import os
import hashlib
import mimetypes

from django import forms
from django.core.files.storage import default_storage
from django.core.exceptions import ValidationError

from university.file_storage.utils import generate_random_file_path
from university.models import Upload, User


class UploadFileForm(forms.Form):

    file = forms.FileField()

    def __init__(self, user, *args, **kwargs):
        self.user = user
        return super(UploadFileForm, self).__init__(*args, **kwargs)

    def save(self):
        file_obj = self.cleaned_data['file']
        content_hash = hashlib.sha1(file_obj.read()).hexdigest()
        content_type, _ = mimetypes.guess_type(file_obj.name, strict=False)
        file_path = generate_random_file_path()
        _, file_extension = os.path.splitext(file_obj.name)
        if file_extension:
            file_path += file_extension
        file_obj.seek(0)
        default_storage.save(file_path, file_obj)
        return Upload.objects.create(
            user=self.user,
            original_filename=file_obj.name,
            filesize=file_obj.size,
            path=file_path,
            sha1=content_hash,
            extension=content_type
        )


class UploadFaceIDImageForm(forms.Form):

    file = forms.ImageField()

    def __init__(self, user, *args, **kwargs):
        self.user = user if user.is_authenticated else None
        return super(UploadFaceIDImageForm, self).__init__(*args, **kwargs)

    def clean_file(self):
        file = self.cleaned_data.get('file')
        if file:
            try:
                file._size
            except Exception:
                pass
            else:
                if file._size > 3 * 1 << 20:
                    raise ValidationError('文件大小超过限制')
            if self.user.face_audit_status not in (
                    User.FACE_AUDIT_NO_IMAGE, User.FACE_AUDIT_FAILED):
                raise ValidationError('当前状态不允许上传图片')
        return file

    def save(self):
        file_obj = self.cleaned_data.get('file')
        if file_obj:
            content_hash = hashlib.sha1(file_obj.read()).hexdigest()
            content_type, _ = mimetypes.guess_type(file_obj.name, strict=False)
            file_path = self.generate_filepath_by_hash(content_hash)
            _, file_extension = os.path.splitext(file_obj.name)
            if file_extension:
                file_path += file_extension
            file_obj.seek(0)
            file_path = default_storage.save(file_path, file_obj)
            return Upload.objects.create(
                user=self.user,
                original_filename=file_obj.name,
                filesize=file_obj.size,
                width=file_obj.image.width,
                height=file_obj.image.height,
                path=file_path,
                sha1=content_hash,
                extension=content_type,
                is_private=True
            )

    def generate_filepath_by_hash(self, file_hash):
        return '{}/{}/{}'.format(
            file_hash[0],
            file_hash[1],
            file_hash
        )