#include <XCEditor/Shell/UIEditorPanelRegistry.h>
#include <XCEditor/Shell/UIEditorWorkspaceModel.h>
#include <XCEditor/Shell/UIEditorWorkspaceSession.h>

#include <cmath>
#include <unordered_set>
#include <utility>

namespace XCEngine::UI::Editor {

namespace {

UIEditorWorkspaceValidationResult MakeValidationError(
    UIEditorWorkspaceValidationCode code,
    std::string message) {
    UIEditorWorkspaceValidationResult result = {};
    result.code = code;
    result.message = std::move(message);
    return result;
}

bool IsValidSplitRatio(float value) {
    return std::isfinite(value) && value > 0.0f && value < 1.0f;
}

std::string BuildSingleTabPanelNodeId(std::string_view stackNodeId) {
    if (stackNodeId.empty()) {
        return "single-tab-panel";
    }

    return std::string(stackNodeId) + "__panel";
}

UIEditorWorkspaceNode WrapStandalonePanelAsTabStack(UIEditorWorkspaceNode panelNode) {
    UIEditorWorkspaceNode panelChild = std::move(panelNode);
    const std::string stackNodeId = panelChild.nodeId;
    panelChild.nodeId = BuildSingleTabPanelNodeId(stackNodeId);

    UIEditorWorkspaceNode tabStack = {};
    tabStack.kind = UIEditorWorkspaceNodeKind::TabStack;
    tabStack.nodeId = stackNodeId;
    tabStack.selectedTabIndex = 0u;
    tabStack.children.push_back(std::move(panelChild));
    return tabStack;
}

void CollapseSplitNodeToOnlyChild(UIEditorWorkspaceNode& node) {
    if (node.kind != UIEditorWorkspaceNodeKind::Split ||
        node.children.size() != 1u) {
        return;
    }

    // Move the remaining child through a temporary object first. Assigning
    // directly from node.children.front() aliases a subobject of node and can
    // trigger use-after-move when the vector storage is torn down.
    UIEditorWorkspaceNode remainingChild = std::move(node.children.front());
    node = std::move(remainingChild);
}

void CanonicalizeNodeRecursive(
    UIEditorWorkspaceNode& node,
    bool allowStandalonePanelLeaf) {
    if (node.kind == UIEditorWorkspaceNodeKind::Panel) {
        if (!allowStandalonePanelLeaf) {
            node = WrapStandalonePanelAsTabStack(std::move(node));
        }
        return;
    }

    for (UIEditorWorkspaceNode& child : node.children) {
        CanonicalizeNodeRecursive(
            child,
            node.kind == UIEditorWorkspaceNodeKind::TabStack);
    }

    if (node.kind == UIEditorWorkspaceNodeKind::TabStack &&
        !node.children.empty() &&
        node.selectedTabIndex >= node.children.size()) {
        node.selectedTabIndex = node.children.size() - 1u;
    }

    if (node.kind == UIEditorWorkspaceNodeKind::Split &&
        node.children.size() == 1u) {
        CollapseSplitNodeToOnlyChild(node);
    }
}

const UIEditorPanelDescriptor& RequirePanelDescriptor(
    const UIEditorPanelRegistry& registry,
    std::string_view panelId) {
    if (const UIEditorPanelDescriptor* descriptor = FindUIEditorPanelDescriptor(registry, panelId);
        descriptor != nullptr) {
        return *descriptor;
    }

    static const UIEditorPanelDescriptor fallbackDescriptor = {};
    return fallbackDescriptor;
}

const UIEditorWorkspacePanelState* FindPanelRecursive(
    const UIEditorWorkspaceNode& node,
    std::string_view panelId) {
    if (node.kind == UIEditorWorkspaceNodeKind::Panel) {
        return node.panel.panelId == panelId ? &node.panel : nullptr;
    }

    for (const UIEditorWorkspaceNode& child : node.children) {
        if (const UIEditorWorkspacePanelState* found = FindPanelRecursive(child, panelId)) {
            return found;
        }
    }

    return nullptr;
}

const UIEditorWorkspaceNode* FindNodeRecursive(
    const UIEditorWorkspaceNode& node,
    std::string_view nodeId) {
    if (node.nodeId == nodeId) {
        return &node;
    }

    for (const UIEditorWorkspaceNode& child : node.children) {
        if (const UIEditorWorkspaceNode* found = FindNodeRecursive(child, nodeId)) {
            return found;
        }
    }

    return nullptr;
}

UIEditorWorkspaceNode* FindMutableNodeRecursive(
    UIEditorWorkspaceNode& node,
    std::string_view nodeId) {
    if (node.nodeId == nodeId) {
        return &node;
    }

    for (UIEditorWorkspaceNode& child : node.children) {
        if (UIEditorWorkspaceNode* found = FindMutableNodeRecursive(child, nodeId)) {
            return found;
        }
    }

    return nullptr;
}

bool FindNodePathRecursive(
    const UIEditorWorkspaceNode& node,
    std::string_view nodeId,
    std::vector<std::size_t>& path) {
    if (node.nodeId == nodeId) {
        return true;
    }

    for (std::size_t index = 0; index < node.children.size(); ++index) {
        path.push_back(index);
        if (FindNodePathRecursive(node.children[index], nodeId, path)) {
            return true;
        }
        path.pop_back();
    }

    return false;
}

UIEditorWorkspaceNode* ResolveMutableNodeByPath(
    UIEditorWorkspaceNode& node,
    const std::vector<std::size_t>& path) {
    UIEditorWorkspaceNode* current = &node;
    for (const std::size_t childIndex : path) {
        if (childIndex >= current->children.size()) {
            return nullptr;
        }
        current = &current->children[childIndex];
    }

    return current;
}

bool IsPanelOpenAndVisibleInSession(
    const UIEditorWorkspaceSession& session,
    std::string_view panelId) {
    const UIEditorPanelSessionState* state = FindUIEditorPanelSessionState(session, panelId);
    return state != nullptr && state->open && state->visible;
}

std::size_t CountVisibleChildren(
    const UIEditorWorkspaceNode& node,
    const UIEditorWorkspaceSession& session) {
    if (node.kind != UIEditorWorkspaceNodeKind::TabStack) {
        return 0u;
    }

    std::size_t visibleCount = 0u;
    for (const UIEditorWorkspaceNode& child : node.children) {
        if (child.kind == UIEditorWorkspaceNodeKind::Panel &&
            IsPanelOpenAndVisibleInSession(session, child.panel.panelId)) {
            ++visibleCount;
        }
    }

    return visibleCount;
}

std::size_t ResolveActualInsertionIndexForVisibleInsertion(
    const UIEditorWorkspaceNode& node,
    const UIEditorWorkspaceSession& session,
    std::size_t targetVisibleInsertionIndex) {
    std::vector<std::size_t> visibleIndices = {};
    visibleIndices.reserve(node.children.size());
    for (std::size_t index = 0; index < node.children.size(); ++index) {
        const UIEditorWorkspaceNode& child = node.children[index];
        if (child.kind == UIEditorWorkspaceNodeKind::Panel &&
            IsPanelOpenAndVisibleInSession(session, child.panel.panelId)) {
            visibleIndices.push_back(index);
        }
    }

    if (targetVisibleInsertionIndex == 0u) {
        return visibleIndices.empty() ? 0u : visibleIndices.front();
    }

    if (visibleIndices.empty()) {
        return 0u;
    }

    if (targetVisibleInsertionIndex >= visibleIndices.size()) {
        return visibleIndices.back() + 1u;
    }

    return visibleIndices[targetVisibleInsertionIndex];
}

void FixTabStackSelectedIndex(
    UIEditorWorkspaceNode& node,
    std::string_view preferredPanelId) {
    if (node.kind != UIEditorWorkspaceNodeKind::TabStack || node.children.empty()) {
        return;
    }

    for (std::size_t index = 0; index < node.children.size(); ++index) {
        if (node.children[index].kind == UIEditorWorkspaceNodeKind::Panel &&
            node.children[index].panel.panelId == preferredPanelId) {
            node.selectedTabIndex = index;
            return;
        }
    }

    if (node.selectedTabIndex >= node.children.size()) {
        node.selectedTabIndex = node.children.size() - 1u;
    }
}

bool RemoveNodeByIdRecursive(
    UIEditorWorkspaceNode& node,
    std::string_view nodeId) {
    if (node.kind != UIEditorWorkspaceNodeKind::Split) {
        return false;
    }

    for (std::size_t index = 0; index < node.children.size(); ++index) {
        if (node.children[index].nodeId == nodeId) {
            node.children.erase(node.children.begin() + static_cast<std::ptrdiff_t>(index));
            if (node.children.size() == 1u) {
                CollapseSplitNodeToOnlyChild(node);
            }
            return true;
        }
    }

    for (UIEditorWorkspaceNode& child : node.children) {
        if (RemoveNodeByIdRecursive(child, nodeId)) {
            if (node.kind == UIEditorWorkspaceNodeKind::Split &&
                node.children.size() == 1u) {
                CollapseSplitNodeToOnlyChild(node);
            }
            return true;
        }
    }

    return false;
}

float ClampDockSplitRatio(float value) {
    constexpr float kMinRatio = 0.1f;
    constexpr float kMaxRatio = 0.9f;
    return (std::min)(kMaxRatio, (std::max)(kMinRatio, value));
}

bool IsLeadingDockPlacement(UIEditorWorkspaceDockPlacement placement) {
    return placement == UIEditorWorkspaceDockPlacement::Left ||
        placement == UIEditorWorkspaceDockPlacement::Top;
}

UIEditorWorkspaceSplitAxis ResolveDockSplitAxis(UIEditorWorkspaceDockPlacement placement) {
    return placement == UIEditorWorkspaceDockPlacement::Left ||
            placement == UIEditorWorkspaceDockPlacement::Right
        ? UIEditorWorkspaceSplitAxis::Horizontal
        : UIEditorWorkspaceSplitAxis::Vertical;
}

std::string MakeUniqueNodeId(
    const UIEditorWorkspaceModel& workspace,
    std::string base) {
    if (base.empty()) {
        base = "workspace-node";
    }

    if (FindUIEditorWorkspaceNode(workspace, base) == nullptr) {
        return base;
    }

    for (std::size_t suffix = 1u; suffix < 1024u; ++suffix) {
        const std::string candidate = base + "-" + std::to_string(suffix);
        if (FindUIEditorWorkspaceNode(workspace, candidate) == nullptr) {
            return candidate;
        }
    }

    return base + "-overflow";
}

bool TryExtractVisiblePanelFromTabStack(
    UIEditorWorkspaceModel& workspace,
    const UIEditorWorkspaceSession& session,
    std::string_view sourceNodeId,
    std::string_view panelId,
    UIEditorWorkspaceNode& extractedPanel) {
    std::vector<std::size_t> sourcePath = {};
    if (!FindNodePathRecursive(workspace.root, sourceNodeId, sourcePath)) {
        return false;
    }

    UIEditorWorkspaceNode* sourceStack =
        ResolveMutableNodeByPath(workspace.root, sourcePath);
    if (sourceStack == nullptr ||
        sourceStack->kind != UIEditorWorkspaceNodeKind::TabStack) {
        return false;
    }

    std::size_t panelIndex = sourceStack->children.size();
    for (std::size_t index = 0; index < sourceStack->children.size(); ++index) {
        const UIEditorWorkspaceNode& child = sourceStack->children[index];
        if (child.kind != UIEditorWorkspaceNodeKind::Panel) {
            return false;
        }

        if (child.panel.panelId == panelId) {
            if (!IsPanelOpenAndVisibleInSession(session, panelId)) {
                return false;
            }
            panelIndex = index;
            break;
        }
    }

    if (panelIndex >= sourceStack->children.size()) {
        return false;
    }

    if (sourcePath.empty() && sourceStack->children.size() == 1u) {
        return false;
    }

    std::string fallbackSelectedPanelId = {};
    if (sourceStack->selectedTabIndex < sourceStack->children.size()) {
        fallbackSelectedPanelId =
            sourceStack->children[sourceStack->selectedTabIndex].panel.panelId;
    }

    extractedPanel = std::move(sourceStack->children[panelIndex]);
    sourceStack->children.erase(
        sourceStack->children.begin() + static_cast<std::ptrdiff_t>(panelIndex));

    if (sourceStack->children.empty()) {
        if (sourcePath.empty()) {
            return false;
        }

        if (!RemoveNodeByIdRecursive(workspace.root, sourceNodeId)) {
            return false;
        }
    } else {
        if (fallbackSelectedPanelId == panelId) {
            const std::size_t nextIndex =
                (std::min)(panelIndex, sourceStack->children.size() - 1u);
            fallbackSelectedPanelId =
                sourceStack->children[nextIndex].panel.panelId;
        }
        FixTabStackSelectedIndex(*sourceStack, fallbackSelectedPanelId);
    }

    workspace = CanonicalizeUIEditorWorkspaceModel(std::move(workspace));
    return true;
}

bool TryActivateRecursive(
    UIEditorWorkspaceNode& node,
    std::string_view panelId) {
    switch (node.kind) {
    case UIEditorWorkspaceNodeKind::Panel:
        return node.panel.panelId == panelId;

    case UIEditorWorkspaceNodeKind::TabStack:
        for (std::size_t index = 0; index < node.children.size(); ++index) {
            UIEditorWorkspaceNode& child = node.children[index];
            if (child.kind == UIEditorWorkspaceNodeKind::Panel &&
                child.panel.panelId == panelId) {
                node.selectedTabIndex = index;
                return true;
            }
        }
        return false;

    case UIEditorWorkspaceNodeKind::Split:
        for (UIEditorWorkspaceNode& child : node.children) {
            if (TryActivateRecursive(child, panelId)) {
                return true;
            }
        }
        return false;
    }

    return false;
}

void CollectVisiblePanelsRecursive(
    const UIEditorWorkspaceNode& node,
    std::string_view activePanelId,
    std::vector<UIEditorWorkspaceVisiblePanel>& outPanels) {
    switch (node.kind) {
    case UIEditorWorkspaceNodeKind::Panel: {
        UIEditorWorkspaceVisiblePanel panel = {};
        panel.panelId = node.panel.panelId;
        panel.title = node.panel.title;
        panel.active = node.panel.panelId == activePanelId;
        panel.placeholder = node.panel.placeholder;
        outPanels.push_back(std::move(panel));
        return;
    }

    case UIEditorWorkspaceNodeKind::TabStack:
        if (node.selectedTabIndex < node.children.size()) {
            CollectVisiblePanelsRecursive(
                node.children[node.selectedTabIndex],
                activePanelId,
                outPanels);
        }
        return;

    case UIEditorWorkspaceNodeKind::Split:
        for (const UIEditorWorkspaceNode& child : node.children) {
            CollectVisiblePanelsRecursive(child, activePanelId, outPanels);
        }
        return;
    }
}

UIEditorWorkspaceValidationResult ValidateNodeRecursive(
    const UIEditorWorkspaceNode& node,
    std::unordered_set<std::string>& panelIds) {
    if (node.nodeId.empty()) {
        return MakeValidationError(
            UIEditorWorkspaceValidationCode::EmptyNodeId,
            "Workspace node id must not be empty.");
    }

    switch (node.kind) {
    case UIEditorWorkspaceNodeKind::Panel:
        if (!node.children.empty()) {
            return MakeValidationError(
                UIEditorWorkspaceValidationCode::NonPanelTabChild,
                "Panel node '" + node.nodeId + "' must not contain child nodes.");
        }

        if (node.panel.panelId.empty()) {
            return MakeValidationError(
                UIEditorWorkspaceValidationCode::EmptyPanelId,
                "Panel node '" + node.nodeId + "' must define a panelId.");
        }

        if (node.panel.title.empty()) {
            return MakeValidationError(
                UIEditorWorkspaceValidationCode::EmptyPanelTitle,
                "Panel node '" + node.nodeId + "' must define a title.");
        }

        if (!panelIds.insert(node.panel.panelId).second) {
            return MakeValidationError(
                UIEditorWorkspaceValidationCode::DuplicatePanelId,
                "Panel id '" + node.panel.panelId + "' is duplicated in the workspace tree.");
        }

        return {};

    case UIEditorWorkspaceNodeKind::TabStack:
        if (node.children.empty()) {
            return MakeValidationError(
                UIEditorWorkspaceValidationCode::EmptyTabStack,
                "Tab stack '" + node.nodeId + "' must contain at least one panel.");
        }

        if (node.selectedTabIndex >= node.children.size()) {
            return MakeValidationError(
                UIEditorWorkspaceValidationCode::InvalidSelectedTabIndex,
                "Tab stack '" + node.nodeId + "' selectedTabIndex is out of range.");
        }

        for (const UIEditorWorkspaceNode& child : node.children) {
            if (child.kind != UIEditorWorkspaceNodeKind::Panel) {
                return MakeValidationError(
                    UIEditorWorkspaceValidationCode::NonPanelTabChild,
                    "Tab stack '" + node.nodeId + "' may only contain panel leaf nodes.");
            }

            if (UIEditorWorkspaceValidationResult result = ValidateNodeRecursive(child, panelIds);
                !result.IsValid()) {
                return result;
            }
        }

        return {};

    case UIEditorWorkspaceNodeKind::Split:
        if (node.children.size() != 2u) {
            return MakeValidationError(
                UIEditorWorkspaceValidationCode::InvalidSplitChildCount,
                "Split node '" + node.nodeId + "' must contain exactly two child nodes.");
        }

        if (!IsValidSplitRatio(node.splitRatio)) {
            return MakeValidationError(
                UIEditorWorkspaceValidationCode::InvalidSplitRatio,
                "Split node '" + node.nodeId + "' must define a ratio in the open interval (0, 1).");
        }

        for (const UIEditorWorkspaceNode& child : node.children) {
            if (UIEditorWorkspaceValidationResult result = ValidateNodeRecursive(child, panelIds);
                !result.IsValid()) {
                return result;
            }
        }

        return {};
    }

    return {};
}

} // namespace

bool AreUIEditorWorkspaceNodesEquivalent(
    const UIEditorWorkspaceNode& lhs,
    const UIEditorWorkspaceNode& rhs) {
    if (lhs.kind != rhs.kind ||
        lhs.nodeId != rhs.nodeId ||
        lhs.splitAxis != rhs.splitAxis ||
        lhs.splitRatio != rhs.splitRatio ||
        lhs.selectedTabIndex != rhs.selectedTabIndex ||
        lhs.panel.panelId != rhs.panel.panelId ||
        lhs.panel.title != rhs.panel.title ||
        lhs.panel.placeholder != rhs.panel.placeholder ||
        lhs.children.size() != rhs.children.size()) {
        return false;
    }

    for (std::size_t index = 0; index < lhs.children.size(); ++index) {
        if (!AreUIEditorWorkspaceNodesEquivalent(lhs.children[index], rhs.children[index])) {
            return false;
        }
    }

    return true;
}

bool AreUIEditorWorkspaceModelsEquivalent(
    const UIEditorWorkspaceModel& lhs,
    const UIEditorWorkspaceModel& rhs) {
    return lhs.activePanelId == rhs.activePanelId &&
        AreUIEditorWorkspaceNodesEquivalent(lhs.root, rhs.root);
}

UIEditorWorkspaceModel BuildDefaultEditorShellWorkspaceModel() {
    const UIEditorPanelRegistry registry = BuildDefaultEditorShellPanelRegistry();
    const UIEditorPanelDescriptor& rootPanel =
        RequirePanelDescriptor(registry, "editor-foundation-root");

    UIEditorWorkspaceModel workspace = {};
    workspace.root = BuildUIEditorWorkspaceSingleTabStack(
        "editor-foundation-root-node",
        rootPanel.panelId,
        rootPanel.defaultTitle,
        rootPanel.placeholder);
    workspace.activePanelId = rootPanel.panelId;
    return workspace;
}

UIEditorWorkspaceNode BuildUIEditorWorkspacePanel(
    std::string nodeId,
    std::string panelId,
    std::string title,
    bool placeholder) {
    UIEditorWorkspaceNode node = {};
    node.kind = UIEditorWorkspaceNodeKind::Panel;
    node.nodeId = std::move(nodeId);
    node.panel.panelId = std::move(panelId);
    node.panel.title = std::move(title);
    node.panel.placeholder = placeholder;
    return node;
}

UIEditorWorkspaceNode BuildUIEditorWorkspaceSingleTabStack(
    std::string nodeId,
    std::string panelId,
    std::string title,
    bool placeholder) {
    UIEditorWorkspaceNode panel = BuildUIEditorWorkspacePanel(
        BuildSingleTabPanelNodeId(nodeId),
        std::move(panelId),
        std::move(title),
        placeholder);
    return BuildUIEditorWorkspaceTabStack(
        std::move(nodeId),
        { std::move(panel) },
        0u);
}

UIEditorWorkspaceNode BuildUIEditorWorkspaceTabStack(
    std::string nodeId,
    std::vector<UIEditorWorkspaceNode> panels,
    std::size_t selectedTabIndex) {
    UIEditorWorkspaceNode node = {};
    node.kind = UIEditorWorkspaceNodeKind::TabStack;
    node.nodeId = std::move(nodeId);
    node.selectedTabIndex = selectedTabIndex;
    node.children = std::move(panels);
    return node;
}

UIEditorWorkspaceNode BuildUIEditorWorkspaceSplit(
    std::string nodeId,
    UIEditorWorkspaceSplitAxis axis,
    float splitRatio,
    UIEditorWorkspaceNode primary,
    UIEditorWorkspaceNode secondary) {
    UIEditorWorkspaceNode node = {};
    node.kind = UIEditorWorkspaceNodeKind::Split;
    node.nodeId = std::move(nodeId);
    node.splitAxis = axis;
    node.splitRatio = splitRatio;
    node.children.push_back(std::move(primary));
    node.children.push_back(std::move(secondary));
    return node;
}

UIEditorWorkspaceValidationResult ValidateUIEditorWorkspace(
    const UIEditorWorkspaceModel& workspace) {
    std::unordered_set<std::string> panelIds = {};
    UIEditorWorkspaceValidationResult result = ValidateNodeRecursive(workspace.root, panelIds);
    if (!result.IsValid()) {
        return result;
    }

    if (!workspace.activePanelId.empty()) {
        const UIEditorWorkspacePanelState* activePanel = FindUIEditorWorkspaceActivePanel(workspace);
        if (activePanel == nullptr) {
            return MakeValidationError(
                UIEditorWorkspaceValidationCode::InvalidActivePanelId,
                "Active panel id '" + workspace.activePanelId + "' is missing or hidden by the current tab selection.");
        }
    }

    return {};
}

UIEditorWorkspaceModel CanonicalizeUIEditorWorkspaceModel(
    UIEditorWorkspaceModel workspace) {
    CanonicalizeNodeRecursive(workspace.root, false);
    return workspace;
}

std::vector<UIEditorWorkspaceVisiblePanel> CollectUIEditorWorkspaceVisiblePanels(
    const UIEditorWorkspaceModel& workspace) {
    std::vector<UIEditorWorkspaceVisiblePanel> visiblePanels = {};
    CollectVisiblePanelsRecursive(workspace.root, workspace.activePanelId, visiblePanels);
    return visiblePanels;
}

bool ContainsUIEditorWorkspacePanel(
    const UIEditorWorkspaceModel& workspace,
    std::string_view panelId) {
    return FindPanelRecursive(workspace.root, panelId) != nullptr;
}

const UIEditorWorkspaceNode* FindUIEditorWorkspaceNode(
    const UIEditorWorkspaceModel& workspace,
    std::string_view nodeId) {
    return FindNodeRecursive(workspace.root, nodeId);
}

const UIEditorWorkspacePanelState* FindUIEditorWorkspaceActivePanel(
    const UIEditorWorkspaceModel& workspace) {
    if (workspace.activePanelId.empty()) {
        return nullptr;
    }

    std::vector<UIEditorWorkspaceVisiblePanel> visiblePanels =
        CollectUIEditorWorkspaceVisiblePanels(workspace);
    for (const UIEditorWorkspaceVisiblePanel& panel : visiblePanels) {
        if (panel.panelId == workspace.activePanelId) {
            return FindPanelRecursive(workspace.root, workspace.activePanelId);
        }
    }

    return nullptr;
}

bool TryActivateUIEditorWorkspacePanel(
    UIEditorWorkspaceModel& workspace,
    std::string_view panelId) {
    if (!TryActivateRecursive(workspace.root, panelId)) {
        return false;
    }

    workspace.activePanelId = std::string(panelId);
    return true;
}

bool TrySetUIEditorWorkspaceSplitRatio(
    UIEditorWorkspaceModel& workspace,
    std::string_view nodeId,
    float splitRatio) {
    if (!IsValidSplitRatio(splitRatio)) {
        return false;
    }

    UIEditorWorkspaceNode* node = FindMutableNodeRecursive(workspace.root, nodeId);
    if (node == nullptr || node->kind != UIEditorWorkspaceNodeKind::Split) {
        return false;
    }

    if (std::fabs(node->splitRatio - splitRatio) <= 0.0001f) {
        return false;
    }

    node->splitRatio = splitRatio;
    return true;
}

bool TryReorderUIEditorWorkspaceTab(
    UIEditorWorkspaceModel& workspace,
    const UIEditorWorkspaceSession& session,
    std::string_view nodeId,
    std::string_view panelId,
    std::size_t targetVisibleInsertionIndex) {
    UIEditorWorkspaceNode* node = FindMutableNodeRecursive(workspace.root, nodeId);
    if (node == nullptr || node->kind != UIEditorWorkspaceNodeKind::TabStack) {
        return false;
    }

    std::vector<std::size_t> visibleChildIndices = {};
    std::vector<UIEditorWorkspaceNode> reorderedVisibleChildren = {};
    visibleChildIndices.reserve(node->children.size());
    reorderedVisibleChildren.reserve(node->children.size());

    std::size_t sourceVisibleIndex = node->children.size();
    for (std::size_t index = 0; index < node->children.size(); ++index) {
        const UIEditorWorkspaceNode& child = node->children[index];
        if (child.kind != UIEditorWorkspaceNodeKind::Panel) {
            return false;
        }

        if (!IsPanelOpenAndVisibleInSession(session, child.panel.panelId)) {
            continue;
        }

        if (child.panel.panelId == panelId) {
            sourceVisibleIndex = visibleChildIndices.size();
        }

        visibleChildIndices.push_back(index);
        reorderedVisibleChildren.push_back(child);
    }

    if (sourceVisibleIndex >= reorderedVisibleChildren.size() ||
        targetVisibleInsertionIndex > reorderedVisibleChildren.size()) {
        return false;
    }

    if (targetVisibleInsertionIndex == sourceVisibleIndex ||
        targetVisibleInsertionIndex == sourceVisibleIndex + 1u) {
        return false;
    }

    UIEditorWorkspaceNode movedChild =
        std::move(reorderedVisibleChildren[sourceVisibleIndex]);
    reorderedVisibleChildren.erase(
        reorderedVisibleChildren.begin() + static_cast<std::ptrdiff_t>(sourceVisibleIndex));

    std::size_t adjustedInsertionIndex = targetVisibleInsertionIndex;
    if (adjustedInsertionIndex > sourceVisibleIndex) {
        --adjustedInsertionIndex;
    }
    if (adjustedInsertionIndex > reorderedVisibleChildren.size()) {
        adjustedInsertionIndex = reorderedVisibleChildren.size();
    }

    reorderedVisibleChildren.insert(
        reorderedVisibleChildren.begin() +
            static_cast<std::ptrdiff_t>(adjustedInsertionIndex),
        std::move(movedChild));

    std::string selectedPanelId = {};
    if (node->selectedTabIndex < node->children.size()) {
        selectedPanelId = node->children[node->selectedTabIndex].panel.panelId;
    }

    const std::vector<UIEditorWorkspaceNode> originalChildren = node->children;
    std::size_t nextVisibleIndex = 0u;
    for (std::size_t index = 0; index < originalChildren.size(); ++index) {
        const UIEditorWorkspaceNode& originalChild = originalChildren[index];
        if (!IsPanelOpenAndVisibleInSession(session, originalChild.panel.panelId)) {
            node->children[index] = originalChild;
            continue;
        }

        node->children[index] = reorderedVisibleChildren[nextVisibleIndex];
        ++nextVisibleIndex;
    }

    for (std::size_t index = 0; index < node->children.size(); ++index) {
        if (node->children[index].panel.panelId == selectedPanelId) {
            node->selectedTabIndex = index;
            break;
        }
    }

    return true;
}

bool TryMoveUIEditorWorkspaceTabToStack(
    UIEditorWorkspaceModel& workspace,
    const UIEditorWorkspaceSession& session,
    std::string_view sourceNodeId,
    std::string_view panelId,
    std::string_view targetNodeId,
    std::size_t targetVisibleInsertionIndex) {
    if (sourceNodeId.empty() ||
        panelId.empty() ||
        targetNodeId.empty()) {
        return false;
    }

    if (sourceNodeId == targetNodeId) {
        return TryReorderUIEditorWorkspaceTab(
            workspace,
            session,
            sourceNodeId,
            panelId,
            targetVisibleInsertionIndex);
    }

    const UIEditorWorkspaceNode* targetNode =
        FindUIEditorWorkspaceNode(workspace, targetNodeId);
    if (targetNode == nullptr ||
        targetNode->kind != UIEditorWorkspaceNodeKind::TabStack) {
        return false;
    }

    if (targetVisibleInsertionIndex > CountVisibleChildren(*targetNode, session)) {
        return false;
    }

    UIEditorWorkspaceNode extractedPanel = {};
    if (!TryExtractVisiblePanelFromTabStack(
            workspace,
            session,
            sourceNodeId,
            panelId,
            extractedPanel)) {
        return false;
    }

    UIEditorWorkspaceNode* targetStack =
        FindMutableNodeRecursive(workspace.root, targetNodeId);
    if (targetStack == nullptr ||
        targetStack->kind != UIEditorWorkspaceNodeKind::TabStack) {
        return false;
    }

    const std::size_t actualInsertionIndex =
        ResolveActualInsertionIndexForVisibleInsertion(
            *targetStack,
            session,
            targetVisibleInsertionIndex);
    if (actualInsertionIndex > targetStack->children.size()) {
        return false;
    }

    targetStack->children.insert(
        targetStack->children.begin() +
            static_cast<std::ptrdiff_t>(actualInsertionIndex),
        std::move(extractedPanel));
    targetStack->selectedTabIndex = actualInsertionIndex;
    workspace.activePanelId = std::string(panelId);
    workspace = CanonicalizeUIEditorWorkspaceModel(std::move(workspace));
    return true;
}

bool TryDockUIEditorWorkspaceTabRelative(
    UIEditorWorkspaceModel& workspace,
    const UIEditorWorkspaceSession& session,
    std::string_view sourceNodeId,
    std::string_view panelId,
    std::string_view targetNodeId,
    UIEditorWorkspaceDockPlacement placement,
    float splitRatio) {
    if (placement == UIEditorWorkspaceDockPlacement::Center) {
        const UIEditorWorkspaceNode* targetNode =
            FindUIEditorWorkspaceNode(workspace, targetNodeId);
        if (targetNode == nullptr ||
            targetNode->kind != UIEditorWorkspaceNodeKind::TabStack) {
            return false;
        }

        return TryMoveUIEditorWorkspaceTabToStack(
            workspace,
            session,
            sourceNodeId,
            panelId,
            targetNodeId,
            CountVisibleChildren(*targetNode, session));
    }

    if (sourceNodeId.empty() ||
        panelId.empty() ||
        targetNodeId.empty()) {
        return false;
    }

    const UIEditorWorkspaceNode* sourceNode =
        FindUIEditorWorkspaceNode(workspace, sourceNodeId);
    const UIEditorWorkspaceNode* targetNode =
        FindUIEditorWorkspaceNode(workspace, targetNodeId);
    if (sourceNode == nullptr ||
        targetNode == nullptr ||
        sourceNode->kind != UIEditorWorkspaceNodeKind::TabStack ||
        targetNode->kind != UIEditorWorkspaceNodeKind::TabStack) {
        return false;
    }

    if (sourceNodeId == targetNodeId &&
        sourceNode->children.size() <= 1u) {
        return false;
    }

    UIEditorWorkspaceNode extractedPanel = {};
    if (!TryExtractVisiblePanelFromTabStack(
            workspace,
            session,
            sourceNodeId,
            panelId,
            extractedPanel)) {
        return false;
    }

    UIEditorWorkspaceNode* targetStack =
        FindMutableNodeRecursive(workspace.root, targetNodeId);
    if (targetStack == nullptr ||
        targetStack->kind != UIEditorWorkspaceNodeKind::TabStack) {
        return false;
    }

    const std::string movedStackNodeId = MakeUniqueNodeId(
        workspace,
        std::string(targetNodeId) + "__dock_" + std::string(panelId) + "_stack");
    UIEditorWorkspaceNode movedStack = {};
    movedStack.kind = UIEditorWorkspaceNodeKind::TabStack;
    movedStack.nodeId = movedStackNodeId;
    movedStack.selectedTabIndex = 0u;
    movedStack.children.push_back(std::move(extractedPanel));

    UIEditorWorkspaceNode existingTarget = std::move(*targetStack);
    UIEditorWorkspaceNode primary = {};
    UIEditorWorkspaceNode secondary = {};
    if (IsLeadingDockPlacement(placement)) {
        primary = std::move(movedStack);
        secondary = std::move(existingTarget);
    } else {
        primary = std::move(existingTarget);
        secondary = std::move(movedStack);
    }

    const float requestedRatio = ClampDockSplitRatio(splitRatio);
    const float resolvedSplitRatio =
        IsLeadingDockPlacement(placement)
            ? requestedRatio
            : (1.0f - requestedRatio);
    *targetStack = BuildUIEditorWorkspaceSplit(
        MakeUniqueNodeId(
            workspace,
            std::string(targetNodeId) + "__dock_split"),
        ResolveDockSplitAxis(placement),
        resolvedSplitRatio,
        std::move(primary),
        std::move(secondary));
    workspace.activePanelId = std::string(panelId);
    workspace = CanonicalizeUIEditorWorkspaceModel(std::move(workspace));
    return true;
}

} // namespace XCEngine::UI::Editor