from django.db import models
from django.contrib.auth.models import User
from django.db.models.signals import post_save
from django.dispatch import receiver
from django.utils.translation import gettext_lazy as _

class Profile(models.Model):
    ROLE_CHOICES = (
        ('SHIPPER', _('Shipper (Need Goods Moved)')),
        ('TRUCK_OWNER', _('Truck Owner (Service Provider)')),
        ('ADMIN', _('Administrator')),
    )
    user = models.OneToOneField(User, on_delete=models.CASCADE)
    role = models.CharField(max_length=20, choices=ROLE_CHOICES, default='SHIPPER')
    phone_number = models.CharField(max_length=20, blank=True)
    
    def __str__(self):
        return f"{self.user.username} - {self.role}"

class Truck(models.Model):
    owner = models.ForeignKey(User, on_delete=models.CASCADE, related_name='trucks')
    truck_type = models.CharField(_('Truck Type'), max_length=100)
    model = models.CharField(_('Model'), max_length=100)
    year = models.PositiveIntegerField(_('Year'))
    plate_no = models.CharField(_('Plate No'), max_length=50)
    load_capacity = models.CharField(_('Load Capacity'), max_length=100)
    color = models.CharField(_('Color'), max_length=50)
    
    # Pictures
    truck_picture = models.ImageField(_('Truck Picture'), upload_to='trucks/', blank=True, null=True)
    registration_front = models.ImageField(_('Registration Front'), upload_to='docs/', blank=True, null=True)
    registration_back = models.ImageField(_('Registration Back'), upload_to='docs/', blank=True, null=True)
    driver_license = models.ImageField(_('Driver License'), upload_to='docs/', blank=True, null=True)

    created_at = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return f"{self.truck_type} - {self.plate_no}"

class Shipment(models.Model):
    STATUS_CHOICES = (
        ('OPEN', _('Open for Bids')),
        ('IN_PROGRESS', _('In Progress')),
        ('COMPLETED', _('Completed')),
        ('CANCELLED', _('Cancelled')),
    )
    shipper = models.ForeignKey(User, on_delete=models.CASCADE, related_name='shipments')
    description = models.TextField(_('Goods Description'))
    weight = models.CharField(_('Weight/Volume'), max_length=100)
    origin = models.CharField(_('Origin'), max_length=255)
    destination = models.CharField(_('Destination'), max_length=255)
    delivery_date = models.DateField(_('Requested Delivery Date'))
    status = models.CharField(max_length=20, choices=STATUS_CHOICES, default='OPEN')
    
    assigned_truck = models.ForeignKey(Truck, on_delete=models.SET_NULL, null=True, blank=True, related_name='assigned_shipments')
    
    created_at = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return f"{self.origin} to {self.destination} - {self.status}"

class Bid(models.Model):
    STATUS_CHOICES = (
        ('PENDING', _('Pending')),
        ('ACCEPTED', _('Accepted')),
        ('REJECTED', _('Rejected')),
    )
    shipment = models.ForeignKey(Shipment, on_delete=models.CASCADE, related_name='bids')
    truck_owner = models.ForeignKey(User, on_delete=models.CASCADE, related_name='bids')
    truck = models.ForeignKey(Truck, on_delete=models.CASCADE)
    amount = models.DecimalField(_('Offer Amount'), max_digits=10, decimal_places=2)
    comments = models.TextField(_('Comments'), blank=True)
    status = models.CharField(max_length=20, choices=STATUS_CHOICES, default='PENDING')
    
    created_at = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return f"Bid by {self.truck_owner.username} for {self.shipment}"

class Message(models.Model):
    shipment = models.ForeignKey(Shipment, on_delete=models.CASCADE, related_name='messages')
    sender = models.ForeignKey(User, on_delete=models.CASCADE, related_name='sent_messages')
    content = models.TextField()
    timestamp = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return f"From {self.sender.username} at {self.timestamp}"

@receiver(post_save, sender=User)
def create_user_profile(sender, instance, created, **kwargs):
    if created:
        Profile.objects.create(user=instance)

@receiver(post_save, sender=User)
def save_user_profile(sender, instance, **kwargs):
    if hasattr(instance, 'profile'):
        instance.profile.save()
    else:
        Profile.objects.create(user=instance)