import calendar
from collections import defaultdict

from django.db.models import Count, Q

from apps.surveys.models import SurveyInstance, SurveyResponse


CATEGORIES = ["Hospital", "Medical", "Non-Medical", "Nursing", "ER", "Support Services"]
SENTIMENTS = ["negative", "positive", "neutral", "gratitude", "suggestion"]


class CommentsReportService:
    def __init__(self, hospital_id, year, quarter):
        self.hospital_id = hospital_id
        self.year = year
        self.quarter = quarter

    def _base_qs(self):
        return SurveyInstance.objects.filter(
            survey_template__hospital_id=self.hospital_id,
            completed_at__year=self.year,
            completed_at__month__in=self._quarter_months(),
        ).exclude(comment="").exclude(comment__isnull=True)

    def _quarter_months(self):
        return {
            1: [1, 2, 3],
            2: [4, 5, 6],
            3: [7, 8, 9],
            4: [10, 11, 12],
        }.get(self.quarter, [1, 2, 3])

    def get_available_periods(self):
        months = (
            SurveyInstance.objects.filter(
                survey_template__hospital_id=self.hospital_id,
            )
            .values_list("completed_at__year", "completed_at__month")
            .distinct()
            .order_by("-completed_at__year", "-completed_at__month")
        )
        periods = set()
        for y, m in months:
            if y is not None and m is not None:
                q = (m - 1) // 3 + 1
                periods.add((y, q))
        return sorted(periods, reverse=True)

    def get_summary(self):
        qs = self._base_qs()
        total = qs.count()
        with_analysis = qs.filter(comment_analyzed=True).count()
        negative = qs.filter(is_negative=True).count()

        return {
            "total": total,
            "with_analysis": with_analysis,
            "negative": negative,
            "positive": total - negative,
        }

    def get_category_breakdown(self):
        qs = self._base_qs().filter(comment_analyzed=True)
        cat_data = defaultdict(int)
        for s in qs.iterator(chunk_size=2000):
            analysis = s.comment_analysis or {}
            cat = analysis.get("category", "Uncategorized")
            cat_data[cat] += 1

        if not cat_data and qs.count() == 0:
            return []

        result = [{"category": c, "count": cat_data.get(c, 0)} for c in CATEGORIES]
        return [r for r in result if r["count"] > 0]

    def get_sentiment_breakdown(self):
        qs = self._base_qs().filter(comment_analyzed=True)
        sent_data = defaultdict(int)
        for s in qs.iterator(chunk_size=2000):
            analysis = s.comment_analysis or {}
            sent = analysis.get("sentiment", "neutral")
            sent_data[sent] += 1

        return [{"sentiment": s, "count": sent_data.get(s, 0)} for s in SENTIMENTS if sent_data.get(s, 0) > 0]

    def get_subcategory_breakdown(self):
        qs = self._base_qs().filter(comment_analyzed=True)
        subcat_data = defaultdict(lambda: defaultdict(int))
        for s in qs.iterator(chunk_size=2000):
            analysis = s.comment_analysis or {}
            cat = analysis.get("category", "Uncategorized")
            subcat = analysis.get("subcategory", "General")
            subcat_data[cat][subcat] += 1

        result = []
        for cat, subcats in sorted(subcat_data.items()):
            for subcat, count in sorted(subcats.items(), key=lambda x: -x[1]):
                result.append({
                    "category": cat,
                    "subcategory": subcat,
                    "count": count,
                })
        return result

    def get_action_plans(self):
        qs = self._base_qs().filter(comment_analyzed=True)
        plans = []
        for s in qs.iterator(chunk_size=2000):
            analysis = s.comment_analysis or {}
            action = analysis.get("suggested_action_en", "") or analysis.get("suggested_action_ar", "")
            if action:
                dept = analysis.get("subcategory", "")
                plans.append({
                    "comment": s.comment[:200] if s.comment else "",
                    "action_plan": action,
                    "responsible": dept,
                    "category": analysis.get("category", ""),
                    "status": "Pending",
                })
        return plans[:100]

    def get_chart_data(self):
        by_category = self.get_category_breakdown()
        by_sentiment = self.get_sentiment_breakdown()

        return {
            "by_category": [
                {"x": c["category"], "y": c["count"]}
                for c in by_category
            ],
            "by_sentiment": [
                {"x": s["sentiment"].title(), "y": s["count"]}
                for s in by_sentiment
            ],
        }