from django.db import models
import os

from django.utils.translation import gettext_lazy as _

from apps.account.models import StudentUser, User
from apps.course.models import Course
from phonenumber_field.modelfields import PhoneNumberField
from utils.validators import validate_possible_number


def receipt_file_upload_to(instance, filename):
    return os.path.join(f"receipts/{instance.transaction.id}/{filename}")


class TransactionParticipant(models.Model):  


    class TransactionStatus(models.TextChoices):
        PENDING = 'pending', _('Pending')
        WAITING_APPROVAL = 'waiting_approval', _('Waiting for Approval')
        SUCCESS = 'success', _('Success')
        FAILED = 'failed', _('Failed')

    class PaymentMethods(models.TextChoices):
        RECEIPT = 'receipt', _('Receipt')
        FREE = 'free', _('Free')
        PAYMENT_GATEWAY = 'Payment_Gateway', _('Payment Gateway')

    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='transactions', verbose_name=_('User'))
    course = models.ForeignKey(Course, on_delete=models.CASCADE, related_name='course_transactions', verbose_name=_('Course'))
    payment_method=models.CharField(max_length=20, choices=PaymentMethods.choices, default=PaymentMethods.PAYMENT_GATEWAY, verbose_name=_('Transaction Payment Method'))   
    # is_paid = models.BooleanField(default=False, verbose_name='Payment Status', help_text='Indicates whether the payment has been completed or not')
    price = models.DecimalField(max_digits=10, decimal_places=2, default=0.00, verbose_name=_('Transaction Price'))
    status = models.CharField(max_length=20, choices=TransactionStatus.choices, default=TransactionStatus.PENDING, verbose_name=_('Transaction Status'))
    created_at = models.DateTimeField(auto_now_add=True, verbose_name=_("Created at"))
    updated_at = models.DateTimeField(auto_now=True, verbose_name=_("Updated at"))
    is_deleted = models.BooleanField(default=False, verbose_name=_('Is Deleted'))

    def __str__(self):
        return f"{self.user.email} - {self.course.title} ({self.status})"
    
    def is_participant_enrolled(self):
        """بررسی اینکه آیا کاربر در دوره ثبت‌نام شده یا نه"""
        from apps.course.models import Participant
        return Participant.objects.filter(
            student=self.user, 
            course=self.course
        ).exists()
    
    def get_participant(self):
        """دریافت شرکت‌کننده دوره اگر وجود داشته باشد"""
        from apps.course.models import Participant
        return Participant.objects.filter(
            student=self.user, 
            course=self.course
        ).first()
    
    class Meta:
        verbose_name = _('Transaction Participant')
        verbose_name_plural = _('Transaction Participants')


class ParticipantInfo(models.Model):
    class GenderChoices(models.TextChoices):
        MALE = 'male', _('Male')
        FEMALE = 'female', _('Female')

    transaction_participant = models.ForeignKey(
        TransactionParticipant,
        on_delete=models.CASCADE,
        related_name='participant_infos',
        verbose_name=_("Transaction Participant")
    )
    fullname = models.CharField(max_length=255, verbose_name=_("Full Name"), help_text=_("Enter the full name of the user."))
    email = models.EmailField(verbose_name=_("Email Address"), help_text=_("Enter the user's email address."))
    phone_number = PhoneNumberField(validators=[validate_possible_number], null=True, blank=True, verbose_name=_('phone'))
    gender = models.CharField(
        max_length=20, choices=GenderChoices.choices, null=True, blank=True, verbose_name=_('Gender'), help_text=_("Select the user's gender.")
    )
    birthdate = models.DateField(verbose_name=_('birthdate'), null=True, blank=True)

    def __str__(self):
        return f"{self.fullname} (Transaction: {self.transaction_participant.id}) - {self.email}"

    class Meta:
        verbose_name = _('Participant Info')
        verbose_name_plural = _('Participant Infos')


class TransactionReceipt(models.Model):
    """
    Model for storing payment receipts uploaded by users for transactions
    """
    transaction = models.ForeignKey(
        TransactionParticipant,
        on_delete=models.CASCADE,
        related_name='receipts',
        verbose_name=_('Transaction')
    )
    file = models.FileField(
        upload_to=receipt_file_upload_to,
        verbose_name=_('Receipt File'),
        help_text=_('Upload payment receipt image or document')
    )
    uploaded_at = models.DateTimeField(auto_now_add=True, verbose_name=_('Uploaded At'))
    description = models.TextField(
        blank=True,
        null=True,
        verbose_name=_('Description'),
        help_text=_('Optional description or notes about the receipt')
    )

    class Meta:
        verbose_name = _('Transaction Receipt')
        verbose_name_plural = _('Transaction Receipts')
        ordering = ['-uploaded_at']

    def __str__(self):
        return f"Receipt for Transaction #{self.transaction.id} - {self.uploaded_at.strftime('%Y-%m-%d %H:%M')}"