"""
Smart Setlist Importer (Streaming Version)
Reducing memory usage by processing data in streams instead of bulk loading.
"""
import requests
import time
import gc
from datetime import datetime
from sqlmodel import Session, select
from database import engine
from models import Show, Song, Performance
from slugify import generate_slug

BASE_URL = "https://elgoose.net/api/v2"

def fetch_json(endpoint, params=None):
    """Fetch JSON from El Goose API with retries"""
    url = f"{BASE_URL}/{endpoint}.json"
    for attempt in range(3):
        try:
            response = requests.get(url, params=params, timeout=30)
            response.raise_for_status()
            data = response.json()
            if data.get('error') == 1:
                return None
            return data.get('data', [])
        except Exception as e:
            print(f"  Error fetching {endpoint} (attempt {attempt+1}): {e}")
            time.sleep(2)
    return None

def main():
    print("=" * 60)
    print("SMART SETLIST IMPORTER (STREAMING)")
    print("=" * 60)
    
    with Session(engine) as session:
        # 1. Build DB Map: Date string -> DB Show ID
        print("\n1. Building DB Map (Date -> Show ID)...")
        shows = session.exec(select(Show.id, Show.date)).all()
        date_to_db_id = {s.date.strftime('%Y-%m-%d'): s.id for s in shows}
        print(f"   Mapped {len(date_to_db_id)} existing shows in DB")

        if not date_to_db_id:
            print("   CRITICAL: No shows in database!")
            return

        del shows
        gc.collect()

        # 2. Build API Map: ElGoose ID -> DB ID
        print("\n2. Building ElGoose ID -> DB ID map (Streaming)...")
        elgoose_id_to_db_id = {}
        
        page = 1
        seen_show_ids = set()
        
        while True:
            print(f"   Fetching shows page {page}...", end="\r", flush=True)
            data = fetch_json("shows", {"page": page})
            if not data:
                break
            
            # Loop Detection (Shows)
            first_id = data[0].get('show_id') if data else None
            if first_id and first_id in seen_show_ids:
                print(f"\n   Loop detected in Shows at page {page} (ID {first_id}). Breaking.")
                break
            if first_id:
                seen_show_ids.add(first_id)

            for s in data:
                s_date = s.get('showdate')
                s_id = s.get('show_id')
                
                if s_date and s_id:
                    db_id = date_to_db_id.get(s_date)
                    if db_id:
                        elgoose_id_to_db_id[s_id] = db_id
            
            page += 1
            if page % 10 == 0:
                gc.collect()
        
        print(f"\n   Mapped {len(elgoose_id_to_db_id)} ElGoose IDs to DB IDs")
        del date_to_db_id
        gc.collect()
        
        # 3. Caching Songs
        print("\n3. Caching Songs...")
        songs = session.exec(select(Song.id, Song.title)).all()
        song_map = {s.title.lower().strip(): s.id for s in songs}
        del songs
        gc.collect()
        print(f"   Cached {len(song_map)} songs")

        # 4. Importing Setlists
        print("\n4. Importing Setlists...")
        page = 1
        total_added = 0
        seen_batch_signatures = set()
        
        # Cache existing performance keys (show_id, song_id, position)
        print("   Caching existing performance keys...")
        perfs = session.exec(select(Performance.show_id, Performance.song_id, Performance.position)).all()
        existing_keys = set((p.show_id, p.song_id, p.position) for p in perfs)
        print(f"   Cached {len(existing_keys)} existing performances")
        del perfs
        gc.collect()

        while True:
            data = fetch_json("setlists", {"page": page})
            if not data:
                break
            
            # Loop Detection (Setlists)
            # Use signature of first item: (uniqueid or show_id+position)
            if data:
                first = data[0]
                signature = f"{first.get('uniqueid')}-{first.get('show_id')}-{first.get('position')}"
                if signature in seen_batch_signatures:
                     print(f"\n   Loop detected in Setlists at page {page} (Sig {signature}). Breaking.")
                     break
                seen_batch_signatures.add(signature)
            
            batch_added = 0
            new_objects = []
            
            for perf in data:
                elgoose_show_id = perf.get('show_id')
                db_show_id = elgoose_id_to_db_id.get(elgoose_show_id)
                if not db_show_id:
                    continue
                
                song_name = perf.get('songname', '').strip()
                song_id = song_map.get(song_name.lower())
                if not song_id:
                    continue
                
                position = perf.get('position', 0)
                
                if (db_show_id, song_id, position) in existing_keys:
                    continue
                
                set_val = str(perf.get('setnumber', '1'))
                if set_val.isdigit():
                    set_name = f"Set {set_val}"
                elif set_val.lower() == 'e':
                    set_name = "Encore"
                elif set_val.lower() == 'e2':
                    set_name = "Encore 2"
                elif set_val.lower() == 's':
                    set_name = "Soundcheck"
                else:
                    set_name = f"Set {set_val}"


                new_perf = Performance(
                    show_id=db_show_id,
                    song_id=song_id,
                    position=position,
                    set_name=set_name,
                    segue=bool(perf.get('segue', 0)),
                    notes=perf.get('footnote'),
                    slug=f"{generate_slug(song_name)}-{db_show_id}-{position}"
                )
                new_objects.append(new_perf)
                existing_keys.add((db_show_id, song_id, position))
                batch_added += 1
                total_added += 1
            
            if new_objects:
                session.add_all(new_objects)
                session.commit()
            
            print(f"   Page {page}: Added {batch_added} (Total {total_added})", end="\r", flush=True)
            page += 1
            
            if page % 20 == 0:
                gc.collect()

        print(f"\nImport Complete! Total Added: {total_added}")

if __name__ == "__main__":
    main()