# coding=utf-8
# Copyright 2024 HuggingFace Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import ast
import os
import re
import shutil
import tempfile
import subprocess
import traceback
import pytest
from pathlib import Path
from typing import List
from dotenv import load_dotenv


class SubprocessCallException(Exception):
    pass


def run_command(command: List[str], return_stdout=False, env=None):
    """
    Runs command with subprocess.check_output and returns stdout if requested.
    Properly captures and handles errors during command execution.
    """
    for i, c in enumerate(command):
        if isinstance(c, Path):
            command[i] = str(c)

    if env is None:
        env = os.environ.copy()

    try:
        output = subprocess.check_output(command, stderr=subprocess.STDOUT, env=env)
        if return_stdout:
            if hasattr(output, "decode"):
                output = output.decode("utf-8")
            return output
    except subprocess.CalledProcessError as e:
        raise SubprocessCallException(
            f"Command `{' '.join(command)}` failed with the following error:\n\n{e.output.decode()}"
        ) from e


class DocCodeExtractor:
    """Handles extraction and validation of Python code from markdown files."""

    @staticmethod
    def extract_python_code(content: str) -> List[str]:
        """Extract Python code blocks from markdown content."""
        pattern = r"```(?:python|py)\n(.*?)\n```"
        matches = re.finditer(pattern, content, re.DOTALL)
        return [match.group(1).strip() for match in matches]

    @staticmethod
    def create_test_script(code_blocks: List[str], tmp_dir: str) -> Path:
        """Create a temporary Python script from code blocks."""
        combined_code = "\n\n".join(code_blocks)
        assert len(combined_code) > 0, "Code is empty!"
        tmp_file = Path(tmp_dir) / "test_script.py"

        with open(tmp_file, "w", encoding="utf-8") as f:
            f.write(combined_code)

        return tmp_file


class TestDocs:
    """Test case for documentation code testing."""

    @classmethod
    def setup_class(cls):
        cls._tmpdir = tempfile.mkdtemp()
        cls.launch_args = ["python3"]
        cls.docs_dir = Path(__file__).parent.parent / "docs" / "source"
        cls.extractor = DocCodeExtractor()

        if not cls.docs_dir.exists():
            raise ValueError(f"Docs directory not found at {cls.docs_dir}")

        load_dotenv()
        cls.hf_token = os.getenv("HF_TOKEN")

        cls.md_files = list(cls.docs_dir.rglob("*.md"))
        if not cls.md_files:
            raise ValueError(f"No markdown files found in {cls.docs_dir}")

    @classmethod
    def teardown_class(cls):
        shutil.rmtree(cls._tmpdir)

    @pytest.mark.timeout(100)
    def test_single_doc(self, doc_path: Path):
        """Test a single documentation file."""
        with open(doc_path, "r", encoding="utf-8") as f:
            content = f.read()

        code_blocks = self.extractor.extract_python_code(content)
        excluded_snippets = [
            "ToolCollection",
            "image_generation_tool",
            "from_langchain",
            "while llm_should_continue(memory):",
        ]
        code_blocks = [
            block
            for block in code_blocks
            if not any(
                [snippet in block for snippet in excluded_snippets]
            )  # Exclude these tools that take longer to run and add dependencies
        ]
        if len(code_blocks) == 0:
            pytest.skip(f"No Python code blocks found in {doc_path.name}")

        # Validate syntax of each block individually by parsing it
        for i, block in enumerate(code_blocks, 1):
            ast.parse(block)

        # Create and execute test script
        try:
            code_blocks = [
                block.replace("<YOUR_HUGGINGFACEHUB_API_TOKEN>", self.hf_token).replace(
                    "{your_username}", "m-ric"
                )
                for block in code_blocks
            ]
            test_script = self.extractor.create_test_script(code_blocks, self._tmpdir)
            run_command(self.launch_args + [str(test_script)])

        except SubprocessCallException as e:
            pytest.fail(f"\nError while testing {doc_path.name}:\n{str(e)}")
        except Exception:
            pytest.fail(
                f"\nUnexpected error while testing {doc_path.name}:\n{traceback.format_exc()}"
            )

    @pytest.fixture(autouse=True)
    def _setup(self):
        """Fixture to ensure temporary directory exists for each test."""
        os.makedirs(self._tmpdir, exist_ok=True)
        yield
        # Clean up test files after each test
        for file in Path(self._tmpdir).glob("*"):
            file.unlink()


def pytest_generate_tests(metafunc):
    """Generate test cases for each markdown file."""
    if "doc_path" in metafunc.fixturenames:
        test_class = metafunc.cls

        # Initialize the class if needed
        if not hasattr(test_class, "md_files"):
            test_class.setup_class()

        # Parameterize with the markdown files
        metafunc.parametrize(
            "doc_path", test_class.md_files, ids=[f.stem for f in test_class.md_files]
        )