#!/usr/bin/env python3
"""
Generate a deck upgrade report comparing collection to existing decks.
Usage:
    python deck_report.py --collection collection_hydrated/deck.json --decks-dir decks/ --output report.md
"""

import argparse
import json
from pathlib import Path


def load_collection(path: str) -> dict:
    with open(path, 'r') as f:
        cards = json.load(f)
    return {c['name']: c for c in cards}


def load_deck(path: str) -> dict:
    with open(path, 'r') as f:
        data = json.load(f)
    if 'cards' in data:
        return data
    return {'cards': data, 'name': Path(path).stem}


def main():
    parser = argparse.ArgumentParser(description='Generate deck upgrade report')
    parser.add_argument('--collection', '-c', required=True)
    parser.add_argument('--decks-dir', '-d', required=True)
    parser.add_argument('--output', '-o', required=True)
    args = parser.parse_args()

    collection = load_collection(args.collection)
    decks = []
    for path in Path(args.decks_dir).glob('*.json'):
        decks.append(load_deck(str(path)))

    # Find all cards in decks
    all_deck_cards = set()
    for deck in decks:
        all_deck_cards.update(deck['cards'].keys())

    available = set(collection.keys()) - all_deck_cards

    report = []
    report.append("# Deck Upgrade Report\n")
    report.append(f"Collection size: {len(collection)} cards")
    report.append(f"Cards in decks: {len(all_deck_cards)}")
    report.append(f"Available for upgrades: {len(available)}\n")

    for deck in decks:
        deck_name = deck.get('name', 'Unknown')
        deck_cards = deck['cards']
        deck_colors = set()
        for name in deck_cards:
            card = collection.get(name, {})
            ci = card.get('color_identity', [])
            deck_colors.update(ci)

        report.append(f"\n---\n## {deck_name}\n")
        report.append(f"**Colors:** {''.join(sorted(deck_colors))}")
        report.append(f"**Total cards:** {sum(deck_cards.values())}")
        report.append(f"**Unique cards:** {len(deck_cards)}\n")

    with open(args.output, 'w') as f:
        f.write('\n'.join(report))
    print(f"Report saved to {args.output}")


if __name__ == '__main__':
    main()