"""
Query By Example (QBE) Paradigm - Visual template-based querying.
"""

import time
from typing import Dict, Any, List, Optional

from ..base import BaseQueryParadigm, QueryResult


class QueryByExampleParadigm(BaseQueryParadigm):
    """Query By Example paradigm for visual template-based data filtering."""

    @property
    def name(self) -> str:
        return "Query By Example"

    @property
    def description(self) -> str:
        return "Visual template-based queries where users fill in example values to define search criteria"

    @property
    def category(self) -> str:
        return "visual"

    @property
    def complexity(self) -> str:
        return "beginner"

    def execute(self, query: str, config: Dict[str, Any] = None) -> QueryResult:
        """Execute QBE query (not yet implemented)."""
        start_time = time.time()

        # This is a documentation paradigm - not yet implemented
        execution_time = (time.time() - start_time) * 1000

        return QueryResult(
            paradigm=self.name,
            query=query,
            execution_time_ms=execution_time,
            result_count=0,
            results=[],
            metadata={
                "status": "not_implemented",
                "implementation_issue": "TBD - to be created",
                "description": "QBE provides a visual interface where users create templates with example values to define search criteria"
            },
            success=False,
            error_message="Query By Example paradigm not yet implemented. This paradigm will provide visual templates for filtering data."
        )

    def get_examples(self) -> List[Dict[str, str]]:
        """Get example QBE templates."""
        return [
            {
                "name": "Filter by author",
                "description": "Template to find files by specific author",
                "query": "{'author': 'John Smith', 'type': '*.md'}"
            },
            {
                "name": "Date range filter",
                "description": "Template to find files within date range",
                "query": "{'created_after': '2024-01-01', 'created_before': '2024-12-31'}"
            },
            {
                "name": "Tag-based filter",
                "description": "Template to find files with specific tags",
                "query": "{'tags': ['documentation', 'api'], 'status': 'published'}"
            },
            {
                "name": "Content pattern",
                "description": "Template to find files matching content patterns",
                "query": "{'content_contains': 'function', 'file_extension': '.py'}"
            }
        ]

    def validate_query(self, query: str) -> tuple[bool, Optional[str]]:
        """Validate QBE template structure."""
        try:
            import json
            template = json.loads(query)
            if not isinstance(template, dict):
                return False, "QBE template must be a JSON object"
            return True, None
        except json.JSONDecodeError:
            return False, "QBE template must be valid JSON"

    def get_syntax_help(self) -> str:
        """Get syntax help for QBE."""
        return """Query By Example (QBE) Syntax:

QBE uses JSON templates where you specify example values for the fields you want to filter by:

Structure:
{
  "field_name": "example_value",
  "another_field": "another_value"
}

Supported Fields:
- author: Author name
- type: File type/extension
- tags: Array of tags
- created_after/created_before: Date filters
- content_contains: Text that should appear in content
- file_extension: Specific file extensions

Example:
{
  "author": "Alice Johnson",
  "tags": ["tutorial", "beginner"],
  "created_after": "2024-01-01"
}

This template finds files by Alice Johnson with tutorial and beginner tags created after Jan 1, 2024.
"""