"""Unit tests for EPUB structure parsing (no rendering involved)."""
import pytest

import app
from tests.helpers import build_epub_tree


def test_missing_container_xml_raises(tmp_path):
    (tmp_path / "META-INF").mkdir()
    with pytest.raises(ValueError, match="missing META-INF/container.xml"):
        app.parse_opf(tmp_path)


def test_container_xml_without_rootfile_raises(tmp_path):
    (tmp_path / "META-INF").mkdir()
    (tmp_path / "META-INF" / "container.xml").write_text(
        '<?xml version="1.0"?><container version="1.0"><rootfiles/></container>',
        encoding="utf-8",
    )
    with pytest.raises(ValueError, match="no rootfile"):
        app.parse_opf(tmp_path)


def test_parse_opf_returns_meta_spine_and_pdir_ltr(tmp_path):
    build_epub_tree(tmp_path)
    meta, opf_dir, spine, pdir = app.parse_opf(tmp_path)
    assert meta["title"] == "Tree Book"
    assert meta["creator"] == "Tree Author"
    assert meta["language"] == "en"
    assert str(opf_dir).endswith("OEBPS")
    assert [i["href"] for i in spine] == ["chapter1.xhtml", "chapter2.xhtml"]  # img filtered out
    assert pdir == "ltr"  # unset defaults to ltr


def test_parse_opf_rtl_page_progression(tmp_path):
    build_epub_tree(tmp_path, pdir="rtl")
    _, _, _, pdir = app.parse_opf(tmp_path)
    assert pdir == "rtl"


def test_nonlinear_spine_items_are_skipped(tmp_path):
    items = [
        ("front", "front.xhtml", "application/xhtml+xml", ""),
        ("ch1", "chapter1.xhtml", "application/xhtml+xml", ""),
    ]
    build_epub_tree(tmp_path, items=items, spine_ids=["ch1"])
    # Add a non-linear itemref for 'front' via raw OPF edit
    opf_path = tmp_path / "OEBPS" / "book.opf"
    text = opf_path.read_text(encoding="utf-8")
    text = text.replace(
        '<spine><itemref idref="ch1"/></spine>',
        '<spine><itemref idref="front" linear="no"/>'
        '<itemref idref="ch1"/></spine>',
    )
    opf_path.write_text(text, encoding="utf-8")
    _, _, spine, _ = app.parse_opf(tmp_path)
    assert [i["href"] for i in spine] == ["chapter1.xhtml"]


def test_empty_spine_falls_back_to_non_nav_html(tmp_path):
    items = [
        ("nav", "nav.xhtml", "application/xhtml+xml", "nav"),
        ("ch1", "chapter1.xhtml", "application/xhtml+xml", ""),
        ("img1", "img.png", "image/png", ""),
    ]
    build_epub_tree(tmp_path, items=items, spine_ids=[])  # spine refs: none
    _, _, spine, _ = app.parse_opf(tmp_path)
    assert [i["href"] for i in spine] == ["chapter1.xhtml"]  # nav + image excluded


def test_no_readable_content_raises(tmp_path):
    items = [("img1", "img.png", "image/png", "")]
    build_epub_tree(tmp_path, items=items, spine_ids=["img1"])
    with pytest.raises(ValueError, match="No readable content"):
        app.parse_opf(tmp_path)