republisher/repub/spiders/rss_spider.py

import logging
from typing import Dict, List, Tuple

import feedparser
from scrapy.crawler import Crawler
from scrapy.spiders import Spider
from scrapy.utils.spider import iterate_spider_output

from repub.items import ChannelElementItem, ElementItem
from repub.rss import (
    ATOM,
    CDATA,
    CONTENT,
    ITUNES,
    MEDIA,
    E,
    munge_cdata_html,
    normalize_date,
    plain_text_summary,
    sanitize_html,
)
from repub.utils import FileType, determine_file_type, local_file_path, local_image_path


class BaseRssFeedSpider(Spider):
    """
    This class intends to be the base class for spiders that scrape
    from RSS feeds.
    """

    def __init__(self, feed_name, **kwargs):
        super().__init__(**kwargs)
        self.feed_name = feed_name

    def _set_crawler(self, crawler: Crawler) -> None:
        super()._set_crawler(crawler)
        for s in [
            "REPUBLISHER_IMAGE_DIR",
            "REPUBLISHER_FILE_DIR",
            "REPUBLISHER_AUDIO_DIR",
            "REPUBLISHER_VIDEO_DIR",
        ]:
            if self.settings.get(s) is None:
                raise RuntimeError(f"Missing setting: {s}")

    def rewrite_file_url(self, file_type: FileType, url):
        file_dir = self.settings["REPUBLISHER_FILE_DIR"]
        local_path = local_file_path(url)
        if file_type == FileType.IMAGE:
            file_dir = self.settings["REPUBLISHER_IMAGE_DIR"]
            local_path = local_image_path(url)
        elif file_type == FileType.VIDEO:
            file_dir = self.settings["REPUBLISHER_VIDEO_DIR"]
        elif file_type == FileType.AUDIO:
            file_dir = self.settings["REPUBLISHER_AUDIO_DIR"]
        relative_path = f"{file_dir}/{local_path}"
        return self.absolute_feed_url(relative_path)

    def rewrite_image_url(self, url):
        return self.rewrite_file_url(FileType.IMAGE, url)

    def absolute_feed_url(self, path: str) -> str:
        feed_url = str(self.settings.get("REPUBLISHER_FEED_URL", "")).rstrip("/")
        if feed_url == "":
            return path
        return f"{feed_url}/feeds/{self.feed_name}/{path.lstrip('/')}"

    def compact_attrib(self, **attrib):
        return {
            key: str(value) for key, value in attrib.items() if value not in (None, "")
        }

    def itunes_explicit_value(self, value) -> str:
        if isinstance(value, str):
            return (
                "true"
                if value.strip().lower() in {"true", "yes", "explicit"}
                else "false"
            )
        return "true" if bool(value) else "false"

    def publisher_email(self, feed) -> str | None:
        publisher_detail = feed.get("publisher_detail")
        if publisher_detail and publisher_detail.get("email"):
            return publisher_detail.get("email")
        publisher = feed.get("publisher")
        if isinstance(publisher, str) and "@" in publisher:
            return publisher
        return None

    def itunes_category(self, feed) -> str:
        del feed
        return "News"

    def latest_entry_date(self, feed) -> str | None:
        published_dates = [
            normalize_date(entry.get("published_parsed"))
            for entry in feed.entries
            if entry.get("published_parsed") is not None
        ]
        if published_dates:
            return max(published_dates)
        return normalize_date(feed.feed.get("updated_parsed")) or normalize_date(
            feed.feed.get("published_parsed")
        )

    def munge_cdata_html(self, html) -> Tuple[str, Dict[FileType, List[str]]]:
        urls = {FileType.IMAGE: [], FileType.VIDEO: [], FileType.AUDIO: []}

        def replace_link(el, attr, old_link):
            if len(old_link) == 0 or el.tag in ["a", "iframe"]:
                return old_link
            file_type = None
            if el.tag in ["img"]:
                file_type = FileType.IMAGE
            elif el.tag in ["source"] and el.getparent() is not None:
                if el.getparent().tag == "video":
                    file_type = FileType.VIDEO
                elif el.getparent().tag == "audio":
                    file_type = FileType.AUDIO
                elif el.getparent().tag == "picture":
                    file_type = FileType.IMAGE
            if not file_type:
                self.logger.warn(
                    f"Could not identify file type of link, skipping. tag={el.tag} attr={attr} link={old_link}"
                )
                return old_link

            urls[file_type].append(old_link)
            new_link = self.rewrite_file_url(file_type, old_link)
            if file_type != FileType.IMAGE:
                print(f"{old_link} -> {new_link}")
            return new_link

        return munge_cdata_html(html, replace_link), urls

    def parse_feed(self, feed_text):
        parsed = feedparser.parse(feed_text, sanitize_html=False)
        if parsed.bozo:
            logging.error(
                "Bozo feed data. %s: %r",
                parsed.bozo_exception.__class__.__name__,
                parsed.bozo_exception,
            )
            if hasattr(parsed.bozo_exception, "getLineNumber") and hasattr(
                parsed.bozo_exception, "getMessage"
            ):
                line = parsed.bozo_exception.getLineNumber()
                logging.error("Line %d: %s", line, parsed.bozo_exception.getMessage())
                segment = feed_text.split("\n")[line - 1]
                logging.info("Body segment with error: %r", segment)
            return None
        return parsed

    def parse_channel_meta(self, response, feed):
        f = feed.feed
        channel = E.channel(
            E.title(f.get("title")),
            E.link(f.get("link")),
            E.description(sanitize_html(f.get("description", ""))),
            E.language(f.get("language")),
            E.copyright(f.get("copyright")),
            E.webMaster(self.WEBMASTER_VALUE),
            E.generator(f.get("generator")),
            E.pubDate(normalize_date(f.get("published_parsed"))),
            E.lastBuildDate(self.latest_entry_date(feed)),
            ITUNES.explicit(
                self.itunes_explicit_value(f.get("itunes_explicit", False))
            ),
            ITUNES.category(text=self.itunes_category(f)),
            (
                ITUNES.owner(ITUNES.email(email))
                if (email := self.publisher_email(f))
                else None
            ),
            (
                ATOM.link(
                    rel="self",
                    href=self.absolute_feed_url("feed.rss"),
                    type="application/rss+xml",
                )
                if self.settings.get("REPUBLISHER_FEED_URL")
                else None
            ),
        )
        for tag in f.get("tags", []):
            channel.append(E.category(tag.term))

        image_urls = []
        if "image" in f:
            if "href" in f.image:
                image = E.image(
                    E.title(f.get("title")),
                    E.link(f.get("link")),
                    E.url(self.rewrite_image_url(f.image.get("href"))),
                    E.description(sanitize_html(f.get("description", ""))),
                )
                image_urls.append(f.image.get("href"))
            else:
                image = E.image(
                    E.title(f.image.get("title")),
                    E.link(f.image.get("link")),
                    E.url(self.rewrite_image_url(f.image.get("url"))),
                    E.description(sanitize_html(f.image.get("description", ""))),
                    E.width(f.image.get("width")),
                    E.height(f.image.get("height")),
                )
                image_urls.append(f.image.get("url"))
            channel.append(image)
        return ChannelElementItem(
            feed_name=self.feed_name, el=channel, image_urls=image_urls, images=[]
        )

    def _parse(self, response, **kwargs):
        response = self.adapt_response(response)
        feed = self.parse_feed(response.body)
        if feed and feed.feed:
            return self.parse_entries(response, feed)

    def parse_entry(self, response, feed, entry):
        """This method must be overridden with your custom spider functionality"""
        raise NotImplementedError

    def parse_entries(self, response, feed):
        channel = self.parse_channel_meta(response, feed)
        yield channel
        for entry in feed.entries:
            ret = iterate_spider_output(self.parse_entry(response, feed, entry))
            yield from self.process_results(response, feed, ret)

    def process_results(self, response, feed, results):
        """This overridable method is called for each result (item or request)
        returned by the spider, and it's intended to perform any last time
        processing required before returning the results to the framework core,
        for example setting the item GUIDs. It receives a list of results and
        the response which originated that results. It must return a list of
        results (items or requests).
        """
        return results

    def adapt_response(self, response):
        """You can override this function in order to make any changes you want
        to into the feed before parsing it. This function must return a
        response.
        """
        return response


class RssFeedSpider(BaseRssFeedSpider):
    """A generic RSS Feed spider"""

    name = "rss_spider"

    def __init__(self, url=None, urls=None, **kwargs):
        if url is not None:
            self.start_urls = [url]
        elif isinstance(urls, str):
            self.start_urls = [urls]
        else:
            self.start_urls = urls or []
        super().__init__(**kwargs)

    def parse_entry(self, response, feed, entry):
        image_urls = []
        file_urls = []
        audio_urls = []
        video_urls = []

        def add_url(file_type, url):
            if file_type == FileType.IMAGE:
                image_urls.append(url)
            elif file_type == FileType.AUDIO:
                audio_urls.append(url)
            elif file_type == FileType.VIDEO:
                video_urls.append(url)
            elif file_type == FileType.FILE:
                file_urls.append(url)

        item = E.item(
            E.title(entry.get("title")),
            E.link(entry.get("link")),
            E.description(sanitize_html(entry.get("description", ""))),
            E.guid(
                entry.get("id"),
                {"isPermaLink": "true" if entry.guidislink else "false"},
            ),
            E.pubDate(normalize_date(entry.get("published_parsed"))),
            E.author(entry.get("author")),
            ITUNES.summary(plain_text_summary(entry.get("summary"))),
            ITUNES.duration(entry.get("itunes_duration")),
            ITUNES.image(
                None,
                (
                    {"href": self.rewrite_image_url(entry.get("image").href)}
                    if "image" in entry
                    else None
                ),
            ),
        )
        if entry.get("image"):
            image_urls.append(entry.get("image").href)
        for enc in entry.enclosures:
            url = enc.get("href")
            file_type = determine_file_type(url=url, mimetype=enc.get("type"))
            item.append(
                E.enclosure(
                    **self.compact_attrib(
                        url=self.rewrite_file_url(file_type, url),
                        length=enc.get("length"),
                        type=enc.get("type"),
                    )
                )
            )
            self.logger.debug(
                f"feed {self.feed_name} encountered enclsoure {url} {file_type}"
            )
            add_url(file_type, url)

        if "content" in entry:
            for c in entry.content:
                raw_html = getattr(c, "value", "") or ""
                if c.type == "text/html" and raw_html.strip() != "":
                    html, urls = self.munge_cdata_html(raw_html)
                    item.append(CONTENT.encoded(CDATA(html)))
                    image_urls.extend(urls[FileType.IMAGE])
                    video_urls.extend(urls[FileType.VIDEO])
                    audio_urls.extend(urls[FileType.AUDIO])

        if isinstance(entry.get("media_content"), list):
            for media in (
                media for media in entry["media_content"] if media.get("url")
            ):
                file_type = determine_file_type(
                    url=media.get("url"),
                    medium=media.get("medium"),
                    mimetype=media.get("type"),
                )
                item.append(
                    MEDIA.content(
                        **self.compact_attrib(
                            url=self.rewrite_file_url(file_type, media.get("url")),
                            type=media.get("type"),
                            medium=media.get("medium"),
                            isDefault=media.get("isDefault"),
                            expression=media.get("expression"),
                            bitrate=media.get("bitrate"),
                            framerate=media.get("framerate"),
                            samplingrate=media.get("samplingrate"),
                            channels=media.get("channels"),
                            duration=media.get("duration"),
                            height=media.get("height"),
                            width=media.get("width"),
                            lang=media.get("lang"),
                        )
                    )
                )
                add_url(file_type, media.get("url"))
        return ElementItem(
            feed_name=self.feed_name,
            el=item,
            images=[],
            image_urls=image_urls,
            files=[],
            file_urls=file_urls,
            audio_urls=audio_urls,
            audios=[],
            video_urls=video_urls,
            videos=[],
        )

    WEBMASTER_VALUE = "support@guardianproject.info (Guardian Project)"