devranta/examples/crawler/crawler.py

import asyncio
import logging
from typing import Set

from database import DatabaseManager

from devranta.api import Api, Rant


class DevRantCrawler:
    def __init__(
        self, api: Api, db: DatabaseManager, rant_consumers: int, user_consumers: int
    ):
        self.api = api
        self.db = db
        self.rant_queue = asyncio.Queue(maxsize=1000000)
        self.user_queue = asyncio.Queue(maxsize=1000000)
        self.shutdown_event = asyncio.Event()

        self.num_rant_consumers = rant_consumers
        self.num_user_consumers = user_consumers

        self.seen_rant_ids: Set[int] = set()
        self.seen_user_ids: Set[int] = set()
        self.stats = {
            "rants_processed": 0,
            "rants_added_to_db": 0,
            "comments_added_to_db": 0,
            "users_processed": 0,
            "users_added_to_db": 0,
            "api_errors": 0,
            "producer_loops": 0,
            "end_of_feed_hits": 0,
            "rants_queued": 0,
            "users_queued": 0,
        }

    async def _queue_user_if_new(self, user_id: int):
        if user_id in self.seen_user_ids:
            return

        self.seen_user_ids.add(user_id)
        if not await self.db.user_exists(user_id):
            await self.user_queue.put(user_id)
            self.stats["users_queued"] += 1

    async def _queue_rant_if_new(self, rant_obj: Rant):
        rant_id = rant_obj["id"]
        if rant_id in self.seen_rant_ids:
            return

        self.seen_rant_ids.add(rant_id)
        if not await self.db.rant_exists(rant_id):
            await self.db.add_rant(rant_obj)
            self.stats["rants_added_to_db"] += 1
            await self.rant_queue.put(rant_id)
            self.stats["rants_queued"] += 1

    async def _initial_seed(self):
        logging.info("Starting initial seeder to re-ignite crawling process...")
        user_ids = await self.db.get_random_user_ids(limit=2000)
        if not user_ids:
            logging.info(
                "Seeder found no existing users. Crawler will start from scratch."
            )
            return

        for user_id in user_ids:
            if user_id not in self.seen_user_ids:
                self.seen_user_ids.add(user_id)
                await self.user_queue.put(user_id)
                self.stats["users_queued"] += 1
        logging.info(
            f"Seeder finished: Queued {len(user_ids)} users to kickstart exploration."
        )

    async def _rant_producer(self):
        logging.info("Rant producer started.")
        skip = 0
        consecutive_empty_responses = 0

        while not self.shutdown_event.is_set():
            try:
                logging.info(f"Producer: Fetching rants with skip={skip}...")
                rants = await self.api.get_rants(sort="recent", limit=50, skip=skip)
                self.stats["producer_loops"] += 1

                if not rants:
                    consecutive_empty_responses += 1
                    logging.info(
                        f"Producer: Feed returned empty. Consecutive empty hits: {consecutive_empty_responses}."
                    )
                    if consecutive_empty_responses >= 5:
                        self.stats["end_of_feed_hits"] += 1
                        logging.info(
                            "Producer: End of feed likely reached. Pausing for 15 minutes before reset."
                        )
                        await asyncio.sleep(900)
                        skip = 0
                        consecutive_empty_responses = 0
                    else:
                        await asyncio.sleep(10)
                    continue

                consecutive_empty_responses = 0
                new_rants_found = 0
                for rant in rants:
                    await self._queue_rant_if_new(rant)
                    new_rants_found += 1

                logging.info(
                    f"Producer: Processed {new_rants_found} rants from feed. Total queued: {self.stats['rants_queued']}."
                )
                skip += len(rants)
                await asyncio.sleep(2)

            except Exception as e:
                logging.critical(
                    f"Producer: Unhandled exception: {e}. Retrying in 60s."
                )
                self.stats["api_errors"] += 1
                await asyncio.sleep(60)

    async def _rant_consumer(self, worker_id: int):
        logging.info(f"Rant consumer #{worker_id} started.")
        while not self.shutdown_event.is_set():
            try:
                rant_id = await self.rant_queue.get()
                logging.info(
                    f"Rant consumer #{worker_id}: Processing rant ID {rant_id}."
                )

                rant_details = await self.api.get_rant(rant_id)
                if not rant_details or not rant_details.get("success"):
                    logging.warning(
                        f"Rant consumer #{worker_id}: Failed to fetch details for rant {rant_id}."
                    )
                    self.rant_queue.task_done()
                    continue

                await self._queue_user_if_new(rant_details["rant"]["user_id"])

                comments = rant_details.get("comments", [])
                for comment in comments:
                    await self.db.add_comment(comment)
                    self.stats["comments_added_to_db"] += 1
                    await self._queue_user_if_new(comment["user_id"])

                logging.info(
                    f"Rant consumer #{worker_id}: Finished processing rant {rant_id}, found {len(comments)} comments."
                )
                self.stats["rants_processed"] += 1
                self.rant_queue.task_done()

            except Exception as e:
                logging.error(f"Rant consumer #{worker_id}: Unhandled exception: {e}")
                self.rant_queue.task_done()

    async def _user_consumer(self, worker_id: int):
        logging.info(f"User consumer #{worker_id} started.")
        while not self.shutdown_event.is_set():
            try:
                user_id = await self.user_queue.get()
                logging.info(
                    f"User consumer #{worker_id}: Processing user ID {user_id}."
                )

                profile = await self.api.get_profile(user_id)
                if not profile:
                    logging.warning(
                        f"User consumer #{worker_id}: Could not fetch profile for user {user_id}."
                    )
                    self.user_queue.task_done()
                    continue

                await self.db.add_user(profile, user_id)
                self.stats["users_added_to_db"] += 1

                rants_found_on_profile = 0
                content_sections = profile.get("content", {}).get("content", {})
                for section_name in ["rants", "upvoted", "favorites"]:
                    for rant_obj in content_sections.get(section_name, []):
                        await self._queue_rant_if_new(rant_obj)
                        rants_found_on_profile += 1

                logging.info(
                    f"User consumer #{worker_id}: Finished user {user_id}, found and queued {rants_found_on_profile} associated rants."
                )
                self.stats["users_processed"] += 1
                self.user_queue.task_done()
            except Exception as e:
                logging.error(f"User consumer #{worker_id}: Unhandled exception: {e}")
                self.user_queue.task_done()

    async def _stats_reporter(self):
        logging.info("Stats reporter started.")
        while not self.shutdown_event.is_set():
            await asyncio.sleep(15)
            logging.info(
                f"[STATS] Rants Q'd/Proc: {self.stats['rants_queued']}/{self.stats['rants_processed']} | "
                f"Users Q'd/Proc: {self.stats['users_queued']}/{self.stats['users_processed']} | "
                f"Comments DB: {self.stats['comments_added_to_db']} | "
                f"Queues (R/U): {self.rant_queue.qsize()}/{self.user_queue.qsize()} | "
                f"API Errors: {self.stats['api_errors']}"
            )

    async def run(self):
        logging.info("Exhaustive crawler starting...")
        await self._initial_seed()

        logging.info("Starting main producer and consumer tasks...")
        tasks = []
        try:
            tasks.append(asyncio.create_task(self._rant_producer()))
            tasks.append(asyncio.create_task(self._stats_reporter()))

            for i in range(self.num_rant_consumers):
                tasks.append(asyncio.create_task(self._rant_consumer(i + 1)))

            for i in range(self.num_user_consumers):
                tasks.append(asyncio.create_task(self._user_consumer(i + 1)))

            await asyncio.gather(*tasks, return_exceptions=True)
        except asyncio.CancelledError:
            logging.info("Crawler run cancelled.")
        finally:
            await self.shutdown()

    async def shutdown(self):
        if self.shutdown_event.is_set():
            return
        logging.info("Shutting down... sending signal to all tasks.")
        self.shutdown_event.set()

        logging.info("Waiting for queues to empty... Press Ctrl+C again to force exit.")
        try:
            await asyncio.wait_for(self.rant_queue.join(), timeout=30)
            await asyncio.wait_for(self.user_queue.join(), timeout=30)
        except (asyncio.TimeoutError, asyncio.CancelledError):
            logging.warning("Could not empty queues in time, proceeding with shutdown.")

        tasks = [t for t in asyncio.all_tasks() if t is not asyncio.current_task()]
        for task in tasks:
            task.cancel()

        await asyncio.gather(*tasks, return_exceptions=True)
        logging.info("All tasks cancelled.")
        logging.info(f"--- FINAL STATS ---\n{self.stats}")