#include "stdafx.h"
#include "CExpandableListCtrl.h"

IMPLEMENT_DYNAMIC(CExpandableListCtrl, CListCtrl)

CExpandableListCtrl::CExpandableListCtrl() {}
CExpandableListCtrl::~CExpandableListCtrl() {}

BEGIN_MESSAGE_MAP(CExpandableListCtrl, CListCtrl)
    ON_WM_CREATE()
    ON_NOTIFY_REFLECT(NM_CLICK, &CExpandableListCtrl::OnClick)
    ON_NOTIFY_REFLECT(NM_CUSTOMDRAW, &CExpandableListCtrl::OnCustomDraw)
END_MESSAGE_MAP()

int CExpandableListCtrl::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
    if (CListCtrl::OnCreate(lpCreateStruct) == -1)
        return -1;

    // 报表风格列举例
    SetExtendedStyle(GetExtendedStyle()
        | LVS_EX_FULLROWSELECT | LVS_EX_HEADERDRAGDROP | LVS_EX_GRIDLINES);

    // 示例列（可在外部设置）
    if (GetHeaderCtrl() == nullptr || GetHeaderCtrl()->GetItemCount() == 0) {
        InsertColumn(0, _T("名称"), LVCFMT_LEFT, 260);
        InsertColumn(1, _T("状态"), LVCFMT_LEFT, 120);
        InsertColumn(2, _T("描述"), LVCFMT_LEFT, 260);
    }

    return 0;
}

CExpandableListCtrl::Node* CExpandableListCtrl::InsertRoot(const std::vector<CString>& cols)
{
    auto n = std::make_unique<Node>((int)max(1, (int)cols.size()));
    for (size_t i = 0; i < cols.size(); ++i) n->cols[i] = cols[i];
    n->level = 0;
    Node* raw = n.get();
    m_roots.emplace_back(std::move(n));
    return raw;
}

CExpandableListCtrl::Node* CExpandableListCtrl::InsertChild(Node* parent, const std::vector<CString>& cols)
{
    ASSERT(parent);
    auto n = std::make_unique<Node>((int)max(1, (int)cols.size()));
    for (size_t i = 0; i < cols.size(); ++i) n->cols[i] = cols[i];
    n->parent = parent;
    n->level = parent->level + 1;
    Node* raw = n.get();
    parent->children.emplace_back(std::move(n));
    return raw;
}

void CExpandableListCtrl::appendVisible(Node* n)
{
    m_visible.push_back(n);
    if (n->expanded) {
        for (auto& ch : n->children) {
            appendVisible(ch.get());
        }
    }
}

void CExpandableListCtrl::RebuildVisible()
{
    // 1) 重建可见序列
    m_visible.clear();
    for (auto& r : m_roots) appendVisible(r.get());

    // 2) 重绘/重填数据
    SetRedraw(FALSE);
    DeleteAllItems();

    // 插入可见行
    for (int i = 0; i < (int)m_visible.size(); ++i) {
        Node* n = m_visible[i];
        LVITEM lvi{};
        lvi.mask = LVIF_TEXT;
        lvi.iItem = i;
        lvi.iSubItem = 0;
        lvi.pszText = const_cast<LPTSTR>((LPCTSTR)(n->cols.empty() ? _T("") : n->cols[0]));
        InsertItem(&lvi);

        for (int col = 1; col < GetHeaderCtrl()->GetItemCount(); ++col) {
            CString txt = (col < (int)n->cols.size()) ? n->cols[col] : _T("");
            SetItemText(i, col, txt);
        }
    }
    SetRedraw(TRUE);
    Invalidate();
}

void CExpandableListCtrl::Expand(Node* n)
{
    if (!n || n->children.empty()) return;
    if (!n->expanded) { n->expanded = true; RebuildVisible(); }
}

void CExpandableListCtrl::Collapse(Node* n)
{
    if (!n || n->children.empty()) return;
    if (n->expanded) { n->expanded = false; RebuildVisible(); }
}

void CExpandableListCtrl::Toggle(Node* n)
{
    if (!n || n->children.empty()) return;
    n->expanded = !n->expanded;
    RebuildVisible();
}

CExpandableListCtrl::Node* CExpandableListCtrl::GetNodeByVisibleIndex(int i) const
{
    if (i < 0 || i >= (int)m_visible.size()) return nullptr;
    return m_visible[i];
}

CRect CExpandableListCtrl::expanderRectForRow(int row) const
{
    CRect rc;
    // 取首列矩形
    if (!GetSubItemRect(row, 0, LVIR_BOUNDS, rc))
        return CRect(0, 0, 0, 0);

    Node* n = const_cast<CExpandableListCtrl*>(this)->GetNodeByVisibleIndex(row);
    int indent = (n ? n->level : 0);

    // 缩进：每级给 16px
    int left = rc.left + m_expanderPadding + indent * 16;
    CRect box(left, rc.CenterPoint().y - m_expanderSize / 2,
        left + m_expanderSize, rc.CenterPoint().y + m_expanderSize / 2);
    return box;
}

void CExpandableListCtrl::OnClick(NMHDR* pNMHDR, LRESULT* pResult)
{
    LPNMITEMACTIVATE pia = reinterpret_cast<LPNMITEMACTIVATE>(pNMHDR);
    if (pia->iItem >= 0) {
        CPoint pt = pia->ptAction;

        // 命中展开按钮？
        CRect expRc = expanderRectForRow(pia->iItem);
        if (expRc.PtInRect(pt)) {
            Node* n = GetNodeByVisibleIndex(pia->iItem);
            if (n && !n->children.empty()) {
                Toggle(n);
            }
        }
    }
    *pResult = 0;
}

void CExpandableListCtrl::OnCustomDraw(NMHDR* pNMHDR, LRESULT* pResult)
{
    LPNMLVCUSTOMDRAW pCD = reinterpret_cast<LPNMLVCUSTOMDRAW>(pNMHDR);

    switch (pCD->nmcd.dwDrawStage)
    {
    case CDDS_PREPAINT:
        *pResult = CDRF_NOTIFYITEMDRAW | CDRF_NOTIFYSUBITEMDRAW;
        return;

    case CDDS_ITEMPREPAINT:
        *pResult = CDRF_NOTIFYSUBITEMDRAW;
        return;

    case CDDS_ITEMPREPAINT | CDDS_SUBITEM:
    {
        int row = (int)pCD->nmcd.dwItemSpec;
        int col = pCD->iSubItem;
        CDC* pDC = CDC::FromHandle(pCD->nmcd.hdc);

        // 仅在首列绘制展开按钮与缩进引导
        if (col == 0) {
            CRect rc;
            GetSubItemRect(row, 0, LVIR_BOUNDS, rc);

            // 默认文本让系统画：我们先画按钮和缩进背景，再返回 CDRF_DODEFAULT
            Node* n = GetNodeByVisibleIndex(row);
            if (n) {
                // 绘制展开三角/方块
                if (!n->children.empty()) {
                    CRect box = expanderRectForRow(row);
                    // 小方框
                    pDC->Rectangle(box);

                    // 画“+”或“-”
                    CPen pen(PS_SOLID, 1, RGB(0, 0, 0));
                    CPen* oldPen = pDC->SelectObject(&pen);
                    // 横线
                    pDC->MoveTo(box.left + 2, box.CenterPoint().y);
                    pDC->LineTo(box.right - 2, box.CenterPoint().y);
                    if (!n->expanded) {
                        // 竖线（表示 + 号）
                        pDC->MoveTo(box.CenterPoint().x, box.top + 2);
                        pDC->LineTo(box.CenterPoint().x, box.bottom - 2);
                    }
                    pDC->SelectObject(oldPen);
                }

                // 把文本左边界右移，留出缩进与按钮空间
                // 这里不改系统绘制的文本起点，而是通过在文本前置空格的方式处理更简单：
                // 我们直接改显示文本（性能足够）：在 RebuildVisible 时已经填了纯文本。
                // 如果你要精准控制文本位置，可以改 OWNERDRAW 或自绘文本。
            }
        }

        *pResult = CDRF_DODEFAULT;
        return;
    }
    }

    *pResult = CDRF_DODEFAULT;
}