1// © 2016 and later: Unicode, Inc. and others.
2// License & terms of use: http://www.unicode.org/copyright.html
3/*
4 ******************************************************************************
5 * Copyright (C) 2013, International Business Machines Corporation
6 * and others. All Rights Reserved.
7 ******************************************************************************
8 *
9 * File DANGICAL.CPP
10 *****************************************************************************
11 */
12
13#include "chnsecal.h"
14#include "dangical.h"
15
16#if !UCONFIG_NO_FORMATTING
17
18#include "gregoimp.h" // Math
19#include "uassert.h"
20#include "ucln_in.h"
21#include "umutex.h"
22#include "unicode/rbtz.h"
23#include "unicode/tzrule.h"
24
25// --- The cache --
26static icu::TimeZone *gDangiCalendarZoneAstroCalc = NULL;
27static icu::UInitOnce gDangiCalendarInitOnce = U_INITONCE_INITIALIZER;
28
29/**
30 * The start year of the Korean traditional calendar (Dan-gi) is the inaugural
31 * year of Dan-gun (BC 2333).
32 */
33static const int32_t DANGI_EPOCH_YEAR = -2332; // Gregorian year
34
35U_CDECL_BEGIN
36static UBool calendar_dangi_cleanup(void) {
37    if (gDangiCalendarZoneAstroCalc) {
38        delete gDangiCalendarZoneAstroCalc;
39        gDangiCalendarZoneAstroCalc = NULL;
40    }
41    gDangiCalendarInitOnce.reset();
42    return TRUE;
43}
44U_CDECL_END
45
46U_NAMESPACE_BEGIN
47
48// Implementation of the DangiCalendar class
49
50//-------------------------------------------------------------------------
51// Constructors...
52//-------------------------------------------------------------------------
53
54DangiCalendar::DangiCalendar(const Locale& aLocale, UErrorCode& success)
55:   ChineseCalendar(aLocale, DANGI_EPOCH_YEAR, getDangiCalZoneAstroCalc(), success)
56{
57}
58
59DangiCalendar::DangiCalendar (const DangiCalendar& other)
60: ChineseCalendar(other)
61{
62}
63
64DangiCalendar::~DangiCalendar()
65{
66}
67
68Calendar*
69DangiCalendar::clone() const
70{
71    return new DangiCalendar(*this);
72}
73
74const char *DangiCalendar::getType() const {
75    return "dangi";
76}
77
78/**
79 * The time zone used for performing astronomical computations for
80 * Dangi calendar. In Korea various timezones have been used historically
81 * (cf. http://www.math.snu.ac.kr/~kye/others/lunar.html):
82 *
83 *            - 1908/04/01: GMT+8
84 * 1908/04/01 - 1911/12/31: GMT+8.5
85 * 1912/01/01 - 1954/03/20: GMT+9
86 * 1954/03/21 - 1961/08/09: GMT+8.5
87 * 1961/08/10 -           : GMT+9
88 *
89 * Note that, in 1908-1911, the government did not apply the timezone change
90 * but used GMT+8. In addition, 1954-1961's timezone change does not affect
91 * the lunar date calculation. Therefore, the following simpler rule works:
92 *
93 * -1911: GMT+8
94 * 1912-: GMT+9
95 *
96 * Unfortunately, our astronomer's approximation doesn't agree with the
97 * references (http://www.math.snu.ac.kr/~kye/others/lunar.html and
98 * http://astro.kasi.re.kr/Life/ConvertSolarLunarForm.aspx?MenuID=115)
99 * in 1897/7/30. So the following ad hoc fix is used here:
100 *
101 *     -1896: GMT+8
102 *      1897: GMT+7
103 * 1898-1911: GMT+8
104 * 1912-    : GMT+9
105 */
106static void U_CALLCONV initDangiCalZoneAstroCalc(void) {
107    U_ASSERT(gDangiCalendarZoneAstroCalc == NULL);
108    const UDate millis1897[] = { (UDate)((1897 - 1970) * 365 * kOneDay) }; // some days of error is not a problem here
109    const UDate millis1898[] = { (UDate)((1898 - 1970) * 365 * kOneDay) }; // some days of error is not a problem here
110    const UDate millis1912[] = { (UDate)((1912 - 1970) * 365 * kOneDay) }; // this doesn't create an issue for 1911/12/20
111    InitialTimeZoneRule* initialTimeZone = new InitialTimeZoneRule(UNICODE_STRING_SIMPLE("GMT+8"), 8*kOneHour, 0);
112    TimeZoneRule* rule1897 = new TimeArrayTimeZoneRule(UNICODE_STRING_SIMPLE("Korean 1897"), 7*kOneHour, 0, millis1897, 1, DateTimeRule::STANDARD_TIME);
113    TimeZoneRule* rule1898to1911 = new TimeArrayTimeZoneRule(UNICODE_STRING_SIMPLE("Korean 1898-1911"), 8*kOneHour, 0, millis1898, 1, DateTimeRule::STANDARD_TIME);
114    TimeZoneRule* ruleFrom1912 = new TimeArrayTimeZoneRule(UNICODE_STRING_SIMPLE("Korean 1912-"), 9*kOneHour, 0, millis1912, 1, DateTimeRule::STANDARD_TIME);
115    UErrorCode status = U_ZERO_ERROR;
116    RuleBasedTimeZone* dangiCalZoneAstroCalc = new RuleBasedTimeZone(UNICODE_STRING_SIMPLE("KOREA_ZONE"), initialTimeZone); // adopts initialTimeZone
117    dangiCalZoneAstroCalc->addTransitionRule(rule1897, status); // adopts rule1897
118    dangiCalZoneAstroCalc->addTransitionRule(rule1898to1911, status);
119    dangiCalZoneAstroCalc->addTransitionRule(ruleFrom1912, status);
120    dangiCalZoneAstroCalc->complete(status);
121    if (U_SUCCESS(status)) {
122        gDangiCalendarZoneAstroCalc = dangiCalZoneAstroCalc;
123    } else {
124        delete dangiCalZoneAstroCalc;
125        gDangiCalendarZoneAstroCalc = NULL;
126    }
127    ucln_i18n_registerCleanup(UCLN_I18N_DANGI_CALENDAR, calendar_dangi_cleanup);
128}
129
130const TimeZone* DangiCalendar::getDangiCalZoneAstroCalc(void) const {
131    umtx_initOnce(gDangiCalendarInitOnce, &initDangiCalZoneAstroCalc);
132    return gDangiCalendarZoneAstroCalc;
133}
134
135
136UOBJECT_DEFINE_RTTI_IMPLEMENTATION(DangiCalendar)
137
138U_NAMESPACE_END
139
140#endif
141
142