import datetime
import logging
from firebase_admin import firestore
from firebase_manager import firebase_manager

logger = logging.getLogger("HamoraServer")

class AnalyticsManager:
    """
    Manages AI Assessment Telemetry and Weekly Reports.
    """
    def _get_db(self):
        return firebase_manager.get_db()

    def update_weekly_analytics(self, uid: str, assessment: dict):
        """
        Updates the weekly analytics document for a user using atomic operations.
        Runs silently.
        """
        if not uid or not assessment:
            return

        db = self._get_db()
        if not db:
            logger.error("❌ [ANALYTICS] Firestore DB not available.")
            return

        try:
            # 1. Parse assessment data
            primary_skill = assessment.get("primary_skill", "Unknown")
            sub_skill = assessment.get("sub_skill", "")
            mastery_score = assessment.get("mastery_score", 0)
            parent_note = assessment.get("parent_note", "")

            # Ensure score is an integer
            try:
                mastery_score = int(mastery_score)
            except (ValueError, TypeError):
                mastery_score = 0

            # 2. Compute week_id (e.g., week_11_2026)
            today = datetime.date.today()
            year, week_num, _ = today.isocalendar()
            week_id = f"week_{week_num:02d}_{year}"

            # 3. Construct the document reference
            # Path: users/{uid}/analytics/{week_id}
            doc_ref = db.collection("users").document(uid).collection("analytics").document(week_id)

            # 4. Construct payload with FieldValue operations for atomic updates
            # Create the nested skill payload
            skill_payload = {
                "sum_scores": firestore.Increment(mastery_score),
                "count": firestore.Increment(1)
            }
            if sub_skill:
                skill_payload["sub_skills"] = firestore.ArrayUnion([sub_skill])

            # Combine into final payload
            payload = {
                "total_exercises": firestore.Increment(1),
                f"skills_data.{primary_skill}": skill_payload,
                "last_updated": firestore.SERVER_TIMESTAMP
            }
            
            if parent_note:
                payload["parent_notes"] = firestore.ArrayUnion([parent_note])

            # 5. Set with merge=True
            doc_ref.set(payload, merge=True)
            logger.info(f"📊 [ANALYTICS] Successfully updated telemetry for {uid} in {week_id}.")

        except Exception as e:
            logger.error(f"❌ [ANALYTICS] Error updating analytics for {uid}: {e}")

# Global instance
analytics_manager = AnalyticsManager()