ArchiveBox/archivebox/plugins/readability/on_Snapshot__56_readability.py

#!/usr/bin/env python3
"""
Extract article content using Mozilla's Readability.

Usage: on_Snapshot__readability.py --url=<url> --snapshot-id=<uuid>
Output: Creates readability/ directory with content.html, content.txt, article.json

Environment variables:
    READABILITY_BINARY: Path to readability-extractor binary
    READABILITY_TIMEOUT: Timeout in seconds (default: 60)
    READABILITY_ARGS: Default Readability arguments (JSON array)
    READABILITY_ARGS_EXTRA: Extra arguments to append (JSON array)
    TIMEOUT: Fallback timeout

Note: Requires readability-extractor from https://github.com/ArchiveBox/readability-extractor
      This extractor looks for HTML source from other extractors (wget, singlefile, dom)
"""

import json
import os
import subprocess
import sys
import tempfile
from pathlib import Path
from urllib.parse import urlparse

import rich_click as click


# Extractor metadata
PLUGIN_NAME = 'readability'
BIN_NAME = 'readability-extractor'
BIN_PROVIDERS = 'npm,env'
OUTPUT_DIR = '.'
OUTPUT_FILE = 'content.html'


def get_env(name: str, default: str = '') -> str:
    return os.environ.get(name, default).strip()


def get_env_int(name: str, default: int = 0) -> int:
    try:
        return int(get_env(name, str(default)))
    except ValueError:
        return default


def get_env_array(name: str, default: list[str] | None = None) -> list[str]:
    """Parse a JSON array from environment variable."""
    val = get_env(name, '')
    if not val:
        return default if default is not None else []
    try:
        result = json.loads(val)
        if isinstance(result, list):
            return [str(item) for item in result]
        return default if default is not None else []
    except json.JSONDecodeError:
        return default if default is not None else []


def find_html_source() -> str | None:
    """Find HTML content from other extractors in the snapshot directory."""
    # Hooks run in snapshot_dir, sibling extractor outputs are in subdirectories
    search_patterns = [
        'singlefile/singlefile.html',
        '*_singlefile/singlefile.html',
        'singlefile/*.html',
        '*_singlefile/*.html',
        'dom/output.html',
        '*_dom/output.html',
        'dom/*.html',
        '*_dom/*.html',
        'wget/**/*.html',
        '*_wget/**/*.html',
        'wget/**/*.htm',
        '*_wget/**/*.htm',
    ]

    for base in (Path.cwd(), Path.cwd().parent):
        for pattern in search_patterns:
            matches = list(base.glob(pattern))
            for match in matches:
                if match.is_file() and match.stat().st_size > 0:
                    return str(match)

    return None


def extract_readability(url: str, binary: str) -> tuple[bool, str | None, str]:
    """
    Extract article using Readability.

    Returns: (success, output_path, error_message)
    """
    timeout = get_env_int('READABILITY_TIMEOUT') or get_env_int('TIMEOUT', 60)
    readability_args = get_env_array('READABILITY_ARGS', [])
    readability_args_extra = get_env_array('READABILITY_ARGS_EXTRA', [])

    # Find HTML source
    html_source = find_html_source()
    if not html_source:
        return False, None, 'No HTML source found (run singlefile, dom, or wget first)'

    # Output directory is current directory (hook already runs in output dir)
    output_dir = Path(OUTPUT_DIR)

    try:
        # Run readability-extractor (outputs JSON by default)
        cmd = [binary, *readability_args, *readability_args_extra, html_source]
        result = subprocess.run(cmd, stdout=subprocess.PIPE, timeout=timeout, text=True)

        if result.stdout:
            sys.stderr.write(result.stdout)
            sys.stderr.flush()

        if result.returncode != 0:
            return False, None, f'readability-extractor failed (exit={result.returncode})'

        # Parse JSON output
        try:
            result_json = json.loads(result.stdout)
        except json.JSONDecodeError:
            return False, None, 'readability-extractor returned invalid JSON'

        # Extract and save content
        # readability-extractor uses camelCase field names (textContent, content)
        text_content = result_json.pop('textContent', result_json.pop('text-content', ''))
        html_content = result_json.pop('content', result_json.pop('html-content', ''))

        if not text_content and not html_content:
            return False, None, 'No content extracted'

        (output_dir / OUTPUT_FILE).write_text(html_content, encoding='utf-8')
        (output_dir / 'content.txt').write_text(text_content, encoding='utf-8')
        (output_dir / 'article.json').write_text(json.dumps(result_json, indent=2), encoding='utf-8')

        # Link images/ to responses capture (if available)
        try:
            hostname = urlparse(url).hostname or ''
            if hostname:
                responses_images = (output_dir / '..' / 'responses' / 'image' / hostname / 'images').resolve()
                link_path = output_dir / 'images'
                if responses_images.exists() and responses_images.is_dir():
                    if link_path.exists() or link_path.is_symlink():
                        if link_path.is_symlink() or link_path.is_file():
                            link_path.unlink()
                        else:
                            responses_images = None
                    if responses_images:
                        rel_target = os.path.relpath(str(responses_images), str(output_dir))
                        link_path.symlink_to(rel_target)
        except Exception:
            pass

        return True, OUTPUT_FILE, ''

    except subprocess.TimeoutExpired:
        return False, None, f'Timed out after {timeout} seconds'
    except Exception as e:
        return False, None, f'{type(e).__name__}: {e}'


@click.command()
@click.option('--url', required=True, help='URL to extract article from')
@click.option('--snapshot-id', required=True, help='Snapshot UUID')
def main(url: str, snapshot_id: str):
    """Extract article content using Mozilla's Readability."""

    try:
        # Get binary from environment
        binary = get_env('READABILITY_BINARY', 'readability-extractor')

        # Run extraction
        success, output, error = extract_readability(url, binary)

        if success:
            # Success - emit ArchiveResult
            result = {
                'type': 'ArchiveResult',
                'status': 'succeeded',
                'output_str': output or ''
            }
            print(json.dumps(result))
            sys.exit(0)
        else:
            # Transient error - emit NO JSONL
            print(f'ERROR: {error}', file=sys.stderr)
            sys.exit(1)

    except Exception as e:
        # Transient error - emit NO JSONL
        print(f'ERROR: {type(e).__name__}: {e}', file=sys.stderr)
        sys.exit(1)


if __name__ == '__main__':
    main()