import json

from django.contrib import admin

from .models import AuditEvent
from .utils import log_event


PATCH_MARKER = "_cmmc_audit_admin_log_patch_installed"


def _message_to_text(message):
    if isinstance(message, str):
        return message
    return json.dumps(message, default=str)


def _admin_change_message(obj, message):
    details = _message_to_text(message)
    if details:
        return f"Admin changed {obj}: {details}"
    return f"Admin changed {obj}"


def install_admin_audit_patch():
    if getattr(admin.ModelAdmin, PATCH_MARKER, False):
        return

    original_log_addition = admin.ModelAdmin.log_addition
    original_log_change = admin.ModelAdmin.log_change
    original_log_deletion = admin.ModelAdmin.log_deletion
    original_log_deletions = admin.ModelAdmin.log_deletions

    def log_addition(self, request, obj, message):
        result = original_log_addition(self, request, obj, message)
        log_event(
            AuditEvent.Action.ADMIN_ADDITION,
            obj,
            message=f"Admin added {obj}",
            actor=getattr(request, "user", None),
            request=request,
            source=AuditEvent.Source.DJANGO_ADMIN,
        )
        return result

    def log_change(self, request, obj, message):
        result = original_log_change(self, request, obj, message)
        log_event(
            AuditEvent.Action.ADMIN_CHANGE,
            obj,
            message=_admin_change_message(obj, message),
            actor=getattr(request, "user", None),
            request=request,
            source=AuditEvent.Source.DJANGO_ADMIN,
        )
        return result

    def log_deletion(self, request, obj, object_repr):
        result = original_log_deletion(self, request, obj, object_repr)
        log_event(
            AuditEvent.Action.ADMIN_DELETION,
            obj,
            message=f"Admin deleted {object_repr}",
            actor=getattr(request, "user", None),
            request=request,
            source=AuditEvent.Source.DJANGO_ADMIN,
            target_repr=object_repr,
        )
        return result

    def log_deletions(self, request, queryset):
        objects = list(queryset)
        result = original_log_deletions(self, request, queryset)
        for obj in objects:
            log_event(
                AuditEvent.Action.ADMIN_DELETION,
                obj,
                message=f"Admin deleted {obj}",
                actor=getattr(request, "user", None),
                request=request,
                source=AuditEvent.Source.DJANGO_ADMIN,
            )
        return result

    admin.ModelAdmin.log_addition = log_addition
    admin.ModelAdmin.log_change = log_change
    admin.ModelAdmin.log_deletion = log_deletion
    admin.ModelAdmin.log_deletions = log_deletions
    setattr(admin.ModelAdmin, PATCH_MARKER, True)