/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
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#include "gfxPlatformFontList.h"

#include "nsIPrefService.h"
#include "nsIPrefBranch2.h"  // for pref changes callback notification
#include "nsServiceManagerUtils.h"
#include "nsUnicharUtils.h"

// font info loader constants
static const PRUint32 kDelayBeforeLoadingCmaps = 8 * 1000; // 8secs
static const PRUint32 kIntervalBetweenLoadingCmaps = 150; // 150ms
static const PRUint32 kNumFontsPerSlice = 10; // read in info 10 fonts at a time

static PRLogModuleInfo *gFontListLog = PR_NewLogModule("fontListLog");


gfxPlatformFontList *gfxPlatformFontList::sPlatformFontList = nsnull;


class gfxFontListPrefObserver : public nsIObserver {
public:
    NS_DECL_ISUPPORTS
    NS_DECL_NSIOBSERVER
};

NS_IMPL_ISUPPORTS1(gfxFontListPrefObserver, nsIObserver)

NS_IMETHODIMP
gfxFontListPrefObserver::Observe(nsISupports     *aSubject,
                                 const char      *aTopic,
                                 const PRUnichar *aData)
{
    NS_ASSERTION(!strcmp(aTopic, NS_PREFBRANCH_PREFCHANGE_TOPIC_ID), "invalid topic");
    // XXX this could be made to only clear out the cache for the prefs that were changed
    // but it probably isn't that big a deal.
    gfxPlatformFontList::PlatformFontList()->ClearPrefFonts();
    return NS_OK;
}


gfxPlatformFontList::gfxPlatformFontList(PRBool aNeedFullnamePostscriptNames)
    : mNeedFullnamePostscriptNames(aNeedFullnamePostscriptNames),
      mStartIndex(0), mIncrement(kNumFontsPerSlice), mNumFamilies(0)
{
    mFontFamilies.Init(100);
    mOtherFamilyNames.Init(30);
    mOtherFamilyNamesInitialized = PR_FALSE;

    if (mNeedFullnamePostscriptNames) {
        mFullnames.Init(100);
        mPostscriptNames.Init(100);
    }
    mFaceNamesInitialized = PR_FALSE;

    mPrefFonts.Init(10);

    mBadUnderlineFamilyNames.Init(10);
    LoadBadUnderlineList();

    // pref changes notification setup
    gfxFontListPrefObserver *observer = new gfxFontListPrefObserver();
    if (observer) {
        nsCOMPtr<nsIPrefBranch2> pref = do_GetService(NS_PREFSERVICE_CONTRACTID);
        if (pref) {
            pref->AddObserver("font.", observer, PR_FALSE);
            pref->AddObserver("font.name-list.", observer, PR_FALSE);
            pref->AddObserver("intl.accept_languages", observer, PR_FALSE);  // hmmmm...
        } else {
            delete observer;
        }
    }
}

void
gfxPlatformFontList::InitFontList()
{
    mFontFamilies.Clear();
    mOtherFamilyNames.Clear();
    mOtherFamilyNamesInitialized = PR_FALSE;
    if (mNeedFullnamePostscriptNames) {
        mFullnames.Clear();
        mPostscriptNames.Clear();
    }
    mFaceNamesInitialized = PR_FALSE;
    mPrefFonts.Clear();
    CancelLoader();

    // initialize ranges of characters for which system-wide font search should be skipped
    mCodepointsWithNoFonts.reset();
    mCodepointsWithNoFonts.SetRange(0,0x1f);     // C0 controls
    mCodepointsWithNoFonts.SetRange(0x7f,0x9f);  // C1 controls
}

void
gfxPlatformFontList::GenerateFontListKey(const nsAString& aKeyName, nsAString& aResult)
{
    aResult = aKeyName;
    ToLowerCase(aResult);
}

void 
gfxPlatformFontList::InitOtherFamilyNames()
{
    mOtherFamilyNamesInitialized = PR_TRUE;

    // iterate over all font families and read in other family names
    mFontFamilies.Enumerate(gfxPlatformFontList::InitOtherFamilyNamesProc, this);
}
                                                         
PLDHashOperator PR_CALLBACK
gfxPlatformFontList::InitOtherFamilyNamesProc(nsStringHashKey::KeyType aKey,
                                              nsRefPtr<gfxFontFamily>& aFamilyEntry,
                                              void* userArg)
{
    gfxPlatformFontList *fc = static_cast<gfxPlatformFontList*>(userArg);
    aFamilyEntry->ReadOtherFamilyNames(fc);
    return PL_DHASH_NEXT;
}

void
gfxPlatformFontList::InitFaceNameLists()
{
    mFaceNamesInitialized = PR_TRUE;

    // iterate over all font families and read in other family names
    mFontFamilies.Enumerate(gfxPlatformFontList::InitFaceNameListsProc, this);
}

PLDHashOperator PR_CALLBACK
gfxPlatformFontList::InitFaceNameListsProc(nsStringHashKey::KeyType aKey,
                                           nsRefPtr<gfxFontFamily>& aFamilyEntry,
                                           void* userArg)
{
    gfxPlatformFontList *fc = static_cast<gfxPlatformFontList*>(userArg);
    aFamilyEntry->ReadFaceNames(fc, fc->NeedFullnamePostscriptNames());
    return PL_DHASH_NEXT;
}

void
gfxPlatformFontList::PreloadNamesList()
{
    nsAutoTArray<nsString, 10> preloadFonts;
    gfxFontUtils::GetPrefsFontList("font.preload-names-list", preloadFonts);

    PRUint32 numFonts = preloadFonts.Length();
    for (PRUint32 i = 0; i < numFonts; i++) {
        PRBool found;
        nsAutoString key;
        GenerateFontListKey(preloadFonts[i], key);
        
        // only search canonical names!
        gfxFontFamily *familyEntry = mFontFamilies.GetWeak(key, &found);
        if (familyEntry) {
            familyEntry->ReadOtherFamilyNames(this);
        }
    }

}

void 
gfxPlatformFontList::SetFixedPitch(const nsAString& aFamilyName)
{
    gfxFontFamily *family = FindFamily(aFamilyName);
    if (!family) return;

    family->FindStyleVariations();
    nsTArray<nsRefPtr<gfxFontEntry> >& fontlist = family->GetFontList();

    PRUint32 i, numFonts = fontlist.Length();

    for (i = 0; i < numFonts; i++) {
        fontlist[i]->mFixedPitch = 1;
    }
}

void
gfxPlatformFontList::LoadBadUnderlineList()
{
    nsAutoTArray<nsString, 10> blacklist;
    gfxFontUtils::GetPrefsFontList("font.blacklist.underline_offset", blacklist);
    PRUint32 numFonts = blacklist.Length();
    for (PRUint32 i = 0; i < numFonts; i++) {
        nsAutoString key;
        GenerateFontListKey(blacklist[i], key);
        mBadUnderlineFamilyNames.Put(key);
    }
}

PRBool 
gfxPlatformFontList::ResolveFontName(const nsAString& aFontName, nsAString& aResolvedFontName)
{
    gfxFontFamily *family = FindFamily(aFontName);
    if (family) {
        aResolvedFontName = family->Name();
        return PR_TRUE;
    }
    return PR_FALSE;
}

struct FontListData {
    FontListData(nsIAtom *aLangGroup,
                 const nsACString& aGenericFamily,
                 nsTArray<nsString>& aListOfFonts) :
        mLangGroup(aLangGroup), mGenericFamily(aGenericFamily),
        mListOfFonts(aListOfFonts) {}
    nsIAtom *mLangGroup;
    const nsACString& mGenericFamily;
    nsTArray<nsString>& mListOfFonts;
};

PLDHashOperator PR_CALLBACK
gfxPlatformFontList::HashEnumFuncForFamilies(nsStringHashKey::KeyType aKey,
                                             nsRefPtr<gfxFontFamily>& aFamilyEntry,
                                             void *aUserArg)
{
    FontListData *data = static_cast<FontListData*>(aUserArg);

    // use the first variation for now.  This data should be the same
    // for all the variations and should probably be moved up to
    // the Family
    gfxFontStyle style;
    style.language = data->mLangGroup;
    PRBool needsBold;
    nsRefPtr<gfxFontEntry> aFontEntry = aFamilyEntry->FindFontForStyle(style, needsBold);
    NS_ASSERTION(aFontEntry, "couldn't find any font entry in family");
    if (!aFontEntry)
        return PL_DHASH_NEXT;

    /* skip symbol fonts */
    if (aFontEntry->IsSymbolFont())
        return PL_DHASH_NEXT;

    if (aFontEntry->SupportsLangGroup(data->mLangGroup) &&
        aFontEntry->MatchesGenericFamily(data->mGenericFamily)) {
        nsAutoString localizedFamilyName;
        aFamilyEntry->LocalizedName(localizedFamilyName);
        data->mListOfFonts.AppendElement(localizedFamilyName);
    }

    return PL_DHASH_NEXT;
}

void
gfxPlatformFontList::GetFontList(nsIAtom *aLangGroup,
                                 const nsACString& aGenericFamily,
                                 nsTArray<nsString>& aListOfFonts)
{
    FontListData data(aLangGroup, aGenericFamily, aListOfFonts);

    mFontFamilies.Enumerate(gfxPlatformFontList::HashEnumFuncForFamilies, &data);

    aListOfFonts.Sort();
    aListOfFonts.Compact();
}

struct FontFamilyListData {
    FontFamilyListData(nsTArray<nsRefPtr<gfxFontFamily> >& aFamilyArray) 
        : mFamilyArray(aFamilyArray)
    {}

    static PLDHashOperator PR_CALLBACK AppendFamily(nsStringHashKey::KeyType aKey,
                                                    nsRefPtr<gfxFontFamily>& aFamilyEntry,
                                                    void *aUserArg)
    {
        FontFamilyListData *data = static_cast<FontFamilyListData*>(aUserArg);
        data->mFamilyArray.AppendElement(aFamilyEntry);
        return PL_DHASH_NEXT;
    }

    nsTArray<nsRefPtr<gfxFontFamily> >& mFamilyArray;
};

void
gfxPlatformFontList::GetFontFamilyList(nsTArray<nsRefPtr<gfxFontFamily> >& aFamilyArray)
{
    FontFamilyListData data(aFamilyArray);
    mFontFamilies.Enumerate(FontFamilyListData::AppendFamily, &data);
}

gfxFontEntry*  
gfxPlatformFontList::FindFontForChar(const PRUint32 aCh, gfxFont *aPrevFont)
{
    // is codepoint with no matching font? return null immediately
    if (mCodepointsWithNoFonts.test(aCh)) {
        return nsnull;
    }

    // TODO: optimize fallback e.g. by caching lists of fonts to try for a given
    // unicode range or script

    // try to short-circuit font fallback for U+FFFD, used to represent encoding errors:
    // just use a platform-specific fallback system font that is guaranteed (or at least
    // highly likely) to be around, or a cached family from last time U+FFFD was seen.
    // this helps speed up pages with lots of encoding errors, binary-as-text, etc.
    if (aCh == 0xFFFD && mReplacementCharFallbackFamily.Length() > 0) {
        gfxFontEntry* fontEntry = nsnull;
        PRBool needsBold;  // ignored in the system fallback case

        if (aPrevFont) {
            fontEntry = FindFontForFamily(mReplacementCharFallbackFamily, aPrevFont->GetStyle(), needsBold);
        } else {
            gfxFontStyle normalStyle;
            fontEntry = FindFontForFamily(mReplacementCharFallbackFamily, &normalStyle, needsBold);
        }

        if (fontEntry && fontEntry->TestCharacterMap(aCh))
            return fontEntry;
    }

    FontSearch data(aCh, aPrevFont);

    // iterate over all font families to find a font that support the character
    mFontFamilies.Enumerate(gfxPlatformFontList::FindFontForCharProc, &data);

    // no match? add to set of non-matching codepoints
    if (!data.mBestMatch) {
        mCodepointsWithNoFonts.set(aCh);
    } else if (aCh == 0xFFFD) {
        mReplacementCharFallbackFamily = data.mBestMatch->FamilyName();
    }

    return data.mBestMatch;
}

PLDHashOperator PR_CALLBACK 
gfxPlatformFontList::FindFontForCharProc(nsStringHashKey::KeyType aKey, nsRefPtr<gfxFontFamily>& aFamilyEntry,
     void *userArg)
{
    FontSearch *data = static_cast<FontSearch*>(userArg);

    // evaluate all fonts in this family for a match
    aFamilyEntry->FindFontForChar(data);
    return PL_DHASH_NEXT;
}

gfxFontFamily* 
gfxPlatformFontList::FindFamily(const nsAString& aFamily)
{
    nsAutoString key;
    gfxFontFamily *familyEntry;
    PRBool found;
    GenerateFontListKey(aFamily, key);

    // lookup in canonical (i.e. English) family name list
    if ((familyEntry = mFontFamilies.GetWeak(key, &found))) {
        return familyEntry;
    }

    // lookup in other family names list (mostly localized names)
    if ((familyEntry = mOtherFamilyNames.GetWeak(key, &found))) {
        return familyEntry;
    }

    // name not found and other family names not yet fully initialized so
    // initialize the rest of the list and try again.  this is done lazily
    // since reading name table entries is expensive
    if (!mOtherFamilyNamesInitialized) {
        InitOtherFamilyNames();
        if ((familyEntry = mOtherFamilyNames.GetWeak(key, &found))) {
            return familyEntry;
        }
    }

    return nsnull;
}

gfxFontEntry*
gfxPlatformFontList::FindFontForFamily(const nsAString& aFamily, const gfxFontStyle* aStyle, PRBool& aNeedsBold)
{
    gfxFontFamily *familyEntry = FindFamily(aFamily);

    aNeedsBold = PR_FALSE;

    if (familyEntry)
        return familyEntry->FindFontForStyle(*aStyle, aNeedsBold);

    return nsnull;
}

PRBool
gfxPlatformFontList::GetPrefFontFamilyEntries(eFontPrefLang aLangGroup, nsTArray<nsRefPtr<gfxFontFamily> > *array)
{
    return mPrefFonts.Get(PRUint32(aLangGroup), array);
}

void
gfxPlatformFontList::SetPrefFontFamilyEntries(eFontPrefLang aLangGroup, nsTArray<nsRefPtr<gfxFontFamily> >& array)
{
    mPrefFonts.Put(PRUint32(aLangGroup), array);
}

void 
gfxPlatformFontList::AddOtherFamilyName(gfxFontFamily *aFamilyEntry, nsAString& aOtherFamilyName)
{
    nsAutoString key;
    PRBool found;
    GenerateFontListKey(aOtherFamilyName, key);

    if (!mOtherFamilyNames.GetWeak(key, &found)) {
        mOtherFamilyNames.Put(key, aFamilyEntry);
        PR_LOG(gFontListLog, PR_LOG_DEBUG, ("(fontlist-otherfamily) canonical family: %s, other family: %s\n", 
                                            NS_ConvertUTF16toUTF8(aFamilyEntry->Name()).get(), 
                                            NS_ConvertUTF16toUTF8(aOtherFamilyName).get()));
        if (mBadUnderlineFamilyNames.Contains(key))
            aFamilyEntry->SetBadUnderlineFamily();
    }
}

void
gfxPlatformFontList::AddFullname(gfxFontEntry *aFontEntry, nsAString& aFullname)
{
    PRBool found;

    if (!mFullnames.GetWeak(aFullname, &found)) {
        mFullnames.Put(aFullname, aFontEntry);
        PR_LOG(gFontListLog, PR_LOG_DEBUG, ("(fontlist-fullname) name: %s, fullname: %s\n", 
                                            NS_ConvertUTF16toUTF8(aFontEntry->Name()).get(), 
                                            NS_ConvertUTF16toUTF8(aFullname).get()));
    }
}

void
gfxPlatformFontList::AddPostscriptName(gfxFontEntry *aFontEntry, nsAString& aPostscriptName)
{
    PRBool found;

    if (!mPostscriptNames.GetWeak(aPostscriptName, &found)) {
        mPostscriptNames.Put(aPostscriptName, aFontEntry);
        PR_LOG(gFontListLog, PR_LOG_DEBUG, ("(fontlist-postscript) name: %s, psname: %s\n", 
                                            NS_ConvertUTF16toUTF8(aFontEntry->Name()).get(), 
                                            NS_ConvertUTF16toUTF8(aPostscriptName).get()));
    }
}

PRBool
gfxPlatformFontList::GetStandardFamilyName(const nsAString& aFontName, nsAString& aFamilyName)
{
    aFamilyName.Truncate();
    ResolveFontName(aFontName, aFamilyName);
    return !aFamilyName.IsEmpty();
}

void 
gfxPlatformFontList::InitLoader()
{
    GetFontFamilyList(mFontFamiliesToLoad);
    mStartIndex = 0;
    mNumFamilies = mFontFamiliesToLoad.Length();
}

PRBool 
gfxPlatformFontList::RunLoader()
{
    PRUint32 i, endIndex = (mStartIndex + mIncrement < mNumFamilies ? mStartIndex + mIncrement : mNumFamilies);

    // for each font family, load in various font info
    for (i = mStartIndex; i < endIndex; i++) {
        gfxFontFamily* familyEntry = mFontFamiliesToLoad[i];

        // find all faces that are members of this family
        familyEntry->FindStyleVariations();
        if (familyEntry->GetFontList().Length() == 0) {
            // failed to load any faces for this family, so discard it
            nsAutoString key;
            GenerateFontListKey(familyEntry->Name(), key);
            mFontFamilies.Remove(key);
            continue;
        }

        // load the cmaps
        familyEntry->ReadCMAP();

        // read in face names
        familyEntry->ReadFaceNames(this, mNeedFullnamePostscriptNames);

        // check whether the family can be considered "simple" for style matching
        familyEntry->CheckForSimpleFamily();
    }

    mStartIndex = endIndex;

    return (mStartIndex >= mNumFamilies);
}

void 
gfxPlatformFontList::FinishLoader()
{
    mFontFamiliesToLoad.Clear();
    mNumFamilies = 0;
}