"""Tests for `agent.markdown_tables.realign_markdown_tables`.

These cover the alignment guarantee on CJK / wide-character tables and
the conservative no-op behaviour on non-table input.
"""

from __future__ import annotations

from textwrap import dedent

from wcwidth import wcswidth

from agent.markdown_tables import (
    is_table_divider,
    looks_like_table_row,
    realign_markdown_tables,
    split_table_row,
)


def _column_offsets(line: str) -> list[int]:
    """Return the display-cell index of every ``|`` in ``line``."""

    cells: list[int] = []
    width = 0
    for ch in line:
        if ch == "|":
            cells.append(width)
        # wcswidth on a single char; clamp negatives.
        w = wcswidth(ch)
        width += w if w > 0 else 1
    return cells


# ---------------------------------------------------------------------------
# split_table_row / is_table_divider / looks_like_table_row
# ---------------------------------------------------------------------------


def test_split_strips_outer_pipes_and_trims():
    assert split_table_row("| a | b | c |") == ["a", "b", "c"]
    assert split_table_row("|配置|状态|") == ["配置", "状态"]
    assert split_table_row("a | b | c") == ["a", "b", "c"]


def test_is_table_divider_handles_alignment_colons():
    assert is_table_divider("|---|---|")
    assert is_table_divider("| :--- | ---: | :---: |")
    assert not is_table_divider("| - | - |")          # 1 dash is not a divider
    assert not is_table_divider("| a | b |")
    assert not is_table_divider("---")                # single column, no pipes


def test_looks_like_table_row():
    assert looks_like_table_row("| a | b |")
    assert looks_like_table_row("a | b | c")          # no leading pipe, ≥2 pipes
    assert not looks_like_table_row("not a table")
    assert not looks_like_table_row("a | b")          # one pipe, no leading pipe
    assert not looks_like_table_row("")


# ---------------------------------------------------------------------------
# realign_markdown_tables
# ---------------------------------------------------------------------------


def test_no_op_on_text_without_tables():
    text = "Hello world\nThis has no | pipes table.\n"
    assert realign_markdown_tables(text) == text


def test_no_op_when_pipes_but_no_divider():
    text = "echo a | grep b\necho c | wc -l\n"
    assert realign_markdown_tables(text) == text


def test_cjk_table_pipes_align_across_rows():
    # Model-emitted (under-padded for CJK) input.
    src = dedent(
        """\
        | 配置 | Config | 论文 (%) | 复现 (%) | 差值 | 状态 |
        |------|--------|---------|---------|------|------|
        | Vicuna (report) | dense | 79.30 | 未完成 | - | × |
        | ChatGLM | chat | 37.60 | 37.82 | +0.22 | ✓ |
        | 通义千问 | qwen | (无) | 报错 | - | × |
        """
    )

    out = realign_markdown_tables(src).rstrip("\n").split("\n")

    # All rows in the rebuilt block must have pipes at identical display
    # columns — that's the alignment guarantee.
    offsets = [_column_offsets(row) for row in out]
    assert all(o == offsets[0] for o in offsets), (
        "rebuilt table rows do not share pipe column offsets:\n"
        + "\n".join(out)
    )
    # And we expect 7 pipes per row (6 columns + outer borders).
    assert len(offsets[0]) == 7


def test_emoji_with_cjk_table_aligns():
    src = dedent(
        """\
        | 模型 | 状态 | 备注 |
        |------|------|------|
        | 千问 | ✅ | 通过 |
        | Claude | ✅ | 推理强 |
        | 文心一言 | ❌ | 报错 |
        """
    )

    out = realign_markdown_tables(src).rstrip("\n").split("\n")
    offsets = [_column_offsets(row) for row in out]
    # The emoji-with-variation-selector case (⚠️) intentionally tolerates
    # 1-cell drift; bare emoji like ✅ / ❌ have stable wcwidth and must
    # align.  Use bare emoji here so the assertion is hard.
    assert all(o == offsets[0] for o in offsets), (
        "emoji+CJK rows do not share pipe column offsets:\n" + "\n".join(out)
    )


def test_already_aligned_ascii_table_remains_aligned():
    src = dedent(
        """\
        | a   | b   |
        |-----|-----|
        | 1   | 2   |
        | foo | bar |
        """
    )
    out = realign_markdown_tables(src).rstrip("\n").split("\n")
    offsets = [_column_offsets(row) for row in out]
    assert all(o == offsets[0] for o in offsets)


def test_passes_non_table_lines_through_around_a_table():
    src = dedent(
        """\
        Here is a comparison:

        | 模型 | 状态 |
        |------|------|
        | 千问 | 通过 |

        And some prose after.
        """
    )

    out = realign_markdown_tables(src)
    assert out.startswith("Here is a comparison:\n")
    assert out.endswith("And some prose after.\n")
    # And the table lines are aligned.
    block = [ln for ln in out.split("\n") if "|" in ln]
    offsets = [_column_offsets(row) for row in block]
    assert all(o == offsets[0] for o in offsets)


def test_handles_ragged_rows_by_padding_short_rows():
    src = dedent(
        """\
        | a | b | c |
        |---|---|---|
        | 1 | 2 |
        | x | y | z |
        """
    )
    out = realign_markdown_tables(src).rstrip("\n").split("\n")
    offsets = [_column_offsets(row) for row in out]
    # Short rows must be padded out so they have the same pipe count
    # and column positions as the header.
    assert all(len(o) == len(offsets[0]) for o in offsets)
    assert all(o == offsets[0] for o in offsets)


def test_multiple_tables_in_one_text():
    src = dedent(
        """\
        First:

        | 配置 | 值 |
        |------|----|
        | 通义 | 1 |

        Second:

        | model | n |
        |-------|---|
        | gpt   | 2 |
        """
    )
    out = realign_markdown_tables(src)
    # Each table block individually aligns.
    blocks: list[list[str]] = []
    current: list[str] = []
    for line in out.split("\n"):
        if "|" in line:
            current.append(line)
        elif current:
            blocks.append(current)
            current = []
    if current:
        blocks.append(current)

    assert len(blocks) == 2
    for block in blocks:
        offsets = [_column_offsets(row) for row in block]
        assert all(o == offsets[0] for o in offsets), (
            f"block did not align:\n" + "\n".join(block)
        )