"""
Gemeinsame Fixtures für die Mailmerge-Tests.

Liefert ein minimales DOCX-Template, eine passende CSV und einen
authentifizierten Django-Testclient.
"""
from __future__ import annotations

import io
from pathlib import Path

import pytest
from django.contrib.auth import get_user_model
from django.core.files.uploadedfile import SimpleUploadedFile
from docx import Document


# ---------------------------------------------------------------------------
# DOCX-Helfer
# ---------------------------------------------------------------------------

def _build_minimal_docx(placeholders: list[str]) -> bytes:
    """Erzeugt ein DOCX im Speicher mit den übergebenen Jinja-Platzhaltern."""
    doc = Document()
    doc.add_paragraph("Sehr {{ anrede_brief }} {{ nachname }},")
    doc.add_paragraph(" ".join(f"{{{{ {p} }}}}" for p in placeholders))
    doc.add_paragraph("Mit freundlichen Grüßen")
    buf = io.BytesIO()
    doc.save(buf)
    return buf.getvalue()


@pytest.fixture
def template_placeholders() -> list[str]:
    return ["anrede_brief", "nachname", "vorname", "ort"]


@pytest.fixture
def docx_bytes(template_placeholders) -> bytes:
    return _build_minimal_docx(template_placeholders)


@pytest.fixture
def docx_file_on_disk(tmp_path, docx_bytes) -> Path:
    p = tmp_path / "template.docx"
    p.write_bytes(docx_bytes)
    return p


# ---------------------------------------------------------------------------
# CSV-Helfer
# ---------------------------------------------------------------------------

CSV_VALID = (
    "anrede_brief,nachname,vorname,ort\n"
    "geehrte Frau,Huber,Andrea,Eisenstadt\n"
    "geehrter Herr,Müller,Bernhard,Neusiedl\n"
)

CSV_MISSING_COLUMN = (
    "anrede_brief,nachname,vorname\n"   # 'ort' fehlt
    "geehrte Frau,Huber,Andrea\n"
)

CSV_EXTRA_COLUMN = (
    "anrede_brief,nachname,vorname,ort,personalnr\n"
    "geehrte Frau,Huber,Andrea,Eisenstadt,12345\n"
)

CSV_NO_DATA = "anrede_brief,nachname,vorname,ort\n"

CSV_NO_HEADER = ""


@pytest.fixture
def csv_valid_bytes() -> bytes:
    return CSV_VALID.encode("utf-8")


@pytest.fixture
def csv_uploaded_valid(csv_valid_bytes) -> SimpleUploadedFile:
    return SimpleUploadedFile(
        "recipients.csv", csv_valid_bytes, content_type="text/csv"
    )


# ---------------------------------------------------------------------------
# Django-User / Client
# ---------------------------------------------------------------------------

@pytest.fixture
def user(db):
    User = get_user_model()
    return User.objects.create_user(
        username="testuser",
        password="topsecret-123",
        email="test@example.com",
    )


@pytest.fixture
def auth_client(client, user):
    client.force_login(user)
    return client


# ---------------------------------------------------------------------------
# LetterTemplate-Fixture (DB-persistent, mit echter DOCX-Datei)
# ---------------------------------------------------------------------------

@pytest.fixture
def letter_template(db, user, docx_bytes, tmp_path, settings):
    """Erzeugt ein LetterTemplate-DB-Objekt inkl. hochgeladener DOCX-Datei."""
    from mailmerge.models import LetterTemplate

    # MEDIA_ROOT auf tmp_path lenken, damit Testdateien isoliert bleiben
    settings.MEDIA_ROOT = str(tmp_path / "media")

    tpl = LetterTemplate(
        name="Testvorlage",
        description="Pytest-Fixture",
        created_by=user,
    )
    tpl.file.save(
        "test-template.docx",
        SimpleUploadedFile("test-template.docx", docx_bytes),
        save=True,
    )
    return tpl