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