// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "sky/engine/config.h"
#include "sky/engine/core/animation/Interpolation.h"

namespace blink {

DEFINE_EMPTY_DESTRUCTOR_WILL_BE_REMOVED(Interpolation);

namespace {

bool typesMatch(const InterpolableValue* start, const InterpolableValue* end)
{
    if (start->isNumber())
        return end->isNumber();
    if (start->isBool())
        return end->isBool();
    if (start->isAnimatableValue())
        return end->isAnimatableValue();
    if (!(start->isList() && end->isList()))
        return false;
    const InterpolableList* startList = toInterpolableList(start);
    const InterpolableList* endList = toInterpolableList(end);
    if (startList->length() != endList->length())
        return false;
    for (size_t i = 0; i < startList->length(); ++i) {
        if (!typesMatch(startList->get(i), endList->get(i)))
            return false;
    }
    return true;
}

}

Interpolation::Interpolation(PassOwnPtr<InterpolableValue> start, PassOwnPtr<InterpolableValue> end)
    : m_start(start)
    , m_end(end)
    , m_cachedFraction(0)
    , m_cachedIteration(0)
    , m_cachedValue(m_start->clone())
{
    RELEASE_ASSERT(typesMatch(m_start.get(), m_end.get()));
}

void Interpolation::interpolate(int iteration, double fraction) const
{
    if (m_cachedFraction != fraction || m_cachedIteration != iteration) {
        m_cachedValue = m_start->interpolate(*m_end, fraction);
        m_cachedIteration = iteration;
        m_cachedFraction = fraction;
    }
}

}