"""
Utility functions for database, logging, and data persistence.
"""
import json
import os
import logging
from datetime import datetime
from pathlib import Path

# ===== LOGGING SETUP =====
def setup_logging():
    """Initialize logging configuration."""
    log_dir = Path("logs")
    log_dir.mkdir(exist_ok=True)
    
    logging.basicConfig(
        level=logging.INFO,
        format='%(asctime)s - %(name)s - %(levelname)s - %(message)s',
        handlers=[
            logging.FileHandler(log_dir / f"{datetime.now().strftime('%Y-%m-%d')}.log"),
            logging.StreamHandler()
        ]
    )
    return logging.getLogger(__name__)

logger = setup_logging()

# ===== JSON DATABASE =====
class JSONDatabase:
    """Simple JSON-based persistence layer for CRM data."""
    
    def __init__(self, filepath: str = "data/crm_database.json"):
        self.filepath = Path(filepath)
        self.filepath.parent.mkdir(parents=True, exist_ok=True)
        self._ensure_file()
    
    def _ensure_file(self):
        """Create database file if it doesn't exist."""
        if not self.filepath.exists():
            self.filepath.write_text(json.dumps({"records": []}, indent=2))
            logger.info(f"Created new database at {self.filepath}")
    
    def load(self) -> list:
        """Load all records from database."""
        try:
            data = json.loads(self.filepath.read_text())
            return data.get("records", [])
        except Exception as e:
            logger.error(f"Error loading database: {e}")
            return []
    
    def save(self, records: list) -> bool:
        """Save records to database."""
        try:
            data = {"records": records, "last_updated": datetime.now().isoformat()}
            self.filepath.write_text(json.dumps(data, indent=2, ensure_ascii=False))
            logger.info(f"Saved {len(records)} records to database")
            return True
        except Exception as e:
            logger.error(f"Error saving database: {e}")
            return False
    
    def add_record(self, record: dict) -> bool:
        """Add a single record to database."""
        records = self.load()
        records.append(record)
        return self.save(records)
    
    def delete_record(self, index: int) -> bool:
        """Delete a record by index."""
        records = self.load()
        if 0 <= index < len(records):
            records.pop(index)
            return self.save(records)
        return False

# ===== VALIDATION =====
def validate_url(url: str) -> bool:
    """Validate if URL is properly formatted."""
    if not url or len(url) < 5:
        return False
    if not url.startswith(('http://', 'https://', 'www.', 'ftp://')):
        return False
    return True

def validate_email(email: str) -> bool:
    """Validate email format."""
    import re
    pattern = r'^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$'
    return re.match(pattern, email) is not None

def validate_pdf(file) -> tuple[bool, str]:
    """Validate PDF file size and type."""
    if file is None:
        return False, "No file selected"
    if file.type != "application/pdf":
        return False, "File must be PDF"
    if file.size > 50 * 1024 * 1024:  # 50MB limit
        return False, "File size exceeds 50MB limit"
    return True, "File is valid"

# ===== ERROR HANDLING =====
def safe_api_call(func, *args, timeout=30, **kwargs):
    """Safely execute API calls with error handling."""
    try:
        return func(*args, **kwargs)
    except TimeoutError:
        logger.error(f"Timeout error in {func.__name__}")
        return None
    except Exception as e:
        logger.error(f"Error in {func.__name__}: {e}")
        return None

# ===== CACHING METADATA =====
def get_cache_metadata() -> dict:
    """Get cache statistics."""
    return {
        "cache_dir": ".streamlit/cache",
        "cache_enabled": True
    }