import logging
from fastapi import APIRouter, HTTPException, Depends
from typing import Optional

from app.core.database import execute_query
from app.models.schemas import Solution, SolutionCreate, SolutionUpdate

logger = logging.getLogger(__name__)
router = APIRouter()

@router.get("/sag/{sag_id}/solution", response_model=Optional[Solution])
async def get_solution(sag_id: int):
    """Get the solution associated with a case."""
    try:
        query = "SELECT * FROM sag_solutions WHERE sag_id = %s"
        result = execute_query(query, (sag_id,))
        if not result:
            return None
        return result[0]
    except Exception as e:
        logger.error("❌ Error getting solution for case %s: %s", sag_id, e)
        raise HTTPException(status_code=500, detail="Failed to get solution")

@router.post("/sag/{sag_id}/solution", response_model=Solution)
async def create_solution(sag_id: int, solution: SolutionCreate):
    """Create a solution for a case."""
    try:
        # Check if case exists
        case_check = execute_query("SELECT id FROM sag_sager WHERE id = %s", (sag_id,))
        if not case_check:
            raise HTTPException(status_code=404, detail="Case not found")
            
        # Check if solution already exists
        check = execute_query("SELECT id FROM sag_solutions WHERE sag_id = %s", (sag_id,))
        if check:
            raise HTTPException(status_code=400, detail="Solution already exists for this case")
            
        query = """
            INSERT INTO sag_solutions 
            (sag_id, title, description, solution_type, result, created_by_user_id)
            VALUES (%s, %s, %s, %s, %s, %s)
            RETURNING *
        """
        params = (
            sag_id,
            solution.title,
            solution.description,
            solution.solution_type,
            solution.result,
            solution.created_by_user_id
        )
        
        result = execute_query(query, params)
        if result:
            logger.info("✅ Solution created for case: %s", sag_id)
            return result[0]
        raise HTTPException(status_code=500, detail="Failed to create solution")
    except HTTPException:
        raise
    except Exception as e:
        logger.error("❌ Error creating solution: %s", e)
        raise HTTPException(status_code=500, detail="Failed to create solution")

@router.patch("/sag/{sag_id}/solution", response_model=Solution)
async def update_solution(sag_id: int, updates: SolutionUpdate):
    """Update a solution."""
    try:
        # Check if solution exists
        check = execute_query("SELECT id FROM sag_solutions WHERE sag_id = %s", (sag_id,))
        if not check:
            raise HTTPException(status_code=404, detail="Solution not found")
        
        # Build dynamic update query
        set_clauses = []
        params = []
        
        # Helper to check and add params
        if updates.title is not None:
            set_clauses.append("title = %s")
            params.append(updates.title)
        if updates.description is not None:
            set_clauses.append("description = %s")
            params.append(updates.description)
        if updates.solution_type is not None:
            set_clauses.append("solution_type = %s")
            params.append(updates.solution_type)
        if updates.result is not None:
            set_clauses.append("result = %s")
            params.append(updates.result)
            
        if not set_clauses:
            raise HTTPException(status_code=400, detail="No fields to update")
            
        set_clauses.append("updated_at = NOW()")
            
        params.append(sag_id)
        query = f"UPDATE sag_solutions SET {', '.join(set_clauses)} WHERE sag_id = %s RETURNING *"
        
        result = execute_query(query, tuple(params))
        if result:
            logger.info("✅ Solution updated for case: %s", sag_id)
            return result[0]
        raise HTTPException(status_code=500, detail="Failed to update solution")
    except HTTPException:
        raise
    except Exception as e:
        logger.error("❌ Error updating solution: %s", e)
        raise HTTPException(status_code=500, detail="Failed to update solution")