/* Copyright 2014 Adobe Systems Incorporated (http://www.adobe.com/). All Rights Reserved.
   This software is licensed as OpenSource, under the Apache License, Version 2.0.
   This license is available at: http://opensource.org/licenses/Apache-2.0. */

#include "kern.h"
#include "sfnt_kern.h"
#include "BLND.h"
#include "sfnt.h"
#include "post.h"

static IntX ms = 0;              /* Flags Microsoft-style table */
static kernTbl *kern = NULL;     /* Apple-style kern table */
static MSkernTbl *MSkern = NULL; /* Microsoft-style kern table */
static IntX loaded = 0;
static IntX nMasters;

/* Read format 0 */
static Format0 *read0(Card32 offset, Card32 length) {
    IntX i;
    IntX nPairs;
    Card32 calcSize;
    Format0 *fmt = memNew(sizeof(Format0));
    /* printf("Offset at start of table: %d.\n", fileTell()); */
    IN1(fmt->nPairs);
    IN1(fmt->searchRange);
    IN1(fmt->entrySelector);
    IN1(fmt->rangeShift);
    /* printf("Offset at start of kern pairs: %d.\n", fileTell()); */
    /* Determine nPairs from table length (table may include sentinel) */
    calcSize = SUBTABLE_HDR_SIZE + FORMAT0_HDR_SIZE + (fmt->nPairs + 1) * PAIR_SIZE(1);
    if (length >= calcSize)
        nPairs = fmt->nPairs + 1;
    else
        nPairs = fmt->nPairs;

    fmt->pair = memNew(sizeof(Pair) * nPairs);
    for (i = 0; i < nPairs; i++) {
        IntX j;
        Pair *pair = &fmt->pair[i];

        IN1(pair->left);
        IN1(pair->right);

        pair->value = memNew(sizeof(FWord) * nMasters);
        for (j = 0; j < nMasters; j++)
            IN1(pair->value[j]);
        /* printf("Offset at end of kern pair '%d': %d.\n", i, fileTell()); */
    }

    return fmt;
}

/* Read format 2 class */
static void read2Class(Class *class, Card32 offset) {
    IntX i;

    SEEK_ABS(offset);

    IN1(class->firstGlyph);
    IN1(class->nGlyphs);

    class->classes = memNew(sizeof(Card16) * class->nGlyphs);
    for (i = 0; i < class->nGlyphs; i++)
        IN1(class->classes[i]);
}

/* Read format 2 */
static Format2 *read2(Card32 offset, Card32 length) {
    IntX i;
    IntX words;
    Format2 *fmt = memNew(sizeof(Format2));

    IN1(fmt->rowWidth);
    IN1(fmt->leftClassOffset);
    IN1(fmt->rightClassOffset);
    IN1(fmt->arrayOffset);

    read2Class(&fmt->left, offset + fmt->leftClassOffset);
    read2Class(&fmt->right, offset + fmt->rightClassOffset);

    /* Determine array size from table length */
    words = (length - (FORMAT2_HDR_SIZE + CLASS_SIZE(fmt->left.nGlyphs) +
                       CLASS_SIZE(fmt->right.nGlyphs))) /
            sizeof(FWord);
    fmt->array = memNew(sizeof(FWord) * words);

    /* Read value array */
    SEEK_ABS(offset + fmt->arrayOffset);
    for (i = 0; i < words; i++)
        IN1(fmt->array[i]);

    return fmt;
}

/* Read format 3 */
static Format3 *read3(Card32 offset, Card32 length) {
    Card32 i;
    Format3 *fmt = memNew(sizeof(Format3));

    Card32 kernIndexSize, tableSize;

    IN1(fmt->glyphCount);
    IN1(fmt->kernValueCount);
    IN1(fmt->leftClassCount);
    IN1(fmt->rightClassCount);
    IN1(fmt->flags);

    kernIndexSize = fmt->leftClassCount * fmt->rightClassCount;
    tableSize = SUBTABLE_HDR_SIZE + FORMAT3_HDR_SIZE + fmt->kernValueCount * sizeof(FWord) + fmt->glyphCount + fmt->glyphCount + kernIndexSize;

    if (tableSize != length) {
        if (tableSize > length) {
            fprintf(OUTPUTBUFF, "Error: kern subtable format 3 size '%u' is greater than subtable length '%u'. Skipping.\n", tableSize, length);
            return fmt;
        } else
            fprintf(OUTPUTBUFF, "Error: kern subtable format 3 size '%u' is less than subtable length '%u'.\n", tableSize, length);
    }

    fmt->kernValue = (FWord *)memNew(sizeof(FWord) * fmt->kernValueCount);
    fmt->leftClass = (Card8 *)memNew(sizeof(Card8) * fmt->glyphCount);
    fmt->rightClass = (Card8 *)memNew(sizeof(Card8) * fmt->glyphCount);
    fmt->kernIndex = (Card8 *)memNew(sizeof(Card8) * kernIndexSize);

    /* Read value arrays */
    for (i = 0; i < fmt->kernValueCount; i++)
        IN1(fmt->kernValue[i]);
    for (i = 0; i < fmt->glyphCount; i++)
        IN1(fmt->leftClass[i]);
    for (i = 0; i < fmt->glyphCount; i++)
        IN1(fmt->rightClass[i]);
    for (i = 0; i < kernIndexSize; i++)
        IN1(fmt->kernIndex[i]);
    return fmt;
}

/* Read format-specific subtable */
static void *readSubtable(IntX type, Card32 offset, Card32 length) {
    switch (type) {
        case 0:
            return read0(offset, length);
        case 2:
            return read2(offset, length);
        case 3:
            return read3(offset, length);
        default:
            warning(SPOT_MSG_kernUNSTAB, type);
            return NULL;
    }
}

/* Read Microsoft-style kern table */
static void readMS(LongN start) {
    IntX i;
    LongN offset = start + MS_TBL_HDR_SIZE;

    ms = 1;
    MSkern = (MSkernTbl *)memNew(sizeof(MSkernTbl));
    SEEK_ABS(start);

    IN1(MSkern->version);
    IN1(MSkern->nTables);

    MSkern->subtable = memNew(sizeof(MSSubtable) * MSkern->nTables);
    for (i = 0; i < MSkern->nTables; i++) {
        MSSubtable *subtable = &MSkern->subtable[i];

        SEEK_ABS(offset);
        IN1(subtable->version);
        IN1(subtable->length);
        IN1(subtable->coverage);
        subtable->format =
            readSubtable((subtable->coverage & MS_COVERAGE_FORMAT) >> 8,
                         offset, subtable->length);
        offset += subtable->length;
    }
}

/* Read Apple-style kern table */
static void readApple(LongN start) {
    IntX i;
    Card32 offset = start + TBL_HDR_SIZE;

    /* Already read version */
    IN1(kern->nTables);

    kern->subtable = memNew(sizeof(Subtable) * kern->nTables);

    for (i = 0; i < (IntX)kern->nTables; i++) {
        Subtable *subtable = &kern->subtable[i];

        SEEK_ABS(offset);
        /* Read subtable header */
        IN1(subtable->length);
        IN1(subtable->coverage);
        IN1(subtable->tupleIndex);
        /* read rest of subtable */
        subtable->format = readSubtable(subtable->coverage & COVERAGE_FORMAT,
                                        offset, subtable->length);
        offset += subtable->length;
    }
}

void kernRead(LongN start, Card32 length) {
    if (loaded)
        return;

    kern = (kernTbl *)memNew(sizeof(kernTbl));

    if (sfntReadTable(BLND_))
        nMasters = 1; /* No BLND table so not MM font */
    else
        nMasters = BLNDGetNMasters();

    SEEK_ABS(start);

    IN1(kern->version);
    if (kern->version != VERSION(1, 0))
        readMS(start);
    else
        readApple(start);

    loaded = 1;
}

/* Dump kerning value */
static void dumpValue(FWord *valueP, IntX level) {
    FWord value = 0;

    if (nMasters == 1) {
        if (valueP != NULL)
            value = valueP[0];
        DL(3, (OUTPUTBUFF, "%hd", value));
    } else {
        IntX i;
        DL(3, (OUTPUTBUFF, "{"));
        for (i = 0; i < nMasters; i++) {
            if (valueP != NULL)
                value = valueP[i];
            DL(3, (OUTPUTBUFF, "%s%hd", (i == 0) ? "" : ",", value));
        }
        DL(3, (OUTPUTBUFF, "}"));
    }
}

static void dump0(Format0 *fmt, Card32 length, IntX level) {
    IntX i;
    IntX nPairs = (length - FORMAT0_HDR_SIZE) / PAIR_SIZE(nMasters);
    IntX dumpNames = level == 4;

    if (dumpNames)
        initGlyphNames();

    DL(2, (OUTPUTBUFF, "--- format 0\n"));
    DLu(2, "nPairs       =", fmt->nPairs);
    DLu(2, "searchRange  =", fmt->searchRange);
    DLu(2, "entrySelector=", fmt->entrySelector);
    DLu(2, "rangeShift   =", fmt->rangeShift);

    if (nPairs > fmt->nPairs + 1)
        nPairs = fmt->nPairs + 1; /* Table larger than # pairs + sentinel */

    DL(3, (OUTPUTBUFF, "--- pair[index]={left,right,value+}\n"));
    for (i = 0; i < fmt->nPairs; i++) {
        Pair *pair = &fmt->pair[i];

        if (dumpNames) {
            fprintf(OUTPUTBUFF, "[%d]={<%s>,", i, getGlyphName(pair->left, 0));
            fprintf(OUTPUTBUFF, "<%s>,", getGlyphName(pair->right, 0));
        } else
            DL(3, (OUTPUTBUFF, "[%d]={%hu,%hu,", i, pair->left, pair->right));
        dumpValue(pair->value, level);
        DL(3, (OUTPUTBUFF, "} "));
    }
    DL(3, (OUTPUTBUFF, "\n"));
}

/* Dump format 2 class */
static void dump2Class(Byte8 *label, Class *class, IntX level) {
    IntX i;

    DL(2, (OUTPUTBUFF, "--- %s class table\n", label));
    DLu(2, "firstGlyph=", class->firstGlyph);
    DLu(2, "nGlyphs   =", class->nGlyphs);

    DL(3, (OUTPUTBUFF, "--- classes[index]=class\n"));
    for (i = 0; i < class->nGlyphs; i++)
        DL(3, (OUTPUTBUFF, "[%d]=%04hx ", i, class->classes[i]));
    DL(3, (OUTPUTBUFF, "\n"));
}

/* Dump format 2 array */
static void dump2Array(Format2 *fmt, Card32 length, IntX level) {
    IntX i;
    IntX j;
    IntX elementSize = sizeof(FWord) * nMasters;
    IntX elements =
        (length - (FORMAT2_HDR_SIZE + CLASS_SIZE(fmt->left.nGlyphs) +
                   CLASS_SIZE(fmt->right.nGlyphs))) /
        elementSize;
    IntX cols = fmt->rowWidth / elementSize;
    IntX rows = elements / cols;

    DL(2, (OUTPUTBUFF, "--- value array[left,right]=non-zero value\n"));
    for (i = 0; i < rows; i++)
        for (j = 0; j < cols; j++) {
            IntX k;
            FWord *value = &fmt->array[(i * cols + j) * nMasters];

            for (k = 0; k < nMasters; k++)
                if (value[k] != 0)
                    goto dump;

            continue; /* Skip all-zero value */

        dump:
            DL(3, (OUTPUTBUFF, "[%d,%d]=", i, j));
            dumpValue(value, level);
            DL(3, (OUTPUTBUFF, " "));
        }
    DL(3, (OUTPUTBUFF, "\n"));
}

static void dump2(Format2 *fmt, Card32 length, IntX level) {
    DL(2, (OUTPUTBUFF, "--- format 2\n"));

    /* Dump header */
    DLu(2, "rowWidth        =", fmt->rowWidth);
    DLx(2, "leftClassOffset =", fmt->leftClassOffset);
    DLx(2, "rightClassOffset=", fmt->rightClassOffset);
    DLx(2, "arrayOffset     =", fmt->arrayOffset);

    dump2Class("left", &fmt->left, level);
    dump2Class("right", &fmt->right, level);
    dump2Array(fmt, length, level);
}

static void dump3(Format3 *fmt, Card32 length, IntX level) {
    Card32 i;
    IntX dumpNames = level == 4;
    Card32 kernIndexSize;
    Card32 tableSize;
    kernIndexSize = fmt->leftClassCount * fmt->rightClassCount;
    tableSize = FORMAT3_HDR_SIZE + fmt->kernValueCount * sizeof(FWord) + fmt->glyphCount + fmt->glyphCount + fmt->leftClassCount * fmt->rightClassCount;

    DL(2, (OUTPUTBUFF, "--- format 3\n"));

    /* Dump header */
    DLu(2, "glyphCount        =", fmt->glyphCount);
    DLu(2, "kernValueCount =", (Card16)fmt->kernValueCount);
    DLu(2, "leftClassCount=", (Card16)fmt->leftClassCount);
    DLu(2, "rightClassCount =", (Card16)fmt->rightClassCount);
    DLu(2, "flags=", (Card16)fmt->flags);

    if (tableSize > length) {
        printf("kern subtable format 3 size is larger than length!\n");
        return;
    }

    if (level > 2) {
        if (dumpNames)
            initGlyphNames();

        DL(3, (OUTPUTBUFF, "--- kernValue[index]=value\n"));
        for (i = 0; i < fmt->kernValueCount; i++) {
            DL(3, (OUTPUTBUFF, "[%u]=", i));
            dumpValue(&fmt->kernValue[i], level);
            DL(3, (OUTPUTBUFF, ", "));
        }
        DL(3, (OUTPUTBUFF, "\n"));

        DL(3, (OUTPUTBUFF, "--- leftClass[glyphIndex]=class value\n"));
        for (i = 0; i < fmt->glyphCount; i++) {
            if (dumpNames) {
                fprintf(OUTPUTBUFF, "[%u]<%s>=%d ", i, getGlyphName((GlyphId)i, 0), fmt->leftClass[i]);
            } else
                DL(3, (OUTPUTBUFF, "[%u=%d ", i, fmt->leftClass[i]));
        }
        DL(3, (OUTPUTBUFF, "\n"));

        DL(3, (OUTPUTBUFF, "--- rightClass[glyphIndex]=class value\n"));
        for (i = 0; i < fmt->glyphCount; i++) {
            if (dumpNames) {
                fprintf(OUTPUTBUFF, "[%u]<%s>=%d ", i, getGlyphName((GlyphId)i, 0), fmt->rightClass[i]);
            } else
                DL(3, (OUTPUTBUFF, "[%u]=%d ", i, fmt->rightClass[i]));
        }
        DL(3, (OUTPUTBUFF, "\n"));

        DL(3, (OUTPUTBUFF, "--- kernValueIndex[index]=kern value index\n"));
        for (i = 0; i < kernIndexSize; i++) {
            DL(3, (OUTPUTBUFF, "[%u]=%d ", i, fmt->kernIndex[i]));
        }
        DL(3, (OUTPUTBUFF, "\n"));
    }
}

/* Interpret format 0 table */
static void run0(Format0 *fmt, Card32 length, IntX level) {
    IntX i;
    IntX nPairs;

    if (nMasters > 1)
        return;
    initGlyphNames();

    fprintf(OUTPUTBUFF, "--- format 0 [left right value]\n");

    nPairs = fmt->nPairs + 1; /* Table larger than # pairs + sentinel */

    for (i = 0; i < nPairs; i++) {
        Pair *pair = &fmt->pair[i];
        fprintf(OUTPUTBUFF, "%s ", getGlyphName(pair->left, 0));
        fprintf(OUTPUTBUFF, "%s %d\n", getGlyphName(pair->right, 0), *pair->value);
    }
}

/* Interpret format 2 array */
static void run2(Format2 *fmt, Card32 length, IntX level) {
    IntX i;
    IntX j;

    if (nMasters > 1)
        return;
    initGlyphNames();

    fprintf(OUTPUTBUFF, "--- format 2 [left right value]\n");

    for (i = 0; i < fmt->left.nGlyphs; i++) {
        long left = fmt->left.classes[i];

        if (left == fmt->arrayOffset)
            continue; /* Ignore row 0 */

        for (j = 0; j < fmt->right.nGlyphs; j++) {
            FWord value;
            long right = fmt->right.classes[j];

            if (right == 0)
                continue; /* Ignore column 0 */

            value = fmt->array[((left - fmt->arrayOffset) + right) / 2];
            if (value != 0) {
                fprintf(OUTPUTBUFF, "%s ", getGlyphName(fmt->left.firstGlyph + i, 0));
                fprintf(OUTPUTBUFF, "%s %d\n", getGlyphName(fmt->right.firstGlyph + j, 0),
                        value);
            }
        }
    }
}

/* Interpret format 0 table */
static void run3(Format3 *fmt, Card32 length, IntX level) {
    IntX giL, giR;
    Card32 kernIndexSize, tableSize;

    if (nMasters > 1)
        return;

    kernIndexSize = fmt->leftClassCount * fmt->rightClassCount;
    tableSize = FORMAT3_HDR_SIZE + fmt->kernValueCount * sizeof(FWord) + fmt->glyphCount + fmt->glyphCount + kernIndexSize;

    if (tableSize > length) {
        fprintf(OUTPUTBUFF, "Error: kern subtable format 3 size '%u' is greater than subtable length '%u'. Skipping.\n", tableSize, length);
        return;
    }
    initGlyphNames();

    fprintf(OUTPUTBUFF, "--- format 3 [left right value]\n");

    for (giL = 0; giL < fmt->glyphCount; giL++) {
        CardX leftClass = fmt->leftClass[giL];

        for (giR = 0; giR < fmt->glyphCount; giR++) {
            FWord value;
            CardX rightClass = fmt->rightClass[giR];
            Card32 kernValueIndex = leftClass * fmt->rightClassCount + rightClass;
            kernValueIndex = fmt->kernIndex[kernValueIndex];
            value = fmt->kernValue[kernValueIndex];
            if (value != 0) {
                fprintf(OUTPUTBUFF, "%s ", getGlyphName(giL, 0));
                fprintf(OUTPUTBUFF, "%s %d\n", getGlyphName(giR, 0),
                        value);
            }
        }
    }
}

/* Dump format-specific subtable */
static void dumpSubtable(IntX type, void *fmt, Card32 length, IntX level) {
    switch (type) {
        case 0:
            if (level == 5)
                run0(fmt, length, level);
            else
                dump0(fmt, length, level);
            break;
        case 2:
            if (level == 5)
                run2(fmt, length, level);
            else
                dump2(fmt, length, level);
            break;
        case 3:
            if (level == 5)
                run3(fmt, length, level);
            else
                dump3(fmt, length, level);
            break;
    }
}

/* Dump Microsoft-style table */
static void dumpMS(IntX level) {
    IntX i;

    DLu(1, "version=", MSkern->version);
    DLu(1, "nTables=", MSkern->nTables);

    for (i = 0; i < MSkern->nTables; i++) {
        IntX type;
        MSSubtable *subtable = &MSkern->subtable[i];
        if (subtable == NULL)
            continue;
        type = (subtable->coverage & MS_COVERAGE_FORMAT) >> 8;

        DL(2, (OUTPUTBUFF, "--- subtable[%d]\n", i));
        DLu(2, "version =", subtable->version);
        DLu(2, "length  =", subtable->length);
        DLx(2, "coverage=", subtable->coverage);

        dumpSubtable(type, subtable->format,
                     subtable->length - MS_SUBTABLE_HDR_SIZE, level);
    }
}

/* Dump Apple-style table */
static void dumpApple(IntX level) {
    IntX i;

    DLV(1, "version=", kern->version);
    DLU(1, "nTables=", kern->nTables);

    for (i = 0; i < (IntX)kern->nTables; i++) {
        IntX type;
        Subtable *subtable = &kern->subtable[i];
        if (subtable == NULL)
            continue;
        type = subtable->coverage & COVERAGE_FORMAT;

        DL(2, (OUTPUTBUFF, "--- subtable[%d]\n", i));
        DLU(2, "length    =", subtable->length);
        DLx(2, "coverage  =", subtable->coverage);
        DLu(2, "tupleIndex=", subtable->tupleIndex);

        dumpSubtable(type, subtable->format,
                     subtable->length - SUBTABLE_HDR_SIZE, level);
    }
}

void kernDump(IntX level, LongN start) {
    DL(1, (OUTPUTBUFF, "### [%s] (%08lx) [%s format]\n",
           (nMasters == 1) ? "kern" : "KERN", start,
           ms ? "Microsoft" : "Apple"));
    if (ms)
        dumpMS(level);
    else
        dumpApple(level);
}

/* Free format 0 subtable */
static void free0(Format0 *fmt, Card32 length) {
    IntX i;
    IntX nPairs = (length - FORMAT0_HDR_SIZE) / PAIR_SIZE(nMasters);

    if (nPairs > fmt->nPairs + 1)
        nPairs = fmt->nPairs + 1;

    for (i = 0; i < nPairs; i++)
        memFree(fmt->pair[i].value);
    memFree(fmt->pair);
}

/* Free format 2 subtable */
static void free2(Format2 *fmt, Card32 length) {
    memFree(fmt->array);
    memFree(fmt->left.classes);
    memFree(fmt->right.classes);
}

static void free3(Format3 *fmt, Card32 length) {
    memFree(fmt->kernValue);
    memFree(fmt->leftClass);
    memFree(fmt->rightClass);
    memFree(fmt->kernIndex);
}

/* Free format-specific table */
static void freeSubtable(IntX type, void *fmt, Card32 length) {
    switch (type) {
        case 0:
            free0(fmt, length);
            memFree(fmt);
            break;
        case 2:
            free2(fmt, length);
            memFree(fmt);
            break;
        case 3:
            free3(fmt, length);
            memFree(fmt);
            break;
    }
}

/* Free Microsoft format table */
static void freeMS(void) {
    IntX i;
    IntX type;

    for (i = 0; i < MSkern->nTables; i++) {
        MSSubtable *subtable = &MSkern->subtable[i];
        if (subtable == NULL)
            continue;
        type = (subtable->coverage & MS_COVERAGE_FORMAT) >> 8;

        freeSubtable(type, subtable->format, subtable->length);
    }
    memFree(MSkern->subtable);
    memFree(MSkern);
    MSkern = NULL;
}

/* Free Apple format table */
static void freeApple(void) {
    IntX i;
    IntX type;

    for (i = 0; i < (IntX)kern->nTables; i++) {
        Subtable *subtable = &kern->subtable[i];
        if (subtable == NULL)
            continue;
        type = subtable->coverage & COVERAGE_FORMAT;
        freeSubtable(type, subtable->format, subtable->length);
    }
    memFree(kern->subtable);
}

void kernFree(void) {
    if (!loaded)
        return;

    if (ms)
        freeMS();
    else
        freeApple();
    loaded = 0;
    memFree(kern);
    kern = NULL;
    ms = 0;
}

void kernUsage(void) {
    fprintf(OUTPUTBUFF,
            "--- kern\n"
            "=2  low level dump of subtable headers\n"
            "=3  low level dump without glyph names\n"
            "=4  low level dump with glyph names\n"
            "=5  Print kern pair list\n");
}
