from __future__ import annotations

import json
from collections.abc import Iterable

from django import urls
from django.contrib import admin
from django.db.models import QuerySet
from django.http import HttpRequest
from django.utils.html import SafeString, format_html

from .models import (
    BotSetting,
    DeletedMessage,
    DocumentationLink,
    Filter,
    FilterList,
    Infraction,
    MessageDeletionContext,
    Nomination,
    OffTopicChannelName,
    OffensiveMessage,
    Role,
    User
)
from .models.bot.nomination import NominationEntry

admin.site.site_header = "Python Discord | Administration"
admin.site.site_title = "Python Discord"


@admin.register(BotSetting)
class BotSettingAdmin(admin.ModelAdmin):
    """Admin formatting for the BotSetting model."""

    fields = ("name", "data")
    list_display = ("name",)
    readonly_fields = ("name",)

    def has_add_permission(self, *args) -> bool:
        """Prevent adding from django admin."""
        return False

    def has_delete_permission(self, *args) -> bool:
        """Prevent deleting from django admin."""
        return False


@admin.register(DocumentationLink)
class DocumentationLinkAdmin(admin.ModelAdmin):
    """Admin formatting for the DocumentationLink model."""

    fields = ("package", "inventory_url", "base_url")
    list_display = ("package", "inventory_url", "base_url")
    list_editable = ("base_url", "inventory_url")
    search_fields = ("package",)


class InfractionActorFilter(admin.SimpleListFilter):
    """Actor Filter for Infraction Admin list page."""

    title = "Actor"
    parameter_name = "actor"

    def lookups(self, request: HttpRequest, model: NominationAdmin) -> Iterable[tuple[int, str]]:
        """Selectable values for viewer to filter by."""
        actor_ids = Infraction.objects.order_by().values_list("actor").distinct()
        actors = User.objects.filter(id__in=actor_ids)
        return ((a.id, a.username) for a in actors)

    def queryset(self, request: HttpRequest, queryset: QuerySet) -> QuerySet | None:
        """Query to filter the list of Users against."""
        if not self.value():
            return None
        return queryset.filter(actor__id=self.value())


@admin.register(Infraction)
class InfractionAdmin(admin.ModelAdmin):
    """Admin formatting for the Infraction model."""

    fieldsets = (
        ("Members", {"fields": ("user", "actor")}),
        ("Action", {"fields": ("type", "hidden", "active")}),
        ("Dates", {"fields": ("inserted_at", "expires_at")}),
        ("Reason", {"fields": ("reason",)}),
    )
    readonly_fields = (
        "user",
        "actor",
        "type",
        "inserted_at",
        "expires_at",
        "active",
        "hidden"
    )
    list_display = (
        "type",
        "active",
        "user",
        "inserted_at",
        "reason",
    )
    search_fields = (
        "id",
        "user__name",
        "user__id",
        "actor__name",
        "actor__id",
        "reason",
        "type"
    )
    list_filter = (
        "type",
        "hidden",
        "active",
        InfractionActorFilter
    )

    def has_add_permission(self, *args) -> bool:
        """Prevent adding from django admin."""
        return False


@admin.register(DeletedMessage)
class DeletedMessageAdmin(admin.ModelAdmin):
    """Admin formatting for the DeletedMessage model."""

    fields = (
        "id",
        "author",
        "channel_id",
        "content",
        "embed_data",
        "context",
        "view_full_log"
    )

    exclude = ("embeds", "deletion_context")

    search_fields = (
        "id",
        "content",
        "author__name",
        "author__id",
        "deletion_context__actor__name",
        "deletion_context__actor__id"
    )

    list_display = ("id", "author", "channel_id")

    def embed_data(self, message: DeletedMessage) -> str | None:
        """Format embed data in a code block for better readability."""
        if message.embeds:
            return format_html(
                "<pre style='word-wrap: break-word; white-space: pre-wrap; overflow-x: auto;'>"
                "<code>{0}</code></pre>",
                json.dumps(message.embeds, indent=4)
            )
        return None

    embed_data.short_description = "Embeds"

    @staticmethod
    def context(message: DeletedMessage) -> str:
        """Provide full context info with a link through to context admin view."""
        link = urls.reverse(
            "admin:api_messagedeletioncontext_change",
            args=[message.deletion_context.id]
        )
        details = (
            f"Deleted by {message.deletion_context.actor} at "
            f"{message.deletion_context.creation}"
        )
        return format_html("<a href='{0}'>{1}</a>", link, details)

    @staticmethod
    def view_full_log(message: DeletedMessage) -> str:
        """Provide a link to the message logs for the relevant context."""
        return format_html(
            "<a href='{0}'>Click to view full context log</a>",
            message.deletion_context.log_url
        )

    def has_add_permission(self, *args) -> bool:
        """Prevent adding from django admin."""
        return False

    def has_change_permission(self, *args) -> bool:
        """Prevent editing from django admin."""
        return False


class DeletedMessageInline(admin.TabularInline):
    """Tabular Inline Admin model for Deleted Message to be viewed within Context."""

    model = DeletedMessage


@admin.register(FilterList)
class FilterListAdmin(admin.ModelAdmin):
    """Admin formatting for the FilterList model."""


@admin.register(Filter)
class FilterAdmin(admin.ModelAdmin):
    """Admin formatting for the Filter model."""


@admin.register(MessageDeletionContext)
class MessageDeletionContextAdmin(admin.ModelAdmin):
    """Admin formatting for the MessageDeletionContext model."""

    fields = ("actor", "creation")
    list_display = ("id", "creation", "actor")
    inlines = (DeletedMessageInline,)

    def has_add_permission(self, *args) -> bool:
        """Prevent adding from django admin."""
        return False

    def has_change_permission(self, *args) -> bool:
        """Prevent editing from django admin."""
        return False


class NominationActorFilter(admin.SimpleListFilter):
    """Actor Filter for Nomination Admin list page."""

    title = "Actor"
    parameter_name = "actor"

    def lookups(self, request: HttpRequest, model: NominationAdmin) -> Iterable[tuple[int, str]]:
        """Selectable values for viewer to filter by."""
        actor_ids = NominationEntry.objects.order_by().values_list("actor").distinct()
        actors = User.objects.filter(id__in=actor_ids)
        return ((a.id, a.username) for a in actors)

    def queryset(self, request: HttpRequest, queryset: QuerySet) -> QuerySet | None:
        """Query to filter the list of Users against."""
        if not self.value():
            return None
        nomination_ids = NominationEntry.objects.filter(
            actor__id=self.value()
        ).values_list("nomination_id").distinct()
        return queryset.filter(id__in=nomination_ids)


@admin.register(Nomination)
class NominationAdmin(admin.ModelAdmin):
    """Admin formatting for the Nomination model."""

    search_fields = (
        "user__name",
        "user__id",
        "end_reason"
    )

    list_filter = ("active", NominationActorFilter)

    list_display = (
        "user",
        "active",
        "reviewed"
    )

    fields = (
        "user",
        "active",
        "inserted_at",
        "ended_at",
        "end_reason",
        "reviewed"
    )

    # only allow end reason field to be edited.
    readonly_fields = (
        "user",
        "active",
        "inserted_at",
        "ended_at",
        "reviewed"
    )

    def has_add_permission(self, *args) -> bool:
        """Prevent adding from django admin."""
        return False


class NominationEntryActorFilter(admin.SimpleListFilter):
    """Actor Filter for NominationEntry Admin list page."""

    title = "Actor"
    parameter_name = "actor"

    def lookups(self, request: HttpRequest, model: NominationAdmin) -> Iterable[tuple[int, str]]:
        """Selectable values for viewer to filter by."""
        actor_ids = NominationEntry.objects.order_by().values_list("actor").distinct()
        actors = User.objects.filter(id__in=actor_ids)
        return ((a.id, a.username) for a in actors)

    def queryset(self, request: HttpRequest, queryset: QuerySet) -> QuerySet | None:
        """Query to filter the list of Users against."""
        if not self.value():
            return None
        return queryset.filter(actor__id=self.value())


@admin.register(NominationEntry)
class NominationEntryAdmin(admin.ModelAdmin):
    """Admin formatting for the NominationEntry model."""

    search_fields = (
        "actor__name",
        "actor__id",
        "reason",
    )

    list_filter = (NominationEntryActorFilter,)

    list_display = (
        "nomination",
        "actor",
    )

    fields = (
        "nomination",
        "actor",
        "reason",
        "inserted_at",
    )

    # only allow reason field to be edited
    readonly_fields = (
        "nomination",
        "actor",
        "inserted_at",
    )

    def has_add_permission(self, request: HttpRequest) -> bool:
        """Disable adding new nomination entry from admin."""
        return False


@admin.register(OffTopicChannelName)
class OffTopicChannelNameAdmin(admin.ModelAdmin):
    """Admin formatting for the OffTopicChannelName model."""

    search_fields = ("name",)
    list_filter = ("used",)


@admin.register(OffensiveMessage)
class OffensiveMessageAdmin(admin.ModelAdmin):
    """Admin formatting for the OffensiveMessage model."""

    def message_jumplink(self, message: OffensiveMessage) -> SafeString:
        """Message ID hyperlinked to the direct discord jumplink."""
        return format_html(
            '<a href="https://canary.discordapp.com/channels/267624335836053506/{0}/{1}">{1}</a>',
            message.channel_id,
            message.id
        )

    message_jumplink.short_description = "Message ID"

    search_fields = ("id", "channel_id")
    list_display = ("id", "channel_id", "delete_date")
    fields = ("message_jumplink", "channel_id", "delete_date")
    readonly_fields = ("message_jumplink", "channel_id")

    def has_add_permission(self, *args) -> bool:
        """Prevent adding from django admin."""
        return False


@admin.register(Role)
class RoleAdmin(admin.ModelAdmin):
    """Admin formatting for the Role model."""

    def coloured_name(self, role: Role) -> SafeString:
        """Role name with html style colouring."""
        return format_html(
            '<span style="color: {0}!important; font-weight: bold;">{1}</span>',
            f"#{role.colour:06X}",
            role.name
        )

    coloured_name.short_description = "Name"

    def colour_with_preview(self, role: Role) -> SafeString:
        """Show colour value in both int and hex, in bolded and coloured style."""
        return format_html(
            "<span style='color: {0}; font-weight: bold;'>{0} ({1})</span>",
            f"#{role.colour:06x}",
            role.colour
        )

    colour_with_preview.short_description = "Colour"

    def permissions_with_calc_link(self, role: Role) -> SafeString:
        """Show permissions with link to API permissions calculator page."""
        return format_html(
            "<a href='https://discordapi.com/permissions.html#{0}' target='_blank'>{0}</a>",
            role.permissions
        )

    permissions_with_calc_link.short_description = "Permissions"

    search_fields = ("name", "id")
    list_display = ("coloured_name",)
    fields = ("id", "name", "colour_with_preview", "permissions_with_calc_link", "position")

    def has_add_permission(self, *args) -> bool:
        """Prevent adding from django admin."""
        return False

    def has_change_permission(self, *args) -> bool:
        """Prevent editing from django admin."""
        return False


class UserRoleFilter(admin.SimpleListFilter):
    """List Filter for User list Admin page."""

    title = "Role"
    parameter_name = "role"

    def lookups(self, request: HttpRequest, model: UserAdmin) -> Iterable[tuple[str, str]]:
        """Selectable values for viewer to filter by."""
        roles = Role.objects.all()
        return ((r.name, r.name) for r in roles)

    def queryset(self, request: HttpRequest, queryset: QuerySet) -> QuerySet | None:
        """Query to filter the list of Users against."""
        if not self.value():
            return None
        role = Role.objects.get(name=self.value())
        return queryset.filter(roles__contains=[role.id])


@admin.register(User)
class UserAdmin(admin.ModelAdmin):
    """Admin formatting for the User model."""

    def top_role_coloured(self, user: User) -> SafeString:
        """Returns the top role of the user with html style matching role colour."""
        return format_html(
            '<span style="color: {0}; font-weight: bold;">{1}</span>',
            f"#{user.top_role.colour:06X}",
            user.top_role.name
        )

    top_role_coloured.short_description = "Top Role"

    def all_roles_coloured(self, user: User) -> SafeString:
        """Returns all user roles with html style matching role colours."""
        roles = Role.objects.filter(id__in=user.roles)
        return format_html(
            "</br>".join(
                f'<span style="color: #{r.colour:06X}; font-weight: bold;">{r.name}</span>'
                for r in roles
            )
        )

    all_roles_coloured.short_description = "All Roles"

    search_fields = ("name", "id", "roles")
    list_filter = (UserRoleFilter, "in_guild")
    list_display = ("username", "top_role_coloured", "in_guild")
    fields = ("username", "id", "in_guild", "all_roles_coloured")
    sortable_by = ("username",)

    def has_add_permission(self, *args) -> bool:
        """Prevent adding from django admin."""
        return False

    def has_change_permission(self, *args) -> bool:
        """Prevent editing from django admin."""
        return False