from django import forms
from .models import Profile, Course, Workshop
from string import punctuation, digits
try:
    from string import letters
except:
    from string import ascii_letters as letters

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



UNAME_CHARS = letters + "._" + digits
PWD_CHARS = letters + punctuation + digits

position_choices = (
    ("coordinator", "Coordinator"),
    ("instructor", "Instructor")
    )

class UserRegistrationForm(forms.Form):
    """A Class to create new form for User's Registration.
    It has the various fields and functions required to register
    a new user to the system"""

    username = forms.CharField(max_length=32, help_text='''Letters, digits,
                               period only.''')
    email = forms.EmailField()
    password = forms.CharField(max_length=32, widget=forms.PasswordInput())
    confirm_password = forms.CharField\
                       (max_length=32, widget=forms.PasswordInput())
    first_name = forms.CharField(max_length=32)
    last_name = forms.CharField(max_length=32)
    phone_number = forms.RegexField(regex=r'^\+?1?\d{9,15}$', 
                                error_message=("Phone number must be entered \
                                                  in the format: '+999999999'.\
                                                 Up to 15 digits allowed."))
    institute = forms.CharField(max_length=128, 
                help_text='Institute/Organization')
    department = forms.CharField(max_length=64, help_text='Department you work \
                                    study at')
    position = forms.ChoiceField(help_text='Instructors, please wait \
                                for our admin approval, if your instructor \
                                account is not activated in 7 days, please\
                                mail us at python[at]fossee[dot]in',
                                choices=position_choices
                                 )

    def clean_username(self):
        u_name = self.cleaned_data["username"]
        if u_name.strip(UNAME_CHARS):
            msg = "Only letters, digits, period  are"\
                  " allowed in username"
            raise forms.ValidationError(msg)
        try:
            User.objects.get(username__exact=u_name)
            raise forms.ValidationError("Username already exists.")
        except User.DoesNotExist:
            return u_name

    def clean_password(self):
        pwd = self.cleaned_data['password']
        if pwd.strip(PWD_CHARS):
            raise forms.ValidationError("Only letters, digits and punctuation\
                                        are allowed in password")
        return pwd

    def clean_confirm_password(self):
        c_pwd = self.cleaned_data['confirm_password']
        pwd = self.data['password']
        if c_pwd != pwd:
            raise forms.ValidationError("Passwords do not match")

        return c_pwd

    def save(self):
        u_name = self.cleaned_data["username"]
        u_name = u_name.lower()
        pwd = self.cleaned_data["password"]
        email = self.cleaned_data["email"]
        new_user = User.objects.create_user(u_name, email, pwd)
        new_user.first_name = self.cleaned_data["first_name"]
        new_user.last_name = self.cleaned_data["last_name"]
        new_user.save()

        cleaned_data = self.cleaned_data
        new_profile = Profile(user=new_user)
        new_profile.institute = cleaned_data["institute"]
        new_profile.department = cleaned_data["department"]
        new_profile.position = cleaned_data["position"]
        new_profile.phone_number = cleaned_data["phone_number"]
        new_profile.save()

        return u_name, pwd

class UserLoginForm(forms.Form):
    """Creates a form which will allow the user to log into the system."""

    username = forms.CharField(max_length=32)
    password = forms.CharField(max_length=32, widget=forms.PasswordInput())

    def clean(self):
        super(UserLoginForm, self).clean()
        try:
            u_name, pwd = self.cleaned_data["username"],\
                          self.cleaned_data["password"]
            user = authenticate(username=u_name, password=pwd)
        except Exception:
            raise forms.ValidationError\
                        ("Username and/or Password is not entered")
        if not user:
            raise forms.ValidationError("Invalid username/password")
        return user

class ProfileForm(forms.ModelForm):
    """ profile form for coordinator and instructor """

    class Meta:
        model = Profile
        fields = ['first_name', 'last_name', 'institute', 'department',
                 'position']

    first_name = forms.CharField(max_length=32)
    last_name = forms.CharField(max_length=32)

    def __init__(self, *args, **kwargs):
        if 'user' in kwargs:
            user = kwargs.pop('user')
        super(ProfileForm, self).__init__(*args, **kwargs)
        self.fields['first_name'].initial = user.first_name
        self.fields['last_name'].initial = user.last_name

class CreateWorkshop(forms.ModelForm):
    """Instructors can create Workshops based on the courses available."""

    def __init__( self, *args, **kwargs ):
        super(CreateWorkshop, self).__init__( *args, **kwargs )
        self.fields['recurrences'].label = " " #the trick to hide field :)

    class Meta:
        model = Workshop
        fields = ['workshop_title', 'recurrences']