import logging
import re
from sqlalchemy.orm import Session
from typing import Optional
from ..database import JobRolePattern, RawJobTitle, Persona, Contact

logger = logging.getLogger(__name__)

class RoleMappingService:
    def __init__(self, db: Session):
        self.db = db

    def get_role_for_job_title(self, job_title: str) -> Optional[str]:
        """
        Finds the corresponding role for a given job title using a multi-step process.
        1. Check for exact matches.
        2. Evaluate regex patterns.
        """
        if not job_title:
            return None

        # Normalize job title for matching
        normalized_title = job_title.lower().strip()

        # 1. Fetch all active patterns from the database, ordered by priority
        patterns = self.db.query(JobRolePattern).filter(
            JobRolePattern.is_active == True
        ).order_by(JobRolePattern.priority.asc()).all()

        # 2. Separate patterns for easier processing
        exact_patterns = {p.pattern_value.lower(): p.role for p in patterns if p.pattern_type == 'exact'}
        regex_patterns = [(p.pattern_value, p.role) for p in patterns if p.pattern_type == 'regex']

        # 3. Check for exact match first (most efficient)
        if normalized_title in exact_patterns:
            return exact_patterns[normalized_title]

        # 4. Evaluate regex patterns
        for pattern, role in regex_patterns:
            try:
                if re.search(pattern, job_title, re.IGNORECASE):
                    return role
            except re.error as e:
                logger.error(f"Invalid regex for role '{role}': {pattern}. Error: {e}")
                continue

        return None

    def add_or_update_unclassified_title(self, job_title: str):
        """
        Logs an unclassified job title or increments its count if already present.
        """
        if not job_title:
            return

        entry = self.db.query(RawJobTitle).filter(RawJobTitle.title == job_title).first()
        if entry:
            entry.count += 1
        else:
            entry = RawJobTitle(title=job_title, count=1)
            self.db.add(entry)
        
        self.db.commit()