from django import forms
from django.contrib.auth import get_user_model, password_validation
from django.contrib.auth.forms import AuthenticationForm, UserCreationForm
from django.core.exceptions import ValidationError
from django.forms import widgets
from django.utils.translation import gettext_lazy as _
from . import utils
from .models import BlogUser


# ------------------------- 登录表单 -------------------------
class LoginForm(AuthenticationForm):
    """登录表单类（继承 Django 内置 AuthenticationForm）"""

    def __init__(self, *args, **kwargs):
        super(LoginForm, self).__init__(*args, **kwargs)
        # 自定义输入框样式
        self.fields['username'].widget = widgets.TextInput(
            attrs={'placeholder': "username", "class": "form-control"})
        self.fields['password'].widget = widgets.PasswordInput(
            attrs={'placeholder': "password", "class": "form-control"})


# ------------------------- 注册表单 -------------------------
class RegisterForm(UserCreationForm):
    """用户注册表单（继承 Django 自带 UserCreationForm）"""

    def __init__(self, *args, **kwargs):
        super(RegisterForm, self).__init__(*args, **kwargs)
        # 为每个字段自定义前端样式与提示文本
        self.fields['username'].widget = widgets.TextInput(
            attrs={'placeholder': "username", "class": "form-control"})
        self.fields['email'].widget = widgets.EmailInput(
            attrs={'placeholder': "email", "class": "form-control"})
        self.fields['password1'].widget = widgets.PasswordInput(
            attrs={'placeholder': "password", "class": "form-control"})
        self.fields['password2'].widget = widgets.PasswordInput(
            attrs={'placeholder': "repeat password", "class": "form-control"})

    def clean_email(self):
        """检查邮箱是否已被注册"""
        email = self.cleaned_data['email']
        if get_user_model().objects.filter(email=email).exists():
            raise ValidationError(_("email already exists"))  # 抛出重复邮箱异常
        return email

    class Meta:
        """指定绑定的模型和表单字段"""
        model = get_user_model()
        fields = ("username", "email")


# ------------------------- 忘记密码表单 -------------------------
class ForgetPasswordForm(forms.Form):
    """用户通过邮箱重置密码的表单"""

    # 新密码输入
    new_password1 = forms.CharField(
        label=_("New password"),
        widget=forms.PasswordInput(
            attrs={
                "class": "form-control",
                'placeholder': _("New password")
            }
        ),
    )

    # 新密码确认输入
    new_password2 = forms.CharField(
        label="确认密码",
        widget=forms.PasswordInput(
            attrs={
                "class": "form-control",
                'placeholder': _("Confirm password")
            }
        ),
    )

    # 邮箱输入
    email = forms.EmailField(
        label='邮箱',
        widget=forms.TextInput(
            attrs={
                'class': 'form-control',
                'placeholder': _("Email")
            }
        ),
    )

    # 验证码输入
    code = forms.CharField(
        label=_('Code'),
        widget=forms.TextInput(
            attrs={
                'class': 'form-control',
                'placeholder': _("Code")
            }
        ),
    )

    # ----------- 字段验证逻辑 -----------
    def clean_new_password2(self):
        """验证两次输入的新密码是否一致，并校验密码强度"""
        password1 = self.data.get("new_password1")
        password2 = self.data.get("new_password2")
        if password1 and password2 and password1 != password2:
            raise ValidationError(_("passwords do not match"))  # 两次密码不一致
        password_validation.validate_password(password2)  # 使用Django内置规则验证密码强度
        return password2

    def clean_email(self):
        """验证邮箱是否存在于数据库"""
        user_email = self.cleaned_data.get("email")
        if not BlogUser.objects.filter(email=user_email).exists():
            # 这里可以根据项目安全策略决定是否提示“邮箱不存在”
            raise ValidationError(_("email does not exist"))
        return user_email

    def clean_code(self):
        """验证邮箱验证码是否正确或过期"""
        code = self.cleaned_data.get("code")
        error = utils.verify(
            email=self.cleaned_data.get("email"),
            code=code,
        )
        if error:  # utils.verify 返回错误信息时表示验证失败
            raise ValidationError(error)
        return code


# ------------------------- 验证码邮箱发送表单 -------------------------
class ForgetPasswordCodeForm(forms.Form):
    """发送邮箱验证码表单，仅校验邮箱格式"""
    email = forms.EmailField(
        label=_('Email'),
    )