"""
LinkSyncServer - Query Executor
"""

from typing import List, Dict, Any, Optional
from sqlalchemy.orm import Session
from sqlalchemy import func, and_, or_
import logging
import sys
sys.path.insert(0, 'models')
from base import Bookmark, User

logger = logging.getLogger(__name__)


def parse_query_expression(query_expression: dict, expressions: list = None) -> Dict[str, Any]:
    """
    Parse query expression in dict format.
    
    Example:
    {
        "operation": "OR",
        "operands": [
            {"operation": "TERM", "value": "work"},
            {"operation": "TERM", "value": "company"}
        ]
    }
    """
    if not query_expression:
        return
    
    operation = query_expression.get('operation')
    operands = query_expression.get('operands', [])
    
    if not operands:
        # Top-level expression (e.g., TERM)
        if operation == 'TERM':
            value = query_expression.get('value', '')
            if value.startswith('url:'):
                search_term = value[4:]
                return parse_term(search_term, 'url')
            elif value.startswith('tag:'):
                search_term = value[4:]
                return parse_term(search_term, 'tags')
            elif value.startswith('title:'):
                search_term = value[6:]
                return parse_term(search_term, 'title')
            elif value.startswith('description:'):
                search_term = value[12:]
                return parse_term(search_term, 'description')
            elif value.startswith('id:'):
                return {'operation': 'EQUALS', 'value': value[3:]}
            else:
                # Default: search title and description
                return {'operation': 'OR', 'operands': [
                    {'operation': 'TERM', 'value': value, 'field': 'title'},
                    {'operation': 'TERM', 'value': value, 'field': 'description'}
                ]}


def parse_term(term: str, field: str):
    """
    Parse field:value term.
    
    Returns SQLAlchemy filter clause.
    """
    # Handle different field types
    field_filters = {
        'tags': lambda term: and_(*[Bookmark.tags.ilike(f'%{term}%') for tag in term.split(',')]),
        'title': lambda term: Bookmark.title.ilike(f'%{term}%'),
        'description': lambda term: Bookmark.description.ilike(f'%{term}%'),
        'url': lambda term: Bookmark.url.ilike(f'%{term}%'),
        'path': lambda term: Bookmark.path.ilike(f'%{term}%')
    }
    
    # Get filter function
    filter_fn = field_filters.get(field, lambda term: Bookmark.tags.ilike(f'%{term}%'))
    
    # Apply filter
    filter_clause = filter_fn(term)
    
    # Return filter clause with field
    return {'field': field, 'value': term, 'clause': filter_clause}


def parse_or_filter(operators: list, operands: list) -> Any:
    """
    Parse OR filter.
    
    Operators: ['AND', 'OR', 'XOR']
    """
    if not operands:
        return False
    
    # Default to AND for safety
    op_type = operators[0] if operators else 'AND'
    
    if op_type == 'OR':
        return or_(*[parse_and_filter(operators[1:], operands[1:]) for _ in range(1)])
    elif op_type == 'AND':
        return and_(*[parse_and_filter(operators[1:], operands[1:]) for _ in range(1)])
    else:
        # XOR: not supported yet
        raise ValueError("XOR not supported")


def parse_and_filter(operands: list) -> Any:
    """Parse AND filter (default)."""
    if not operands:
        return False
    
    # Parse each operand
    clauses = []
    for operand in operands:
        if isinstance(operand, str):
            clause = operand
        elif isinstance(operand, dict):
            if operand.get('operation') == 'EQUALS':
                clause = operand['value']
            elif operand.get('operation') == 'TERM':
                clauses.append(parse_term(operand.get('value', ''), operand.get('field', 'tags')))
            # Add other term types as needed
            else:
                clauses.append(operand)
        else:
            raise ValueError(f"Unknown operand type: {type(operand)}")
    
    if not clauses:
        return False
    
    return clauses


def execute_query(query_expression: dict) -> List[Dict[str, Any]]:
    """
    Execute query and return results.
    
    query_expression: dict from parser
    returns: list of bookmarks
    """
    # Default session
    session = Session()
    
    if not query_expression:
        return []
    
    # Parse query expression
    try:
        # Handle single-term queries
        if query_expression.get('operation') == 'TERM':
            search_term = query_expression.get('value', '')
            field = query_expression.get('field', 'title')
            
            if field == 'tags':
                tags = search_term.split(',')
                filters = [Bookmark.tags.contains(tag) for tag in tags]
                result = session.query(Bookmark).filter(or_(*filters)).all()
            elif field == 'title':
                result = session.query(Bookmark).filter(Bookmark.title.contains(search_term)).all()
            elif field == 'description':
                result = session.query(Bookmark).filter(Bookmark.description.contains(search_term)).all()
            elif field == 'url':
                result = session.query(Bookmark).filter(Bookmark.url.contains(search_term)).all()
            else:
                # Default: search title and description
                filters = [
                    or_(Bookmark.title.contains(search_term), 
                        Bookmark.description.contains(search_term))
                ]
                result = session.query(Bookmark).filter(or_(*filters)).all()
        elif query_expression.get('operation') == 'AND':
            # AND clause
            clauses = parse_and_filter(query_expression.get('operands', []))
            if isinstance(clauses, list):
                result = session.query(Bookmark).filter(and_(*clauses)).all()
            else:
                result = session.query(Bookmark).filter(clauses).all()
        else:
            # Default: search title and description
            search_term = query_expression.get('value', '')
            result = session.query(Bookmark).filter(
                or_(Bookmark.title.contains(search_term), 
                    Bookmark.description.contains(search_term))
            ).all()
    
    except Exception as e:
        logger.error(f"Query execution error: {e}")
        result = []
    
    return result


def create_bookmarks_from_sync(sync_data: dict):
    """
    Create bookmarks from sync response.
    
    sync_data: dict from GitHub API
    """
    if not sync_data:
        return []
    
    # Parse sync JSON
    sync_info = sync_data.get('_links', {}).get('sync', {}).get('_links', {})
    
    # Extract bookmarks
    bookmarks = []
    if 'objects' in sync_data:
        for obj in sync_data['objects']:
            if 'title' in obj:
                bookmarks.append({
                    'url': obj.get('url', ''),
                    'title': obj.get('title', ''),
                    'description': obj.get('description', ''),
                    'tags': obj.get('tags', []),
                    'favicon_url': obj.get('favicon_url', ''),
                    'path': obj.get('path', ''),
                    'visit_count': obj.get('visit_count', 0)
                })
    
    return bookmarks