"""Base models using UUIDv7 for all id fields."""

__package__ = 'archivebox.base_models'

import io
import csv
import json
from uuid import UUID
from archivebox.uuid_compat import uuid7
from typing import Any, Iterable, ClassVar
from pathlib import Path

from django.contrib import admin
from django.db import models
from django.db.models import F
from django.utils import timezone
from django.contrib.auth import get_user_model
from django.urls import reverse_lazy
from django.conf import settings

from django_stubs_ext.db.models import TypedModelMeta

from archivebox import DATA_DIR
from archivebox.misc.util import to_json
from archivebox.misc.hashing import get_dir_info


def get_or_create_system_user_pk(username='system'):
    User = get_user_model()
    # If there's exactly one superuser, use that for all system operations
    if User.objects.filter(is_superuser=True).count() == 1:
        return User.objects.filter(is_superuser=True).values_list('pk', flat=True)[0]
    # Otherwise get or create the system user
    user, _ = User.objects.get_or_create(
        username=username,
        defaults={'is_staff': True, 'is_superuser': True, 'email': '', 'password': '!'}
    )
    return user.pk


class AutoDateTimeField(models.DateTimeField):
    """DateTimeField that automatically updates on save (legacy compatibility)."""
    def pre_save(self, model_instance, add):
        if add or not getattr(model_instance, self.attname):
            value = timezone.now()
            setattr(model_instance, self.attname, value)
            return value
        return super().pre_save(model_instance, add)


class ModelWithUUID(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid7, editable=False, unique=True)
    created_at = models.DateTimeField(default=timezone.now, db_index=True)
    modified_at = models.DateTimeField(auto_now=True)
    created_by = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, default=get_or_create_system_user_pk, null=False, db_index=True)

    class Meta(TypedModelMeta):
        abstract = True

    def __str__(self):
        return f'[{self.id}] {self.__class__.__name__}'

    @property
    def admin_change_url(self) -> str:
        return f"/admin/{self._meta.app_label}/{self._meta.model_name}/{self.pk}/change/"

    @property
    def api_url(self) -> str:
        return reverse_lazy('api-1:get_any', args=[self.id])

    @property
    def api_docs_url(self) -> str:
        return f'/api/v1/docs#/{self._meta.app_label.title()}%20Models/api_v1_{self._meta.app_label}_get_{self._meta.db_table}'

    def as_json(self, keys: Iterable[str] = ()) -> dict:
        default_keys = ('id', 'created_at', 'modified_at')
        return {key: getattr(self, key) for key in (keys or default_keys) if hasattr(self, key)}


class ModelWithSerializers(ModelWithUUID):
    class Meta(TypedModelMeta):
        abstract = True

    def as_csv_row(self, keys: Iterable[str] = (), separator: str = ',') -> str:
        buffer = io.StringIO()
        csv.writer(buffer, delimiter=separator).writerow(str(getattr(self, key, '')) for key in (keys or self.as_json().keys()))
        return buffer.getvalue()

    def as_jsonl_row(self, keys: Iterable[str] = (), **json_kwargs) -> str:
        return json.dumps({key: getattr(self, key, '') for key in (keys or self.as_json().keys())}, sort_keys=True, indent=None, **json_kwargs)


class ModelWithNotes(models.Model):
    """Mixin for models with a notes field."""
    notes = models.TextField(blank=True, null=False, default='')

    class Meta:
        abstract = True


class ModelWithHealthStats(models.Model):
    """Mixin for models with health tracking fields."""
    num_uses_failed = models.PositiveIntegerField(default=0)
    num_uses_succeeded = models.PositiveIntegerField(default=0)

    class Meta:
        abstract = True

    @property
    def health(self) -> int:
        total = max(self.num_uses_failed + self.num_uses_succeeded, 1)
        return round((self.num_uses_succeeded / total) * 100)

    def increment_health_stats(self, success: bool):
        """Atomically increment success or failure counter using F() expression."""
        field = 'num_uses_succeeded' if success else 'num_uses_failed'
        type(self).objects.filter(pk=self.pk).update(**{field: F(field) + 1})


class ModelWithConfig(models.Model):
    """Mixin for models with a JSON config field."""
    config = models.JSONField(default=dict, null=True, blank=True, editable=True)

    class Meta:
        abstract = True


class ModelWithOutputDir(ModelWithSerializers):
    class Meta:
        abstract = True

    def save(self, *args, **kwargs):
        super().save(*args, **kwargs)
        self.OUTPUT_DIR.mkdir(parents=True, exist_ok=True)
        self.save_json_index()

    @property
    def output_dir_parent(self) -> str:
        return f'{self._meta.model_name}s'

    @property
    def output_dir_name(self) -> str:
        return str(self.id)

    @property
    def output_dir_str(self) -> str:
        return f'{self.output_dir_parent}/{self.output_dir_name}'

    @property
    def OUTPUT_DIR(self) -> Path:
        return DATA_DIR / self.output_dir_str

    def save_json_index(self):
        (self.OUTPUT_DIR / 'index.json').write_text(to_json(self.as_json()))