"""Regression tests for the recon package — type round-trips, join_path,
and column_to_tables index."""

from api.recon.types import Recon, Relationship, Table, Column, Metric


def _sample_recon() -> Recon:
    cols_account = [
        Column("account_id", "BIGINT", False),
        Column("district_id", "BIGINT", True),
    ]
    cols_district = [
        Column("district_id", "BIGINT", False),
        Column("A2", "TEXT", True),
        Column("A11", "BIGINT", True),
    ]
    cols_loan = [
        Column("loan_id", "BIGINT", False),
        Column("account_id", "BIGINT", True),
        Column("amount", "BIGINT", True),
        Column("status", "TEXT", True),
    ]
    rels = [
        Relationship("account", "district_id", "district", "district_id"),
        Relationship("loan", "account_id", "account", "account_id"),
    ]
    c2t = {
        "account_id": sorted(["account", "loan"]),
        "district_id": sorted(["account", "district"]),
        "A2": ["district"],
        "A11": ["district"],
        "loan_id": ["loan"],
        "amount": ["loan"],
        "status": ["loan"],
    }
    return Recon(
        schema="financial",
        tables={
            "account": Table("account", "Accounts", cols_account),
            "district": Table("district", "Districts", cols_district),
            "loan": Table("loan", "Loans", cols_loan),
        },
        metrics={
            "loan_volume": Metric("loan_volume", "Total CZK lent",
                                  "SUM(amount)", "loan", None, "CZK"),
        },
        column_to_tables=c2t,
        relationships=rels,
    )


def test_owning_tables():
    r = _sample_recon()
    assert r.owning_tables("A2") == ["district"]
    assert r.owning_tables("amount") == ["loan"]
    assert r.owning_tables("account_id") == ["account", "loan"]
    assert r.owning_tables("nonsense") == []


def test_join_path_direct():
    r = _sample_recon()
    assert r.join_path("loan", "account") == ["loan", "account"]
    assert r.join_path("account", "district") == ["account", "district"]


def test_join_path_multi_hop():
    r = _sample_recon()
    assert r.join_path("loan", "district") == ["loan", "account", "district"]


def test_join_path_same():
    r = _sample_recon()
    assert r.join_path("loan", "loan") == ["loan"]


def test_join_path_unknown_returns_none():
    r = _sample_recon()
    assert r.join_path("loan", "does_not_exist") is None


def test_recon_to_dict_from_dict_roundtrip():
    r = _sample_recon()
    d = r.to_dict()
    r2 = Recon.from_dict(d)
    assert r2.schema == r.schema
    assert sorted(r2.tables) == sorted(r.tables)
    assert sorted(r2.metrics) == sorted(r.metrics)
    assert r2.column_to_tables == r.column_to_tables
    assert len(r2.relationships) == len(r.relationships)
    assert r2.join_path("loan", "district") == ["loan", "account", "district"]


def test_relationship_parse_dotted():
    r = Relationship.parse({"from": "loan.account_id", "to": "account.account_id"})
    assert r.from_table == "loan"
    assert r.from_column == "account_id"
    assert r.to_table == "account"
    assert r.to_column == "account_id"


def test_relationship_parse_explicit():
    r = Relationship.parse({
        "from_table": "loan", "from_column": "account_id",
        "to_table": "account", "to_column": "account_id",
    })
    assert r.from_table == "loan"