"""
Import Panorama Issues & Deviations XLSX do MongoDB (databáze: Panorama).

Kolekce: IssuesAndDeviations
Filtr:   pouze řádky s Country Name == "Czechia"
Historie: při změně fields se stará verze uloží do pole history[]

Použití:
    python import_to_mongo.py                          # importuje všechny xlsx z Downloads/
    python import_to_mongo.py Downloads/konkretni.xlsx  # jeden soubor
"""

import re
import shutil
import sys
from datetime import datetime, date
from pathlib import Path

import openpyxl
from pymongo import MongoClient, ASCENDING

MONGO_URI = "mongodb://192.168.1.76:27017"
DB_NAME = "Panorama"
COLLECTION_NAME = "IssuesAndDeviations"
DOWNLOADS_DIR = Path(__file__).parent / "Downloads"
PROCESSED_DIR = DOWNLOADS_DIR / "Zpracovano"

COUNTRY_FILTER = None       # None = všechny země
HEADER_ROW = 5          # 0-indexed řádek s hlavičkou
DATA_START_ROW = 6      # 0-indexed první datový řádek
UPSERT_KEY = "ID"       # unikátní klíč pro upsert


# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------

def extract_snapshot_date(filename: str) -> str:
    match = re.match(r"(\d{4}-\d{2}-\d{2})", Path(filename).name)
    return match.group(1) if match else datetime.now().strftime("%Y-%m-%d")


def clean_value(val):
    """Převede datetime na ISO string, None nechá, zbytek strip."""
    if val is None:
        return None
    if isinstance(val, datetime):
        return val.isoformat()
    if isinstance(val, date):
        return val.isoformat()
    if isinstance(val, str):
        val = val.strip()
        return val if val else None
    return val


# ---------------------------------------------------------------------------
# Import jednoho souboru
# ---------------------------------------------------------------------------

def import_file(xlsx_path: str, collection) -> dict:
    filename = Path(xlsx_path).name
    snapshot_date = extract_snapshot_date(filename)

    wb = openpyxl.load_workbook(xlsx_path, read_only=True)
    ws = wb[wb.sheetnames[0]]
    rows = list(ws.iter_rows(values_only=True))
    wb.close()

    header = rows[HEADER_ROW]

    inserted = changed = unchanged = filtered_out = 0

    for row in rows[DATA_START_ROW:]:
        raw = dict(zip(header, row))

        country = (raw.get("Country Name") or "")
        if COUNTRY_FILTER and country != COUNTRY_FILTER:
            filtered_out += 1
            continue

        record_id = raw.get(UPSERT_KEY)
        if record_id is None:
            continue
        record_id = str(int(record_id)) if isinstance(record_id, (int, float)) else str(record_id).strip()

        fields = {}
        for k, v in raw.items():
            if k is None:
                continue
            fields[k] = clean_value(v)

        existing = collection.find_one({"record_id": record_id})

        if existing is None:
            doc = {
                "record_id": record_id,
                "fields": fields,
                "sourceFile": filename,
                "firstSeen": snapshot_date,
                "lastSeen": snapshot_date,
                "history": [],
            }
            collection.insert_one(doc)
            inserted += 1

        elif existing.get("fields") != fields:
            old_entry = {
                "date": existing.get("lastSeen", snapshot_date),
                "fields": existing["fields"],
            }
            collection.update_one(
                {"_id": existing["_id"]},
                {
                    "$push": {"history": old_entry},
                    "$set": {
                        "fields": fields,
                        "sourceFile": filename,
                        "lastSeen": snapshot_date,
                    },
                },
            )
            changed += 1

        else:
            collection.update_one(
                {"_id": existing["_id"]},
                {"$set": {"lastSeen": snapshot_date, "sourceFile": filename}},
            )
            unchanged += 1

    stats = {
        "snapshot": snapshot_date,
        "inserted": inserted,
        "changed": changed,
        "unchanged": unchanged,
        "filtered_out": filtered_out,
    }
    print(f"  {COLLECTION_NAME} [{snapshot_date}]: +{inserted} new, ~{changed} changed, ={unchanged} same, -{filtered_out} non-CZ")
    return stats


# ---------------------------------------------------------------------------
# Main
# ---------------------------------------------------------------------------

def main():
    paths: list[Path] = []

    if len(sys.argv) > 1:
        for arg in sys.argv[1:]:
            p = Path(arg)
            if p.is_file():
                paths.append(p)
            else:
                print(f"Soubor nenalezen: {arg}")
    else:
        paths = sorted(DOWNLOADS_DIR.glob("*.xlsx"))

    if not paths:
        print("Zadne XLSX soubory k importu.")
        return

    print(f"Nalezeno {len(paths)} souboru.\n")

    client = MongoClient(MONGO_URI, serverSelectionTimeoutMS=5000)
    client.admin.command("ping")
    db = client[DB_NAME]
    collection = db[COLLECTION_NAME]

    collection.create_index([("record_id", ASCENDING)], unique=True)
    collection.create_index([("fields.Country Name", ASCENDING)])
    collection.create_index([("fields.Site ID", ASCENDING)])
    collection.create_index([("fields.Status", ASCENDING)])
    collection.create_index([("fields.Brief Description - Subject ID", ASCENDING)])

    PROCESSED_DIR.mkdir(exist_ok=True)

    total = {"inserted": 0, "changed": 0, "unchanged": 0}

    for xlsx_path in paths:
        print(f"Import: {xlsx_path.name}")
        stats = import_file(str(xlsx_path), collection)
        for k in total:
            total[k] += stats.get(k, 0)

        dest = PROCESSED_DIR / xlsx_path.name
        shutil.move(str(xlsx_path), str(dest))
        print(f"  -> presunut do Zpracovano/")

    client.close()

    print(f"\nCelkem: +{total['inserted']} new, ~{total['changed']} changed, ={total['unchanged']} same")


if __name__ == "__main__":
    main()