#include <XCEditor/Shell/UIEditorWindowWorkspaceModel.h>

#include <unordered_set>
#include <utility>

namespace XCEngine::UI::Editor {

namespace {

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

} // namespace

UIEditorWindowWorkspaceSet BuildDefaultUIEditorWindowWorkspaceSet(
    const UIEditorPanelRegistry& panelRegistry,
    const UIEditorWorkspaceModel& workspace,
    std::string primaryWindowId) {
    if (primaryWindowId.empty()) {
        primaryWindowId = "main-window";
    }

    UIEditorWindowWorkspaceSet windowSet = {};
    windowSet.primaryWindowId = primaryWindowId;
    windowSet.activeWindowId = primaryWindowId;

    UIEditorWindowWorkspaceState state = {};
    state.windowId = primaryWindowId;
    state.workspace = CanonicalizeUIEditorWorkspaceModel(workspace);
    state.session = BuildDefaultUIEditorWorkspaceSession(panelRegistry, state.workspace);
    windowSet.windows.push_back(std::move(state));
    return windowSet;
}

const UIEditorWindowWorkspaceState* FindUIEditorWindowWorkspaceState(
    const UIEditorWindowWorkspaceSet& windowSet,
    std::string_view windowId) {
    for (const UIEditorWindowWorkspaceState& state : windowSet.windows) {
        if (state.windowId == windowId) {
            return &state;
        }
    }

    return nullptr;
}

UIEditorWindowWorkspaceState* FindMutableUIEditorWindowWorkspaceState(
    UIEditorWindowWorkspaceSet& windowSet,
    std::string_view windowId) {
    for (UIEditorWindowWorkspaceState& state : windowSet.windows) {
        if (state.windowId == windowId) {
            return &state;
        }
    }

    return nullptr;
}

UIEditorWindowWorkspaceValidationResult ValidateUIEditorWindowWorkspaceSet(
    const UIEditorPanelRegistry& panelRegistry,
    const UIEditorWindowWorkspaceSet& windowSet) {
    const UIEditorPanelRegistryValidationResult registryValidation =
        ValidateUIEditorPanelRegistry(panelRegistry);
    if (!registryValidation.IsValid()) {
        return MakeValidationError(
            UIEditorWindowWorkspaceValidationCode::InvalidPanelRegistry,
            registryValidation.message);
    }

    if (windowSet.primaryWindowId.empty()) {
        return MakeValidationError(
            UIEditorWindowWorkspaceValidationCode::MissingPrimaryWindow,
            "Primary window id must not be empty.");
    }

    if (windowSet.activeWindowId.empty()) {
        return MakeValidationError(
            UIEditorWindowWorkspaceValidationCode::MissingActiveWindow,
            "Active window id must not be empty.");
    }

    std::unordered_set<std::string> seenWindowIds = {};
    bool hasPrimaryWindow = false;
    bool hasActiveWindow = false;
    for (const UIEditorWindowWorkspaceState& state : windowSet.windows) {
        if (state.windowId.empty()) {
            return MakeValidationError(
                UIEditorWindowWorkspaceValidationCode::EmptyWindowId,
                "Window id must not be empty.");
        }

        if (!seenWindowIds.insert(state.windowId).second) {
            return MakeValidationError(
                UIEditorWindowWorkspaceValidationCode::DuplicateWindowId,
                "Window id '" + state.windowId + "' is duplicated.");
        }

        if (state.windowId == windowSet.primaryWindowId) {
            hasPrimaryWindow = true;
        }
        if (state.windowId == windowSet.activeWindowId) {
            hasActiveWindow = true;
        }

        const UIEditorWorkspaceValidationResult workspaceValidation =
            ValidateUIEditorWorkspace(state.workspace);
        if (!workspaceValidation.IsValid()) {
            return MakeValidationError(
                UIEditorWindowWorkspaceValidationCode::InvalidWorkspace,
                "Window '" + state.windowId + "' workspace invalid: " +
                    workspaceValidation.message);
        }

        const UIEditorWorkspaceSessionValidationResult sessionValidation =
            ValidateUIEditorWorkspaceSession(panelRegistry, state.workspace, state.session);
        if (!sessionValidation.IsValid()) {
            return MakeValidationError(
                UIEditorWindowWorkspaceValidationCode::InvalidSession,
                "Window '" + state.windowId + "' session invalid: " +
                    sessionValidation.message);
        }
    }

    if (!hasPrimaryWindow) {
        return MakeValidationError(
            UIEditorWindowWorkspaceValidationCode::MissingPrimaryWindow,
            "Primary window '" + windowSet.primaryWindowId + "' does not exist.");
    }

    if (!hasActiveWindow) {
        return MakeValidationError(
            UIEditorWindowWorkspaceValidationCode::MissingActiveWindow,
            "Active window '" + windowSet.activeWindowId + "' does not exist.");
    }

    return {};
}

} // namespace XCEngine::UI::Editor