#include "Windowing/System/EditorWindowSystem.h"

#include "Windowing/System/EditorWindowSynchronizationPlanner.h"

#include <XCEditor/Workspace/UIEditorWindowWorkspaceModel.h>

#include <algorithm>
#include <utility>

namespace XCEngine::UI::Editor::App {

EditorWindowSystem::EditorWindowSystem(UIEditorPanelRegistry panelRegistry)
    : m_workspaceStore(std::move(panelRegistry)) {}

const UIEditorPanelRegistry& EditorWindowSystem::GetPanelRegistry() const {
    return m_workspaceStore.GetPanelRegistry();
}

bool EditorWindowSystem::BootstrapPrimaryWindow(
    std::string_view primaryWindowId,
    const UIEditorWorkspaceController& workspaceController,
    std::string& outError) {
    const std::string resolvedPrimaryWindowId =
        primaryWindowId.empty() ? std::string("main-window") : std::string(primaryWindowId);

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

    UIEditorWindowWorkspaceState primaryWindowState = {};
    primaryWindowState.windowId = resolvedPrimaryWindowId;
    primaryWindowState.workspace = workspaceController.GetWorkspace();
    primaryWindowState.session = workspaceController.GetSession();
    windowSet.windows.push_back(std::move(primaryWindowState));

    return m_workspaceStore.TrySetWindowSet(std::move(windowSet), outError);
}

bool EditorWindowSystem::ValidateWindowSet(
    const UIEditorWindowWorkspaceSet& windowSet,
    std::string& outError) const {
    return m_workspaceStore.ValidateWindowSet(windowSet, outError);
}

bool EditorWindowSystem::IsPrimaryWindowId(std::string_view windowId) const {
    return m_workspaceStore.IsPrimaryWindowId(windowId);
}

const UIEditorWindowWorkspaceSet& EditorWindowSystem::GetWindowSet() const {
    return m_workspaceStore.GetWindowSet();
}

UIEditorWindowWorkspaceController EditorWindowSystem::BuildWorkspaceMutationController() const {
    return UIEditorWindowWorkspaceController(GetPanelRegistry(), GetWindowSet());
}

EditorWindowSynchronizationPlan EditorWindowSystem::BuildPlanForWindowSet(
    const UIEditorWindowWorkspaceSet& targetWindowSet,
    const std::vector<EditorWindowHostSnapshot>& hostWindows,
    std::wstring_view primaryWindowTitle,
    std::string_view preferredNewWindowId,
    const EditorWindowSynchronizationPlacement& preferredPlacement,
    std::string& outError) const {
    return BuildSynchronizationPlan(
        EditorWindowSynchronizationPlannerInput{
            .targetWindowSet = &targetWindowSet,
            .primaryWindowTitle = primaryWindowTitle,
            .preferredNewWindowId = preferredNewWindowId,
            .preferredPlacement = preferredPlacement,
            .hostWindows = hostWindows,
        },
        outError);
}

EditorWindowSynchronizationPlan EditorWindowSystem::BuildPlanForLiveWindowMutation(
    std::string_view windowId,
    const UIEditorWorkspaceController& workspaceController,
    const std::vector<EditorWindowHostSnapshot>& hostWindows,
    std::wstring_view primaryWindowTitle,
    std::string& outError) const {
    EditorWindowWorkspaceMutationRequest request = {};
    request.windowState.windowId = std::string(windowId);
    request.windowState.workspace = workspaceController.GetWorkspace();
    request.windowState.session = workspaceController.GetSession();
    return BuildPlanForWorkspaceMutationRequest(
        request,
        hostWindows,
        primaryWindowTitle,
        outError);
}

EditorWindowSynchronizationPlan EditorWindowSystem::BuildPlanForWorkspaceMutationRequest(
    const EditorWindowWorkspaceMutationRequest& request,
    const std::vector<EditorWindowHostSnapshot>& hostWindows,
    std::wstring_view primaryWindowTitle,
    std::string& outError) const {
    if (!request.IsValid()) {
        outError = "live window mutation request missing window id";
        return {};
    }

    UIEditorWindowWorkspaceSet nextWindowSet = GetWindowSet();
    UIEditorWindowWorkspaceState* existingState =
        FindMutableUIEditorWindowWorkspaceState(nextWindowSet, request.windowState.windowId);
    if (existingState == nullptr) {
        outError =
            "live window mutation references unknown window '" +
            request.windowState.windowId + "'";
        return {};
    }

    existingState->workspace = request.windowState.workspace;
    existingState->session = request.windowState.session;
    return BuildPlanForWindowSet(
        nextWindowSet,
        hostWindows,
        primaryWindowTitle,
        {},
        {},
        outError);
}

EditorWindowSynchronizationPlan EditorWindowSystem::BuildPlanForDestroyedWindow(
    std::string_view windowId,
    const std::vector<EditorWindowHostSnapshot>& hostWindows,
    std::wstring_view primaryWindowTitle,
    std::string& outError) const {
    if (windowId.empty()) {
        outError = "window destroy event missing window id";
        return {};
    }

    UIEditorWindowWorkspaceSet nextWindowSet = GetWindowSet();
    const bool destroyedPrimary = nextWindowSet.primaryWindowId == windowId;
    if (!RemoveWindowStateFromSet(nextWindowSet, windowId)) {
        outError =
            "window destroy event references unknown authoritative window '" +
            std::string(windowId) + "'";
        return {};
    }
    if (destroyedPrimary) {
        EditorWindowSynchronizationPlan plan = {};
        plan.valid = true;
        plan.targetWindowSet = {};
        for (const EditorWindowHostSnapshot& snapshot : hostWindows) {
            if (!snapshot.workspaceWindow ||
                !snapshot.hasNativeWindow ||
                !snapshot.running ||
                snapshot.windowId == windowId) {
                continue;
            }

            EditorWindowSynchronizationAction action = {};
            action.kind = EditorWindowSynchronizationActionKind::CloseWorkspaceWindow;
            action.close.windowId = snapshot.windowId;
            plan.actions.push_back(std::move(action));
        }
        outError.clear();
        return plan;
    }

    return BuildPlanForWindowSet(
        nextWindowSet,
        hostWindows,
        primaryWindowTitle,
        {},
        {},
        outError);
}

EditorWindowSynchronizationPlan EditorWindowSystem::BuildSynchronizationPlan(
    const EditorWindowSynchronizationPlannerInput& input,
    std::string& outError) const {
    if (input.targetWindowSet == nullptr) {
        outError = "window synchronization planner missing target window set";
        return {};
    }

    if (!ValidateWindowSet(*input.targetWindowSet, outError)) {
        return {};
    }

    EditorWindowSynchronizationPlannerInput resolvedInput = input;
    resolvedInput.panelRegistry = &GetPanelRegistry();
    EditorWindowSynchronizationPlan plan =
        EditorWindowSynchronizationPlanner::Build(resolvedInput);
    if (!plan.valid) {
        outError = plan.errorMessage;
        return {};
    }

    outError.clear();
    return plan;
}

bool EditorWindowSystem::CommitSynchronizationPlan(
    const EditorWindowSynchronizationPlan& plan,
    std::string& outError) {
    if (!plan.valid) {
        outError = !plan.errorMessage.empty()
            ? plan.errorMessage
            : "cannot commit invalid synchronization plan";
        return false;
    }

    if (plan.targetWindowSet.windows.empty()) {
        m_workspaceStore.ClearWindowSet();
        outError.clear();
        return true;
    }

    return m_workspaceStore.TrySetWindowSet(plan.targetWindowSet, outError);
}

UIEditorWindowWorkspaceOperationResult EditorWindowSystem::EvaluateDetachPanelToNewWindow(
    std::string_view sourceWindowId,
    std::string_view sourceNodeId,
    std::string_view panelId,
    UIEditorWindowWorkspaceController& outController) const {
    outController = BuildWorkspaceMutationController();
    return outController.DetachPanelToNewWindow(sourceWindowId, sourceNodeId, panelId);
}

bool EditorWindowSystem::RemoveWindowStateFromSet(
    UIEditorWindowWorkspaceSet& windowSet,
    std::string_view windowId) {
    const auto originalSize = windowSet.windows.size();
    windowSet.windows.erase(
        std::remove_if(
            windowSet.windows.begin(),
            windowSet.windows.end(),
            [windowId](const UIEditorWindowWorkspaceState& state) {
                return state.windowId == windowId;
            }),
        windowSet.windows.end());
    if (windowSet.windows.size() == originalSize) {
        return false;
    }

    if (windowSet.windows.empty()) {
        windowSet = {};
        return true;
    }

    if (windowSet.primaryWindowId == windowId ||
        FindUIEditorWindowWorkspaceState(windowSet, windowSet.primaryWindowId) == nullptr) {
        windowSet.primaryWindowId = windowSet.windows.front().windowId;
    }
    if (windowSet.activeWindowId == windowId ||
        FindUIEditorWindowWorkspaceState(windowSet, windowSet.activeWindowId) == nullptr) {
        windowSet.activeWindowId = windowSet.primaryWindowId;
    }

    return true;
}

} // namespace XCEngine::UI::Editor::App