from django.db import models
from rems.models.Task import Task

class Project(models.Model):
id = models.IntegerField('id', primary_key=True)
name = models.CharField('name', max_length=45, unique=False)
code = models.CharField('code', unique=True, max_length=8)
description = models.CharField('description', max_length=255)
created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now=True)

class Meta:
    db_table = 'project'
    verbose_name = 'project'
    verbose_name_plural = 'projects'
    ordering = ('-code',)

def natural_key(self):
    return self.id

def project_get_tree(self):
    children_tree = self.get_children_tree()

    returned_data = {
        "id": self.id,
        "name": self.name,
        "code": self.code,
        "description": self.description,
        "tasks": children_tree
    }

    return returned_data

def get_children_tree(self):
    task_collection = Task.objects.filter(project_id=self.id)
    returned_array = []
    if len(task_collection) > 0:
        for child in task_collection:
            returned_array.append(child.get_tree())
    return returned_array

@staticmethod
def get_object(id):
    try:
        return Project.objects.get(id=id)
    except Project.DoesNotExist:
        return False

def can_be_deleted(self):
    children_count = Task.objects.filter(project_id=self.id).count()
    if children_count > 0:
        return False
    return True

from rest_framework import serializers
from rems.models.Project import Project
from rest_framework.validators import UniqueValidator

class ProjectSerializer(serializers.HyperlinkedModelSerializer):
    id = serializers.IntegerField(read_only=True)
    name = serializers.CharField(required=True, min_length=1, max_length=45)
    code = serializers.CharField(required=True, min_length=1, max_length=8,
                             validators=[UniqueValidator(queryset=Project.objects.all())])
 description = serializers.CharField(required=False, min_length=1, max_length=255)

class Meta:
    model = Project
    fields = ('id', 'code', 'name', 'description')