import os
import sys
import copy
import argparse
from collections import defaultdict

# Configure UTF-8 for Windows console
sys.stdout.reconfigure(encoding="utf-8")
sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "config.settings.develop")

import django
django.setup()

from django.db import transaction
from apps.hadis.models import HadisCategory
from utils.text_normalizer import build_search_blob


def deduplicate_category_titles(dry_run=True):
    print("=" * 70)
    print("           HADIS CATEGORY TITLE DEDUPLICATION SCRIPT           ")
    print(f" Mode: {'DRY RUN (Simulation only, no DB changes)' if dry_run else 'EXECUTE (Applying changes to DB)'}")
    print("=" * 70)

    categories = list(HadisCategory.objects.all().order_by("id"))
    total_categories = len(categories)
    print(f"\nLoaded {total_categories} categories from database.\n")

    # Map: lang -> normalized_title -> list of occurrences
    # each occurrence: {"cat_id": cat.id, "item_idx": idx, "original_val": val, "cat_obj": cat}
    lang_title_map = defaultdict(lambda: defaultdict(list))

    for cat in categories:
        if not isinstance(cat.title, list):
            continue
        for idx, item in enumerate(cat.title):
            if not isinstance(item, dict):
                continue
            l_code = item.get("language_code")
            val = item.get("title") or item.get("text") or ""
            val = val.strip()
            if l_code and val:
                lang_title_map[l_code][val.lower()].append({
                    "cat_id": cat.id,
                    "item_idx": idx,
                    "original_val": val,
                    "cat_obj": cat,
                })

    # Prepare changes
    # cat_id -> {"cat_obj": cat, "title_copy": [...], "changes": [{"lang": l, "old": o, "new": n}]}
    pending_updates = {}

    for cat in categories:
        pending_updates[cat.id] = {
            "cat_obj": cat,
            "title_copy": copy.deepcopy(cat.title) if isinstance(cat.title, list) else cat.title,
            "changes": [],
        }

    total_duplicate_groups = 0

    print("--- Scanning for duplicate titles by language ---")
    for l_code in sorted(lang_title_map.keys()):
        title_dict = lang_title_map[l_code]
        dup_groups = {k: v for k, v in title_dict.items() if len(v) > 1}
        print(f"  Language '{l_code}': {len(dup_groups)} duplicate title groups")
        total_duplicate_groups += len(dup_groups)

        for lower_val, occ_list in dup_groups.items():
            # Sort occurrences deterministically by category ID
            occ_list.sort(key=lambda x: x["cat_id"])
            for rank, occ in enumerate(occ_list, start=1):
                cat_id = occ["cat_id"]
                idx = occ["item_idx"]
                orig_val = occ["original_val"]
                new_val = f"{orig_val} {rank}"

                entry = pending_updates[cat_id]
                title_item = entry["title_copy"][idx]

                if "title" in title_item:
                    title_item["title"] = new_val
                if "text" in title_item:
                    title_item["text"] = new_val
                if "value" in title_item:
                    title_item["value"] = new_val

                entry["changes"].append({
                    "lang": l_code,
                    "old": orig_val,
                    "new": new_val,
                })

    # Filter only categories that actually have changes
    cats_to_update = [info for info in pending_updates.values() if len(info["changes"]) > 0]

    print(f"\nFound {len(cats_to_update)} categories out of {total_categories} requiring title deduplication.")

    if not cats_to_update:
        print("✅ No duplicate category titles found. Everything is already unique.")
        return

    print("\n--- Detailed List of Updates ---")
    for info in cats_to_update:
        cat = info["cat_obj"]
        changes_str = ", ".join(f"[{c['lang']}] '{c['old']}' -> '{c['new']}'" for c in info["changes"])
        print(f"  Category #{cat.id} (slug: {cat.slug}, source: {cat.source_type}): {changes_str}")

    if dry_run:
        print("\n" + "=" * 70)
        print("ℹ️ DRY RUN COMPLETED. No database changes were made.")
        print("To apply changes to the database, run with: python scripts/deduplicate_category_titles.py --execute")
        print("=" * 70)
        return

    print("\nApplying updates to database...")
    with transaction.atomic():
        updated_count = 0
        for info in cats_to_update:
            cat = info["cat_obj"]
            cat.title = info["title_copy"]
            cat.normalized_text = build_search_blob(cat.title, cat.description)
            cat.save(update_fields=["title", "normalized_text"])
            updated_count += 1

    print("\n" + "=" * 70)
    print(f"✅ SUCCESS: Successfully updated {updated_count} categories in database.")
    print("All duplicate titles have been resolved with incremental numbers.")
    print("=" * 70)


if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Deduplicate HadisCategory titles across languages.")
    parser.add_argument(
        "--execute",
        "--apply",
        action="store_true",
        dest="execute",
        help="Apply changes to the database (default is dry-run).",
    )
    args = parser.parse_args()
    deduplicate_category_titles(dry_run=not args.execute)