"""Unit tests for TreeView component."""
import shutil

import pytest
from fasthtml.components import *

from myfasthtml.controls.Keyboard import Keyboard
from myfasthtml.controls.TreeView import TreeView, TreeNode
from myfasthtml.test.matcher import matches, TestObject, TestCommand, TestIcon, find_one, find, Contains, DoesNotContain
from .conftest import root_instance


@pytest.fixture(autouse=True)
def cleanup_db():
  shutil.rmtree(".myFastHtmlDb", ignore_errors=True)


class TestTreeviewBehaviour:
  """Tests for TreeView behavior and logic."""
  
  def test_i_can_create_tree_node_with_auto_generated_id(self):
    """Test that TreeNode generates UUID automatically."""
    node = TreeNode(label="Test Node", type="folder")
    
    assert node.id is not None
    assert isinstance(node.id, str)
    assert len(node.id) > 0
  
  def test_i_can_create_tree_node_with_default_values(self):
    """Test that TreeNode has correct default values."""
    node = TreeNode()
    
    assert node.label == ""
    assert node.type == "default"
    assert node.parent is None
    assert node.children == []
  
  def test_i_can_initialize_tree_view_state(self, root_instance):
    """Test that TreeViewState initializes with default values."""
    tree_view = TreeView(root_instance)
    state = tree_view._state
    
    assert isinstance(state.items, dict)
    assert len(state.items) == 0
    assert state.opened == []
    assert state.selected is None
    assert state.editing is None
    assert state.icon_config == {}
  
  def test_i_can_create_empty_treeview(self, root_instance):
    """Test creating an empty TreeView."""
    tree_view = TreeView(root_instance)
    
    assert tree_view is not None
    assert len(tree_view._state.items) == 0
  
  def test_i_can_add_node_to_treeview(self, root_instance):
    """Test adding a root node to the TreeView."""
    tree_view = TreeView(root_instance)
    node = TreeNode(label="Root Node", type="folder")
    
    tree_view.add_node(node)
    
    assert node.id in tree_view._state.items
    assert tree_view._state.items[node.id].label == "Root Node"
    assert tree_view._state.items[node.id].parent is None
  
  def test_i_can_add_child_node(self, root_instance):
    """Test adding a child node to a parent."""
    tree_view = TreeView(root_instance)
    parent = TreeNode(label="Parent", type="folder")
    child = TreeNode(label="Child", type="file")
    
    tree_view.add_node(parent)
    tree_view.add_node(child, parent_id=parent.id)
    
    assert child.id in tree_view._state.items
    assert child.id in parent.children
    assert child.parent == parent.id
  
  def test_i_can_set_icon_config(self, root_instance):
    """Test setting icon configuration."""
    tree_view = TreeView(root_instance)
    config = {
        "folder": "fluent.folder",
        "file": "fluent.document"
    }
    
    tree_view.set_icon_config(config)
    
    assert tree_view._state.icon_config == config
    assert tree_view._state.icon_config["folder"] == "fluent.folder"
  
  def test_i_can_toggle_node(self, root_instance):
    """Test expand/collapse a node."""
    tree_view = TreeView(root_instance)
    node = TreeNode(label="Node", type="folder")
    tree_view.add_node(node)
    
    # Initially closed
    assert node.id not in tree_view._state.opened
    
    # Toggle to open
    tree_view._toggle_node(node.id)
    assert node.id in tree_view._state.opened
    
    # Toggle to close
    tree_view._toggle_node(node.id)
    assert node.id not in tree_view._state.opened
  
  def test_i_can_expand_all_nodes(self, root_instance):
    """Test that expand_all opens all nodes with children."""
    tree_view = TreeView(root_instance)
    
    # Create hierarchy: root -> child1 -> grandchild
    #                        -> child2 (leaf)
    root = TreeNode(label="Root", type="folder")
    child1 = TreeNode(label="Child 1", type="folder")
    grandchild = TreeNode(label="Grandchild", type="file")
    child2 = TreeNode(label="Child 2", type="file")
    
    tree_view.add_node(root)
    tree_view.add_node(child1, parent_id=root.id)
    tree_view.add_node(grandchild, parent_id=child1.id)
    tree_view.add_node(child2, parent_id=root.id)
    
    # Initially all closed
    assert len(tree_view._state.opened) == 0
    
    # Expand all
    tree_view.expand_all()
    
    # Nodes with children should be opened
    assert root.id in tree_view._state.opened
    assert child1.id in tree_view._state.opened
    
    # Leaf nodes should not be in opened list
    assert grandchild.id not in tree_view._state.opened
    assert child2.id not in tree_view._state.opened
  
  def test_i_can_select_node(self, root_instance):
    """Test selecting a node."""
    tree_view = TreeView(root_instance)
    node = TreeNode(label="Node", type="folder")
    tree_view.add_node(node)
    
    tree_view._select_node(node.id)
    
    assert tree_view._state.selected == node.id
  
  def test_i_can_start_rename_node(self, root_instance):
    """Test starting rename mode for a node."""
    tree_view = TreeView(root_instance)
    node = TreeNode(label="Old Name", type="folder")
    tree_view.add_node(node)
    
    tree_view._start_rename(node.id)
    
    assert tree_view._state.editing == node.id
  
  def test_i_can_save_rename_node(self, root_instance):
    """Test saving renamed node with new label."""
    tree_view = TreeView(root_instance)
    node = TreeNode(label="Old Name", type="folder")
    tree_view.add_node(node)
    tree_view._start_rename(node.id)
    
    tree_view._save_rename(node.id, "New Name")
    
    assert tree_view._state.items[node.id].label == "New Name"
    assert tree_view._state.editing is None
  
  def test_i_can_cancel_rename_node(self, root_instance):
    """Test canceling rename operation."""
    tree_view = TreeView(root_instance)
    node = TreeNode(label="Name", type="folder")
    tree_view.add_node(node)
    tree_view._start_rename(node.id)
    
    tree_view._cancel_rename()
    
    assert tree_view._state.editing is None
    assert tree_view._state.items[node.id].label == "Name"
  
  def test_i_can_delete_leaf_node(self, root_instance):
    """Test deleting a node without children."""
    tree_view = TreeView(root_instance)
    parent = TreeNode(label="Parent", type="folder")
    child = TreeNode(label="Child", type="file")
    
    tree_view.add_node(parent)
    tree_view.add_node(child, parent_id=parent.id)
    
    # Delete child (leaf node)
    tree_view._delete_node(child.id)
    
    assert child.id not in tree_view._state.items
    assert child.id not in parent.children
  
  def test_i_can_add_sibling_node(self, root_instance):
    """Test adding a sibling node."""
    tree_view = TreeView(root_instance)
    parent = TreeNode(label="Parent", type="folder")
    child1 = TreeNode(label="Child 1", type="file")
    
    tree_view.add_node(parent)
    tree_view.add_node(child1, parent_id=parent.id)
    
    # Add sibling to child1
    tree_view._add_sibling(child1.id, new_label="Child 2")
    
    assert len(parent.children) == 2
    # Sibling should be after child1
    assert parent.children.index(child1.id) < len(parent.children) - 1
  
  def test_i_cannot_delete_node_with_children(self, root_instance):
    """Test that deleting a node with children raises an error."""
    tree_view = TreeView(root_instance)
    parent = TreeNode(label="Parent", type="folder")
    child = TreeNode(label="Child", type="file")
    
    tree_view.add_node(parent)
    tree_view.add_node(child, parent_id=parent.id)
    
    # Try to delete parent (has children)
    with pytest.raises(ValueError, match="Cannot delete node.*with children"):
      tree_view._delete_node(parent.id)
  
  def test_i_cannot_add_sibling_to_root(self, root_instance):
    """Test that adding sibling to root node raises an error."""
    tree_view = TreeView(root_instance)
    root = TreeNode(label="Root", type="folder")
    tree_view.add_node(root)
    
    # Try to add sibling to root (no parent)
    with pytest.raises(ValueError, match="Cannot add sibling to root node"):
      tree_view._add_sibling(root.id)
  
  def test_i_cannot_select_nonexistent_node(self, root_instance):
    """Test that selecting a nonexistent node raises an error."""
    tree_view = TreeView(root_instance)
    
    # Try to select node that doesn't exist
    with pytest.raises(ValueError, match="Node.*does not exist"):
      tree_view._select_node("nonexistent_id")
  
  def test_add_node_prevents_duplicate_children(self, root_instance):
    """Test that add_node prevents adding duplicate child IDs."""
    tree_view = TreeView(root_instance)
    parent = TreeNode(label="Parent", type="folder")
    child = TreeNode(label="Child", type="file")
    
    tree_view.add_node(parent)
    tree_view.add_node(child, parent_id=parent.id)
    
    # Try to add the same child again
    tree_view.add_node(child, parent_id=parent.id)
    
    # Child should appear only once in parent's children list
    assert parent.children.count(child.id) == 1
  
  def test_sibling_is_inserted_at_correct_position(self, root_instance):
    """Test that _add_sibling inserts sibling exactly after reference node."""
    tree_view = TreeView(root_instance)
    parent = TreeNode(label="Parent", type="folder")
    child1 = TreeNode(label="Child 1", type="file")
    child3 = TreeNode(label="Child 3", type="file")
    
    tree_view.add_node(parent)
    tree_view.add_node(child1, parent_id=parent.id)
    tree_view.add_node(child3, parent_id=parent.id)
    
    # Add sibling after child1
    tree_view._add_sibling(child1.id, new_label="Child 2")
    
    # Get the newly added sibling
    sibling_id = parent.children[1]
    
    # Verify order: child1, sibling (child2), child3
    assert parent.children[0] == child1.id
    assert tree_view._state.items[sibling_id].label == "Child 2"
    assert parent.children[2] == child3.id
    assert len(parent.children) == 3
  
  def test_add_child_auto_expands_parent(self, root_instance):
    """Test that _add_child automatically expands the parent node."""
    tree_view = TreeView(root_instance)
    parent = TreeNode(label="Parent", type="folder")
    
    tree_view.add_node(parent)
    
    # Parent should not be expanded initially
    assert parent.id not in tree_view._state.opened
    
    # Add child
    tree_view._add_child(parent.id, new_label="Child")
    
    # Parent should now be expanded
    assert parent.id in tree_view._state.opened
  
  def test_i_cannot_add_child_to_nonexistent_parent(self, root_instance):
    """Test that adding child to nonexistent parent raises error."""
    tree_view = TreeView(root_instance)
    
    # Try to add child to parent that doesn't exist
    with pytest.raises(ValueError, match="Parent node.*does not exist"):
      tree_view._add_child("nonexistent_parent_id")
  
  def test_delete_node_clears_selection_if_selected(self, root_instance):
    """Test that deleting a selected node clears the selection."""
    tree_view = TreeView(root_instance)
    parent = TreeNode(label="Parent", type="folder")
    child = TreeNode(label="Child", type="file")
    
    tree_view.add_node(parent)
    tree_view.add_node(child, parent_id=parent.id)
    
    # Select the child
    tree_view._select_node(child.id)
    assert tree_view._state.selected == child.id
    
    # Delete the selected child
    tree_view._delete_node(child.id)
    
    # Selection should be cleared
    assert tree_view._state.selected is None
  
  def test_delete_node_removes_from_opened_if_expanded(self, root_instance):
    """Test that deleting an expanded node removes it from opened list."""
    tree_view = TreeView(root_instance)
    parent = TreeNode(label="Parent", type="folder")
    child = TreeNode(label="Child", type="file")
    
    tree_view.add_node(parent)
    tree_view.add_node(child, parent_id=parent.id)
    
    # Expand the parent
    tree_view._toggle_node(parent.id)
    assert parent.id in tree_view._state.opened
    
    # Delete the child (making parent a leaf)
    tree_view._delete_node(child.id)
    
    # Now delete the parent (now a leaf node)
    # First remove it from root by creating a grandparent
    grandparent = TreeNode(label="Grandparent", type="folder")
    tree_view.add_node(grandparent)
    parent.parent = grandparent.id
    grandparent.children.append(parent.id)
    
    tree_view._delete_node(parent.id)
    
    # Parent should be removed from opened list
    assert parent.id not in tree_view._state.opened
  
  def test_i_cannot_start_rename_nonexistent_node(self, root_instance):
    """Test that starting rename on nonexistent node raises error."""
    tree_view = TreeView(root_instance)
    
    # Try to start rename on node that doesn't exist
    with pytest.raises(ValueError, match="Node.*does not exist"):
      tree_view._start_rename("nonexistent_id")
  
  def test_i_cannot_save_rename_nonexistent_node(self, root_instance):
    """Test that saving rename for nonexistent node raises error."""
    tree_view = TreeView(root_instance)
    
    # Try to save rename for node that doesn't exist
    with pytest.raises(ValueError, match="Node.*does not exist"):
      tree_view._save_rename("nonexistent_id", "New Name")
  
  def test_i_cannot_add_sibling_to_nonexistent_node(self, root_instance):
    """Test that adding sibling to nonexistent node raises error."""
    tree_view = TreeView(root_instance)
    
    # Try to add sibling to node that doesn't exist
    with pytest.raises(ValueError, match="Node.*does not exist"):
      tree_view._add_sibling("nonexistent_id")


class TestTreeViewRender:
  """Tests for TreeView HTML rendering."""
  
  def test_empty_treeview_is_rendered(self, root_instance):
    """Test that empty TreeView generates correct HTML structure.

    Why these elements matter:
    - TestObject Keyboard: Essential for keyboard shortcuts (Escape to cancel rename)
    - _id: Required for HTMX targeting and component identification
    - cls "mf-treeview": Root CSS class for TreeView styling
    """
    # Step 1: Create empty TreeView
    tree_view = TreeView(root_instance)

    # Step 2: Define expected structure
    expected = Div(
      TestObject(Keyboard, combinations={"esc": TestCommand("CancelRename")}),
      _id=tree_view.get_id(),
      cls="mf-treeview"
    )

    # Step 3: Compare
    assert matches(tree_view.__ft__(), expected)
  
  @pytest.fixture
  def tree_view(self, root_instance):
    return TreeView(root_instance)

  def test_node_with_children_collapsed_is_rendered(self, tree_view):
    """Test that a collapsed node with children renders correctly.

    Why these elements matter:
    - TestIcon chevron_right: Indicates visually that the node is collapsed
    - Span with label: Displays the node's text content
    - Action buttons (add_child, edit, delete): Enable user interactions
    - cls "mf-treenode": Required CSS class for node styling
    - data_node_id: Essential for identifying the node in DOM operations
    - No children in container: Verifies children are hidden when collapsed
    """
    parent = TreeNode(label="Parent", type="folder")
    child = TreeNode(label="Child", type="file")

    tree_view.add_node(parent)
    tree_view.add_node(child, parent_id=parent.id)

    # Step 1: Extract the node element to test
    rendered = tree_view.render()
    node_container = find_one(rendered, Div(data_node_id=parent.id))

    # Step 2: Define expected structure
    expected = Div(
      TestIcon("chevron_right20_regular"),  # Collapsed toggle icon
      Span("Parent"),  # Label
      Div(  # Action buttons
        TestIcon("add_circle20_regular"),
        TestIcon("edit20_regular"),
        TestIcon("delete20_regular"),
        cls=Contains("mf-treenode-actions")
      ),
      cls=Contains("mf-treenode"),
      data_node_id=parent.id
    )

    # Step 3: Compare
    assert matches(node_container, expected)

    # Verify no children are rendered (collapsed)
    child_containers = find(node_container, Div(data_node_id=child.id))
    assert len(child_containers) == 0, "Children should not be rendered when node is collapsed"

  def test_node_with_children_expanded_is_rendered(self, tree_view):
    """Test that an expanded node with children renders correctly.

    Why these elements matter:
    - TestIcon chevron_down: Indicates visually that the node is expanded
    - Children rendered: Verifies that child nodes are visible when parent is expanded
    - Child has its own node structure: Ensures recursive rendering works correctly
    """
    parent = TreeNode(label="Parent", type="folder")
    child = TreeNode(label="Child", type="file")

    tree_view.add_node(parent)
    tree_view.add_node(child, parent_id=parent.id)
    tree_view._toggle_node(parent.id)  # Expand the parent

    # Step 1: Extract the parent node element to test
    rendered = tree_view.render()
    parent_node = find_one(rendered, Div(data_node_id=parent.id))

    # Step 2: Define expected structure for toggle icon
    expected = Div(
      TestIcon("chevron_down20_regular"),  # Expanded toggle icon
      cls=Contains("mf-treenode")
    )

    # Step 3: Compare
    assert matches(parent_node, expected)

    # Verify children ARE rendered (expanded)
    child_containers = find(rendered, Div(data_node_id=child.id))
    assert len(child_containers) == 1, "Child should be rendered when parent is expanded"

    # Verify child has proper node structure
    child_node = child_containers[0]
    child_expected = Div(
      Span("Child"),
      cls=Contains("mf-treenode"),
      data_node_id=child.id
    )
    assert matches(child_node, child_expected)

  def test_leaf_node_is_rendered(self, tree_view):
    """Test that a leaf node (no children) renders without toggle icon.

    Why these elements matter:
    - No toggle icon (or empty space): Leaf nodes don't need expand/collapse functionality
    - Span with label: Displays the node's text content
    - Action buttons present: Even leaf nodes can be edited, deleted, or receive children
    """
    leaf = TreeNode(label="Leaf Node", type="file")
    tree_view.add_node(leaf)

    # Step 1: Extract the leaf node element to test
    rendered = tree_view.render()
    leaf_node = find_one(rendered, Div(data_node_id=leaf.id))

    # Step 2: Define expected structure
    expected = Div(
      Span("Leaf Node"),  # Label
      Div(  # Action buttons still present
        TestIcon("add_circle20_regular"),
        TestIcon("edit20_regular"),
        TestIcon("delete20_regular"),
        cls=Contains("mf-treenode-actions")
      ),
      cls=Contains("mf-treenode"),
      data_node_id=leaf.id
    )

    # Step 3: Compare
    assert matches(leaf_node, expected)

  def test_selected_node_has_selected_class(self, tree_view):
    """Test that a selected node has the 'selected' CSS class.

    Why these elements matter:
    - cls Contains "selected": Enables visual highlighting of the selected node
    - data_node_id: Required for identifying which node is selected
    """
    node = TreeNode(label="Selected Node", type="file")
    tree_view.add_node(node)
    tree_view._select_node(node.id)

    # Step 1: Extract the selected node element to test
    rendered = tree_view.render()
    selected_node = find_one(rendered, Div(data_node_id=node.id))

    # Step 2: Define expected structure
    expected = Div(
      cls=Contains("mf-treenode", "selected"),
      data_node_id=node.id
    )

    # Step 3: Compare
    assert matches(selected_node, expected)

  def test_node_in_editing_mode_shows_input(self, tree_view):
    """Test that a node in editing mode renders an Input instead of Span.

    Why these elements matter:
    - Input element: Enables user to modify the node label inline
    - cls "mf-treenode-input": Required CSS class for input field styling
    - name "node_label": Essential for form data submission
    - value with current label: Pre-fills the input with existing text
    - cls does NOT contain "selected": Avoids double highlighting during editing
    """
    node = TreeNode(label="Edit Me", type="file")
    tree_view.add_node(node)
    tree_view._start_rename(node.id)

    # Step 1: Extract the editing node element to test
    rendered = tree_view.render()
    editing_node = find_one(rendered, Div(data_node_id=node.id))

    # Step 2: Define expected structure
    expected = Div(
      Input(
        name="node_label",
        value="Edit Me",
        cls=Contains("mf-treenode-input")
      ),
      cls=Contains("mf-treenode"),
      data_node_id=node.id
    )

    # Step 3: Compare
    assert matches(editing_node, expected)

    # Verify "selected" class is NOT present
    no_selected = Div(
      cls=DoesNotContain("selected")
    )
    assert matches(editing_node, no_selected)

  def test_node_indentation_increases_with_level(self, tree_view):
    """Test that node indentation increases correctly with hierarchy level.

    Why these elements matter:
    - style Contains "padding-left: 0px": Root node has no indentation
    - style Contains "padding-left: 20px": Child is indented by 20px
    - style Contains "padding-left: 40px": Grandchild is indented by 40px
    - Progressive padding: Creates the visual hierarchy of the tree structure
    """
    root = TreeNode(label="Root", type="folder")
    child = TreeNode(label="Child", type="folder")
    grandchild = TreeNode(label="Grandchild", type="file")

    tree_view.add_node(root)
    tree_view.add_node(child, parent_id=root.id)
    tree_view.add_node(grandchild, parent_id=child.id)

    # Expand all to make hierarchy visible
    tree_view._toggle_node(root.id)
    tree_view._toggle_node(child.id)

    rendered = tree_view.render()

    # Step 1 & 2 & 3: Test root node (level 0)
    root_node = find_one(rendered, Div(data_node_id=root.id))
    root_expected = Div(
      style=Contains("padding-left: 0px")
    )
    assert matches(root_node, root_expected)

    # Step 1 & 2 & 3: Test child node (level 1)
    child_node = find_one(rendered, Div(data_node_id=child.id))
    child_expected = Div(
      style=Contains("padding-left: 20px")
    )
    assert matches(child_node, child_expected)

    # Step 1 & 2 & 3: Test grandchild node (level 2)
    grandchild_node = find_one(rendered, Div(data_node_id=grandchild.id))
    grandchild_expected = Div(
      style=Contains("padding-left: 40px")
    )
    assert matches(grandchild_node, grandchild_expected)