#!/usr/bin/env python3
"""
Script to detect changes in bills by comparing current data to previous snapshot.

This script compares the current known_bills_visualize.json to the most recent snapshot
to identify new bills and bills with status changes. Results are saved to a CSV file.
"""

import json
import csv
import logging
import os
import sys
import time
from pathlib import Path
from datetime import datetime
from typing import Dict, List, Optional, Tuple

# Add the project root to the path
sys.path.append(str(Path(__file__).parent.parent))

# Pipeline status tracking (no-op when running standalone)
_PIPELINE_SCRIPT = os.environ.get("PIPELINE_CURRENT_SCRIPT")
_pipeline = None
_last_status_write = 0.0
if _PIPELINE_SCRIPT:
    try:
        from pipeline_status import PipelineStatus
        _pipeline = PipelineStatus()
    except Exception:
        pass

def _update_pipeline_progress(current, total, unit="changes", message=""):
    global _last_status_write
    if not _pipeline:
        return
    now = time.time()
    if now - _last_status_write < 3.0:
        return
    _last_status_write = now
    try:
        _pipeline.update_progress(_PIPELINE_SCRIPT, current, total, unit, message)
    except Exception:
        pass

# Paths
DATA_DIR = Path("data")
SNAPSHOTS_DIR = DATA_DIR / "snapshots"
CHANGES_DIR = DATA_DIR / "weekly_changes"
CURRENT_BILLS_FILE = DATA_DIR / "known_bills_visualize.json"

# Create directories
SNAPSHOTS_DIR.mkdir(parents=True, exist_ok=True)
CHANGES_DIR.mkdir(parents=True, exist_ok=True)
os.makedirs("data_updating_scripts/logs", exist_ok=True)

# Configure logging
logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s [%(levelname)s] %(message)s",
    handlers=[
        logging.StreamHandler(),
        logging.FileHandler("data_updating_scripts/logs/detect_changes.log")
    ]
)
logger = logging.getLogger(__name__)


def bill_key(bill: Dict) -> str:
    """Generate unique key for a bill."""
    return f"{bill.get('state', 'Unknown')}_{bill.get('bill_number', 'Unknown')}"


def load_json(file_path: Path) -> List[Dict]:
    """Load JSON file, return empty list if not found."""
    try:
        with open(file_path, 'r', encoding='utf-8') as f:
            return json.load(f)
    except FileNotFoundError:
        logger.warning(f"File not found: {file_path}")
        return []
    except Exception as e:
        logger.error(f"Error loading {file_path}: {e}")
        return []


def save_json(file_path: Path, data: List[Dict]):
    """Save data to JSON file."""
    file_path.parent.mkdir(parents=True, exist_ok=True)
    with open(file_path, 'w', encoding='utf-8') as f:
        json.dump(data, f, indent=2, ensure_ascii=False)


def save_csv(file_path: Path, changes: List[Dict]):
    """Save changes to CSV file."""
    if not changes:
        logger.info("No changes to save to CSV")
        return

    file_path.parent.mkdir(parents=True, exist_ok=True)

    # Define CSV columns
    fieldnames = ['bill_number', 'state', 'change_type', 'status_change_detail',
                  'old_status', 'new_status', 'title', 'session_year']

    with open(file_path, 'w', newline='', encoding='utf-8') as f:
        writer = csv.DictWriter(f, fieldnames=fieldnames)
        writer.writeheader()
        writer.writerows(changes)

    logger.info(f"Saved {len(changes)} changes to {file_path}")


def get_most_recent_snapshot() -> Optional[Path]:
    """Find the most recent snapshot file."""
    if not SNAPSHOTS_DIR.exists():
        return None

    # Find all snapshot files
    snapshots = list(SNAPSHOTS_DIR.glob("known_bills_*.json"))
    if not snapshots:
        return None

    # Sort by modification time and return most recent
    snapshots.sort(key=lambda p: p.stat().st_mtime, reverse=True)
    return snapshots[0]


STATUS_LABELS = {
    0: "Inactive", 1: "Active", 2: "Active", 3: "Active",
    4: "Signed Into Law", 5: "Vetoed", 6: "Inactive",
    7: "Signed Into Law", 8: "Signed Into Law", 9: "Active",
    10: "Active", 11: "Inactive", 12: "Active",
    "0": "Inactive", "1": "Active", "2": "Active", "3": "Active",
    "4": "Signed Into Law", "5": "Vetoed", "6": "Inactive",
    "7": "Signed Into Law", "8": "Signed Into Law", "9": "Active",
    "10": "Active", "11": "Inactive", "12": "Active",
}


def resolve_status(raw_status):
    """Convert raw numeric status to human-readable label."""
    if raw_status in STATUS_LABELS:
        return STATUS_LABELS[raw_status]
    # Already a label string
    if isinstance(raw_status, str) and raw_status in ("Active", "Inactive", "Signed Into Law", "Vetoed"):
        return raw_status
    return str(raw_status)


def classify_change(old_label: str, new_label: str) -> str:
    """Classify a status change into a specific change type."""
    if new_label == "Signed Into Law":
        return "signed_into_law"
    elif new_label == "Vetoed":
        return "vetoed"
    elif new_label == "Inactive" and old_label == "Active":
        return "went_inactive"
    else:
        return "status_change"


def detect_changes(current_bills: List[Dict], previous_bills: List[Dict]) -> Tuple[List[Dict], int, int, int, int]:
    """
    Compare current bills to previous snapshot and detect changes.

    Returns:
        (changes_list, new_count, status_change_count, signed_count, vetoed_count)
    """
    changes = []

    # Create lookup dictionaries
    current_dict = {bill_key(b): b for b in current_bills}
    previous_dict = {bill_key(b): b for b in previous_bills}

    new_count = 0
    status_change_count = 0
    signed_count = 0
    vetoed_count = 0

    # Check for new bills
    for key, bill in current_dict.items():
        new_label = resolve_status(bill.get('status', ''))

        if key not in previous_dict:
            # New bill
            changes.append({
                'bill_number': bill.get('bill_number', 'Unknown'),
                'state': bill.get('state', 'Unknown'),
                'change_type': 'new_bill',
                'status_change_detail': '',
                'old_status': '',
                'new_status': new_label,
                'title': bill.get('title', '')[:100],
                'session_year': bill.get('session_year', '')
            })
            new_count += 1
        else:
            # Check for status change
            old_bill = previous_dict[key]
            old_label = resolve_status(old_bill.get('status', ''))

            if old_label != new_label and old_label and new_label:
                change_type = classify_change(old_label, new_label)
                status_detail = f"{old_label} → {new_label}"
                changes.append({
                    'bill_number': bill.get('bill_number', 'Unknown'),
                    'state': bill.get('state', 'Unknown'),
                    'change_type': change_type,
                    'status_change_detail': status_detail,
                    'old_status': old_label,
                    'new_status': new_label,
                    'title': bill.get('title', '')[:100],
                    'session_year': bill.get('session_year', '')
                })
                status_change_count += 1
                if change_type == "signed_into_law":
                    signed_count += 1
                elif change_type == "vetoed":
                    vetoed_count += 1

    return changes, new_count, status_change_count, signed_count, vetoed_count


def main():
    """Main execution function."""
    logger.info("Starting change detection...")

    # Load current bills
    current_bills = load_json(CURRENT_BILLS_FILE)
    if not current_bills:
        logger.error(f"No current bills found in {CURRENT_BILLS_FILE}")
        return

    logger.info(f"Loaded {len(current_bills)} current bills")

    # Find most recent snapshot
    snapshot_file = get_most_recent_snapshot()

    if snapshot_file:
        logger.info(f"Found previous snapshot: {snapshot_file}")
        previous_bills = load_json(snapshot_file)
        logger.info(f"Loaded {len(previous_bills)} bills from snapshot")

        # Detect changes
        changes, new_count, status_change_count, signed_count, vetoed_count = detect_changes(current_bills, previous_bills)

        logger.info(f"Detected {len(changes)} total changes:")
        logger.info(f"  - New bills: {new_count}")
        logger.info(f"  - Status changes: {status_change_count}")
        logger.info(f"  - Signed into law: {signed_count}")
        logger.info(f"  - Vetoed: {vetoed_count}")

        # Save changes to CSV
        timestamp = datetime.now().strftime("%Y-%m-%d")
        csv_file = CHANGES_DIR / f"weekly_changes_{timestamp}.csv"
        save_csv(csv_file, changes)

        print(f"✅ Change detection complete!")
        print(f"   New bills: {new_count}")
        print(f"   Status changes: {status_change_count}")
        print(f"   Signed into law: {signed_count}")
        print(f"   Vetoed: {vetoed_count}")
        print(f"   CSV saved: {csv_file}")

        _update_pipeline_progress(1, 1, "changes", f"{len(changes)} changes detected")
    else:
        logger.info("No previous snapshot found - this is the first run")
        print("ℹ️  No previous snapshot found - establishing baseline")

    # Save current state as new snapshot
    timestamp = datetime.now().strftime("%Y-%m-%d_%H-%M-%S")
    snapshot_file = SNAPSHOTS_DIR / f"known_bills_{timestamp}.json"
    save_json(snapshot_file, current_bills)
    logger.info(f"Saved snapshot: {snapshot_file}")
    print(f"✅ Snapshot saved: {snapshot_file}")

    # Upload snapshots and weekly changes to HF dataset for persistence
    _upload_change_data_to_hf()


def _upload_change_data_to_hf():
    """Upload the latest snapshot and all weekly CSVs to HF dataset."""
    try:
        from huggingface_hub import HfApi
        from dotenv import load_dotenv
        load_dotenv()

        token = os.environ.get("HUGGINGFACE_HUB_TOKEN")
        repo_id = os.environ.get("HF_REPO_ID")
        if not token or not repo_id:
            logger.info("HF credentials not configured — skipping change data upload")
            return

        api = HfApi(token=token)

        # Upload the most recent snapshot only (to save space)
        snapshot = get_most_recent_snapshot()
        if snapshot:
            dest = f"snapshots/{snapshot.name}"
            logger.info(f"Uploading snapshot to HF: {dest}")
            api.upload_file(
                path_or_fileobj=str(snapshot),
                path_in_repo=dest,
                repo_id=repo_id,
                repo_type="dataset",
                commit_message=f"Update snapshot: {snapshot.name}",
            )

        # Upload all weekly change CSVs
        csv_files = list(CHANGES_DIR.glob("*.csv"))
        for csv_file in csv_files:
            dest = f"weekly_changes/{csv_file.name}"
            logger.info(f"Uploading CSV to HF: {dest}")
            api.upload_file(
                path_or_fileobj=str(csv_file),
                path_in_repo=dest,
                repo_id=repo_id,
                repo_type="dataset",
                commit_message=f"Update weekly changes: {csv_file.name}",
            )

        logger.info("Change data uploaded to HF dataset")
        print("✅ Change data synced to HuggingFace")
    except Exception as e:
        logger.warning(f"Failed to upload change data to HF: {e}")
        print(f"⚠️  HF sync skipped: {e}")


if __name__ == "__main__":
    main()