from apify import Actor
from typing import Set

class StateManager:
    """
    Manages the persistent state of the actor, specifically for deduplication.
    """
    def __init__(self):
        self.seen_urls: Set[str] = set()

    async def load_state(self):
        """
        Loads the state from the default key-value store.
        """
        state = await Actor.get_value("STATE")
        
        if not state:
            # Fallback for local development
            import json
            from pathlib import Path
            cwd = Path.cwd()
            local_state = cwd / "local_state.json"
            Actor.log.info(f"Checking for local state at: {local_state}")
            if local_state.exists():
                try:
                    state = json.loads(local_state.read_text(encoding="utf-8"))
                    Actor.log.info(f"Loaded state from local file: {local_state}")
                except Exception as e:
                    Actor.log.warning(f"Failed to load local state: {e}")
                    state = {}
            else:
                state = {}

        self.seen_urls = set(state.get("seen_urls", []))
        Actor.log.info(f"Loaded state: {len(self.seen_urls)} seen URLs.")

    async def save_state(self):
        """
        Saves the current state to the default key-value store.
        """
        state = {
            "seen_urls": list(self.seen_urls)
        }
        await Actor.set_value("STATE", state)
        
        # Backup for local development
        import json
        from pathlib import Path
        cwd = Path.cwd()
        local_state = cwd / "local_state.json"
        try:
            local_state.write_text(json.dumps(state, indent=2), encoding="utf-8")
            Actor.log.info(f"Backed up state to local file: {local_state}")
        except Exception as e:
            Actor.log.warning(f"Failed to backup local state: {e}")

        Actor.log.info(f"Saved state: {len(self.seen_urls)} seen URLs.")

    def is_seen(self, url: str) -> bool:
        """
        Checks if a URL has already been seen.
        """
        return url in self.seen_urls

    def add_seen(self, url: str):
        """
        Adds a URL to the set of seen URLs.
        """
        self.seen_urls.add(url)