"""
Datenmodell – Templates, Jobs, Log-Einträge.
"""
import uuid
from pathlib import Path

from django.conf import settings
from django.db import models


def template_upload_path(instance, filename: str) -> str:
    return f"templates/{instance.id}/{Path(filename).name}"


def csv_upload_path(instance, filename: str) -> str:
    return f"jobs/{instance.id}/recipients/{Path(filename).name}"


def result_upload_path(instance, filename: str) -> str:
    return f"jobs/{instance.id}/result/{Path(filename).name}"


class LetterTemplate(models.Model):
    """DOCX-Vorlage mit Jinja-Platzhaltern."""

    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    name = models.CharField(max_length=200)
    description = models.TextField(blank=True)
    file = models.FileField(upload_to=template_upload_path)
    placeholders = models.JSONField(default=list, blank=True,
                                    help_text="Aus dem DOCX extrahierte Variablen.")
    created_by = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.PROTECT,
                                   related_name="templates")
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        ordering = ["-created_at"]

    def __str__(self) -> str:
        return self.name


class MailMergeJob(models.Model):
    class Status(models.TextChoices):
        PENDING = "pending", "Wartet"
        RUNNING = "running", "Läuft"
        DONE = "done", "Fertig"
        FAILED = "failed", "Fehlgeschlagen"

    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    template = models.ForeignKey(LetterTemplate, on_delete=models.PROTECT,
                                 related_name="jobs")
    recipients_csv = models.FileField(upload_to=csv_upload_path)
    status = models.CharField(max_length=20, choices=Status.choices,
                              default=Status.PENDING)
    result_pdf = models.FileField(upload_to=result_upload_path, null=True, blank=True)
    total_rows = models.PositiveIntegerField(default=0)
    processed_rows = models.PositiveIntegerField(default=0)
    error_message = models.TextField(blank=True)
    created_by = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.PROTECT,
                                   related_name="jobs")
    created_at = models.DateTimeField(auto_now_add=True)
    started_at = models.DateTimeField(null=True, blank=True)
    finished_at = models.DateTimeField(null=True, blank=True)

    class Meta:
        ordering = ["-created_at"]

    def __str__(self) -> str:
        return f"Job {self.id} ({self.template.name})"


class JobLogEntry(models.Model):
    class Level(models.TextChoices):
        INFO = "info", "Info"
        WARNING = "warning", "Warnung"
        ERROR = "error", "Fehler"

    job = models.ForeignKey(MailMergeJob, on_delete=models.CASCADE, related_name="logs")
    level = models.CharField(max_length=10, choices=Level.choices, default=Level.INFO)
    message = models.TextField()
    timestamp = models.DateTimeField(auto_now_add=True)

    class Meta:
        ordering = ["timestamp"]