/*
 * Copyright (C) 2009 Apple Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
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 *     notice, this list of conditions and the following disclaimer in the
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 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
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 */

#include "config.h"
#include "AccessibilityARIAGridRow.h"

#include "AccessibilityObject.h"
#include "AccessibilityTable.h"

namespace WebCore {
    
AccessibilityARIAGridRow::AccessibilityARIAGridRow(RenderObject* renderer)
    : AccessibilityTableRow(renderer)
{
}

AccessibilityARIAGridRow::~AccessibilityARIAGridRow() = default;

Ref<AccessibilityARIAGridRow> AccessibilityARIAGridRow::create(RenderObject* renderer)
{
    return adoptRef(*new AccessibilityARIAGridRow(renderer));
}

bool AccessibilityARIAGridRow::isARIATreeGridRow() const
{
    AccessibilityObject* parent = parentTable();
    if (!parent)
        return false;
    
    return parent->isTreeGrid();
}
    
AXCoreObject::AccessibilityChildrenVector AccessibilityARIAGridRow::disclosedRows()
{
    AccessibilityChildrenVector disclosedRows;
    // The contiguous disclosed rows will be the rows in the table that 
    // have an aria-level of plus 1 from this row.
    AccessibilityObject* parent = parentObjectUnignored();
    if (!is<AccessibilityTable>(*parent) || !downcast<AccessibilityTable>(*parent).isExposable())
        return disclosedRows;

    // Search for rows that match the correct level. 
    // Only take the subsequent rows from this one that are +1 from this row's level.
    int index = rowIndex();
    if (index < 0)
        return disclosedRows;

    unsigned level = hierarchicalLevel();
    auto allRows = parent->rows();
    int rowCount = allRows.size();
    for (int k = index + 1; k < rowCount; ++k) {
        auto* row = allRows[k].get();
        // Stop at the first row that doesn't match the correct level.
        if (row->hierarchicalLevel() != level + 1)
            break;

        disclosedRows.append(row);
    }

    return disclosedRows;
}
    
AXCoreObject* AccessibilityARIAGridRow::disclosedByRow() const
{
    // The row that discloses this one is the row in the table
    // that is aria-level subtract 1 from this row.
    AccessibilityObject* parent = parentObjectUnignored();
    if (!is<AccessibilityTable>(*parent) || !downcast<AccessibilityTable>(*parent).isExposable())
        return nullptr;

    // If the level is 1 or less, than nothing discloses this row.
    unsigned level = hierarchicalLevel();
    if (level <= 1)
        return nullptr;

    // Search for the previous row that matches the correct level.
    int index = rowIndex();
    auto allRows = parent->rows();
    int rowCount = allRows.size();
    if (index >= rowCount)
        return nullptr;

    for (int k = index - 1; k >= 0; --k) {
        auto* row = allRows[k].get();
        if (row->hierarchicalLevel() == level - 1)
            return row;
    }

    return nullptr;
}

AccessibilityObject* AccessibilityARIAGridRow::parentObjectUnignored() const
{
    if (auto* table = parentTable())
        return table;
    return AccessibilityTableRow::parentObjectUnignored();
}

AccessibilityTable* AccessibilityARIAGridRow::parentTable() const
{
    // The parent table might not be the direct ancestor of the row unfortunately. ARIA states that role="grid" should
    // only have "row" elements, but if not, we still should handle it gracefully by finding the right table.
    return downcast<AccessibilityTable>(Accessibility::findAncestor<AccessibilityObject>(*this, false, [this] (const auto& ancestor) {
        // The parent table for an ARIA grid row should be an ARIA table.
        // Unless the row is a native tr element.
        if (is<AccessibilityTable>(ancestor)) {
            auto& ancestorTable = downcast<AccessibilityTable>(ancestor);
            return ancestorTable.isExposable() && (ancestorTable.isAriaTable() || node()->hasTagName(HTMLNames::trTag));
        }

        return false;
    }));
}

AXCoreObject* AccessibilityARIAGridRow::headerObject()
{
    for (const auto& child : children()) {
        if (child->ariaRoleAttribute() == AccessibilityRole::RowHeader)
            return child.get();
    }
    
    return nullptr;
}

} // namespace WebCore