import asyncio
import json
import logging
import uuid
from datetime import datetime, timedelta

from . import order_reader, validation_service, import_service, sqlite_service, invoice_service, gomag_client
from ..config import settings
from .. import database

logger = logging.getLogger(__name__)

# Sync state
_sync_lock = asyncio.Lock()
_current_sync = None  # dict with run_id, status, progress info

# In-memory text log buffer per run
_run_logs: dict[str, list[str]] = {}


def _log_line(run_id: str, message: str):
    """Append a timestamped line to the in-memory log buffer."""
    if run_id not in _run_logs:
        _run_logs[run_id] = []
    ts = datetime.now().strftime("%H:%M:%S")
    _run_logs[run_id].append(f"[{ts}] {message}")


def get_run_text_log(run_id: str) -> str | None:
    """Return the accumulated text log for a run, or None if not found."""
    lines = _run_logs.get(run_id)
    if lines is None:
        return None
    return "\n".join(lines)


def _update_progress(phase: str, phase_text: str, current: int = 0, total: int = 0,
                     counts: dict = None):
    """Update _current_sync with progress details for polling."""
    global _current_sync
    if _current_sync is None:
        return
    _current_sync["phase"] = phase
    _current_sync["phase_text"] = phase_text
    _current_sync["progress_current"] = current
    _current_sync["progress_total"] = total
    _current_sync["counts"] = counts or {"imported": 0, "skipped": 0, "errors": 0, "already_imported": 0}


async def get_sync_status():
    """Get current sync status."""
    if _current_sync:
        return {**_current_sync}
    return {"status": "idle"}


async def prepare_sync(id_pol: int = None, id_sectie: int = None) -> dict:
    """Prepare a sync run - creates run_id and sets initial state.
    Returns {"run_id": ..., "status": "starting"} or {"error": ...} if already running.
    """
    global _current_sync
    if _sync_lock.locked():
        return {"error": "Sync already running", "run_id": _current_sync.get("run_id") if _current_sync else None}

    run_id = datetime.now().strftime("%Y%m%d_%H%M%S") + "_" + uuid.uuid4().hex[:6]
    _current_sync = {
        "run_id": run_id,
        "status": "running",
        "started_at": datetime.now().isoformat(),
        "finished_at": None,
        "phase": "starting",
        "phase_text": "Starting...",
        "progress_current": 0,
        "progress_total": 0,
        "counts": {"imported": 0, "skipped": 0, "errors": 0, "already_imported": 0},
    }
    return {"run_id": run_id, "status": "starting"}


def _derive_customer_info(order):
    """Extract shipping/billing names and customer from an order."""
    shipping_name = ""
    if order.shipping:
        shipping_name = f"{getattr(order.shipping, 'firstname', '') or ''} {getattr(order.shipping, 'lastname', '') or ''}".strip()
    billing_name = f"{getattr(order.billing, 'firstname', '') or ''} {getattr(order.billing, 'lastname', '') or ''}".strip()
    if not shipping_name:
        shipping_name = billing_name
    customer = shipping_name or order.billing.company_name or billing_name
    payment_method = getattr(order, 'payment_name', None) or None
    delivery_method = getattr(order, 'delivery_name', None) or None
    return shipping_name, billing_name, customer, payment_method, delivery_method


async def run_sync(id_pol: int = None, id_sectie: int = None, run_id: str = None) -> dict:
    """Run a full sync cycle. Returns summary dict."""
    global _current_sync

    if _sync_lock.locked():
        return {"error": "Sync already running"}

    async with _sync_lock:
        # Use provided run_id or generate one
        if not run_id:
            run_id = datetime.now().strftime("%Y%m%d_%H%M%S") + "_" + uuid.uuid4().hex[:6]
            _current_sync = {
                "run_id": run_id,
                "status": "running",
                "started_at": datetime.now().isoformat(),
                "finished_at": None,
                "phase": "reading",
                "phase_text": "Reading JSON files...",
                "progress_current": 0,
                "progress_total": 0,
                "counts": {"imported": 0, "skipped": 0, "errors": 0, "already_imported": 0},
            }

        _update_progress("reading", "Reading JSON files...")

        started_dt = datetime.now()
        _run_logs[run_id] = [
            f"=== Sync Run {run_id} ===",
            f"Inceput: {started_dt.strftime('%d.%m.%Y %H:%M:%S')}",
            ""
        ]

        json_dir = settings.JSON_OUTPUT_DIR

        try:
            # Phase 0: Download orders from GoMag API
            _update_progress("downloading", "Descărcare comenzi din GoMag API...")
            _log_line(run_id, "Descărcare comenzi din GoMag API...")
            # Read GoMag settings from SQLite (override config defaults)
            dl_settings = await sqlite_service.get_app_settings()
            gomag_key = dl_settings.get("gomag_api_key") or None
            gomag_shop = dl_settings.get("gomag_api_shop") or None
            gomag_days_str = dl_settings.get("gomag_order_days_back")
            gomag_days = int(gomag_days_str) if gomag_days_str else None
            gomag_limit_str = dl_settings.get("gomag_limit")
            gomag_limit = int(gomag_limit_str) if gomag_limit_str else None
            dl_result = await gomag_client.download_orders(
                json_dir, log_fn=lambda msg: _log_line(run_id, msg),
                api_key=gomag_key, api_shop=gomag_shop,
                days_back=gomag_days, limit=gomag_limit,
            )
            if dl_result["files"]:
                _log_line(run_id, f"GoMag: {dl_result['total']} comenzi în {dl_result['pages']} pagini → {len(dl_result['files'])} fișiere")

            _update_progress("reading", "Citire fisiere JSON...")
            _log_line(run_id, "Citire fisiere JSON...")

            # Step 1: Read orders and sort chronologically (oldest first - R3)
            orders, json_count = order_reader.read_json_orders()
            orders.sort(key=lambda o: o.date or '')
            await sqlite_service.create_sync_run(run_id, json_count)
            _update_progress("reading", f"Found {len(orders)} orders in {json_count} files", 0, len(orders))
            _log_line(run_id, f"Gasite {len(orders)} comenzi in {json_count} fisiere")

            # Populate web_products catalog from all orders (R4)
            web_product_items = [
                (item.sku, item.name)
                for order in orders
                for item in order.items
                if item.sku and item.name
            ]
            await sqlite_service.upsert_web_products_batch(web_product_items)

            if not orders:
                _log_line(run_id, "Nicio comanda gasita.")
                await sqlite_service.update_sync_run(run_id, "completed", 0, 0, 0, 0)
                _update_progress("completed", "No orders found")
                summary = {"run_id": run_id, "status": "completed", "message": "No orders found", "json_files": json_count}
                return summary

            _update_progress("validation", f"Validating {len(orders)} orders...", 0, len(orders))

            # ── Single Oracle connection for entire validation phase ──
            conn = await asyncio.to_thread(database.get_oracle_connection)
            try:
                # Step 2a: Find orders already in Oracle (date-range query)
                order_dates = [o.date for o in orders if o.date]
                if order_dates:
                    min_date_str = min(order_dates)
                    try:
                        min_date = datetime.strptime(min_date_str[:10], "%Y-%m-%d") - timedelta(days=1)
                    except (ValueError, TypeError):
                        min_date = datetime.now() - timedelta(days=90)
                else:
                    min_date = datetime.now() - timedelta(days=90)

                existing_map = await asyncio.to_thread(
                    validation_service.check_orders_in_roa, min_date, conn
                )

                # Step 2b: Validate SKUs (reuse same connection)
                all_skus = order_reader.get_all_skus(orders)
                validation = await asyncio.to_thread(validation_service.validate_skus, all_skus, conn)
                importable, skipped = validation_service.classify_orders(orders, validation)

                # ── Split importable into truly_importable vs already_in_roa ──
                truly_importable = []
                already_in_roa = []
                for order in importable:
                    if order.number in existing_map:
                        already_in_roa.append(order)
                    else:
                        truly_importable.append(order)

                _update_progress("validation",
                                f"{len(truly_importable)} new, {len(already_in_roa)} already imported, {len(skipped)} skipped",
                                0, len(truly_importable))
                _log_line(run_id, f"Validare: {len(truly_importable)} noi, {len(already_in_roa)} deja importate, {len(skipped)} nemapate")

                # Step 2c: Build SKU context from skipped orders
                sku_context = {}
                for order, missing_skus_list in skipped:
                    customer = order.billing.company_name or \
                        f"{order.billing.firstname} {order.billing.lastname}"
                    for sku in missing_skus_list:
                        if sku not in sku_context:
                            sku_context[sku] = {"orders": [], "customers": []}
                        if order.number not in sku_context[sku]["orders"]:
                            sku_context[sku]["orders"].append(order.number)
                        if customer not in sku_context[sku]["customers"]:
                            sku_context[sku]["customers"].append(customer)

                # Track missing SKUs with context
                for sku in validation["missing"]:
                    product_name = ""
                    for order in orders:
                        for item in order.items:
                            if item.sku == sku:
                                product_name = item.name
                                break
                        if product_name:
                            break
                    ctx = sku_context.get(sku, {})
                    await sqlite_service.track_missing_sku(
                        sku, product_name,
                        order_count=len(ctx.get("orders", [])),
                        order_numbers=json.dumps(ctx.get("orders", [])) if ctx.get("orders") else None,
                        customers=json.dumps(ctx.get("customers", [])) if ctx.get("customers") else None,
                    )

                # Step 2d: Pre-validate prices for importable articles
                # Load app settings (for transport/discount CODMAT config AND id_pol/id_sectie override)
                app_settings = await sqlite_service.get_app_settings()
                id_pol = id_pol or int(app_settings.get("id_pol") or 0) or settings.ID_POL
                id_sectie = id_sectie or int(app_settings.get("id_sectie") or 0) or settings.ID_SECTIE
                logger.info(f"Sync params: ID_POL={id_pol}, ID_SECTIE={id_sectie}")
                _log_line(run_id, f"Parametri import: ID_POL={id_pol}, ID_SECTIE={id_sectie}")
                if id_pol and (truly_importable or already_in_roa):
                    _update_progress("validation", "Validating prices...", 0, len(truly_importable))
                    _log_line(run_id, "Validare preturi...")
                    all_codmats = set()
                    for order in (truly_importable + already_in_roa):
                        for item in order.items:
                            if item.sku in validation["mapped"]:
                                pass
                            elif item.sku in validation["direct"]:
                                all_codmats.add(item.sku)
                    if all_codmats:
                        price_result = await asyncio.to_thread(
                            validation_service.validate_prices, all_codmats, id_pol,
                            conn, validation.get("direct_id_map")
                        )
                        if price_result["missing_price"]:
                            logger.info(
                                f"Auto-adding price 0 for {len(price_result['missing_price'])} "
                                f"direct articles in policy {id_pol}"
                            )
                            await asyncio.to_thread(
                                validation_service.ensure_prices,
                                price_result["missing_price"], id_pol,
                                conn, validation.get("direct_id_map")
                            )
            finally:
                await asyncio.to_thread(database.pool.release, conn)

            # Step 3a: Record already-imported orders (batch)
            already_imported_count = len(already_in_roa)
            already_batch = []
            for order in already_in_roa:
                shipping_name, billing_name, customer, payment_method, delivery_method = _derive_customer_info(order)
                id_comanda_roa = existing_map.get(order.number)
                order_items_data = [
                    {"sku": item.sku, "product_name": item.name,
                     "quantity": item.quantity, "price": item.price, "vat": item.vat,
                     "mapping_status": "mapped" if item.sku in validation["mapped"] else "direct",
                     "codmat": None, "id_articol": None, "cantitate_roa": None}
                    for item in order.items
                ]
                already_batch.append({
                    "sync_run_id": run_id, "order_number": order.number,
                    "order_date": order.date, "customer_name": customer,
                    "status": "ALREADY_IMPORTED", "status_at_run": "ALREADY_IMPORTED",
                    "id_comanda": id_comanda_roa, "id_partener": None,
                    "error_message": None, "missing_skus": None,
                    "items_count": len(order.items),
                    "shipping_name": shipping_name, "billing_name": billing_name,
                    "payment_method": payment_method, "delivery_method": delivery_method,
                    "order_total": order.total or None,
                    "delivery_cost": order.delivery_cost or None,
                    "discount_total": order.discount_total or None,
                    "items": order_items_data,
                })
                _log_line(run_id, f"#{order.number} [{order.date or '?'}] {customer} → DEJA IMPORTAT (ID: {id_comanda_roa})")
            await sqlite_service.save_orders_batch(already_batch)

            # Step 3b: Record skipped orders + store items (batch)
            skipped_count = len(skipped)
            skipped_batch = []
            for order, missing_skus in skipped:
                shipping_name, billing_name, customer, payment_method, delivery_method = _derive_customer_info(order)
                order_items_data = [
                    {"sku": item.sku, "product_name": item.name,
                     "quantity": item.quantity, "price": item.price, "vat": item.vat,
                     "mapping_status": "missing" if item.sku in validation["missing"] else
                                       "mapped" if item.sku in validation["mapped"] else "direct",
                     "codmat": None, "id_articol": None, "cantitate_roa": None}
                    for item in order.items
                ]
                skipped_batch.append({
                    "sync_run_id": run_id, "order_number": order.number,
                    "order_date": order.date, "customer_name": customer,
                    "status": "SKIPPED", "status_at_run": "SKIPPED",
                    "id_comanda": None, "id_partener": None,
                    "error_message": None, "missing_skus": missing_skus,
                    "items_count": len(order.items),
                    "shipping_name": shipping_name, "billing_name": billing_name,
                    "payment_method": payment_method, "delivery_method": delivery_method,
                    "order_total": order.total or None,
                    "delivery_cost": order.delivery_cost or None,
                    "discount_total": order.discount_total or None,
                    "items": order_items_data,
                })
                _log_line(run_id, f"#{order.number} [{order.date or '?'}] {customer} → OMIS (lipsa: {', '.join(missing_skus)})")
            await sqlite_service.save_orders_batch(skipped_batch)
            _update_progress("skipped", f"Skipped {skipped_count}",
                             0, len(truly_importable),
                             {"imported": 0, "skipped": skipped_count, "errors": 0, "already_imported": already_imported_count})

            # Step 4: Import only truly new orders
            imported_count = 0
            error_count = 0

            for i, order in enumerate(truly_importable):
                shipping_name, billing_name, customer, payment_method, delivery_method = _derive_customer_info(order)

                _update_progress("import",
                                 f"Import {i+1}/{len(truly_importable)}: #{order.number} {customer}",
                                 i + 1, len(truly_importable),
                                 {"imported": imported_count, "skipped": len(skipped), "errors": error_count,
                                  "already_imported": already_imported_count})

                result = await asyncio.to_thread(
                    import_service.import_single_order,
                    order, id_pol=id_pol, id_sectie=id_sectie,
                    app_settings=app_settings
                )

                # Build order items data for storage (R9)
                order_items_data = []
                for item in order.items:
                    ms = "mapped" if item.sku in validation["mapped"] else "direct"
                    order_items_data.append({
                        "sku": item.sku, "product_name": item.name,
                        "quantity": item.quantity, "price": item.price, "vat": item.vat,
                        "mapping_status": ms, "codmat": None, "id_articol": None,
                        "cantitate_roa": None
                    })

                if result["success"]:
                    imported_count += 1
                    await sqlite_service.upsert_order(
                        sync_run_id=run_id,
                        order_number=order.number,
                        order_date=order.date,
                        customer_name=customer,
                        status="IMPORTED",
                        id_comanda=result["id_comanda"],
                        id_partener=result["id_partener"],
                        items_count=len(order.items),
                        shipping_name=shipping_name,
                        billing_name=billing_name,
                        payment_method=payment_method,
                        delivery_method=delivery_method,
                        order_total=order.total or None,
                        delivery_cost=order.delivery_cost or None,
                        discount_total=order.discount_total or None,
                    )
                    await sqlite_service.add_sync_run_order(run_id, order.number, "IMPORTED")
                    # Store ROA address IDs (R9)
                    await sqlite_service.update_import_order_addresses(
                        order.number,
                        id_adresa_facturare=result.get("id_adresa_facturare"),
                        id_adresa_livrare=result.get("id_adresa_livrare")
                    )
                    await sqlite_service.add_order_items(order.number, order_items_data)
                    _log_line(run_id, f"#{order.number} [{order.date or '?'}] {customer} → IMPORTAT (ID: {result['id_comanda']})")
                else:
                    error_count += 1
                    await sqlite_service.upsert_order(
                        sync_run_id=run_id,
                        order_number=order.number,
                        order_date=order.date,
                        customer_name=customer,
                        status="ERROR",
                        id_partener=result.get("id_partener"),
                        error_message=result["error"],
                        items_count=len(order.items),
                        shipping_name=shipping_name,
                        billing_name=billing_name,
                        payment_method=payment_method,
                        delivery_method=delivery_method,
                        order_total=order.total or None,
                        delivery_cost=order.delivery_cost or None,
                        discount_total=order.discount_total or None,
                    )
                    await sqlite_service.add_sync_run_order(run_id, order.number, "ERROR")
                    await sqlite_service.add_order_items(order.number, order_items_data)
                    _log_line(run_id, f"#{order.number} [{order.date or '?'}] {customer} → EROARE: {result['error']}")

                # Safety: stop if too many errors
                if error_count > 10:
                    logger.warning("Too many errors, stopping sync")
                    break

            # Step 4b: Invoice check — update cached invoice data
            _update_progress("invoices", "Checking invoices...", 0, 0)
            invoices_updated = 0
            try:
                uninvoiced = await sqlite_service.get_uninvoiced_imported_orders()
                if uninvoiced:
                    id_comanda_list = [o["id_comanda"] for o in uninvoiced]
                    invoice_data = await asyncio.to_thread(
                        invoice_service.check_invoices_for_orders, id_comanda_list
                    )
                    # Build reverse map: id_comanda → order_number
                    id_to_order = {o["id_comanda"]: o["order_number"] for o in uninvoiced}
                    for idc, inv in invoice_data.items():
                        order_num = id_to_order.get(idc)
                        if order_num and inv.get("facturat"):
                            await sqlite_service.update_order_invoice(
                                order_num,
                                serie=inv.get("serie_act"),
                                numar=str(inv.get("numar_act", "")),
                                total_fara_tva=inv.get("total_fara_tva"),
                                total_tva=inv.get("total_tva"),
                                total_cu_tva=inv.get("total_cu_tva"),
                            )
                            invoices_updated += 1
                    if invoices_updated:
                        _log_line(run_id, f"Facturi actualizate: {invoices_updated} comenzi facturate")
            except Exception as e:
                logger.warning(f"Invoice check failed: {e}")

            # Step 5: Update sync run
            total_imported = imported_count + already_imported_count  # backward-compat
            status = "completed" if error_count <= 10 else "failed"
            await sqlite_service.update_sync_run(
                run_id, status, len(orders), total_imported, len(skipped), error_count,
                already_imported=already_imported_count, new_imported=imported_count
            )

            summary = {
                "run_id": run_id,
                "status": status,
                "json_files": json_count,
                "total_orders": len(orders),
                "new_orders": len(truly_importable),
                "imported": total_imported,
                "new_imported": imported_count,
                "already_imported": already_imported_count,
                "skipped": len(skipped),
                "errors": error_count,
                "missing_skus": len(validation["missing"]),
                "invoices_updated": invoices_updated,
            }

            _update_progress("completed",
                             f"Completed: {imported_count} new, {already_imported_count} already, {len(skipped)} skipped, {error_count} errors",
                             len(truly_importable), len(truly_importable),
                             {"imported": imported_count, "skipped": len(skipped), "errors": error_count,
                              "already_imported": already_imported_count})
            if _current_sync:
                _current_sync["status"] = status
                _current_sync["finished_at"] = datetime.now().isoformat()

            logger.info(
                f"Sync {run_id} completed: {imported_count} new, {already_imported_count} already imported, "
                f"{len(skipped)} skipped, {error_count} errors"
            )

            duration = (datetime.now() - started_dt).total_seconds()
            _log_line(run_id, "")
            _run_logs[run_id].append(
                f"Finalizat: {imported_count} importate, {already_imported_count} deja importate, "
                f"{len(skipped)} nemapate, {error_count} erori din {len(orders)} comenzi | Durata: {int(duration)}s"
            )

            return summary

        except Exception as e:
            logger.error(f"Sync {run_id} failed: {e}")
            _log_line(run_id, f"EROARE FATALA: {e}")
            await sqlite_service.update_sync_run(run_id, "failed", 0, 0, 0, 1, error_message=str(e))
            if _current_sync:
                _current_sync["status"] = "failed"
                _current_sync["finished_at"] = datetime.now().isoformat()
                _current_sync["error"] = str(e)
            return {"run_id": run_id, "status": "failed", "error": str(e)}
        finally:
            # Keep _current_sync for 10 seconds so status endpoint can show final result
            async def _clear_current_sync():
                await asyncio.sleep(10)
                global _current_sync
                _current_sync = None
            asyncio.ensure_future(_clear_current_sync())

            async def _clear_run_logs():
                await asyncio.sleep(300)  # 5 minutes
                _run_logs.pop(run_id, None)
            asyncio.ensure_future(_clear_run_logs())


def stop_sync():
    """Signal sync to stop. Currently sync runs to completion."""
    pass