"""The `file` connector (ingest-spec §4, §8).

CSV under `root` with fail-closed boundary-checked path resolution,
utf-8-sig decoding (BOM never leaks into the first header cell), streaming
max_rows cap (error, never silent truncation), and ragged-row rejection.
"""

from __future__ import annotations

import os
from pathlib import Path

import pytest

from llm_ingestion_okf.connectors import read_csv
from llm_ingestion_okf.errors import IngestError, SourceError


def write_csv(root: Path, name: str, text: str) -> Path:
    path = root / name
    path.parent.mkdir(parents=True, exist_ok=True)
    path.write_text(text, encoding="utf-8", newline="")
    return path


# --- error hierarchy ---


def test_source_error_is_ingest_error() -> None:
    assert issubclass(SourceError, IngestError)


# --- happy path ---


def test_reads_header_and_rows_in_source_order(tmp_path: Path) -> None:
    write_csv(tmp_path, "orders.csv", "a,b\n1,x\n2,y\n")
    header, rows = read_csv(tmp_path, "orders.csv", max_rows=10)
    assert header == ["a", "b"]
    assert rows == [["1", "x"], ["2", "y"]]


def test_reads_csv_in_subdirectory(tmp_path: Path) -> None:
    write_csv(tmp_path, "sub/orders.csv", "a\n1\n")
    header, rows = read_csv(tmp_path, "sub/orders.csv", max_rows=10)
    assert header == ["a"]
    assert rows == [["1"]]


def test_cells_are_verbatim_text(tmp_path: Path) -> None:
    # No escaping at the connector layer — that is render_table's job.
    write_csv(tmp_path, "t.csv", 'a\n"pipe|and\\slash"\n')
    _, rows = read_csv(tmp_path, "t.csv", max_rows=10)
    assert rows == [["pipe|and\\slash"]]


def test_quoted_cell_with_embedded_newline_survives_verbatim(tmp_path: Path) -> None:
    write_csv(tmp_path, "t.csv", 'a,b\n"line1\nline2",x\n')
    _, rows = read_csv(tmp_path, "t.csv", max_rows=10)
    assert rows == [["line1\nline2", "x"]]


def test_bom_never_leaks_into_first_header_cell(tmp_path: Path) -> None:
    write_csv(tmp_path, "t.csv", "\ufeffa,b\n1,2\n")
    header, _ = read_csv(tmp_path, "t.csv", max_rows=10)
    assert header == ["a", "b"]


# --- boundary check: fail-closed path resolution (the OKF path rule) ---


def test_dotdot_traversal_rejected(tmp_path: Path) -> None:
    root = tmp_path / "root"
    root.mkdir()
    write_csv(tmp_path, "outside.csv", "a\n1\n")
    with pytest.raises(SourceError):
        read_csv(root, "../outside.csv", max_rows=10)


def test_absolute_query_path_rejected(tmp_path: Path) -> None:
    root = tmp_path / "root"
    root.mkdir()
    outside = write_csv(tmp_path, "outside.csv", "a\n1\n")
    with pytest.raises(SourceError):
        read_csv(root, str(outside), max_rows=10)


def test_symlink_escape_rejected(tmp_path: Path) -> None:
    root = tmp_path / "root"
    root.mkdir()
    write_csv(tmp_path, "outside.csv", "a\n1\n")
    os.symlink(tmp_path / "outside.csv", root / "link.csv")
    with pytest.raises(SourceError):
        read_csv(root, "link.csv", max_rows=10)


def test_prefix_collision_sibling_rejected(tmp_path: Path) -> None:
    root = tmp_path / "data"
    root.mkdir()
    write_csv(tmp_path, "data-evil/t.csv", "a\n1\n")
    with pytest.raises(SourceError):
        read_csv(root, "../data-evil/t.csv", max_rows=10)


# --- input-shape failures: typed errors, never leaked OSError ---


def test_missing_root_rejected(tmp_path: Path) -> None:
    with pytest.raises(SourceError):
        read_csv(tmp_path / "nope", "t.csv", max_rows=10)


def test_root_that_is_a_file_rejected(tmp_path: Path) -> None:
    file_root = write_csv(tmp_path, "afile", "x")
    with pytest.raises(SourceError):
        read_csv(file_root, "t.csv", max_rows=10)


def test_query_not_resolving_to_file_rejected(tmp_path: Path) -> None:
    with pytest.raises(SourceError):
        read_csv(tmp_path, "missing.csv", max_rows=10)


def test_empty_csv_rejected(tmp_path: Path) -> None:
    write_csv(tmp_path, "t.csv", "")
    with pytest.raises(SourceError):
        read_csv(tmp_path, "t.csv", max_rows=10)


def test_ragged_row_rejected(tmp_path: Path) -> None:
    write_csv(tmp_path, "t.csv", "a,b\n1\n")
    with pytest.raises(SourceError):
        read_csv(tmp_path, "t.csv", max_rows=10)


# --- max_rows cap (spec §8): error, never silent truncation ---


def test_row_count_at_cap_is_allowed(tmp_path: Path) -> None:
    write_csv(tmp_path, "t.csv", "a\n1\n2\n")
    _, rows = read_csv(tmp_path, "t.csv", max_rows=2)
    assert len(rows) == 2


def test_exceeding_cap_is_an_error(tmp_path: Path) -> None:
    write_csv(tmp_path, "t.csv", "a\n1\n2\n3\n")
    with pytest.raises(SourceError):
        read_csv(tmp_path, "t.csv", max_rows=2)


def test_header_does_not_count_toward_cap(tmp_path: Path) -> None:
    write_csv(tmp_path, "t.csv", "a\n1\n")
    _, rows = read_csv(tmp_path, "t.csv", max_rows=1)
    assert rows == [["1"]]