from django.db.models.signals import post_save
from django.dispatch import receiver
from . import models

# @receiver(post_save, sender=models.Candidate)
# def parse_resume(sender, instance, created, **kwargs):
#     if instance.resume and not instance.summary:
#         from .utils import extract_summary_from_pdf,match_resume_with_job_description
#         summary = extract_summary_from_pdf(instance.resume.path)
#         if 'error' not in summary:
#             instance.summary = summary
#             instance.save()

        # match_resume_with_job_description

import logging
logger = logging.getLogger(__name__)
import os
from .utils import extract_text_from_pdf,score_resume_with_openrouter



@receiver(post_save, sender=models.Candidate)
def score_candidate_resume(sender, instance, created, **kwargs):
    # Skip if no resume or OpenRouter not configured
    if instance.resume is None:
        return 
    if kwargs.get('update_fields') is not None:
        return

    # Optional: Only re-score if resume changed (advanced: track file hash)
    # For simplicity, we score on every save with a resume

    try:
        # Get absolute file path
        file_path = instance.resume.path
        if not os.path.exists(file_path):
            logger.warning(f"Resume file not found: {file_path}")
            return

        resume_text = extract_text_from_pdf(file_path)
        # if not resume_text:
        #     instance.scoring_error = "Could not extract text from resume."
        #     instance.save(update_fields=['scoring_error'])
        #     return

        result = score_resume_with_openrouter(resume_text)

        # Update candidate with scoring results
        instance.match_score = result.get('match_score')
        instance.strengths = result.get('strengths', '')
        instance.weaknesses = result.get('weaknesses', '')
        instance.criteria_checklist = result.get('criteria_checklist', {})
       
       

        # Save only scoring-related fields to avoid recursion
        instance.save(update_fields=[
            'match_score', 'strengths', 'weaknesses',
            'criteria_checklist'
        ])

        logger.info(f"Successfully scored resume for candidate {instance.id}")

    except Exception as e:
        # error_msg = str(e)[:500]  # Truncate to fit TextField
        # instance.scoring_error = error_msg
        # instance.save(update_fields=['scoring_error'])
        logger.error(f"Failed to score resume for candidate {instance.id}: {e}")