"""Direct PostgreSQL implementation of the DWH port."""

from tht.config import DatabaseConfig
from sqlalchemy.exc import SQLAlchemyError

from tht.db import execute, sampling
from tht.db.connection import make_engine, ping
from tht.db.introspect import introspect
from tht.execute import ExecResult, PlanSummary
from tht.mschema.models import PhysicalSchema
from tht.ports.dwh import DistinctValues, DwhCapabilities, DwhHealth


class PostgresDwhAdapter:
    capabilities = DwhCapabilities()

    def __init__(self, config: DatabaseConfig):
        self._config = config
        self._engine = make_engine(config)

    def health(self) -> DwhHealth:
        try:
            ping(self._engine)
        except SQLAlchemyError as exc:
            return DwhHealth(ok=False, detail=str(exc))
        return DwhHealth(ok=True)

    def introspect(self) -> PhysicalSchema:
        return introspect(self._engine, self._config.database, self._config.db_schema)

    def run_query(self, sql: str, *, limit: int) -> ExecResult:
        return execute.run_query(self._engine, sql, limit=limit)

    def explain(self, sql: str) -> PlanSummary:
        return execute.explain(self._engine, sql)

    def sample_column(self, table: str, column: str, *, limit: int) -> list[object]:
        return sampling.sample_column(
            self._engine, self._config.db_schema, table, column, limit=limit
        )

    def distinct_values(self, table: str, column: str) -> DistinctValues:
        return sampling.distinct_values(
            self._engine, self._config.db_schema, table, column
        )