"""Date-range resolver tests — bounds parsing + dispatch on column type/encoding.

`resolve_date_range` now returns an `exp` node and takes the effective encoding
map (built-in defaults overlaid with any dataset overrides). Tests render the
node to SQL to assert on the predicate.
"""

import pytest
from sqlglot import exp

from api.composer.dates import _bounds, resolve_date_range
from api.composer.encodings import DEFAULT_ENCODINGS, effective_encodings
from api.composer.types import PickValidationError
from api.recon.types import Column, Recon


def _col(name: str = "date", table: str = "l") -> exp.Column:
    return exp.column(name, table=table, quoted=True)


def _sql(node: exp.Expression) -> str:
    return node.sql(dialect="postgres", identify=True)


def test_bounds_year():
    assert _bounds("1996") == ("1996-01-01", "1996-12-31")


def test_bounds_quarter_q1():
    assert _bounds("1996-Q1") == ("1996-01-01", "1996-03-31")


def test_bounds_quarter_q3():
    assert _bounds("1996-Q3") == ("1996-07-01", "1996-09-30")


def test_bounds_unsupported_raises():
    with pytest.raises(PickValidationError, match="unsupported"):
        _bounds("Q3-1996")


def test_resolve_real_date_column():
    col = Column(name="date", sql_type="DATE", nullable=False)
    out = _sql(resolve_date_range("1996", col, _col(), {}))
    assert out == "\"l\".\"date\" BETWEEN '1996-01-01' AND '1996-12-31'"


def test_resolve_timestamp_column():
    col = Column(name="created_at", sql_type="TIMESTAMP WITHOUT TIME ZONE", nullable=True)
    out = _sql(resolve_date_range("1996-Q2", col, _col("created_at", "x"), {}))
    assert out == "\"x\".\"created_at\" BETWEEN '1996-04-01' AND '1996-06-30'"


def test_resolve_yymmdd_via_default_encoding():
    col = Column(name="date", sql_type="INTEGER", nullable=False,
                 semantic_type="date_yymmdd")
    out = _sql(resolve_date_range("1996", col, _col(), DEFAULT_ENCODINGS))
    assert "TO_DATE(LPAD(" in out
    assert "BETWEEN '1996-01-01' AND '1996-12-31'" in out


def test_dataset_encoding_overrides_default():
    # A dataset can override a built-in encoding with its own coercion SQL.
    col = Column(name="d", sql_type="INTEGER", nullable=False,
                 semantic_type="date_yymmdd")
    override = {"date_yymmdd": {"as_date": "MAKE_DATE(1900 + {col} / 10000, 1, 1)"}}
    out = _sql(resolve_date_range("1996", col, _col("d"), override))
    assert "MAKE_DATE(" in out
    assert "TO_DATE" not in out


def test_resolve_semantic_type_without_encoding_raises():
    # Declared semantic_type but no matching encoding and not a native date type.
    col = Column(name="d", sql_type="INTEGER", nullable=False,
                 semantic_type="date_yymmdd")
    with pytest.raises(PickValidationError, match="not supported"):
        resolve_date_range("1996", col, _col("d"), {})


def test_resolve_unsupported_column_type_raises():
    col = Column(name="x", sql_type="TEXT", nullable=True)
    with pytest.raises(PickValidationError, match="not supported"):
        resolve_date_range("1996", col, _col("x", "x"), {})


def test_effective_encodings_merges_defaults_with_dataset():
    recon = Recon(schema="t", tables={}, metrics={},
                  encodings={"my_epoch": {"as_date": "TO_TIMESTAMP({col})::date"}})
    eff = effective_encodings(recon)
    assert "date_yymmdd" in eff          # default survives
    assert eff["my_epoch"]["as_date"].startswith("TO_TIMESTAMP")  # dataset added

    # Dataset entry wins on key collision.
    recon2 = Recon(schema="t", tables={}, metrics={},
                   encodings={"date_yymmdd": {"as_date": "CUSTOM({col})"}})
    assert effective_encodings(recon2)["date_yymmdd"]["as_date"] == "CUSTOM({col})"