import re

from sqlalchemy import text

import ingestor.metrics as metrics

# fullmatch (no ^/$ anchors) so a trailing newline can't slip through — `$` would
# match before a trailing '\n', which is not what we want for a SQL identifier.
_IDENTIFIER_RE = re.compile(r'\w+', re.ASCII)


class DataSink:
    """Gateway egress wrapper: fans a reading out to every configured name/collection."""

    def __init__(self, data_manager, postgres) -> None:
        self.data_manager = data_manager
        self.postgres = postgres

    async def emit_metric(self, **kwargs) -> None:
        # ponytail: delegate to data_manager, it's already a SientiaMonitoring
        await self.data_manager.emit_metric(**kwargs)

    async def publish_reading(self, tag: str, value, timestamp, names: list[dict]) -> None:
        """Publish one MongoDB document per name entry and record its tag value metric."""
        for name in names:
            doc = {
                'tag': tag,
                'name': name['tag_name'],
                'model_id': name['model_id'],
                'timestamp': timestamp,
                'value': value,
            }
            await self.data_manager.publish(name['collection'], doc)
            await self.emit_metric(
                metric_object=metrics.OPC_TAG_VALUE,
                method='set',
                value=value,
                tags={
                    'pod_id': self.data_manager.pod_id,
                    'tag_name': name['tag_name'],
                    'model_id': name['model_id'],
                },
            )

    async def update_write_status(self, cmd: dict, result) -> None:  # NOSONAR
        """UPDATE the per-model prediction row's write_status (C3), by timestamp+model_id.

        schema/table_name are per-model SQL identifiers, not values — they can't be
        bound params, so they're checked against an allowlist before interpolation.
        status/timestamp/model_id ARE bound params, never f-stringed.
        """
        schema = self._validate_identifier(cmd['schema'])
        table = self._validate_identifier(cmd['table_name'])
        # schema/table are allowlist-validated identifiers above; status/timestamp/model_id
        # are bound params below, never interpolated — not a real injection vector.
        stmt = text(
            f'UPDATE {schema}.{table} SET write_status = :status '  # noqa: S608 # nosec B608
            'WHERE timestamp = :timestamp AND model_id = :model_id'
        )
        params = {
            'status': result.status,
            'timestamp': cmd['timestamp'],
            'model_id': cmd['model_id'],
        }
        # ponytail: sync engine call inside async def — same pattern sientia_do's own
        # Postgres activities use (e.g. export_data_to_postgres); no async pg driver here.
        with self.postgres.engine.begin() as connection:
            connection.execute(stmt, params)

    @staticmethod
    def _validate_identifier(name: str) -> str:
        if not isinstance(name, str) or not _IDENTIFIER_RE.fullmatch(name):
            raise ValueError(f'invalid SQL identifier: {name!r}')
        return name