"""Import ADR-0004 tree into content plane (CSOC-WP-0001-T04 rehearsal path)."""

from pathlib import Path

import pytest
from django.core.management import call_command

from coulomb_social.apps.members.models import Member, User
from coulomb_social.apps.spaces import pageops
from coulomb_social.apps.spaces.content import load_space_page
from coulomb_social.apps.spaces.import_tree import import_space_tree
from coulomb_social.apps.spaces.models import Space, SpaceMembership


@pytest.fixture
def content_root(tmp_path, settings):
    root = tmp_path / "content"
    settings.CONTENT_ROOT = str(root)
    return root


def _write_sample_tree(root: Path) -> Path:
    tree = root / "sample-space"
    pages = tree / "pages"
    assets = tree / "assets"
    pages.mkdir(parents=True)
    assets.mkdir(parents=True)
    (pages / "index.md").write_text(
        "---\n"
        'title: "Sample Space"\n'
        'abstractor: "From export"\n'
        'visual: ""\n'
        'space: "sample-space"\n'
        "bubble_type: space\n"
        'source_created_at: "2001-01-02T03:04:05Z"\n'
        "---\n\n"
        "# Sample Space\n\nLanding.\n",
        encoding="utf-8",
    )
    (pages / "notes.md").write_text(
        "---\n"
        'title: "Notes"\n'
        'abstractor: "Scratch"\n'
        'visual: "assets/notes-visual.png"\n'
        'space: "sample-space"\n'
        "bubble_type: article\n"
        'source_created_at: "2001-01-03T04:05:06Z"\n'
        "---\n\n"
        "# Notes\n\nBody text.\n",
        encoding="utf-8",
    )
    (assets / "notes-visual.png").write_bytes(b"\x89PNG\r\n")
    return tree


@pytest.mark.django_db
def test_import_space_tree(content_root, tmp_path):
    tree = _write_sample_tree(tmp_path / "export")
    user = User.objects.create_user(username="imp")
    member = Member.objects.create(
        tenant_id="tenant:a",
        user=user,
        user_engine_user_id="usr_imp",
        issuer="https://local.dev/issuer",
        subject="imp-sub",
        display_name="Importer",
    )
    report = import_space_tree(
        tree,
        tenant_id="tenant:a",
        member=member,
    )
    assert report.pages_copied == 2
    assert report.assets_copied == 1
    assert report.space_created

    space = Space.objects.get(tenant_id="tenant:a", slug="sample-space")
    assert space.title == "Sample Space"
    assert space.description == "From export"
    assert SpaceMembership.objects.filter(space=space, member=member).exists()

    notes = pageops.read_page("sample-space", "notes")
    assert notes.exists
    assert notes.title == "Notes"
    assert "Body text" in notes.body
    assert (pageops.space_dir("sample-space") / "assets" / "notes-visual.png").is_file()

    rendered = load_space_page(space, "notes")
    assert rendered.error is None
    assert rendered.source == "content-plane"
    assert "Body text" in rendered.html


@pytest.mark.django_db
def test_import_refuses_overwrite_without_replace(content_root, tmp_path):
    tree = _write_sample_tree(tmp_path / "export")
    import_space_tree(tree, tenant_id="tenant:a")
    with pytest.raises(pageops.PageOpsError):
        import_space_tree(tree, tenant_id="tenant:a", replace=False)
    report = import_space_tree(tree, tenant_id="tenant:a", replace=True)
    assert report.space_updated or report.space_created
    assert report.pages_copied == 2


@pytest.mark.django_db
def test_import_content_tree_command(content_root, tmp_path, capsys):
    tree = _write_sample_tree(tmp_path / "export")
    call_command("import_content_tree", str(tree), "--tenant", "tenant:cmd", "--dry-run")
    out = capsys.readouterr().out
    assert "Dry run" in out
    assert not Space.objects.filter(slug="sample-space").exists()

    call_command(
        "import_content_tree",
        str(tree),
        "--tenant",
        "tenant:cmd",
        "--slug",
        "cmd-space",
    )
    space = Space.objects.get(slug="cmd-space", tenant_id="tenant:cmd")
    assert space.title == "Sample Space"
    assert pageops.read_page("cmd-space", "index").exists


@pytest.mark.django_db
def test_import_rejects_other_tenant_before_writes(content_root, tmp_path):
    tree = _write_sample_tree(tmp_path / "export")
    member = Member.objects.create(
        tenant_id="tenant:b", user=User.objects.create_user(username="other"),
        user_engine_user_id="other", issuer="https://issuer.test", subject="other",
    )
    with pytest.raises(pageops.PageOpsError, match="another tenant"):
        import_space_tree(tree, tenant_id="tenant:a", member=member)
    assert not content_root.exists()
    assert not Space.objects.exists()


@pytest.mark.django_db
def test_import_rejects_cross_tenant_slug(content_root, tmp_path):
    tree = _write_sample_tree(tmp_path / "export")
    import_space_tree(tree, tenant_id="tenant:a")
    before = pageops.page_file("sample-space", "index").read_bytes()
    with pytest.raises(pageops.PageOpsError, match="another tenant"):
        import_space_tree(tree, tenant_id="tenant:b", replace=True)
    assert pageops.page_file("sample-space", "index").read_bytes() == before
    assert not Space.objects.filter(tenant_id="tenant:b").exists()


@pytest.mark.django_db
def test_import_rejects_symlink_in_dry_run(content_root, tmp_path):
    from django.core.management.base import CommandError

    tree = _write_sample_tree(tmp_path / "export")
    (tree / "assets" / "outside").symlink_to(tmp_path)
    with pytest.raises(CommandError, match="symlink"):
        call_command("import_content_tree", str(tree), "--dry-run")
    assert not content_root.exists()


@pytest.mark.django_db
def test_import_rolls_back_content_on_publish_error(content_root, tmp_path, monkeypatch):
    tree = _write_sample_tree(tmp_path / "export")
    import_space_tree(tree, tenant_id="tenant:a")
    path = pageops.page_file("sample-space", "index")
    original = path.read_bytes()
    meta, _ = pageops.parse_frontmatter((tree / "pages" / "index.md").read_text())
    meta["title"] = "Changed"
    (tree / "pages" / "index.md").write_text(pageops.dump_frontmatter(meta, '# Changed\n'))
    real_rename = Path.rename

    def fail_publish(self, target):
        if self.name == "staged":
            raise OSError("simulated publish failure")
        return real_rename(self, target)

    monkeypatch.setattr(Path, "rename", fail_publish)
    with pytest.raises(OSError, match="simulated"):
        import_space_tree(tree, tenant_id="tenant:a", replace=True)
    assert path.read_bytes() == original
    assert Space.objects.get(slug="sample-space").title == "Sample Space"


@pytest.mark.django_db
def test_single_import_subject_cannot_fall_back_to_other_tenant(content_root, tmp_path):
    from django.core.management.base import CommandError

    tree = _write_sample_tree(tmp_path / "export")
    Member.objects.create(
        tenant_id="tenant:b", user=User.objects.create_user(username="foreign"),
        user_engine_user_id="foreign", issuer="https://issuer.test", subject="foreign",
    )
    with pytest.raises(CommandError, match="exactly one"):
        call_command("import_content_tree", str(tree), tenant="tenant:a",
                     member_subject="foreign", dry_run=True)
    assert not content_root.exists()


@pytest.mark.django_db(transaction=True)
def test_import_restores_tree_when_database_commit_fails(content_root, tmp_path, monkeypatch):
    from django.db import DatabaseError, connection

    tree = _write_sample_tree(tmp_path / "export")
    import_space_tree(tree, tenant_id="tenant:a")
    path = pageops.page_file("sample-space", "index")
    original = path.read_bytes()
    meta, _ = pageops.parse_frontmatter((tree / "pages" / "index.md").read_text())
    meta["title"] = "Changed"
    (tree / "pages" / "index.md").write_text(pageops.dump_frontmatter(meta, '# Changed\n'))

    def fail_commit():
        raise DatabaseError("simulated database commit failure")

    monkeypatch.setattr(connection, "commit", fail_commit)
    with pytest.raises(DatabaseError):
        import_space_tree(tree, tenant_id="tenant:a", replace=True)
    assert path.read_bytes() == original
    assert Space.objects.get(slug="sample-space").title == "Sample Space"


@pytest.mark.django_db
@pytest.mark.parametrize("failure", ["overlap", "page-name", "metadata"])
def test_shared_validation_rejects_bad_trees(content_root, tmp_path, failure):
    from django.core.management.base import CommandError

    tree = _write_sample_tree(tmp_path / "export")
    if failure == "overlap":
        import shutil

        content_root.mkdir()
        shutil.copytree(tree, content_root / "source")
        tree = content_root / "source"
    elif failure == "page-name":
        (tree / "pages" / "notes.md").rename(tree / "pages" / "Bad Name.md")
    else:
        (tree / "pages" / "index.md").write_text(
            '---\ntitle: "' + ('x' * 256) + '"\n---\n\nbody\n'
        )
    with pytest.raises(CommandError):
        call_command("import_content_tree", str(tree), dry_run=True)
    assert not Space.objects.exists()
    assert not (content_root / "spaces").exists()


@pytest.mark.django_db
def test_failed_restore_preserves_previous_tree(content_root, tmp_path, monkeypatch):
    tree = _write_sample_tree(tmp_path / "export")
    import_space_tree(tree, tenant_id="tenant:a")
    original = pageops.page_file("sample-space", "index").read_bytes()
    real_rename = Path.rename

    def fail_publish_and_restore(self, target):
        if self.name in {"staged", "previous"}:
            raise OSError("simulated filesystem failure")
        return real_rename(self, target)

    monkeypatch.setattr(Path, "rename", fail_publish_and_restore)
    with pytest.raises(pageops.PageOpsError, match="retained"):
        import_space_tree(tree, tenant_id="tenant:a", replace=True)
    saved = list((content_root / "spaces").glob(".import-*/previous/pages/index.md"))
    assert len(saved) == 1
    assert saved[0].read_bytes() == original
    assert Space.objects.get(slug="sample-space").title == "Sample Space"