"""EPIC R08-T12: WorkspaceFileTree / DocumentPreviewManager / FolderTab,
real Qt offscreen.

Scope note: the AI-Edit panel's send -> plan -> edit -> apply pipeline
(``ai_edit_pipeline.py``) runs on a real ``core.worker.AgentWorker`` QThread
and had ZERO existing tests before this task (confirmed by grep — nothing
under tests/ exercised ``ui/folder_tab.py``'s AI methods except the routing
surface test, fixed alongside this task in
``tests/integration/test_routing_surfaces.py``). Driving that full async
pipeline end to end is out of scope here; what's covered is everything that
doesn't need a live QThread: navigation, preview rendering, and — the
concrete R08-T12 deliverable — that saves/creates actually go through
``FileWorkspaceService`` (containment enforced, not just "writes a file").
"""
from __future__ import annotations

import os
from pathlib import Path

import pytest

os.environ.setdefault("QT_QPA_PLATFORM", "offscreen")

from cowork_local.config import AppConfig  # noqa: E402
from cowork_local.state import AppContext  # noqa: E402

pytest.importorskip("PySide6", reason="Qt is required for the integration suite")


@pytest.fixture(scope="module")
def qt_app():
    from PySide6.QtWidgets import QApplication

    return QApplication.instance() or QApplication([])


@pytest.fixture
def ctx(qt_app, tmp_path: Path):
    return AppContext(AppConfig.load(tmp_path / "config.json"))


@pytest.fixture
def root(tmp_path: Path) -> Path:
    d = tmp_path / "workspace"
    d.mkdir()
    return d


# ---- WorkspaceFileTree ----------------------------------------------------- #
def test_workspace_file_tree_set_root_updates_label_and_model(qt_app, root):
    from cowork_local.presentation.folder.workspace_file_tree import WorkspaceFileTree

    tree = WorkspaceFileTree(str(root))
    other = root.parent / "other-root"
    other.mkdir()

    tree.set_root(str(other))

    assert tree.root == str(other)
    assert tree.path_lbl.text() == str(other)


def test_workspace_file_tree_ignores_an_invalid_root(qt_app, root):
    from cowork_local.presentation.folder.workspace_file_tree import WorkspaceFileTree

    tree = WorkspaceFileTree(str(root))
    tree.set_root(str(root / "does-not-exist"))

    assert tree.root == str(root)   # unchanged


def test_workspace_file_tree_click_emits_file_selected(qt_app, root):
    from cowork_local.presentation.folder.workspace_file_tree import WorkspaceFileTree

    f = root / "a.txt"
    f.write_text("hello", encoding="utf-8")
    tree = WorkspaceFileTree(str(root))
    seen = []
    tree.file_selected.connect(seen.append)

    index = tree.model.index(str(f))
    tree._on_tree_clicked(index)

    assert seen and os.path.normpath(seen[0]) == os.path.normpath(str(f))


# ---- DocumentPreviewManager ------------------------------------------------- #
def test_open_file_renders_code_into_the_editor(qt_app, root):
    from cowork_local.presentation.folder.document_preview_manager import DocumentPreviewManager

    f = root / "script.py"
    f.write_text("print('hi')\n", encoding="utf-8")
    preview = DocumentPreviewManager(str(root))

    preview.open_file(str(f))

    assert preview.stack.currentWidget() is preview.editor
    assert preview.editor.toPlainText() == "print('hi')\n"
    assert preview.current_file == str(f)


def test_open_file_on_a_binary_file_shows_the_placeholder(qt_app, root):
    from cowork_local.presentation.folder.document_preview_manager import DocumentPreviewManager

    f = root / "data.bin"
    f.write_bytes(b"\x00\x01\x02binary")
    preview = DocumentPreviewManager(str(root))

    preview.open_file(str(f))

    assert preview.stack.currentWidget() is preview._placeholder


def test_save_writes_through_file_workspace_service(qt_app, root):
    """The concrete R08-T12/R06-T05 deliverable: FileWorkspaceService (built
    at R06, unused until this task) is now the actual write path."""
    from cowork_local.presentation.folder.document_preview_manager import DocumentPreviewManager

    f = root / "note.txt"
    f.write_text("old", encoding="utf-8")
    preview = DocumentPreviewManager(str(root))
    preview.open_file(str(f))

    preview.editor.setPlainText("new content")
    preview.save()

    assert f.read_text(encoding="utf-8") == "new content"


def test_create_new_file_writes_inside_root_via_file_workspace_service(qt_app, root):
    from cowork_local.presentation.folder.document_preview_manager import DocumentPreviewManager

    preview = DocumentPreviewManager(str(root))

    dest = preview.create_new_file("sub/new.md", "# hello")

    assert dest == str(root / "sub" / "new.md")
    assert (root / "sub" / "new.md").read_text(encoding="utf-8") == "# hello"
    assert preview.current_file == dest   # opened it, kept the AI chat (reset_ai=False)


def test_create_new_file_rejects_a_path_escaping_the_root(qt_app, root):
    from cowork_local.presentation.folder.document_preview_manager import DocumentPreviewManager

    preview = DocumentPreviewManager(str(root))
    messages = []
    preview.status_message.connect(messages.append)

    dest = preview.create_new_file("../escaped.txt", "nope")

    assert dest is None
    assert not (root.parent / "escaped.txt").exists()
    assert messages   # a save_error status was emitted


def test_write_content_persists_and_refreshes_html_preview(qt_app, root):
    from cowork_local.presentation.folder.document_preview_manager import DocumentPreviewManager

    f = root / "page.html"
    f.write_text("<p>old</p>", encoding="utf-8")
    preview = DocumentPreviewManager(str(root))
    preview.open_file(str(f))   # HTML opens in preview mode by default

    preview.write_content("<p>new</p>")

    assert f.read_text(encoding="utf-8") == "<p>new</p>"


# ---- FolderTab shell -------------------------------------------------------- #
def test_folder_tab_builds_and_wires_tree_to_preview(ctx, root):
    from cowork_local.presentation.folder.folder_tab import FolderTab

    tab = FolderTab(ctx)
    tab.set_root(str(root))
    f = root / "hello.py"
    f.write_text("x = 1\n", encoding="utf-8")

    tab.tree.file_selected.emit(str(f))   # simulate a tree click

    assert tab.preview.current_file == str(f)
    assert tab.preview.editor.toPlainText() == "x = 1\n"


def test_folder_tab_ai_panel_toggle_updates_button_badge(ctx, root):
    from cowork_local.presentation.folder.folder_tab import FolderTab

    tab = FolderTab(ctx)
    assert tab.ai_panel.isHidden()

    tab.ai_btn.setChecked(True)
    tab._toggle_ai_panel()

    assert not tab.ai_panel.isHidden()