",
    )
    args = parser.parse_args()

    password = args.password or os.environ.get(args.password_env, "")
    if not password:
        parser.error(
            f"sin contrasena: define la env var {args.password_env!r} "
            f"(p.ej. MSSQL_PASSWORD=$(pass navision/password)) o pasa --password."
        )

    params = tuple(args.params) if args.params else None

    result = run_mssql_query(
        args.host, args.database, args.user, password,
        args.sql, params=params, port=args.port, max_rows=args.max_rows,
        login_timeout=args.login_timeout, query_timeout=args.query_timeout,
    )

    if args.fmt == "csv":
        sys.stdout.write(_to_csv(result))
    else:
        print(json.dumps(result, default=str, ensure_ascii=False))