from django.db import models
from django.contrib.auth.models import User

class Company(models.Model):
    name = models.CharField(max_length=255)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    def __str__(self):
        return self.name

class Membership(models.Model):
    ROLE_CHOICES = [
        ('owner', 'Owner'),
        ('admin', 'Admin'),
        ('member', 'Member'),
    ]
    user = models.ForeignKey(User, on_delete=models.CASCADE)
    company = models.ForeignKey(Company, on_delete=models.CASCADE)
    role = models.CharField(max_length=20, choices=ROLE_CHOICES)

    def __str__(self):
        return f"{self.user.username} - {self.company.name} ({self.role})"

class Tender(models.Model):
    company = models.ForeignKey(Company, on_delete=models.CASCADE)
    title = models.CharField(max_length=255)
    description = models.TextField()
    deadline = models.DateTimeField()
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    def __str__(self):
        return self.title

class Bid(models.Model):
    tender = models.ForeignKey(Tender, on_delete=models.CASCADE)
    company = models.ForeignKey(Company, on_delete=models.CASCADE)
    amount = models.DecimalField(max_digits=10, decimal_places=2)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    def __str__(self):
        return f"Bid for {self.tender.title} by {self.company.name}"

class Document(models.Model):
    tender = models.ForeignKey(Tender, on_delete=models.CASCADE, null=True, blank=True)
    bid = models.ForeignKey(Bid, on_delete=models.CASCADE, null=True, blank=True)
    uploaded_by = models.ForeignKey(User, on_delete=models.CASCADE, null=True)
    file = models.FileField(upload_to='documents/')
    description = models.TextField(blank=True)
    uploaded_at = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return self.file.name

class Note(models.Model):
    tender = models.ForeignKey(Tender, on_delete=models.CASCADE)
    user = models.ForeignKey(User, on_delete=models.CASCADE)
    note = models.TextField()
    created_at = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return f"Note on {self.tender.title} by {self.user.username}"

class Approval(models.Model):
    STATUS_CHOICES = [
        ('pending', 'Pending'),
        ('approved', 'Approved'),
        ('rejected', 'Rejected'),
    ]
    bid = models.ForeignKey(Bid, on_delete=models.CASCADE)
    approver = models.ForeignKey(User, on_delete=models.CASCADE)
    status = models.CharField(max_length=20, choices=STATUS_CHOICES, default='pending')
    comments = models.TextField(blank=True)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    def __str__(self):
        return f"Approval for {self.bid} by {self.approver.username}"