/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * The contents of this file are subject to the Netscape Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License.  You may obtain a copy of the License at
 * http://www.mozilla.org/NPL/
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See
 * the License for the specific language governing rights and limitations
 * under the License.
 *
 * The Original Code is Mozilla Communicator client code.
 *
 * The Initial Developer of the Original Code is Netscape Communications
 * Corporation.  Portions created by Netscape are Copyright (C) 1998
 * Netscape Communications Corporation.  All Rights Reserved.
 */
#include "nsFrameReflowState.h"
#include "nsIStyleContext.h"
#include "nsStyleConsts.h"
#include "nsIFrame.h"
#include "nsIHTMLReflow.h"
#include "nsIContent.h"
#include "nsHTMLAtoms.h"

const nsHTMLReflowState*
nsHTMLReflowState::GetContainingBlockReflowState(const nsReflowState* aParentRS)
{
  while (nsnull != aParentRS) {
    if (nsnull != aParentRS->frame) {
      PRBool isContainingBlock;
      nsresult rv = aParentRS->frame->IsPercentageBase(isContainingBlock);
      if (NS_SUCCEEDED(rv) && isContainingBlock) {
        return (const nsHTMLReflowState*) aParentRS;
      }
    }
    aParentRS = aParentRS->parentReflowState;
  }
  return nsnull;
}

const nsHTMLReflowState*
nsHTMLReflowState::GetPageBoxReflowState(const nsReflowState* aParentRS)
{
  // XXX write me as soon as we can ask a frame if it's a page frame...
  return nsnull;
}

nscoord
nsHTMLReflowState::GetContainingBlockContentWidth(const nsReflowState* aParentRS)
{
  nscoord width = 0;
  const nsHTMLReflowState* rs =
    GetContainingBlockReflowState(aParentRS);
  if (nsnull != rs) {
    return ((nsHTMLReflowState*)aParentRS)->GetContentWidth();/* XXX cast */
  }
  return width;
}

nscoord
nsHTMLReflowState::GetContentWidth() const
{
  nscoord width = 0;
  if (HaveFixedContentWidth()) {
    width = minWidth;
  }
  else if (NS_UNCONSTRAINEDSIZE != maxSize.width) {
    width = maxSize.width;
    if (nsnull != frame) {
      // Subtract out the border and padding values because the
      // percentage is to be computed relative to the content
      // width, not the outer width.
      const nsStyleSpacing* spacing;
      nsresult rv;
      rv = frame->GetStyleData(eStyleStruct_Spacing,
                               (const nsStyleStruct*&) spacing);
      if (NS_SUCCEEDED(rv) && (nsnull != spacing)) {
        nsMargin borderPadding;
        ComputeBorderPaddingFor(frame,
                                parentReflowState,
                                borderPadding);
        width -= borderPadding.left + borderPadding.right;
      }
    }
  }
  return width;
}

static inline PRBool
IsReplaced(nsIAtom* aTag)
{
  return (nsHTMLAtoms::img == aTag) ||
    (nsHTMLAtoms::applet == aTag) ||
    (nsHTMLAtoms::object == aTag) ||
    (nsHTMLAtoms::input == aTag) ||
    (nsHTMLAtoms::select == aTag) ||
    (nsHTMLAtoms::textarea == aTag) ||
    (nsHTMLAtoms::iframe == aTag);
}

// XXX there is no CLEAN way to detect the "replaced" attribute (yet)
void
nsHTMLReflowState::DetermineFrameType(nsIPresContext& aPresContext)
{
  nsIAtom* tag = nsnull;
  nsIContent* content;
  if ((NS_OK == frame->GetContent(content)) && (nsnull != content)) {
    content->GetTag(tag);
    NS_RELEASE(content);
  }

  // Section 9.7 indicates that absolute position takes precedence
  // over float which takes precedence over display.
  const nsStyleDisplay* display;
  frame->GetStyleData(eStyleStruct_Display, (const nsStyleStruct*&)display);
  const nsStylePosition* pos;
  frame->GetStyleData(eStyleStruct_Position, (const nsStyleStruct*&)pos);
  if ((nsnull != pos) && (NS_STYLE_POSITION_ABSOLUTE == pos->mPosition)) {
    // XXX replaced?
    frameType = eCSSFrameType_Absolute;
  }
  else if (NS_STYLE_FLOAT_NONE != display->mFloats) {
    // XXX replaced?
    frameType = eCSSFrameType_Floating;
  }
  else {
    switch (display->mDisplay) {
    case NS_STYLE_DISPLAY_BLOCK:
    case NS_STYLE_DISPLAY_LIST_ITEM:
    case NS_STYLE_DISPLAY_TABLE:
    case NS_STYLE_DISPLAY_TABLE_CELL:
    case NS_STYLE_DISPLAY_TABLE_CAPTION:
      frameType = eCSSFrameType_Block;
      break;

    case NS_STYLE_DISPLAY_INLINE:
    case NS_STYLE_DISPLAY_MARKER:
    case NS_STYLE_DISPLAY_INLINE_TABLE:
      if (IsReplaced(tag)) {
        frameType = eCSSFrameType_InlineReplaced;
      }
      else {
        frameType = eCSSFrameType_Inline;
      }
      break;

    case NS_STYLE_DISPLAY_RUN_IN:
    case NS_STYLE_DISPLAY_COMPACT:
      // XXX need to look ahead at the frame's sibling
      frameType = eCSSFrameType_Block;
      break;

    case NS_STYLE_DISPLAY_TABLE_ROW_GROUP:
    case NS_STYLE_DISPLAY_TABLE_COLUMN:
    case NS_STYLE_DISPLAY_TABLE_COLUMN_GROUP:
    case NS_STYLE_DISPLAY_TABLE_HEADER_GROUP:
    case NS_STYLE_DISPLAY_TABLE_FOOTER_GROUP:
    case NS_STYLE_DISPLAY_TABLE_ROW:
      // XXX I don't know what to do about these yet...later
      frameType = eCSSFrameType_Inline;
      break;

    case NS_STYLE_DISPLAY_NONE:
    default:
      frameType = eCSSFrameType_Unknown;
      break;
    }
    NS_IF_RELEASE(tag);
  }
}

void
nsHTMLReflowState::InitConstraints(nsIPresContext& aPresContext)
{
  // Determine whether the values are constrained or unconstrained
  // by looking at the maxSize
  widthConstraint = NS_UNCONSTRAINEDSIZE == maxSize.width ?
                      eHTMLFrameConstraint_Unconstrained :
                      eHTMLFrameConstraint_Constrained;
  heightConstraint = NS_UNCONSTRAINEDSIZE == maxSize.height ?
                      eHTMLFrameConstraint_Unconstrained :
                      eHTMLFrameConstraint_Constrained;
  minWidth = 0;
  minHeight = 0;

  // Some frame types are not constrained by width/height style
  // attributes. Return if the frame is one of those types.
  switch (frameType) {
  case eCSSFrameType_Unknown:
  case eCSSFrameType_Inline:
    return;

  default:
    break;
  }

  // Look for stylistic constraints on the width/height
  const nsStylePosition* pos;
  nsresult result = frame->GetStyleData(eStyleStruct_Position,
                                        (const nsStyleStruct*&)pos);
  if (NS_OK == result) {
    nscoord containingBlockWidth, containingBlockHeight;
    nscoord width = -1, height = -1;
    PRIntn widthUnit = pos->mWidth.GetUnit();
    PRIntn heightUnit = pos->mHeight.GetUnit();

    // When a percentage is specified we need to find the containing
    // block to use as the basis for the percentage computation.
    if ((eStyleUnit_Percent == widthUnit) ||
        (eStyleUnit_Percent == heightUnit)) {
      const nsHTMLReflowState* cbrs =
        GetContainingBlockReflowState(parentReflowState);

      // If there is no containing block then pretend the width or
      // height units are auto.
      if (nsnull == cbrs) {
        if (eStyleUnit_Percent == widthUnit) {
          widthUnit = eStyleUnit_Auto;
        }
        if (eStyleUnit_Percent == heightUnit) {
          heightUnit = eStyleUnit_Auto;
        }
      }
      else {
        if (eStyleUnit_Percent == widthUnit) {
          containingBlockWidth = cbrs->GetContentWidth();
        }
        if (eStyleUnit_Percent == heightUnit) {
          if (NS_UNCONSTRAINEDSIZE == cbrs->maxSize.height) {
            // CSS2 spec, 10.5: if the height of the containing block
            // is not specified explicitly then the value is
            // interpreted like auto.
            heightUnit = eStyleUnit_Auto;
          }
          else {
            containingBlockHeight = cbrs->maxSize.height;
          }
        }
      }
    }

    switch (widthUnit) {
    case eStyleUnit_Coord:
      width = pos->mWidth.GetCoordValue();
      break;
    case eStyleUnit_Percent:
      width = nscoord(pos->mWidth.GetPercentValue() * containingBlockWidth);
      break;
    case eStyleUnit_Auto:
      // XXX See section 10.3 of the css2 spec and then write this code!
      break;
    }
    switch (heightUnit) {
    case eStyleUnit_Coord:
      height = pos->mHeight.GetCoordValue();
      break;
    case eStyleUnit_Percent:
      height = nscoord(pos->mHeight.GetPercentValue() * containingBlockHeight);
      break;
    case eStyleUnit_Auto:
      // XXX See section 10.6 of the css2 spec and then write this code!
      break;
    }

    if (width > 0) {
      // XXX If the size constraint is a fixed content width then we also
      // need to set the max width as well, but then we bust tables...
#if 0
      minWidth = maxSize.width = width;
#else
      minWidth = width;
#endif
      widthConstraint = eHTMLFrameConstraint_FixedContent;
    }
    if (height > 0) {
      // XXX If the size constraint is a fixed content width then we also
      // need to set the max height as well...
#if 0
      minHeight = maxSize.height = height;
#else
      minHeight = height;
#endif
      heightConstraint = eHTMLFrameConstraint_FixedContent;
    }
  }

  // XXX this is probably a good place to calculate auto margins too
  // (section 10.3/10.6 of the spec)
}

void
nsHTMLReflowState::ComputeHorizontalValue(const nsHTMLReflowState& aRS,
                                          nsStyleUnit aUnit,
                                          nsStyleCoord& aCoord,
                                          nscoord& aResult)
{
  aResult = 0;
  if (eStyleUnit_Percent == aUnit) {
    nscoord width = aRS.GetContentWidth();
    float pct = aCoord.GetPercentValue();
    aResult = NSToCoordFloor(width * pct);
  }
}

void
nsHTMLReflowState::ComputeVerticalValue(const nsHTMLReflowState& aRS,
                                        nsStyleUnit aUnit,
                                        nsStyleCoord& aCoord,
                                        nscoord& aResult)
{
  aResult = 0;
  if (eStyleUnit_Percent == aUnit) {
    // XXX temporary!
    nscoord width = aRS.GetContentWidth();
    float pct = aCoord.GetPercentValue();
    aResult = NSToCoordFloor(width * pct);
  }
}

void
nsHTMLReflowState::ComputeMarginFor(nsIFrame* aFrame,
                                    const nsReflowState* aParentRS,
                                    nsMargin& aResult)
{
  const nsStyleSpacing* spacing;
  nsresult rv;
  rv = aFrame->GetStyleData(eStyleStruct_Spacing,
                            (const nsStyleStruct*&) spacing);
  if (NS_SUCCEEDED(rv) && (nsnull != spacing)) {
    // If style style can provide us the margin directly, then use it.
#if 0
    if (!spacing->GetMargin(aResult) && (nsnull != aParentRS))
#else
    spacing->CalcMarginFor(aFrame, aResult);
    if ((eStyleUnit_Percent == spacing->mMargin.GetTopUnit()) ||
        (eStyleUnit_Percent == spacing->mMargin.GetRightUnit()) ||
        (eStyleUnit_Percent == spacing->mMargin.GetBottomUnit()) ||
        (eStyleUnit_Percent == spacing->mMargin.GetLeftUnit()))
#endif
    {
      // We have to compute the value (because it's uncomputable by
      // the style code).
      const nsHTMLReflowState* rs = GetContainingBlockReflowState(aParentRS);
      if (nsnull != rs) {
        nsStyleCoord left, right;
        ComputeHorizontalValue(*rs, spacing->mMargin.GetLeftUnit(),
                               spacing->mMargin.GetLeft(left), aResult.left);
        ComputeHorizontalValue(*rs, spacing->mMargin.GetRightUnit(),
                               spacing->mMargin.GetRight(right),
                               aResult.right);
      }
      else {
        aResult.left = 0;
        aResult.right = 0;
      }

      const nsHTMLReflowState* rs2 = GetPageBoxReflowState(aParentRS);
      nsStyleCoord top, bottom;
      if (nsnull != rs2) {
        // According to the CSS2 spec, margin percentages are
        // calculated with respect to the *height* of the containing
        // block when in a paginated context.
        ComputeVerticalValue(*rs2, spacing->mMargin.GetTopUnit(),
                             spacing->mMargin.GetTop(top), aResult.top);
        ComputeVerticalValue(*rs2, spacing->mMargin.GetBottomUnit(),
                             spacing->mMargin.GetBottom(bottom),
                             aResult.bottom);
      }
      else if (nsnull != rs) {
        // According to the CSS2 spec, margin percentages are
        // calculated with respect to the *width* of the containing
        // block, even for margin-top and margin-bottom.
        ComputeHorizontalValue(*rs, spacing->mMargin.GetTopUnit(),
                               spacing->mMargin.GetTop(top), aResult.top);
        ComputeHorizontalValue(*rs, spacing->mMargin.GetBottomUnit(),
                               spacing->mMargin.GetBottom(bottom),
                               aResult.bottom);
      }
      else {
        aResult.top = 0;
        aResult.bottom = 0;
      }
    }
  }
}

void
nsHTMLReflowState::ComputePaddingFor(nsIFrame* aFrame,
                                     const nsReflowState* aParentRS,
                                     nsMargin& aResult)
{
  const nsStyleSpacing* spacing;
  nsresult rv;
  rv = aFrame->GetStyleData(eStyleStruct_Spacing,
                            (const nsStyleStruct*&) spacing);
  if (NS_SUCCEEDED(rv) && (nsnull != spacing)) {
    // If style can provide us the padding directly, then use it.
    spacing->CalcPaddingFor(aFrame, aResult);
#if 0
    if (!spacing->GetPadding(aResult) && (nsnull != aParentRS))
#else
    spacing->CalcPaddingFor(aFrame, aResult);
    if ((eStyleUnit_Percent == spacing->mPadding.GetTopUnit()) ||
        (eStyleUnit_Percent == spacing->mPadding.GetRightUnit()) ||
        (eStyleUnit_Percent == spacing->mPadding.GetBottomUnit()) ||
        (eStyleUnit_Percent == spacing->mPadding.GetLeftUnit()))
#endif
    {
      // We have to compute the value (because it's uncomputable by
      // the style code).
      const nsHTMLReflowState* rs = GetContainingBlockReflowState(aParentRS);
      if (nsnull != rs) {
        nsStyleCoord left, right, top, bottom;
        ComputeHorizontalValue(*rs, spacing->mPadding.GetLeftUnit(),
                               spacing->mPadding.GetLeft(left), aResult.left);
        ComputeHorizontalValue(*rs, spacing->mPadding.GetRightUnit(),
                               spacing->mPadding.GetRight(right),
                               aResult.right);

        // According to the CSS2 spec, padding percentages are
        // calculated with respect to the *width* of the containing
        // block, even for padding-top and padding-bottom.
        ComputeHorizontalValue(*rs, spacing->mPadding.GetTopUnit(),
                               spacing->mPadding.GetTop(top), aResult.top);
        ComputeHorizontalValue(*rs, spacing->mPadding.GetBottomUnit(),
                               spacing->mPadding.GetBottom(bottom),
                               aResult.bottom);
      }
      else {
        aResult.SizeTo(0, 0, 0, 0);
      }
    }
  }
  else {
    aResult.SizeTo(0, 0, 0, 0);
  }
}

void
nsHTMLReflowState::ComputeBorderFor(nsIFrame* aFrame,
                                    nsMargin& aResult)
{
  const nsStyleSpacing* spacing;
  nsresult rv;
  rv = aFrame->GetStyleData(eStyleStruct_Spacing,
                            (const nsStyleStruct*&) spacing);
  if (NS_SUCCEEDED(rv) && (nsnull != spacing)) {
    // If style can provide us the border directly, then use it.
    if (!spacing->GetBorder(aResult)) {
      // CSS2 has no percentage borders
      aResult.SizeTo(0, 0, 0, 0);
    }
  }
  else {
    aResult.SizeTo(0, 0, 0, 0);
  }
}

void
nsHTMLReflowState::ComputeBorderPaddingFor(nsIFrame* aFrame,
                                           const nsReflowState* aParentRS,
                                           nsMargin& aResult)
{
  const nsStyleSpacing* spacing;
  nsresult rv;
  rv = aFrame->GetStyleData(eStyleStruct_Spacing,
                            (const nsStyleStruct*&) spacing);
  if (NS_SUCCEEDED(rv) && (nsnull != spacing)) {
    nsMargin b, p;

    // If style style can provide us the margin directly, then use it.
    if (!spacing->GetBorder(b)) {
      b.SizeTo(0, 0, 0, 0);
    }
#if 0
    if (!spacing->GetPadding(p) && (nsnull != aParentRS))
#else
    spacing->CalcPaddingFor(aFrame, p);
    if ((eStyleUnit_Percent == spacing->mPadding.GetTopUnit()) ||
        (eStyleUnit_Percent == spacing->mPadding.GetRightUnit()) ||
        (eStyleUnit_Percent == spacing->mPadding.GetBottomUnit()) ||
        (eStyleUnit_Percent == spacing->mPadding.GetLeftUnit()))
#endif
    {
      // We have to compute the value (because it's uncomputable by
      // the style code).
      const nsHTMLReflowState* rs = GetContainingBlockReflowState(aParentRS);
      if (nsnull != rs) {
        nsStyleCoord left, right, top, bottom;
        ComputeHorizontalValue(*rs, spacing->mPadding.GetLeftUnit(),
                               spacing->mPadding.GetLeft(left), p.left);
        ComputeHorizontalValue(*rs, spacing->mPadding.GetRightUnit(),
                               spacing->mPadding.GetRight(right), p.right);

        // According to the CSS2 spec, padding percentages are
        // calculated with respect to the *width* of the containing
        // block, even for padding-top and padding-bottom.
        ComputeHorizontalValue(*rs, spacing->mPadding.GetTopUnit(),
                               spacing->mPadding.GetTop(top), p.top);
        ComputeHorizontalValue(*rs, spacing->mPadding.GetBottomUnit(),
                               spacing->mPadding.GetBottom(bottom), p.bottom);
      }
      else {
        p.SizeTo(0, 0, 0, 0);
      }
    }

    aResult.top = b.top + p.top;
    aResult.right = b.right + p.right;
    aResult.bottom = b.bottom + p.bottom;
    aResult.left = b.left + p.left;
  }
  else {
    aResult.SizeTo(0, 0, 0, 0);
  }
}

//----------------------------------------------------------------------

nsFrameReflowState::nsFrameReflowState(nsIPresContext& aPresContext,
                                       const nsHTMLReflowState& aReflowState,
                                       const nsHTMLReflowMetrics& aMetrics)
  : nsHTMLReflowState(aReflowState),
    mPresContext(aPresContext)
{
  // While we skip around the reflow state that our parent gave us so
  // that the parentReflowState is linked properly, we don't want to
  // skip over it's reason.
  reason = aReflowState.reason;
  mNextRCFrame = nsnull;

  // Initialize max-element-size
  mComputeMaxElementSize = nsnull != aMetrics.maxElementSize;
  mMaxElementSize.width = 0;
  mMaxElementSize.height = 0;

  // Get style data that we need
  frame->GetStyleData(eStyleStruct_Text,
                      (const nsStyleStruct*&) mStyleText);
  frame->GetStyleData(eStyleStruct_Display,
                      (const nsStyleStruct*&) mStyleDisplay);
  frame->GetStyleData(eStyleStruct_Spacing,
                      (const nsStyleStruct*&) mStyleSpacing);

  // Calculate our border and padding value
  ComputeBorderPaddingFor(frame, parentReflowState, mBorderPadding);

  // Set mNoWrap flag
  switch (mStyleText->mWhiteSpace) {
  case NS_STYLE_WHITESPACE_PRE:
  case NS_STYLE_WHITESPACE_NOWRAP:
    mNoWrap = PR_TRUE;
    break;
  default:
    mNoWrap = PR_FALSE;
    break;
  }

  // Set mDirection value
  mDirection = mStyleDisplay->mDirection;

  // See if this container frame will act as a root for margin
  // collapsing behavior.
  mIsMarginRoot = PR_FALSE;
  if ((0 != mBorderPadding.top) || (0 != mBorderPadding.bottom)) {
    mIsMarginRoot = PR_TRUE;
  }
  mCarriedOutTopMargin = 0;
  mPrevBottomMargin = 0;
  mCarriedOutMarginFlags = 0;
}

nsFrameReflowState::~nsFrameReflowState()
{
}

void
nsFrameReflowState::SetupChildReflowState(nsHTMLReflowState& aChildRS)
{
  // Get reflow reason set correctly. It's possible that a child was
  // created and then it was decided that it could not be reflowed
  // (for example, a block frame that isn't at the start of a
  // line). In this case the reason will be wrong so we need to check
  // the frame state.
  nsReflowReason reason = eReflowReason_Resize;
  nsIFrame* frame = aChildRS.frame;
  nsFrameState state;
  frame->GetFrameState(state);
  if (NS_FRAME_FIRST_REFLOW & state) {
    reason = eReflowReason_Initial;
  }
  else if (mNextRCFrame == frame) {
    reason = eReflowReason_Incremental;
    // Make sure we only incrementally reflow once
    mNextRCFrame = nsnull;/* XXX bad coupling */
  }
  aChildRS.reason = reason;
}