"""FC-6.1 — chapter layer over series_page."""

import pytest
from sqlalchemy import func, select

from backend.app.models import ImageRecord, TagKind
from backend.app.models.series_chapter import SeriesChapter
from backend.app.models.series_page import SeriesPage
from backend.app.services.series_service import SeriesError, SeriesService
from backend.app.services.tag_service import TagService

pytestmark = pytest.mark.integration

_SEQ = 0


async def _img(db):
    global _SEQ
    _SEQ += 1
    rec = ImageRecord(
        path=f"/tmp/fc_sc_{_SEQ}.png", sha256=f"{_SEQ:064d}",
        size_bytes=1, mime="image/png", origin="uploaded",
    )
    db.add(rec)
    await db.flush()
    return rec.id


async def _series(db, name):
    return (await TagService(db).find_or_create(name, TagKind.series)).id


async def _chapter_numbers(db, sid):
    rows = (
        await db.execute(
            select(SeriesChapter.id, SeriesChapter.chapter_number)
            .where(SeriesChapter.series_tag_id == sid)
            .order_by(SeriesChapter.chapter_number)
        )
    ).all()
    return [(r.id, r.chapter_number) for r in rows]


async def _page_order(db, chapter_id):
    rows = (
        await db.execute(
            select(SeriesPage.image_id)
            .where(SeriesPage.chapter_id == chapter_id)
            .order_by(SeriesPage.page_number)
        )
    ).scalars().all()
    return list(rows)


@pytest.mark.asyncio
async def test_add_images_creates_default_chapter(db):
    svc = SeriesService(db)
    sid = await _series(db, "C1")
    i1, i2 = await _img(db), await _img(db)
    await svc.add_images(sid, [i1, i2])
    chapters = await _chapter_numbers(db, sid)
    assert len(chapters) == 1
    assert chapters[0][1] == 1
    assert await _page_order(db, chapters[0][0]) == [i1, i2]


@pytest.mark.asyncio
async def test_create_and_target_specific_chapter(db):
    svc = SeriesService(db)
    sid = await _series(db, "C2")
    i1, i2 = await _img(db), await _img(db)
    await svc.add_images(sid, [i1])  # default chapter 1
    ch2 = await svc.create_chapter(sid, title="Two")
    assert ch2["chapter_number"] == 2
    await svc.add_images(sid, [i2], chapter_id=ch2["id"])
    assert await _page_order(db, ch2["id"]) == [i2]
    # i1 stayed in chapter 1.
    chapters = await _chapter_numbers(db, sid)
    assert len(chapters) == 2


@pytest.mark.asyncio
async def test_reorder_chapters(db):
    svc = SeriesService(db)
    sid = await _series(db, "C3")
    c1 = (await svc.create_chapter(sid))["id"]
    c2 = (await svc.create_chapter(sid))["id"]
    c3 = (await svc.create_chapter(sid))["id"]
    await svc.reorder_chapters(sid, [c3, c1, c2])
    assert await _chapter_numbers(db, sid) == [(c3, 1), (c1, 2), (c2, 3)]
    with pytest.raises(SeriesError):
        await svc.reorder_chapters(sid, [c1, c2])


@pytest.mark.asyncio
async def test_reorder_pages_within_chapter(db):
    svc = SeriesService(db)
    sid = await _series(db, "C4")
    i1, i2, i3 = await _img(db), await _img(db), await _img(db)
    await svc.add_images(sid, [i1, i2, i3])
    cid = (await _chapter_numbers(db, sid))[0][0]
    await svc.reorder_pages(sid, cid, [i3, i1, i2])
    assert await _page_order(db, cid) == [i3, i1, i2]


@pytest.mark.asyncio
async def test_legacy_reorder_rejects_multi_chapter(db):
    svc = SeriesService(db)
    sid = await _series(db, "C5")
    i1 = await _img(db)
    await svc.add_images(sid, [i1])
    await svc.create_chapter(sid)  # now 2 chapters
    with pytest.raises(SeriesError):
        await svc.reorder(sid, [i1])


@pytest.mark.asyncio
async def test_merge_chapter_moves_pages_and_renumbers(db):
    svc = SeriesService(db)
    sid = await _series(db, "C6")
    i1, i2, i3 = await _img(db), await _img(db), await _img(db)
    await svc.add_images(sid, [i1])  # chapter 1
    c2 = (await svc.create_chapter(sid))["id"]
    await svc.add_images(sid, [i2, i3], chapter_id=c2)
    c1 = (await _chapter_numbers(db, sid))[0][0]
    moved = await svc.merge_chapter(sid, c2, c1)
    assert moved == 2
    assert await _page_order(db, c1) == [i1, i2, i3]
    # source chapter gone; remaining renumbered 1..N.
    assert await _chapter_numbers(db, sid) == [(c1, 1)]


@pytest.mark.asyncio
async def test_delete_chapter_cascades_pages_and_renumbers(db):
    svc = SeriesService(db)
    sid = await _series(db, "C7")
    i1, i2 = await _img(db), await _img(db)
    await svc.add_images(sid, [i1])
    c2 = (await svc.create_chapter(sid))["id"]
    await svc.add_images(sid, [i2], chapter_id=c2)
    await svc.delete_chapter(sid, c2)
    assert [c for _, c in await _chapter_numbers(db, sid)] == [1]
    # i2's page cascaded away with its chapter.
    cnt = await db.scalar(
        select(func.count()).select_from(SeriesPage)
        .where(SeriesPage.image_id == i2)
    )
    assert cnt == 0


@pytest.mark.asyncio
async def test_set_cover_brings_chapter_and_page_to_front(db):
    svc = SeriesService(db)
    sid = await _series(db, "C8")
    i1, i2, i3 = await _img(db), await _img(db), await _img(db)
    await svc.add_images(sid, [i1])  # chapter 1
    c2 = (await svc.create_chapter(sid))["id"]
    await svc.add_images(sid, [i2, i3], chapter_id=c2)
    await svc.set_cover(sid, i3)
    chapters = await _chapter_numbers(db, sid)
    assert chapters[0][0] == c2  # i3's chapter is now first
    assert (await _page_order(db, c2))[0] == i3  # i3 first in its chapter


@pytest.mark.asyncio
async def test_list_pages_flags_gaps_from_stated_ranges(db):
    svc = SeriesService(db)
    sid = await _series(db, "C9")
    await svc.create_chapter(sid, stated_page_start=1, stated_page_end=4)
    await svc.create_chapter(sid, stated_page_start=9, stated_page_end=12)
    out = await svc.list_pages(sid)
    assert len(out["chapters"]) == 2
    assert len(out["gaps"]) == 1
    assert out["gaps"][0]["start"] == 5
    assert out["gaps"][0]["end"] == 8


@pytest.mark.asyncio
async def test_add_with_stated_pages_records_them(db):
    svc = SeriesService(db)
    sid = await _series(db, "C10")
    i1, i2 = await _img(db), await _img(db)
    await svc.add_images(sid, [i1, i2], stated_pages={i1: 9, i2: 10})
    rows = dict(
        (
            await db.execute(
                select(SeriesPage.image_id, SeriesPage.stated_page)
                .where(SeriesPage.series_tag_id == sid)
            )
        ).all()
    )
    assert rows[i1] == 9
    assert rows[i2] == 10