/* 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. */

#if OSX
#include <sys/time.h>
#else
#include <time.h>
#endif

#include "Dhead.h"
#include "sfnt_head.h"
#include "Dsfnt.h"

static headTbl head1;
static headTbl head2;
static IntX loaded1 = 0;
static IntX loaded2 = 0;
static char *dateFormat = "%a %b %d %H:%M:%S %Y";

void headRead(Card8 which, LongN start, Card32 length) {
    headTbl *head = NULL;

    if (which == 1) {
        if (loaded1)
            return;
        else
            head = &head1;
    } else if (which == 2) {
        if (loaded2)
            return;
        else
            head = &head2;
    }

    SEEK_ABS(which, start);

    IN(which, head->version);
    IN(which, head->fontRevision);
    IN(which, head->checkSumAdjustment);
    IN(which, head->magicNumber);
    IN(which, head->flags);
    IN(which, head->unitsPerEm);
    IN_BYTES(which, sizeof(head->created), head->created);
    IN_BYTES(which, sizeof(head->modified), head->modified);
    IN(which, head->xMin);
    IN(which, head->yMin);
    IN(which, head->xMax);
    IN(which, head->yMax);
    IN(which, head->macStyle);
    IN(which, head->lowestRecPPEM);
    IN(which, head->fontDirectionHint);
    IN(which, head->indexToLocFormat);
    IN(which, head->glyphDataFormat);

    if (which == 1)
        loaded1 = 1;
    else if (which == 2)
        loaded2 = 1;
}

#if FOR_REFERENCE_ONLY
/* Convert ANSI standard date/time format to Apple LongDateTime format.
   Algorithm adapted from standard Julian Day calculation. */
void ANSITime2LongDateTime(struct tm *ansi, longDateTime ldt) {
    unsigned long elapsed;
    int month = ansi->tm_mon + 1;
    int year = ansi->tm_year;

    if (month < 3) {
        /* Jan and Feb become months 13 and 14 of the previous year */
        month += 12;
        year--;
    }

    /* Calculate elapsed seconds since 1 Jan 1904 00:00:00 */
    elapsed = (((year - 4L) * 365 +             /* Add years (as days) */
                year / 4 +                      /* Add leap year days */
                (306 * (month + 1)) / 10 - 64 + /* Add month days */
                ansi->tm_mday) *                /* Add days */
                   24 * 60 * 60 +               /* Convert days to secs */
               ansi->tm_hour * 60 * 60 +        /* Add hours (as secs) */
               ansi->tm_min * 60 +              /* Add minutes (as secs) */
               ansi->tm_sec);                   /* Add seconds */

    /* Set value */
    ldt[0] = ldt[1] = ldt[2] = ldt[3] = 0;
    ldt[4] = (char)(elapsed >> 24);
    ldt[5] = (char)(elapsed >> 16);
    ldt[6] = (char)(elapsed >> 8);
    ldt[7] = (char)elapsed;
}
#endif

/* Convert Apple LongDateTime format to ANSI standard date/time format.
   Algorithm adapted from standard Julian Day calculation. */
static void LongDateTime2ANSITime(struct tm *ansitime, longDateTime ldt) {
    unsigned long elapsed = ((unsigned long)ldt[4] << 24 |
                             (unsigned long)ldt[5] << 16 |
                             ldt[6] << 8 |
                             ldt[7]);
    long A = elapsed / (24 * 60 * 60L);
    long B = A + 1524;
    long C = (long)((B - 122.1) / 365.25);
    long D = (long)(C * 365.25);
    long E = (long)((B - D) / 30.6001);
    long F = (long)(E * 30.6001);
    long secs = elapsed - A * (24 * 60 * 60L);

    if (E > 13) {
        ansitime->tm_year = C + 1;
        ansitime->tm_mon = E - 14;
        ansitime->tm_yday = B - D - 429;
    } else {
        ansitime->tm_year = C;
        ansitime->tm_mon = E - 2;
        ansitime->tm_yday = B - D - 64;
    }
    ansitime->tm_mday = B - D - F;
    ansitime->tm_hour = secs / (60 * 60);
    secs -= ansitime->tm_hour * (60 * 60);
    ansitime->tm_min = secs / 60;
    ansitime->tm_sec = secs - ansitime->tm_min * 60;
    ansitime->tm_wday = (A + 5) % 7;
    ansitime->tm_isdst = 0;
#if SUNOS
    ansitime->tm_zone = "GMT";
#endif
}

#define CHECKREADASSIGN                         \
    if (which == 1) {                           \
        if (!loaded1) {                         \
            if (sfntReadATable(which, head_)) { \
                tableMissing(head_, client);    \
                goto out;                       \
            }                                   \
        }                                       \
        head = &head1;                          \
    } else if (which == 2) {                    \
        if (!loaded2) {                         \
            if (sfntReadATable(which, head_)) { \
                tableMissing(head_, client);    \
                goto out;                       \
            }                                   \
        }                                       \
        head = &head2;                          \
    }

Byte8 tday[32];

Byte8 *headGetCreatedDate(Card8 which, Card32 client) {
    struct tm tmp;
    headTbl *head = NULL;

    tday[0] = '\0';

    CHECKREADASSIGN
    LongDateTime2ANSITime(&tmp, head->created);
    if (strftime(tday, sizeof(tday), dateFormat, &tmp) == 0) {
        fprintf(stderr, "strftime returned 0");
        exit(EXIT_FAILURE);
    }
out:
    return tday;
}

Byte8 *headGetModifiedDate(Card8 which, Card32 client) {
    struct tm tmp;
    headTbl *head = NULL;

    tday[0] = '\0';

    CHECKREADASSIGN
    LongDateTime2ANSITime(&tmp, head->created);
    if (strftime(tday, sizeof(tday), dateFormat, &tmp) == 0) {
        fprintf(stderr, "strftime returned 0");
        exit(EXIT_FAILURE);
    }
out:
    return tday;
}

void headDiff(LongN offset1, LongN offset2) {
    if (head1.version != head2.version) {
        DiffExists++;
        note("< head version=%ld.%ld (%08lx)\n", VERSION_ARG(head1.version));
        note("> head version=%ld.%ld (%08lx)\n", VERSION_ARG(head2.version));
    }
    if (head1.fontRevision != head2.fontRevision) {
        DiffExists++;
        note("< head fontRevision=%ld.%ld (%08lx)\n", VERSION_ARG(head1.fontRevision));
        note("> head fontRevision=%ld.%ld (%08lx)\n", VERSION_ARG(head2.fontRevision));
    }
    if (head1.checkSumAdjustment != head2.checkSumAdjustment) {
        DiffExists++;
        note("< head checkSumAdjustment=%08x\n", head1.checkSumAdjustment);
        note("> head checkSumAdjustment=%08x\n", head2.checkSumAdjustment);
    }
    if (head1.magicNumber != head2.magicNumber) {
        DiffExists++;
        note("< head magicNumber=%08x\n", head1.magicNumber);
        note("> head magicNumber=%08x\n", head2.magicNumber);
    }
    if (head1.flags != head2.flags) {
        DiffExists++;
        note("< head flags=%04hx\n", head1.flags);
        note("> head flags=%04hx\n", head2.flags);
    }
    if (head1.unitsPerEm != head2.unitsPerEm) {
        DiffExists++;
        note("< head unitsPerEm=%hu\n", head1.unitsPerEm);
        note("> head unitsPerEm=%hu\n", head2.unitsPerEm);
    }
    if (head1.created != head2.created) {
        DiffExists++;
        note("< head created=%x%x%x%x%x%x%x%x (%s)\n",
             head1.created[0], head1.created[1],
             head1.created[2], head1.created[3],
             head1.created[4], head1.created[5],
             head1.created[6], head1.created[7], headGetCreatedDate(1, head_));
        note("> head created=%x%x%x%x%x%x%x%x (%s)\n",
             head2.created[0], head2.created[1],
             head2.created[2], head2.created[3],
             head2.created[4], head2.created[5],
             head2.created[6], head2.created[7], headGetCreatedDate(2, head_));
    }
    if (head1.modified != head2.modified) {
        DiffExists++;
        note("< head modified=%x%x%x%x%x%x%x%x (%s)\n",
             head1.modified[0], head1.modified[1],
             head1.modified[2], head1.modified[3],
             head1.modified[4], head1.modified[5],
             head1.modified[6], head1.modified[7], headGetModifiedDate(1, head_));

        note("> head modified=%x%x%x%x%x%x%x%x (%s)\n",
             head2.modified[0], head2.modified[1],
             head2.modified[2], head2.modified[3],
             head2.modified[4], head2.modified[5],
             head2.modified[6], head2.modified[7], headGetModifiedDate(2, head_));
    }
    if (head1.xMin != head2.xMin) {
        DiffExists++;
        note("< head xMin=%hd\n", head1.xMin);
        note("> head xMin=%hd\n", head2.xMin);
    }
    if (head1.yMin != head2.yMin) {
        DiffExists++;
        note("< head yMin=%hd\n", head1.yMin);
        note("> head yMin=%hd\n", head2.yMin);
    }
    if (head1.xMax != head2.xMax) {
        DiffExists++;
        note("< head xMax=%hd\n", head1.xMax);
        note("> head xMax=%hd\n", head2.xMax);
    }
    if (head1.yMax != head2.yMax) {
        DiffExists++;
        note("< head yMax=%hd\n", head1.yMax);
        note("> head yMax=%hd\n", head2.yMax);
    }
    if (head1.macStyle != head2.macStyle) {
        DiffExists++;
        note("< head macStyle=%04hx\n", head1.macStyle);
        note("> head macStyle=%04hx\n", head2.macStyle);
    }
    if (head1.lowestRecPPEM != head2.lowestRecPPEM) {
        DiffExists++;
        note("< head lowestRecPPEM=%hu\n", head1.lowestRecPPEM);
        note("> head lowestRecPPEM=%hu\n", head2.lowestRecPPEM);
    }
    if (head1.fontDirectionHint != head2.fontDirectionHint) {
        DiffExists++;
        note("< head fontDirectionHint=%hd\n", head1.fontDirectionHint);
        note("> head fontDirectionHint=%hd\n", head2.fontDirectionHint);
    }
    if (head1.indexToLocFormat != head2.indexToLocFormat) {
        DiffExists++;
        note("< head indexToLocFormat=%hd\n", head1.indexToLocFormat);
        note("> head indexToLocFormat=%hd\n", head2.indexToLocFormat);
    }
    if (head1.glyphDataFormat != head2.glyphDataFormat) {
        DiffExists++;
        note("< head glyphDataFormat=%hd\n", head1.glyphDataFormat);
        note("> head glyphDataFormat=%hd\n", head2.glyphDataFormat);
    }
}

void headFree(Card8 which) {
    if (which == 1)
        loaded1 = 0;
    else if (which == 2)
        loaded2 = 0;
}

/* Return head.indexToLocFormat */
IntX headGetLocFormat(Card8 which, Card16 *locFormat, Card32 client) {
    headTbl *head = NULL;

    CHECKREADASSIGN

    *locFormat = head->indexToLocFormat;
    return 0;

out:
    return 1;
}

/* Return head.uintsPerEm */
IntX headGetUnitsPerEm(Card8 which, Card16 *unitsPerEm, Card32 client) {
    headTbl *head = NULL;
    CHECKREADASSIGN
    *unitsPerEm = head->unitsPerEm;
    return 0;
out:
    return 1;
}

/* Return head.flags & head_SET_LSB */
IntX headGetSetLsb(Card8 which, Card16 *setLsb, Card32 client) {
    headTbl *head = NULL;
    CHECKREADASSIGN
    *setLsb = (head->flags & head_SET_LSB) != 0;
    return 0;
out:
    return 1;
}

/* Return head.xMin, head.yMin, head.xMax, head.yMax */
IntX headGetBBox(Card8 which, Int16 *xMin, Int16 *yMin, Int16 *xMax, Int16 *yMax,
                 Card32 client) {
    headTbl *head = NULL;

    CHECKREADASSIGN

    *xMin = head->xMin;
    *yMin = head->yMin;
    *xMax = head->xMax;
    *yMax = head->yMax;
    return 0;

out:
    *xMin = 0;
    *yMin = 0;
    *xMax = 0;
    *yMax = 0;
    return 1;
}