import ast
from pathlib import Path
from sys import argv

# Also requires the `tabulate` package.
import pandas as pd


if not (len(argv) == 2 and Path(argv[1]).exists()):
    message = "Correct script usage = `pytest_adoption.py <iris_root_dir>`"
    raise ValueError(message)

IRIS_ROOT = Path(argv[1])
IRIS_TREE_URL = "https://github.com/SciTools/iris/tree/main/"
markdown_path = Path(__file__).with_suffix(".md")

tests_dir = IRIS_ROOT / "lib" / "iris" / "tests"
dataframe_data = []
total_asserts = 0
total_asserts_pytest = 0

for file_path in tests_dir.rglob("*.py"):
    file_text = file_path.read_text()
    parsed = ast.parse(source=file_text)
    calls = filter(lambda node: hasattr(node, "func"), ast.walk(parsed))
    assert_calls = filter(
        lambda c: getattr(c.func, "attr", "")[:6] == "assert", calls
    )
    assert_calls_methods = filter(lambda c: hasattr(c.func, "value"), assert_calls)
    assert_calls_methods_self = filter(
        lambda m: getattr(m.func.value, "id", "") == "self", assert_calls_methods
    )
    num_asserts_unittest = len(list(assert_calls_methods_self))

    assert_keywords = filter(
        lambda node: isinstance(node, ast.Assert), ast.walk(parsed)
    )
    num_asserts_pytest = len(list(assert_keywords))

    both_asserts = num_asserts_unittest + num_asserts_pytest
    if both_asserts == 0:
        percent_adoption = "N/A"
    else:
        percent_adoption = f"{num_asserts_pytest / both_asserts * 100:.0f}"

    total_asserts += both_asserts
    total_asserts_pytest += num_asserts_pytest

    file_url = IRIS_TREE_URL + str(file_path.relative_to(IRIS_ROOT))
    file_link_text = f"{file_path.relative_to(tests_dir).stem}"

    dataframe_data.append(
        {
            "% adoption": percent_adoption,
            # "File Path": f"[{file_link_text}]({file_url})",
            "File Path": f"{file_link_text}",
            "Number of `self.assertSomething()`": num_asserts_unittest,
            "Number of `assert something`": num_asserts_pytest,
        }
    )

pytest_adoption_df = pd.DataFrame(dataframe_data)

total_percent_adoption = f"{total_asserts_pytest / total_asserts * 100:.0f}%"
total_line = (
    "## Total adoption\n\n"
    f"### {total_asserts_pytest} out of {total_asserts} : {total_percent_adoption}"
)

script_line = (
    "## Generated using this script\n\n"
    "<details>\n"
    "<summary>Click to expand <b>this section...</b></summary>\n\n"
    "```python\n"
    f"{Path(__file__).read_text()}"
    "```\n\n"
    "</details>"
)

# pytest_adoption_df.to_markdown(markdown_path, index=False)
pytest_adoption_df.to_html(markdown_path, index=False)

full_text = (
    "# Iris approximate pytest adoption\n\n"
    f"{script_line}\n\n"
    f"{total_line}\n\n"
    "## Breakdown\n\n"
    f"{markdown_path.read_text()}"
)

markdown_path.write_text(full_text)