import binascii
import hashlib
import logging
import os
from typing import List

from django import forms
from django.conf import settings
from django.contrib.auth.models import User
from django.core.validators import MinValueValidator
from django.db import models
from django.db.models.signals import post_save, post_delete
from django.dispatch import receiver
from django.http import QueryDict

from bookmarks.utils import unique
from bookmarks.validators import BookmarkURLValidator

logger = logging.getLogger(__name__)


class Tag(models.Model):
    name = models.CharField(max_length=64)
    date_added = models.DateTimeField()
    owner = models.ForeignKey(User, on_delete=models.CASCADE)

    def __str__(self):
        return self.name


def sanitize_tag_name(tag_name: str):
    # strip leading/trailing spaces
    # replace inner spaces with replacement char
    return tag_name.strip().replace(" ", "-")


def parse_tag_string(tag_string: str, delimiter: str = ","):
    if not tag_string:
        return []
    names = tag_string.strip().split(delimiter)
    # remove empty names, sanitize remaining names
    names = [sanitize_tag_name(name) for name in names if name]
    # remove duplicates
    names = unique(names, str.lower)
    names.sort(key=str.lower)

    return names


def build_tag_string(tag_names: List[str], delimiter: str = ","):
    return delimiter.join(tag_names)


class Bookmark(models.Model):
    url = models.CharField(max_length=2048, validators=[BookmarkURLValidator()])
    title = models.CharField(max_length=512, blank=True)
    description = models.TextField(blank=True)
    notes = models.TextField(blank=True)
    # Obsolete field, kept to not remove column when generating migrations
    website_title = models.CharField(max_length=512, blank=True, null=True)
    # Obsolete field, kept to not remove column when generating migrations
    website_description = models.TextField(blank=True, null=True)
    web_archive_snapshot_url = models.CharField(max_length=2048, blank=True)
    favicon_file = models.CharField(max_length=512, blank=True)
    preview_image_file = models.CharField(max_length=512, blank=True)
    unread = models.BooleanField(default=False)
    is_archived = models.BooleanField(default=False)
    shared = models.BooleanField(default=False)
    date_added = models.DateTimeField()
    date_modified = models.DateTimeField()
    date_accessed = models.DateTimeField(blank=True, null=True)
    owner = models.ForeignKey(User, on_delete=models.CASCADE)
    tags = models.ManyToManyField(Tag)

    @property
    def resolved_title(self):
        if self.title:
            return self.title
        else:
            return self.url

    @property
    def resolved_description(self):
        return self.description

    @property
    def tag_names(self):
        names = [tag.name for tag in self.tags.all()]
        return sorted(names)

    def __str__(self):
        return self.resolved_title + " (" + self.url[:30] + "...)"


@receiver(post_delete, sender=Bookmark)
def bookmark_deleted(sender, instance, **kwargs):
    if instance.preview_image_file:
        filepath = os.path.join(settings.LD_PREVIEW_FOLDER, instance.preview_image_file)
        if os.path.isfile(filepath):
            try:
                os.remove(filepath)
            except Exception as error:
                logger.error(
                    f"Failed to delete preview image: {filepath}", exc_info=error
                )


class BookmarkAsset(models.Model):
    TYPE_SNAPSHOT = "snapshot"
    TYPE_UPLOAD = "upload"

    CONTENT_TYPE_HTML = "text/html"

    STATUS_PENDING = "pending"
    STATUS_COMPLETE = "complete"
    STATUS_FAILURE = "failure"

    bookmark = models.ForeignKey(Bookmark, on_delete=models.CASCADE)
    date_created = models.DateTimeField(auto_now_add=True, null=False)
    file = models.CharField(max_length=2048, blank=True, null=False)
    file_size = models.IntegerField(null=True)
    asset_type = models.CharField(max_length=64, blank=False, null=False)
    content_type = models.CharField(max_length=128, blank=False, null=False)
    display_name = models.CharField(max_length=2048, blank=True, null=False)
    status = models.CharField(max_length=64, blank=False, null=False)
    gzip = models.BooleanField(default=False, null=False)

    def save(self, *args, **kwargs):
        if self.file:
            try:
                file_path = os.path.join(settings.LD_ASSET_FOLDER, self.file)
                if os.path.isfile(file_path):
                    self.file_size = os.path.getsize(file_path)
            except Exception:
                pass
        super().save(*args, **kwargs)

    def __str__(self):
        return self.display_name or f"Bookmark Asset #{self.pk}"


@receiver(post_delete, sender=BookmarkAsset)
def bookmark_asset_deleted(sender, instance, **kwargs):
    if instance.file:
        filepath = os.path.join(settings.LD_ASSET_FOLDER, instance.file)
        if os.path.isfile(filepath):
            try:
                os.remove(filepath)
            except Exception as error:
                logger.error(f"Failed to delete asset file: {filepath}", exc_info=error)


class BookmarkSearch:
    SORT_ADDED_ASC = "added_asc"
    SORT_ADDED_DESC = "added_desc"
    SORT_TITLE_ASC = "title_asc"
    SORT_TITLE_DESC = "title_desc"

    FILTER_SHARED_OFF = "off"
    FILTER_SHARED_SHARED = "yes"
    FILTER_SHARED_UNSHARED = "no"

    FILTER_UNREAD_OFF = "off"
    FILTER_UNREAD_YES = "yes"
    FILTER_UNREAD_NO = "no"

    params = ["q", "user", "sort", "shared", "unread"]
    preferences = ["sort", "shared", "unread"]
    defaults = {
        "q": "",
        "user": "",
        "sort": SORT_ADDED_DESC,
        "shared": FILTER_SHARED_OFF,
        "unread": FILTER_UNREAD_OFF,
    }

    def __init__(
        self,
        q: str = None,
        user: str = None,
        sort: str = None,
        shared: str = None,
        unread: str = None,
        preferences: dict = None,
    ):
        if not preferences:
            preferences = {}
        self.defaults = {**BookmarkSearch.defaults, **preferences}

        self.q = q or self.defaults["q"]
        self.user = user or self.defaults["user"]
        self.sort = sort or self.defaults["sort"]
        self.shared = shared or self.defaults["shared"]
        self.unread = unread or self.defaults["unread"]

    def is_modified(self, param):
        value = self.__dict__[param]
        return value != self.defaults[param]

    @property
    def modified_params(self):
        return [field for field in self.params if self.is_modified(field)]

    @property
    def modified_preferences(self):
        return [
            preference
            for preference in self.preferences
            if self.is_modified(preference)
        ]

    @property
    def has_modifications(self):
        return len(self.modified_params) > 0

    @property
    def has_modified_preferences(self):
        return len(self.modified_preferences) > 0

    @property
    def query_params(self):
        return {param: self.__dict__[param] for param in self.modified_params}

    @property
    def preferences_dict(self):
        return {
            preference: self.__dict__[preference] for preference in self.preferences
        }

    @staticmethod
    def from_request(query_dict: QueryDict, preferences: dict = None):
        initial_values = {}
        for param in BookmarkSearch.params:
            value = query_dict.get(param)
            if value:
                initial_values[param] = value

        return BookmarkSearch(**initial_values, preferences=preferences)


class BookmarkSearchForm(forms.Form):
    SORT_CHOICES = [
        (BookmarkSearch.SORT_ADDED_ASC, "Added ↑"),
        (BookmarkSearch.SORT_ADDED_DESC, "Added ↓"),
        (BookmarkSearch.SORT_TITLE_ASC, "Title ↑"),
        (BookmarkSearch.SORT_TITLE_DESC, "Title ↓"),
    ]
    FILTER_SHARED_CHOICES = [
        (BookmarkSearch.FILTER_SHARED_OFF, "Off"),
        (BookmarkSearch.FILTER_SHARED_SHARED, "Shared"),
        (BookmarkSearch.FILTER_SHARED_UNSHARED, "Unshared"),
    ]
    FILTER_UNREAD_CHOICES = [
        (BookmarkSearch.FILTER_UNREAD_OFF, "Off"),
        (BookmarkSearch.FILTER_UNREAD_YES, "Unread"),
        (BookmarkSearch.FILTER_UNREAD_NO, "Read"),
    ]

    q = forms.CharField()
    user = forms.ChoiceField(required=False)
    sort = forms.ChoiceField(choices=SORT_CHOICES)
    shared = forms.ChoiceField(choices=FILTER_SHARED_CHOICES, widget=forms.RadioSelect)
    unread = forms.ChoiceField(choices=FILTER_UNREAD_CHOICES, widget=forms.RadioSelect)

    def __init__(
        self,
        search: BookmarkSearch,
        editable_fields: List[str] = None,
        users: List[User] = None,
    ):
        super().__init__()
        editable_fields = editable_fields or []
        self.editable_fields = editable_fields

        # set choices for user field if users are provided
        if users:
            user_choices = [(user.username, user.username) for user in users]
            user_choices.insert(0, ("", "Everyone"))
            self.fields["user"].choices = user_choices

        for param in search.params:
            # set initial values for modified params
            self.fields[param].initial = search.__dict__[param]

            # Mark non-editable modified fields as hidden. That way, templates
            # rendering a form can just loop over hidden_fields to ensure that
            # all necessary search options are kept when submitting the form.
            if search.is_modified(param) and param not in editable_fields:
                self.fields[param].widget = forms.HiddenInput()


class UserProfile(models.Model):
    THEME_AUTO = "auto"
    THEME_LIGHT = "light"
    THEME_DARK = "dark"
    THEME_CHOICES = [
        (THEME_AUTO, "Auto"),
        (THEME_LIGHT, "Light"),
        (THEME_DARK, "Dark"),
    ]
    BOOKMARK_DATE_DISPLAY_RELATIVE = "relative"
    BOOKMARK_DATE_DISPLAY_ABSOLUTE = "absolute"
    BOOKMARK_DATE_DISPLAY_HIDDEN = "hidden"
    BOOKMARK_DATE_DISPLAY_CHOICES = [
        (BOOKMARK_DATE_DISPLAY_RELATIVE, "Relative"),
        (BOOKMARK_DATE_DISPLAY_ABSOLUTE, "Absolute"),
        (BOOKMARK_DATE_DISPLAY_HIDDEN, "Hidden"),
    ]
    BOOKMARK_DESCRIPTION_DISPLAY_INLINE = "inline"
    BOOKMARK_DESCRIPTION_DISPLAY_SEPARATE = "separate"
    BOOKMARK_DESCRIPTION_DISPLAY_CHOICES = [
        (BOOKMARK_DESCRIPTION_DISPLAY_INLINE, "Inline"),
        (BOOKMARK_DESCRIPTION_DISPLAY_SEPARATE, "Separate"),
    ]
    BOOKMARK_LINK_TARGET_BLANK = "_blank"
    BOOKMARK_LINK_TARGET_SELF = "_self"
    BOOKMARK_LINK_TARGET_CHOICES = [
        (BOOKMARK_LINK_TARGET_BLANK, "New page"),
        (BOOKMARK_LINK_TARGET_SELF, "Same page"),
    ]
    WEB_ARCHIVE_INTEGRATION_DISABLED = "disabled"
    WEB_ARCHIVE_INTEGRATION_ENABLED = "enabled"
    WEB_ARCHIVE_INTEGRATION_CHOICES = [
        (WEB_ARCHIVE_INTEGRATION_DISABLED, "Disabled"),
        (WEB_ARCHIVE_INTEGRATION_ENABLED, "Enabled"),
    ]
    TAG_SEARCH_STRICT = "strict"
    TAG_SEARCH_LAX = "lax"
    TAG_SEARCH_CHOICES = [
        (TAG_SEARCH_STRICT, "Strict"),
        (TAG_SEARCH_LAX, "Lax"),
    ]
    TAG_GROUPING_ALPHABETICAL = "alphabetical"
    TAG_GROUPING_DISABLED = "disabled"
    TAG_GROUPING_CHOICES = [
        (TAG_GROUPING_ALPHABETICAL, "Alphabetical"),
        (TAG_GROUPING_DISABLED, "Disabled"),
    ]
    user = models.OneToOneField(User, related_name="profile", on_delete=models.CASCADE)
    theme = models.CharField(
        max_length=10, choices=THEME_CHOICES, blank=False, default=THEME_AUTO
    )
    bookmark_date_display = models.CharField(
        max_length=10,
        choices=BOOKMARK_DATE_DISPLAY_CHOICES,
        blank=False,
        default=BOOKMARK_DATE_DISPLAY_RELATIVE,
    )
    bookmark_description_display = models.CharField(
        max_length=10,
        choices=BOOKMARK_DESCRIPTION_DISPLAY_CHOICES,
        blank=False,
        default=BOOKMARK_DESCRIPTION_DISPLAY_INLINE,
    )
    bookmark_description_max_lines = models.IntegerField(
        null=False,
        default=1,
    )
    bookmark_link_target = models.CharField(
        max_length=10,
        choices=BOOKMARK_LINK_TARGET_CHOICES,
        blank=False,
        default=BOOKMARK_LINK_TARGET_BLANK,
    )
    web_archive_integration = models.CharField(
        max_length=10,
        choices=WEB_ARCHIVE_INTEGRATION_CHOICES,
        blank=False,
        default=WEB_ARCHIVE_INTEGRATION_DISABLED,
    )
    tag_search = models.CharField(
        max_length=10,
        choices=TAG_SEARCH_CHOICES,
        blank=False,
        default=TAG_SEARCH_STRICT,
    )
    tag_grouping = models.CharField(
        max_length=12,
        choices=TAG_GROUPING_CHOICES,
        blank=False,
        default=TAG_GROUPING_ALPHABETICAL,
    )
    enable_sharing = models.BooleanField(default=False, null=False)
    enable_public_sharing = models.BooleanField(default=False, null=False)
    enable_favicons = models.BooleanField(default=False, null=False)
    enable_preview_images = models.BooleanField(default=False, null=False)
    display_url = models.BooleanField(default=False, null=False)
    display_view_bookmark_action = models.BooleanField(default=True, null=False)
    display_edit_bookmark_action = models.BooleanField(default=True, null=False)
    display_archive_bookmark_action = models.BooleanField(default=True, null=False)
    display_remove_bookmark_action = models.BooleanField(default=True, null=False)
    permanent_notes = models.BooleanField(default=False, null=False)
    custom_css = models.TextField(blank=True, null=False)
    custom_css_hash = models.CharField(blank=True, null=False, max_length=32)
    auto_tagging_rules = models.TextField(blank=True, null=False)
    search_preferences = models.JSONField(default=dict, null=False)
    enable_automatic_html_snapshots = models.BooleanField(default=True, null=False)
    default_mark_unread = models.BooleanField(default=False, null=False)
    items_per_page = models.IntegerField(
        null=False, default=30, validators=[MinValueValidator(10)]
    )
    sticky_pagination = models.BooleanField(default=False, null=False)
    collapse_side_panel = models.BooleanField(default=False, null=False)

    def save(self, *args, **kwargs):
        if self.custom_css:
            self.custom_css_hash = hashlib.md5(
                self.custom_css.encode("utf-8")
            ).hexdigest()
        else:
            self.custom_css_hash = ""
        super().save(*args, **kwargs)


class UserProfileForm(forms.ModelForm):
    class Meta:
        model = UserProfile
        fields = [
            "theme",
            "bookmark_date_display",
            "bookmark_description_display",
            "bookmark_description_max_lines",
            "bookmark_link_target",
            "web_archive_integration",
            "tag_search",
            "tag_grouping",
            "enable_sharing",
            "enable_public_sharing",
            "enable_favicons",
            "enable_preview_images",
            "enable_automatic_html_snapshots",
            "display_url",
            "display_view_bookmark_action",
            "display_edit_bookmark_action",
            "display_archive_bookmark_action",
            "display_remove_bookmark_action",
            "permanent_notes",
            "default_mark_unread",
            "custom_css",
            "auto_tagging_rules",
            "items_per_page",
            "sticky_pagination",
            "collapse_side_panel",
        ]


@receiver(post_save, sender=User)
def create_user_profile(sender, instance, created, **kwargs):
    if created:
        UserProfile.objects.create(user=instance)


@receiver(post_save, sender=User)
def save_user_profile(sender, instance, **kwargs):
    instance.profile.save()


class Toast(models.Model):
    key = models.CharField(max_length=50)
    message = models.TextField()
    acknowledged = models.BooleanField(default=False)
    owner = models.ForeignKey(User, on_delete=models.CASCADE)


class FeedToken(models.Model):
    """
    Adapted from authtoken.models.Token
    """

    key = models.CharField(max_length=40, primary_key=True)
    user = models.OneToOneField(
        User,
        related_name="feed_token",
        on_delete=models.CASCADE,
    )
    created = models.DateTimeField(auto_now_add=True)

    def save(self, *args, **kwargs):
        if not self.key:
            self.key = self.generate_key()
        return super().save(*args, **kwargs)

    @classmethod
    def generate_key(cls):
        return binascii.hexlify(os.urandom(20)).decode()

    def __str__(self):
        return self.key


class GlobalSettings(models.Model):
    LANDING_PAGE_LOGIN = "login"
    LANDING_PAGE_SHARED_BOOKMARKS = "shared_bookmarks"
    LANDING_PAGE_CHOICES = [
        (LANDING_PAGE_LOGIN, "Login"),
        (LANDING_PAGE_SHARED_BOOKMARKS, "Shared Bookmarks"),
    ]

    landing_page = models.CharField(
        max_length=50,
        choices=LANDING_PAGE_CHOICES,
        blank=False,
        default=LANDING_PAGE_LOGIN,
    )
    guest_profile_user = models.ForeignKey(
        User, on_delete=models.SET_NULL, null=True, blank=True
    )
    enable_link_prefetch = models.BooleanField(default=False, null=False)

    @classmethod
    def get(cls):
        instance = GlobalSettings.objects.first()
        if not instance:
            instance = GlobalSettings()
            instance.save()
        return instance

    def save(self, *args, **kwargs):
        if not self.pk and GlobalSettings.objects.exists():
            raise Exception("There is already one instance of GlobalSettings")
        return super(GlobalSettings, self).save(*args, **kwargs)


class GlobalSettingsForm(forms.ModelForm):
    class Meta:
        model = GlobalSettings
        fields = ["landing_page", "guest_profile_user", "enable_link_prefetch"]

    def __init__(self, *args, **kwargs):
        super(GlobalSettingsForm, self).__init__(*args, **kwargs)
        self.fields["guest_profile_user"].empty_label = "Standard profile"