// Copyright 2016 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.

#ifndef NGLengthUtils_h
#define NGLengthUtils_h

#include "core/CoreExport.h"
#include "core/layout/ng/ng_units.h"
#include "core/layout/ng/ng_writing_mode.h"
#include "platform/text/TextDirection.h"
#include "wtf/Optional.h"

namespace blink {
class ComputedStyle;
class LayoutUnit;
class Length;
struct MinAndMaxContentSizes;
class NGConstraintSpace;
struct NGBoxStrut;
class NGFragment;

enum class LengthResolveType {
  kMinSize,
  kMaxSize,
  kContentSize,
  kMarginBorderPaddingSize
};

#define NGSizeIndefinite LayoutUnit(-1)

// Whether the caller needs to compute min-content and max-content sizes to
// pass them to ResolveInlineLength / ComputeInlineSizeForFragment.
// If this function returns false, it is safe to pass an empty
// MinAndMaxContentSizes struct to those functions.
CORE_EXPORT bool NeedMinAndMaxContentSizes(const NGConstraintSpace&,
                                           const ComputedStyle&);

// Like NeedMinAndMaxContentSizes, but for use when calling
// ComputeMinAndMaxContentContribution.
CORE_EXPORT bool NeedMinAndMaxContentSizesForContentContribution(
    const ComputedStyle&);

// Convert an inline-axis length to a layout unit using the given constraint
// space.
CORE_EXPORT LayoutUnit
ResolveInlineLength(const NGConstraintSpace&,
                    const ComputedStyle&,
                    const WTF::Optional<MinAndMaxContentSizes>&,
                    const Length&,
                    LengthResolveType);

// Convert a block-axis length to a layout unit using the given constraint
// space and content size.
CORE_EXPORT LayoutUnit ResolveBlockLength(const NGConstraintSpace&,
                                          const ComputedStyle&,
                                          const Length&,
                                          LayoutUnit content_size,
                                          LengthResolveType);

// For the given style and min/max content sizes, computes the min and max
// content contribution (https://drafts.csswg.org/css-sizing/#contributions).
// This is similar to ComputeInlineSizeForFragment except that it does not
// require a constraint space (percentage sizes as well as auto margins compute
// to zero) and that an auto inline size resolves to the respective min/max
// content size.
// Also, the min/max contribution does include the inline margins as well.
CORE_EXPORT MinAndMaxContentSizes ComputeMinAndMaxContentContribution(
    const ComputedStyle&,
    const WTF::Optional<MinAndMaxContentSizes>&);

// Resolves the given length to a layout unit, constraining it by the min
// logical width and max logical width properties from the ComputedStyle
// object.
CORE_EXPORT LayoutUnit
ComputeInlineSizeForFragment(const NGConstraintSpace&,
                             const ComputedStyle&,
                             const WTF::Optional<MinAndMaxContentSizes>&);

// Resolves the given length to a layout unit, constraining it by the min
// logical height and max logical height properties from the ComputedStyle
// object.
CORE_EXPORT LayoutUnit ComputeBlockSizeForFragment(const NGConstraintSpace&,
                                                   const ComputedStyle&,
                                                   LayoutUnit content_size);

// Based on available inline size, CSS computed column-width, CSS computed
// column-count and CSS used column-gap, return CSS used column-count.
CORE_EXPORT int ResolveUsedColumnCount(int computed_count,
                                       LayoutUnit computed_size,
                                       LayoutUnit used_gap,
                                       LayoutUnit available_size);

// Based on available inline size, CSS computed column-width, CSS computed
// column-count and CSS used column-gap, return CSS used column-width.
CORE_EXPORT LayoutUnit ResolveUsedColumnInlineSize(int computed_count,
                                                   LayoutUnit computed_size,
                                                   LayoutUnit used_gap,
                                                   LayoutUnit available_size);
CORE_EXPORT LayoutUnit ResolveUsedColumnInlineSize(LayoutUnit available_size,
                                                   const ComputedStyle&);

CORE_EXPORT LayoutUnit ResolveUsedColumnGap(const ComputedStyle&);

CORE_EXPORT NGBoxStrut ComputeMargins(const NGConstraintSpace&,
                                      const ComputedStyle&,
                                      const NGWritingMode writing_mode,
                                      const TextDirection direction);

CORE_EXPORT NGBoxStrut ComputeBorders(const ComputedStyle&);

CORE_EXPORT NGBoxStrut ComputePadding(const NGConstraintSpace&,
                                      const ComputedStyle&);

// Resolves margin: auto in the inline direction after a box has been laid out.
// This uses the available size from the constraint space and the box size from
// the fragment to compute the margins that are auto, if any, and adjusts
// the given NGBoxStrut accordingly.
CORE_EXPORT void ApplyAutoMargins(const NGConstraintSpace&,
                                  const ComputedStyle&,
                                  const NGFragment&,
                                  NGBoxStrut* margins);

}  // namespace blink

#endif  // NGLengthUtils_h