// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*******************************************************************************
* Copyright (C) 2007-2016, International Business Machines Corporation and
* others. All Rights Reserved.
*******************************************************************************
*/

#include "unicode/utypes.h"

#if !UCONFIG_NO_FORMATTING

#include <stdlib.h>

#include "unicode/datefmt.h"
#include "unicode/reldatefmt.h"
#include "unicode/simpleformatter.h"
#include "unicode/smpdtfmt.h"
#include "unicode/udisplaycontext.h"
#include "unicode/uchar.h"
#include "unicode/brkiter.h"
#include "unicode/ucasemap.h"
#include "reldtfmt.h"
#include "cmemory.h"
#include "uresimp.h"

U_NAMESPACE_BEGIN


/**
 * An array of URelativeString structs is used to store the resource data loaded out of the bundle.
 */
struct URelativeString {
    int32_t offset;         /** offset of this item, such as, the relative date **/
    int32_t len;            /** length of the string **/
    const char16_t* string;    /** string, or nullptr if not set **/
};

UOBJECT_DEFINE_RTTI_IMPLEMENTATION(RelativeDateFormat)

RelativeDateFormat::RelativeDateFormat(const RelativeDateFormat& other) :
 DateFormat(other), fDateTimeFormatter(nullptr), fDatePattern(other.fDatePattern),
 fTimePattern(other.fTimePattern), fCombinedFormat(nullptr),
 fDateStyle(other.fDateStyle), fLocale(other.fLocale),
 fDatesLen(other.fDatesLen), fDates(nullptr),
 fCombinedHasDateAtStart(other.fCombinedHasDateAtStart),
 fCapitalizationInfoSet(other.fCapitalizationInfoSet),
 fCapitalizationOfRelativeUnitsForUIListMenu(other.fCapitalizationOfRelativeUnitsForUIListMenu),
 fCapitalizationOfRelativeUnitsForStandAlone(other.fCapitalizationOfRelativeUnitsForStandAlone),
 fCapitalizationBrkIter(nullptr)
{
    if(other.fDateTimeFormatter != nullptr) {
        fDateTimeFormatter = other.fDateTimeFormatter->clone();
    }
    if(other.fCombinedFormat != nullptr) {
        fCombinedFormat = new SimpleFormatter(*other.fCombinedFormat);
    }
    if (fDatesLen > 0) {
        fDates = (URelativeString*) uprv_malloc(sizeof(fDates[0])*(size_t)fDatesLen);
        uprv_memcpy(fDates, other.fDates, sizeof(fDates[0])*(size_t)fDatesLen);
    }
#if !UCONFIG_NO_BREAK_ITERATION
    if (other.fCapitalizationBrkIter != nullptr) {
        fCapitalizationBrkIter = (other.fCapitalizationBrkIter)->clone();
    }
#endif
}

RelativeDateFormat::RelativeDateFormat( UDateFormatStyle timeStyle, UDateFormatStyle dateStyle,
                                        const Locale& locale, UErrorCode& status) :
 DateFormat(), fDateTimeFormatter(nullptr), fDatePattern(), fTimePattern(), fCombinedFormat(nullptr),
 fDateStyle(dateStyle), fLocale(locale), fDatesLen(0), fDates(nullptr),
 fCombinedHasDateAtStart(false), fCapitalizationInfoSet(false),
 fCapitalizationOfRelativeUnitsForUIListMenu(false), fCapitalizationOfRelativeUnitsForStandAlone(false),
 fCapitalizationBrkIter(nullptr)
{
    if(U_FAILURE(status) ) {
        return;
    }
    if (dateStyle != UDAT_FULL_RELATIVE &&
        dateStyle != UDAT_LONG_RELATIVE &&
        dateStyle != UDAT_MEDIUM_RELATIVE &&
        dateStyle != UDAT_SHORT_RELATIVE &&
        dateStyle != UDAT_RELATIVE) {
        status = U_ILLEGAL_ARGUMENT_ERROR;
        return;
    }

    if (timeStyle < UDAT_NONE || timeStyle > UDAT_SHORT) {
        // don't support other time styles (e.g. relative styles), for now
        status = U_ILLEGAL_ARGUMENT_ERROR;
        return;
    }
    UDateFormatStyle baseDateStyle = (dateStyle > UDAT_SHORT)? (UDateFormatStyle)(dateStyle & ~UDAT_RELATIVE): dateStyle;
    DateFormat * df;
    // Get fDateTimeFormatter from either date or time style (does not matter, we will override the pattern).
    // We do need to get separate patterns for the date & time styles.
    if (baseDateStyle != UDAT_NONE) {
        df = createDateInstance((EStyle)baseDateStyle, locale);
        fDateTimeFormatter=dynamic_cast<SimpleDateFormat *>(df);
        if (fDateTimeFormatter == nullptr) {
            status = U_UNSUPPORTED_ERROR;
             return;
        }
        fDateTimeFormatter->toPattern(fDatePattern);
        if (timeStyle != UDAT_NONE) {
            df = createTimeInstance((EStyle)timeStyle, locale);
            SimpleDateFormat *sdf = dynamic_cast<SimpleDateFormat *>(df);
            if (sdf != nullptr) {
                sdf->toPattern(fTimePattern);
                delete sdf;
            }
        }
    } else {
        // does not matter whether timeStyle is UDAT_NONE, we need something for fDateTimeFormatter
        df = createTimeInstance((EStyle)timeStyle, locale);
        fDateTimeFormatter=dynamic_cast<SimpleDateFormat *>(df);
        if (fDateTimeFormatter == nullptr) {
            status = U_UNSUPPORTED_ERROR;
            delete df;
            return;
        }
        fDateTimeFormatter->toPattern(fTimePattern);
    }

    // Initialize the parent fCalendar, so that parse() works correctly.
    initializeCalendar(nullptr, locale, status);
    loadDates(status);
}

RelativeDateFormat::~RelativeDateFormat() {
    delete fDateTimeFormatter;
    delete fCombinedFormat;
    uprv_free(fDates);
#if !UCONFIG_NO_BREAK_ITERATION
    delete fCapitalizationBrkIter;
#endif
}


RelativeDateFormat* RelativeDateFormat::clone() const {
    return new RelativeDateFormat(*this);
}

bool RelativeDateFormat::operator==(const Format& other) const {
    if(DateFormat::operator==(other)) {
        // The DateFormat::operator== check for fCapitalizationContext equality above
        //   is sufficient to check equality of all derived context-related data.
        // DateFormat::operator== guarantees following cast is safe
        RelativeDateFormat* that = (RelativeDateFormat*)&other;
        return (fDateStyle==that->fDateStyle   &&
                fDatePattern==that->fDatePattern   &&
                fTimePattern==that->fTimePattern   &&
                fLocale==that->fLocale );
    }
    return false;
}

static const char16_t APOSTROPHE = (char16_t)0x0027;

UnicodeString& RelativeDateFormat::format(  Calendar& cal,
                                UnicodeString& appendTo,
                                FieldPosition& pos) const {
                                
    UErrorCode status = U_ZERO_ERROR;
    UnicodeString relativeDayString;
    UDisplayContext capitalizationContext = getContext(UDISPCTX_TYPE_CAPITALIZATION, status);
    
    // calculate the difference, in days, between 'cal' and now.
    int dayDiff = dayDifference(cal, status);

    // look up string
    int32_t len = 0;
    const char16_t *theString = getStringForDay(dayDiff, len, status);
    if(U_SUCCESS(status) && (theString!=nullptr)) {
        // found a relative string
        relativeDayString.setTo(theString, len);
    }

    if ( relativeDayString.length() > 0 && !fDatePattern.isEmpty() && 
         (fTimePattern.isEmpty() || fCombinedFormat == nullptr || fCombinedHasDateAtStart)) {
#if !UCONFIG_NO_BREAK_ITERATION
        // capitalize relativeDayString according to context for relative, set formatter no context
        if ( u_islower(relativeDayString.char32At(0)) && fCapitalizationBrkIter!= nullptr &&
             ( capitalizationContext==UDISPCTX_CAPITALIZATION_FOR_BEGINNING_OF_SENTENCE ||
               (capitalizationContext==UDISPCTX_CAPITALIZATION_FOR_UI_LIST_OR_MENU && fCapitalizationOfRelativeUnitsForUIListMenu) ||
               (capitalizationContext==UDISPCTX_CAPITALIZATION_FOR_STANDALONE && fCapitalizationOfRelativeUnitsForStandAlone) ) ) {
            // titlecase first word of relativeDayString
            relativeDayString.toTitle(fCapitalizationBrkIter, fLocale, U_TITLECASE_NO_LOWERCASE | U_TITLECASE_NO_BREAK_ADJUSTMENT);
        }
#endif
        fDateTimeFormatter->setContext(UDISPCTX_CAPITALIZATION_NONE, status);
    } else {
        // set our context for the formatter
        fDateTimeFormatter->setContext(capitalizationContext, status);
    }

    if (fDatePattern.isEmpty()) {
        fDateTimeFormatter->applyPattern(fTimePattern);
        fDateTimeFormatter->format(cal,appendTo,pos);
    } else if (fTimePattern.isEmpty() || fCombinedFormat == nullptr) {
        if (relativeDayString.length() > 0) {
            appendTo.append(relativeDayString);
        } else {
            fDateTimeFormatter->applyPattern(fDatePattern);
            fDateTimeFormatter->format(cal,appendTo,pos);
        }
    } else {
        UnicodeString datePattern;
        if (relativeDayString.length() > 0) {
            // Need to quote the relativeDayString to make it a legal date pattern
            relativeDayString.findAndReplace(UNICODE_STRING("'", 1), UNICODE_STRING("''", 2)); // double any existing APOSTROPHE
            relativeDayString.insert(0, APOSTROPHE); // add APOSTROPHE at beginning...
            relativeDayString.append(APOSTROPHE); // and at end
            datePattern.setTo(relativeDayString);
        } else {
            datePattern.setTo(fDatePattern);
        }
        UnicodeString combinedPattern;
        fCombinedFormat->format(fTimePattern, datePattern, combinedPattern, status);
        fDateTimeFormatter->applyPattern(combinedPattern);
        fDateTimeFormatter->format(cal,appendTo,pos);
    }

    return appendTo;
}



UnicodeString&
RelativeDateFormat::format(const Formattable& obj, 
                         UnicodeString& appendTo, 
                         FieldPosition& pos,
                         UErrorCode& status) const
{
    // this is just here to get around the hiding problem
    // (the previous format() override would hide the version of
    // format() on DateFormat that this function correspond to, so we
    // have to redefine it here)
    return DateFormat::format(obj, appendTo, pos, status);
}


void RelativeDateFormat::parse( const UnicodeString& text,
                    Calendar& cal,
                    ParsePosition& pos) const {

    int32_t startIndex = pos.getIndex();
    if (fDatePattern.isEmpty()) {
        // no date pattern, try parsing as time
        fDateTimeFormatter->applyPattern(fTimePattern);
        fDateTimeFormatter->parse(text,cal,pos);
    } else if (fTimePattern.isEmpty() || fCombinedFormat == nullptr) {
        // no time pattern or way to combine, try parsing as date
        // first check whether text matches a relativeDayString
        UBool matchedRelative = false;
        for (int n=0; n < fDatesLen && !matchedRelative; n++) {
            if (fDates[n].string != nullptr &&
                    text.compare(startIndex, fDates[n].len, fDates[n].string) == 0) {
                // it matched, handle the relative day string
                UErrorCode status = U_ZERO_ERROR;
                matchedRelative = true;

                // Set the calendar to now+offset
                cal.setTime(Calendar::getNow(),status);
                cal.add(UCAL_DATE,fDates[n].offset, status);

                if(U_FAILURE(status)) { 
                    // failure in setting calendar field, set offset to beginning of rel day string
                    pos.setErrorIndex(startIndex);
                } else {
                    pos.setIndex(startIndex + fDates[n].len);
                }
            }
        }
        if (!matchedRelative) {
            // just parse as normal date
            fDateTimeFormatter->applyPattern(fDatePattern);
            fDateTimeFormatter->parse(text,cal,pos);
        }
    } else {
        // Here we replace any relativeDayString in text with the equivalent date
        // formatted per fDatePattern, then parse text normally using the combined pattern.
        UnicodeString modifiedText(text);
        FieldPosition fPos;
        int32_t dateStart = 0, origDateLen = 0, modDateLen = 0;
        UErrorCode status = U_ZERO_ERROR;
        for (int n=0; n < fDatesLen; n++) {
            int32_t relativeStringOffset;
            if (fDates[n].string != nullptr &&
                    (relativeStringOffset = modifiedText.indexOf(fDates[n].string, fDates[n].len, startIndex)) >= startIndex) {
                // it matched, replace the relative date with a real one for parsing
                UnicodeString dateString;
                Calendar * tempCal = cal.clone();

                // Set the calendar to now+offset
                tempCal->setTime(Calendar::getNow(),status);
                tempCal->add(UCAL_DATE,fDates[n].offset, status);
                if(U_FAILURE(status)) { 
                    pos.setErrorIndex(startIndex);
                    delete tempCal;
                    return;
                }

                fDateTimeFormatter->applyPattern(fDatePattern);
                fDateTimeFormatter->format(*tempCal, dateString, fPos);
                dateStart = relativeStringOffset;
                origDateLen = fDates[n].len;
                modDateLen = dateString.length();
                modifiedText.replace(dateStart, origDateLen, dateString);
                delete tempCal;
                break;
            }
        }
        UnicodeString combinedPattern;
        fCombinedFormat->format(fTimePattern, fDatePattern, combinedPattern, status);
        fDateTimeFormatter->applyPattern(combinedPattern);
        fDateTimeFormatter->parse(modifiedText,cal,pos);

        // Adjust offsets
        UBool noError = (pos.getErrorIndex() < 0);
        int32_t offset = (noError)? pos.getIndex(): pos.getErrorIndex();
        if (offset >= dateStart + modDateLen) {
            // offset at or after the end of the replaced text,
            // correct by the difference between original and replacement
            offset -= (modDateLen - origDateLen);
        } else if (offset >= dateStart) {
            // offset in the replaced text, set it to the beginning of that text
            // (i.e. the beginning of the relative day string)
            offset = dateStart;
        }
        if (noError) {
            pos.setIndex(offset);
        } else {
            pos.setErrorIndex(offset);
        }
    }
}

UDate
RelativeDateFormat::parse( const UnicodeString& text,
                         ParsePosition& pos) const {
    // redefined here because the other parse() function hides this function's
    // counterpart on DateFormat
    return DateFormat::parse(text, pos);
}

UDate
RelativeDateFormat::parse(const UnicodeString& text, UErrorCode& status) const
{
    // redefined here because the other parse() function hides this function's
    // counterpart on DateFormat
    return DateFormat::parse(text, status);
}


const char16_t *RelativeDateFormat::getStringForDay(int32_t day, int32_t &len, UErrorCode &status) const {
    if(U_FAILURE(status)) {
        return nullptr;
    }

    // Is it inside the resource bundle's range?
    int n = day + UDAT_DIRECTION_THIS;
    if (n >= 0 && n < fDatesLen) {
        if (fDates[n].offset == day && fDates[n].string != nullptr) {
            len = fDates[n].len;
            return fDates[n].string;
        }
    }
    return nullptr;  // not found.
}

UnicodeString&
RelativeDateFormat::toPattern(UnicodeString& result, UErrorCode& status) const
{
    if (!U_FAILURE(status)) {
        result.remove();
        if (fDatePattern.isEmpty()) {
            result.setTo(fTimePattern);
        } else if (fTimePattern.isEmpty() || fCombinedFormat == nullptr) {
            result.setTo(fDatePattern);
        } else {
            fCombinedFormat->format(fTimePattern, fDatePattern, result, status);
        }
    }
    return result;
}

UnicodeString&
RelativeDateFormat::toPatternDate(UnicodeString& result, UErrorCode& status) const
{
    if (!U_FAILURE(status)) {
        result.remove();
        result.setTo(fDatePattern);
    }
    return result;
}

UnicodeString&
RelativeDateFormat::toPatternTime(UnicodeString& result, UErrorCode& status) const
{
    if (!U_FAILURE(status)) {
        result.remove();
        result.setTo(fTimePattern);
    }
    return result;
}

void
RelativeDateFormat::applyPatterns(const UnicodeString& datePattern, const UnicodeString& timePattern, UErrorCode &status)
{
    if (!U_FAILURE(status)) {
        fDatePattern.setTo(datePattern);
        fTimePattern.setTo(timePattern);
    }
}

const DateFormatSymbols*
RelativeDateFormat::getDateFormatSymbols() const
{
    return fDateTimeFormatter->getDateFormatSymbols();
}

// override the DateFormat implementation in order to
// lazily initialize relevant items
void
RelativeDateFormat::setContext(UDisplayContext value, UErrorCode& status)
{
    DateFormat::setContext(value, status);
    if (U_SUCCESS(status)) {
        if (!fCapitalizationInfoSet &&
                (value==UDISPCTX_CAPITALIZATION_FOR_UI_LIST_OR_MENU || value==UDISPCTX_CAPITALIZATION_FOR_STANDALONE)) {
            initCapitalizationContextInfo(fLocale);
            fCapitalizationInfoSet = true;
        }
#if !UCONFIG_NO_BREAK_ITERATION
        if ( fCapitalizationBrkIter == nullptr && (value==UDISPCTX_CAPITALIZATION_FOR_BEGINNING_OF_SENTENCE ||
                (value==UDISPCTX_CAPITALIZATION_FOR_UI_LIST_OR_MENU && fCapitalizationOfRelativeUnitsForUIListMenu) ||
                (value==UDISPCTX_CAPITALIZATION_FOR_STANDALONE && fCapitalizationOfRelativeUnitsForStandAlone)) ) {
            status = U_ZERO_ERROR;
            fCapitalizationBrkIter = BreakIterator::createSentenceInstance(fLocale, status);
            if (U_FAILURE(status)) {
                delete fCapitalizationBrkIter;
                fCapitalizationBrkIter = nullptr;
            }
        }
#endif
    }
}

void
RelativeDateFormat::initCapitalizationContextInfo(const Locale& thelocale)
{
#if !UCONFIG_NO_BREAK_ITERATION
    const char * localeID = (thelocale != nullptr)? thelocale.getBaseName(): nullptr;
    UErrorCode status = U_ZERO_ERROR;
    LocalUResourceBundlePointer rb(ures_open(nullptr, localeID, &status));
    ures_getByKeyWithFallback(rb.getAlias(),
                              "contextTransforms/relative",
                               rb.getAlias(), &status);
    if (U_SUCCESS(status) && rb != nullptr) {
        int32_t len = 0;
        const int32_t * intVector = ures_getIntVector(rb.getAlias(),
                                                      &len, &status);
        if (U_SUCCESS(status) && intVector != nullptr && len >= 2) {
            fCapitalizationOfRelativeUnitsForUIListMenu = static_cast<UBool>(intVector[0]);
            fCapitalizationOfRelativeUnitsForStandAlone = static_cast<UBool>(intVector[1]);
        }
    }
#endif
}

namespace {

/**
 * Sink for getting data from fields/day/relative data.
 * For loading relative day names, e.g., "yesterday", "today".
 */

struct RelDateFmtDataSink : public ResourceSink {
  URelativeString *fDatesPtr;
  int32_t fDatesLen;

  RelDateFmtDataSink(URelativeString* fDates, int32_t len) : fDatesPtr(fDates), fDatesLen(len) {
    for (int32_t i = 0; i < fDatesLen; ++i) {
      fDatesPtr[i].offset = 0;
      fDatesPtr[i].string = nullptr;
      fDatesPtr[i].len = -1;
    }
  }

  virtual ~RelDateFmtDataSink();

  virtual void put(const char *key, ResourceValue &value,
                   UBool /*noFallback*/, UErrorCode &errorCode) override {
      ResourceTable relDayTable = value.getTable(errorCode);
      int32_t n = 0;
      int32_t len = 0;
      for (int32_t i = 0; relDayTable.getKeyAndValue(i, key, value); ++i) {
        // Find the relative offset.
        int32_t offset = atoi(key);

        // Put in the proper spot, but don't override existing data.
        n = offset + UDAT_DIRECTION_THIS; // Converts to index in UDAT_R
        if (n < fDatesLen && fDatesPtr[n].string == nullptr) {
          // Not found and n is an empty slot.
          fDatesPtr[n].offset = offset;
          fDatesPtr[n].string = value.getString(len, errorCode);
          fDatesPtr[n].len = len;
        }
      }
  }
};


// Virtual destructors must be defined out of line.
RelDateFmtDataSink::~RelDateFmtDataSink() {}

}  // Namespace


static const char16_t patItem1[] = {0x7B,0x31,0x7D}; // "{1}"
static const int32_t patItem1Len = 3;

void RelativeDateFormat::loadDates(UErrorCode &status) {
    UResourceBundle *rb = ures_open(nullptr, fLocale.getBaseName(), &status);
    LocalUResourceBundlePointer dateTimePatterns(
        ures_getByKeyWithFallback(rb,
                                  "calendar/gregorian/DateTimePatterns",
                                  (UResourceBundle*)nullptr, &status));
    if(U_SUCCESS(status)) {
        int32_t patternsSize = ures_getSize(dateTimePatterns.getAlias());
        if (patternsSize > kDateTime) {
            int32_t resStrLen = 0;
            int32_t glueIndex = kDateTime;
            if (patternsSize >= (kDateTimeOffset + kShort + 1)) {
                int32_t offsetIncrement = (fDateStyle & ~kRelative); // Remove relative bit.
                if (offsetIncrement >= (int32_t)kFull &&
                    offsetIncrement <= (int32_t)kShortRelative) {
                    glueIndex = kDateTimeOffset + offsetIncrement;
                }
            }

            const char16_t *resStr = ures_getStringByIndex(dateTimePatterns.getAlias(), glueIndex, &resStrLen, &status);
            if (U_SUCCESS(status) && resStrLen >= patItem1Len && u_strncmp(resStr,patItem1,patItem1Len)==0) {
                fCombinedHasDateAtStart = true;
            }
            fCombinedFormat = new SimpleFormatter(UnicodeString(true, resStr, resStrLen), 2, 2, status);
        }
    }

    // Data loading for relative names, e.g., "yesterday", "today", "tomorrow".
    fDatesLen = UDAT_DIRECTION_COUNT; // Maximum defined by data.
    fDates = (URelativeString*) uprv_malloc(sizeof(fDates[0])*fDatesLen);

    RelDateFmtDataSink sink(fDates, fDatesLen);
    ures_getAllItemsWithFallback(rb, "fields/day/relative", sink, status);

    ures_close(rb);

    if(U_FAILURE(status)) {
        fDatesLen=0;
        return;
    }
}

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

// this should to be in DateFormat, instead it was copied from SimpleDateFormat.

Calendar*
RelativeDateFormat::initializeCalendar(TimeZone* adoptZone, const Locale& locale, UErrorCode& status)
{
    if(!U_FAILURE(status)) {
        fCalendar = Calendar::createInstance(adoptZone?adoptZone:TimeZone::createDefault(), locale, status);
    }
    if (U_SUCCESS(status) && fCalendar == nullptr) {
        status = U_MEMORY_ALLOCATION_ERROR;
    }
    return fCalendar;
}

int32_t RelativeDateFormat::dayDifference(Calendar &cal, UErrorCode &status) {
    if(U_FAILURE(status)) {
        return 0;
    }
    // TODO: Cache the nowCal to avoid heap allocs? Would be difficult, don't know the calendar type
    Calendar *nowCal = cal.clone();
    nowCal->setTime(Calendar::getNow(), status);

    // For the day difference, we are interested in the difference in the (modified) julian day number
    // which is midnight to midnight.  Using fieldDifference() is NOT correct here, because 
    // 6pm Jan 4th  to 10am Jan 5th should be considered "tomorrow".
    int32_t dayDiff = cal.get(UCAL_JULIAN_DAY, status) - nowCal->get(UCAL_JULIAN_DAY, status);

    delete nowCal;
    return dayDiff;
}

U_NAMESPACE_END

#endif  /* !UCONFIG_NO_FORMATTING */