import os
import secrets
import shutil
import mimetypes
import re
from urllib.parse import urlparse

from django.conf import settings
from django.core.files import File
from django.http import HttpRequest
from django.core.mail import send_mail

from rest_framework import serializers, status
from rest_framework.generics import GenericAPIView
from rest_framework.parsers import MultiPartParser, FormParser
from rest_framework.response import Response
from unidecode import unidecode
from django.utils.text import slugify
import random
import string

from django.conf import settings

from django.utils.translation import gettext_lazy as _

from cachetools.func import lru_cache
from django.http import HttpRequest
from django.contrib import admin

# Moved filer imports to avoid circular imports
# These will be imported when needed in functions

@lru_cache
def qs_thumbs():
    from filer.models import ThumbnailOption
    return ThumbnailOption.objects.all()


def get_thumbs(obj, request: HttpRequest = None) -> dict:
    # print(f'----> {obj}')
    if not obj:
        return {}

    try:
        # تعریف سه سایز ثابت
        sizes = ['sm', 'md', 'lg']
        thumbnail_object = {}
        
        # گرفتن URL اصلی تصویر
        if hasattr(obj, 'url'):
            original_url = obj.url
        else:
            return {}
        
        # برای هر سه سایز، همان URL اصلی را برگردان
        for size in sizes:
            if request:
                url = request.build_absolute_uri(original_url)
            else:
                url = original_url
            
            thumbnail_object[size] = url

        return thumbnail_object

    except Exception as p:
        print(p)
        return {}


def environment_callback(request):
    if settings.DEBUG:
        return [_("Development"), "primary"]

    return [_("Production"), "primary"]



def send_email(recipient, code):
    send_mail(
        'Test Email',
        f'This is a test email {code} from Django using Gmail SMTP.',
        'aliabdolahi.171@gmail.com', 
        recipient,  
        fail_silently=False,
    )    
    return True


def is_valid_email(email):
    # تعریف الگوی regex برای یک ایمیل معتبر
    email_regex = r'^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$'
    
    # بررسی اینکه آیا ایمیل با regex مطابقت دارد یا خیر
    if re.match(email_regex, email):
        return True
    return False


def generate_slug_for_model(model, value: str, recycled_count: int = 0):
    from slugify import slugify
    try:

        base_slug = slugify(unidecode(value))
        slug = base_slug
        if recycled_count > 0:
            slug = f"{base_slug}-{recycled_count}"
    
        if model.objects.filter(slug=slug).exists():
            return generate_slug_for_model(model, value, recycled_count + 1)
    
        return slug[:50]
    except Exception as exp:
        letters = string.ascii_lowercase
        result_str = ''.join(random.choice(letters) for i in range(8))
        return result_str


def generate_slugen_for_model(model, value_en, value_pk):
    try:
        unique_slug = value_en
        if not value_pk or not value_en:
            base_slug = slugify(unidecode(value_en))
            unique_slug = base_slug
            num = 1
            while model.objects.filter(slug=unique_slug).exists():
                unique_slug = f"{base_slug}-{num}"
                num += 1
                
        return unique_slug
    except Exception as exp:
        letters = string.ascii_lowercase
        result_str = ''.join(random.choice(letters) for i in range(8))
        return result_str


def exclude_host_from_url(url):
    # Parse the URL
    parsed_url = urlparse(url)

    # Extract the path and query parameters
    path_with_query = parsed_url.path + parsed_url.query

    return path_with_query


def generate_slug_for_model(model, value: str, recycled_count: int = 0):
    from slugify import slugify

    slug = slugify(value)
    if model.objects.filter(slug=slug).exists():
        recycled_count += 1
        if value.endswith(f'-{recycled_count - 1}'):
            value = value.replace(f'-{recycled_count - 1}', f'-{recycled_count}')
        else:
            value = f"{value}-{recycled_count}"
        return generate_slug_for_model(model, value, recycled_count)

    return slug[:50]


def generate_language_slugs(translations):
    """
    Build a list of {language_code, title} where title is a slugified string
    from provided multilingual translations list.
    Expected input shape:
      - list[dict]: [{'language_code': 'fa', 'title': 'متن'}, ...]
    Fallback keys supported: code/lang/language for language, value/text for content.
    """
    try:
        result = []
        if isinstance(translations, list):
            for tr in translations:
                if isinstance(tr, dict):
                    language_code = tr.get('language_code') or tr.get('code') or tr.get('lang') or tr.get('language')
                    text = tr.get('title') or tr.get('text') or tr.get('value')
                    if language_code and text:
                        slug_text = slugify(text, allow_unicode=True)
                        result.append({'language_code': str(language_code), 'title': slug_text})
        return result
    except Exception as e:
        print(f"Error generating slugs: {e}")
        return []

def absolute_url(req, url):
    """
        can either be a file instance or a URL string
    """
    try:
        return req.build_absolute_uri(url.url if hasattr(url, 'url') else url)
    except Exception:
        return None

def sizeof_fmt(num, suffix="B"):
    for unit in ["", "K", "M", "G"]:
        if abs(num) < 1024.0:
            return f"{num:3.1f} {unit}{suffix}"
        num /= 1024.0
    return f"{num:.1f} Yi{suffix}"


def file_location(path):
    from django.conf import settings
    import os

    if path.startswith('http'):
        path = exclude_host_from_url(path)

    if path.startswith("/static"):
        path = path[7:]

    if path.startswith('/'):
        path = path[1:]

    return os.path.join(settings.STATIC_ROOT, path)


def guess_file_type(filename):
    try:
        mimetype = mimetypes.guess_type(filename)[0].split('/')[0]
        return mimetype

    except Exception:
        return False

class FileFieldSerializer(serializers.CharField):
    """
        a field to handle uploaded file
    """

    def get_rpath(self, p):
        # extract relative path of doc
        return p[p.find('/static/') + 7:]

    def to_representation(self, value):
        request = self.context.get('request', None)
        if value:
            if isinstance(value, str):
                # If value is a string, assume it's a file path
                return value
            elif hasattr(value, 'url'):
                if 'http://' in str(value) or 'https://' in str(value):
                    return str(value)

                return absolute_url(request, value.url) if request else value.url
        return None

    def to_internal_value(self, data):
        if not data:
            return None

        if "/tmp/" not in data:
            # value not changed and here we simply return old file path
            return self.get_rpath(data)

        if data.startswith('http'):
            data = self.get_rpath(data)
            
        fpath = file_location(data)
        if not os.path.exists(fpath):
            raise serializers.ValidationError(f"File: '{fpath}' Does not exist")

        return File(open(fpath, 'rb'), os.path.basename(data))


class UploadChatMediaSerializer(serializers.Serializer):
    """Upload files permanently to /media/chat/"""
    file = serializers.FileField()
    url = serializers.URLField(read_only=True)
    name = serializers.CharField(read_only=True)
    size = serializers.CharField(read_only=True)
    mime_type = serializers.CharField(read_only=True)
    thumbnail_url = serializers.URLField(read_only=True, required=False)

    def to_representation(self, instance):
        data = super(UploadChatMediaSerializer, self).to_representation(instance)
        data['file'] = instance['file']
        return data

    def store_file(self, file):
        from django.conf import settings
        from utils.image_utils import (
            create_thumbnail, 
            is_image_file, 
            is_video_file, 
            extract_video_thumbnail
        )
        media_path = settings.MEDIA_ROOT

        os.makedirs(f'{media_path}/chat/uploads', exist_ok=True)
        fpath = f"/chat/uploads/{secrets.token_urlsafe(4)}-{file.name}"
        full_path = media_path + fpath
        shutil.move(file.temporary_file_path(), full_path)
        os.chmod(full_path, 0o644)

        result = {
            'file': fpath,
            'url': absolute_url(self.context['request'], f"/media{fpath}"),
            'name': file.name,
            'size': sizeof_fmt(file.size),
            'mime_type': guess_file_type(fpath)
        }

        # Generate thumbnail if file is an image (low quality for preview)
        if is_image_file(full_path):
            try:
                thumbnail_path = create_thumbnail(full_path, size=(200, 200), quality=60)
                thumbnail_relative = thumbnail_path.replace(media_path, '')
                result['thumbnail_url'] = absolute_url(
                    self.context['request'], 
                    f"/media{thumbnail_relative}"
                )
            except Exception as e:
                print(f"Failed to generate image thumbnail: {e}")
                result['thumbnail_url'] = None
        # Generate thumbnail if file is a video (low quality for preview)
        elif is_video_file(full_path):
            try:
                thumbnail_path = extract_video_thumbnail(
                    full_path, 
                    time_offset='00:00:01',
                    size=(200, 200), 
                    quality=60
                )
                thumbnail_relative = thumbnail_path.replace(media_path, '')
                result['thumbnail_url'] = absolute_url(
                    self.context['request'], 
                    f"/media{thumbnail_relative}"
                )
            except Exception as e:
                print(f"Failed to generate video thumbnail: {e}")
                result['thumbnail_url'] = None
        else:
            result['thumbnail_url'] = None

        return result

    def validate(self, attrs):
        file_details = self.store_file(attrs['file'])
        return file_details


class UploadTmpSerializer(serializers.Serializer):
    file = serializers.FileField()
    url = serializers.URLField(read_only=True)
    name = serializers.CharField(read_only=True)
    size = serializers.CharField(read_only=True)
    mime_type = serializers.CharField(read_only=True)
    thumbnail_url = serializers.URLField(read_only=True, required=False)

    def to_representation(self, instance):
        data = super(UploadTmpSerializer, self).to_representation(instance)
        data['file'] = instance['file']
        return data

    def store_file(self, file):
        from django.conf import settings
        from utils.image_utils import (
            create_thumbnail, 
            is_image_file, 
            is_video_file, 
            extract_video_thumbnail
        )
        static_path = settings.STATIC_ROOT

        os.makedirs(f'{static_path}/tmp', exist_ok=True)
        fpath = f"/tmp/{secrets.token_urlsafe(4)}-{file.name}"
        full_path = static_path + fpath
        shutil.move(file.temporary_file_path(), full_path)
        os.chmod(full_path, 0o644)

        result = {
            'file': fpath,
            'url': absolute_url(self.context['request'], f"/static{fpath}"),
            'name': file.name,
            'size': sizeof_fmt(file.size),
            'mime_type': guess_file_type(fpath)
        }

        # Generate thumbnail if file is an image (low quality for preview)
        if is_image_file(full_path):
            try:
                thumbnail_path = create_thumbnail(full_path, size=(200, 200), quality=60)
                thumbnail_relative = thumbnail_path.replace(static_path, '')
                result['thumbnail_url'] = absolute_url(
                    self.context['request'], 
                    f"/static{thumbnail_relative}"
                )
            except Exception as e:
                print(f"Failed to generate image thumbnail: {e}")
                result['thumbnail_url'] = None
        # Generate thumbnail if file is a video (low quality for preview)
        elif is_video_file(full_path):
            try:
                thumbnail_path = extract_video_thumbnail(
                    full_path, 
                    time_offset='00:00:01',
                    size=(200, 200), 
                    quality=60
                )
                thumbnail_relative = thumbnail_path.replace(static_path, '')
                result['thumbnail_url'] = absolute_url(
                    self.context['request'], 
                    f"/static{thumbnail_relative}"
                )
            except Exception as e:
                print(f"Failed to generate video thumbnail: {e}")
                result['thumbnail_url'] = None
        else:
            result['thumbnail_url'] = None

        return result

    def validate(self, attrs):
        file_details = self.store_file(attrs['file'])
        return file_details


class UploadChatMedia(GenericAPIView):
    """
    Upload files permanently to /media/chat/
    Files are stored permanently and will NOT be removed
    """
    parser_classes = (FormParser, MultiPartParser)
    serializer_class = UploadChatMediaSerializer

    def post(self, request: HttpRequest, *args, **kwargs):
        serializer = UploadChatMediaSerializer(data=request.FILES, context={'request': request})
        is_valid = serializer.is_valid(raise_exception=True)
        if not is_valid:
            return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

        return Response(serializer.data)


class UploadTmpMedia(GenericAPIView):
    """
    Upload files temporarily to /static/tmp/
    Files will be removed every 1 hour
    """
    parser_classes = (FormParser, MultiPartParser)
    serializer_class = UploadTmpSerializer

    def post(self, request: HttpRequest, *args, **kwargs):
        serializer = UploadTmpSerializer(data=request.FILES, context={'request': request})
        is_valid = serializer.is_valid(raise_exception=True)
        if not is_valid:
            return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

        return Response(serializer.data)

# Configure filer admin after Django is fully loaded
def configure_filer_admin():
    try:
        from filer.admin.fileadmin import FileAdmin
        from filer.apps import FilerConfig

        FileAdmin.readonly_fields += ('owner',)
        FilerConfig.icon = 'icon-folder'
    except ImportError:
        pass

# This will be executed when this module is imported after Django is fully loaded