"""Unit tests — contract symbol parsing and root aliases."""
from __future__ import annotations

import pytest
from core.errors import ApiError
from futures.symbols import (
    ALIASES_OF_ROOT,
    ROOT_ALIASES,
    canonical_symbol,
    expand_year,
    normalize_root,
    parse_symbol,
    symbol_from_file_stem,
)


@pytest.mark.parametrize("raw, root, mc, year", [
    ("ESZ25", "ES", "Z", 2025),
    ("ESZ2025", "ES", "Z", 2025),
    ("ES_Z25", "ES", "Z", 2025),
    ("ES-Z25", "ES", "Z", 2025),
    ("esz25", "ES", "Z", 2025),
    ("  esz2025 ", "ES", "Z", 2025),
    ("CLF26", "CL", "F", 2026),
    ("M2KH25", "M2K", "H", 2025),
    ("FDAXZ2024", "FDAX", "Z", 2024),
    ("SR3Z24", "SR3", "Z", 2024),
    ("ZKZ25", "ZK", "Z", 2025),       # root ending with a month letter
    ("HHZ25", "HH", "Z", 2025),
    ("CZ25", "C", "Z", 2025),          # 1-char root (London cocoa)
    ("USZ24", "US", "Z", 2024),
    ("ESZ99", "ES", "Z", 1999),
    ("ESZ79", "ES", "Z", 2079),
    ("ESZ80", "ES", "Z", 1980),
])
def test_parse_symbol(raw, root, mc, year):
    cs = parse_symbol(raw)
    assert (cs.root, cs.month_code, cs.year) == (root, mc, year)
    assert cs.short == f"{root}{mc}{year % 100:02d}"
    assert cs.long == f"{root}{mc}{year}"
    assert cs.file_stem == f"{root}_{mc}{year % 100:02d}"


@pytest.mark.parametrize("raw, root", [
    ("6EZ25", "E6"), ("6JZ25", "J1"), ("6BZ25", "B6"), ("6AZ25", "A6"), ("6CZ25", "AD"), ("6SZ25", "E1"),
    ("6NZ25", "N6"), ("6MZ25", "MP"), ("6LZ25", "BR"), ("6ZZ25", "T6"), ("ZBZ25", "US"), ("E6Z25", "E6"),
])
def test_aliases_resolve_to_lake_roots(raw, root):
    assert parse_symbol(raw).root == root
    assert canonical_symbol(raw) == f"{root}Z25"


def test_alias_tables_are_consistent():
    for alias, root in ROOT_ALIASES.items():
        assert alias in ALIASES_OF_ROOT[root]
        assert normalize_root(alias) == root
        assert normalize_root(alias.lower()) == root
    assert normalize_root("es") == "ES"
    assert "6E" in ALIASES_OF_ROOT["E6"] and "ZB" in ALIASES_OF_ROOT["US"]


@pytest.mark.parametrize("bad", ["", "ES", "ESA25", "ESZ5", "ESZ2025X", "TOOLONGZ25", "ES Z 25", "Z25", "ES25", "ESZ125",
                                 "ES_Z_25", "ÉSZ25", "BOGUS", "ESZ1800"])
def test_invalid_symbols_raise_400(bad):
    with pytest.raises(ApiError) as e:
        parse_symbol(bad)
    assert e.value.status == 400 and e.value.code == "INVALID_CONTRACT_SYMBOL"
    assert e.value.payload()["error"]["docs"].endswith("#invalid_contract_symbol")


def test_expand_year():
    assert expand_year(0) == 2000 and expand_year(79) == 2079 and expand_year(80) == 1980 and expand_year(99) == 1999
    assert expand_year(2031) == 2031


def test_symbol_from_file_stem():
    cs = symbol_from_file_stem("ES_Z24_1day")
    assert cs is not None and cs.short == "ESZ24" and cs.year == 2024
    assert symbol_from_file_stem("ES_Z24").short == "ESZ24"
    assert symbol_from_file_stem("ES_1day") is None
    assert symbol_from_file_stem("AAPL") is None
    assert symbol_from_file_stem("ES_ZZ4_1day") is None