from django.db.models.signals import post_save, pre_save
from django.dispatch import receiver

from core.apps.evaluation.choices.auto import AutoEvaluationStatus
from core.apps.evaluation.choices.history import EvaluationEventType
from core.apps.evaluation.choices.quick import QuickEvaluationStatus
from core.apps.evaluation.models import (
    AutoEvaluationModel,
    QuickEvaluationModel,
    ValuationDocumentModel,
    ValuationModel,
)
from core.apps.evaluation.services.history import EvaluationHistoryService


# ─────────────────────────────────────────────────────────────────────────────
# AutoEvaluation — order_created va status_changed
# ─────────────────────────────────────────────────────────────────────────────

@receiver(pre_save, sender=AutoEvaluationModel)
def auto_eval_pre_save(sender, instance, **kwargs):
    """Status o'zgarishini kuzatish uchun eski qiymatni saqlaydi."""
    if instance.pk:
        try:
            old = AutoEvaluationModel.objects.get(pk=instance.pk)
            instance._old_status = old.status
        except AutoEvaluationModel.DoesNotExist:
            instance._old_status = None
    else:
        instance._old_status = None


@receiver(post_save, sender=AutoEvaluationModel)
def auto_eval_post_save(sender, instance, created, **kwargs):
    if created:
        actor = None
        if instance.valuation_id:
            try:
                actor = instance.valuation.created_by
            except Exception:
                pass
        EvaluationHistoryService.log_auto(
            auto_evaluation=instance,
            event_type=EvaluationEventType.ORDER_CREATED,
            actor=actor,
        )
    else:
        old_status = getattr(instance, "_old_status", None)
        if old_status is not None and old_status != instance.status:
            status_labels = dict(AutoEvaluationStatus.choices)
            EvaluationHistoryService.log_auto(
                auto_evaluation=instance,
                event_type=EvaluationEventType.STATUS_CHANGED,
                meta={
                    "from_status": old_status,
                    "from_status_display": status_labels.get(old_status, old_status),
                    "to_status": instance.status,
                    "to_status_display": status_labels.get(instance.status, instance.status),
                },
            )


# ─────────────────────────────────────────────────────────────────────────────
# Valuation — evaluator_assigned (assigned_to o'zgarganda)
# ─────────────────────────────────────────────────────────────────────────────

@receiver(pre_save, sender=ValuationModel)
def valuation_pre_save(sender, instance, **kwargs):
    """assigned_to o'zgarishini kuzatish uchun eski qiymatni saqlaydi."""
    if instance.pk:
        try:
            old = ValuationModel.objects.get(pk=instance.pk)
            instance._old_assigned_to_id = old.assigned_to_id
        except ValuationModel.DoesNotExist:
            instance._old_assigned_to_id = None
    else:
        instance._old_assigned_to_id = None


@receiver(post_save, sender=ValuationModel)
def valuation_post_save(sender, instance, created, **kwargs):
    if created:
        return
    old_assigned_id = getattr(instance, "_old_assigned_to_id", None)
    if instance.assigned_to_id and old_assigned_id != instance.assigned_to_id:
        try:
            auto_eval = instance.auto_detail
        except AutoEvaluationModel.DoesNotExist:
            return
        evaluator = instance.assigned_to
        evaluator_name = ""
        if evaluator:
            evaluator_name = evaluator.get_full_name().strip() or str(evaluator.phone)
        EvaluationHistoryService.log_auto(
            auto_evaluation=auto_eval,
            event_type=EvaluationEventType.EVALUATOR_ASSIGNED,
            meta={
                "evaluator_id": instance.assigned_to_id,
                "evaluator_name": evaluator_name,
            },
        )


# ─────────────────────────────────────────────────────────────────────────────
# ValuationDocument — document_uploaded
# ─────────────────────────────────────────────────────────────────────────────

@receiver(post_save, sender=ValuationDocumentModel)
def document_post_save(sender, instance, created, **kwargs):
    if not created:
        return
    try:
        auto_eval = instance.valuation.auto_detail
    except (AttributeError, AutoEvaluationModel.DoesNotExist):
        return
    file_name = ""
    if instance.file:
        file_name = instance.file.name.split("/")[-1]
    EvaluationHistoryService.log_auto(
        auto_evaluation=auto_eval,
        event_type=EvaluationEventType.DOCUMENT_UPLOADED,
        actor=instance.uploaded_by,
        meta={
            "document_type": instance.document_type,
            "document_type_display": instance.get_document_type_display(),
            "file_name": file_name,
            "title": instance.title or "",
        },
    )


# ─────────────────────────────────────────────────────────────────────────────
# Payment — payment_made (status COMPLETED bo'lganda)
# ─────────────────────────────────────────────────────────────────────────────

@receiver(pre_save, sender="payment.PaymentModel")
def payment_pre_save(sender, instance, **kwargs):
    if instance.pk:
        try:
            old = sender.objects.get(pk=instance.pk)
            instance._old_payment_status = old.status
        except sender.DoesNotExist:
            instance._old_payment_status = None
    else:
        instance._old_payment_status = None


@receiver(post_save, sender="payment.PaymentModel")
def payment_post_save(sender, instance, created, **kwargs):
    old_status = getattr(instance, "_old_payment_status", None)
    is_newly_completed = (
        instance.status == "completed"
        and (created or old_status != "completed")
    )
    if not is_newly_completed:
        return
    try:
        auto_eval = instance.valuation.auto_detail
    except (AttributeError, AutoEvaluationModel.DoesNotExist):
        return
    EvaluationHistoryService.log_auto(
        auto_evaluation=auto_eval,
        event_type=EvaluationEventType.PAYMENT_MADE,
        actor=instance.payer,
        meta={
            "amount": str(instance.amount),
            "payment_method": instance.payment_method,
            "transaction_id": instance.transaction_id or "",
        },
    )


# ─────────────────────────────────────────────────────────────────────────────
# QuickEvaluation — order_created va status_changed
# ─────────────────────────────────────────────────────────────────────────────

@receiver(pre_save, sender=QuickEvaluationModel)
def quick_eval_pre_save(sender, instance, **kwargs):
    if instance.pk:
        try:
            old = QuickEvaluationModel.objects.get(pk=instance.pk)
            instance._old_status = old.status
        except QuickEvaluationModel.DoesNotExist:
            instance._old_status = None
    else:
        instance._old_status = None


@receiver(post_save, sender=QuickEvaluationModel)
def quick_eval_post_save(sender, instance, created, **kwargs):
    if created:
        EvaluationHistoryService.log_quick(
            quick_evaluation=instance,
            event_type=EvaluationEventType.ORDER_CREATED,
            actor=instance.created_by,
        )
    else:
        old_status = getattr(instance, "_old_status", None)
        if old_status is not None and old_status != instance.status:
            status_labels = dict(QuickEvaluationStatus.choices)
            EvaluationHistoryService.log_quick(
                quick_evaluation=instance,
                event_type=EvaluationEventType.STATUS_CHANGED,
                meta={
                    "from_status": old_status,
                    "from_status_display": status_labels.get(old_status, old_status),
                    "to_status": instance.status,
                    "to_status_display": status_labels.get(instance.status, instance.status),
                },
            )