package com.sismics.util;

import com.google.common.collect.ImmutableMap;

import java.util.Map.Entry;

/**
 * Date utilities.
 * 
 * @author jtremeaux
 */
public class DateUtil {
    
    private final static ImmutableMap<String, String> TIMEZONE_CODE_MAP = new ImmutableMap.Builder<String, String>()
            .put(" ACDT", " +10:30")
            .put(" ACST", " +09:30")
            .put(" ACT", " +08")
            .put(" ADT", " −03")
            .put(" AEDT", " +11")
            .put(" AEST", " +10")
            .put(" AFT", " +04:30")
            .put(" AKDT", " −08")
            .put(" AKST", " −09")
            .put(" AMST", " +05")
            .put(" AMT", " +04")
            .put(" ART", " −03")
//            .put(" AST", " +03")
            .put(" AST", " −04")
            .put(" AWDT", " +09")
            .put(" AWST", " +08")
            .put(" AZOST", " −01")
            .put(" AZT", " +04")
            .put(" BDT", " +08")
            .put(" BIOT", " +06")
            .put(" BIT", " −12")
            .put(" BOT", " −04")
            .put(" BRT", " −03")
//            .put(" BST", " +06")
            .put(" BST", " +01")
            .put(" BTT", " +06")
            .put(" CAT", " +02")
            .put(" CCT", " +06:30")
            .put(" CDT", " −05")
//            .put(" CDT", " −04")
            .put(" CEDT", " +02")
            .put(" CEST", " +02")
            .put(" CET", " +01")
            .put(" CHADT", " +13:45")
            .put(" CHAST", " +12:45")
            .put(" CHOT", " −08")
            .put(" ChST", " +10")
            .put(" CHUT", " +10")
            .put(" CIST", " −08")
            .put(" CIT", " +08")
            .put(" CKT", " −10")
            .put(" CLST", " −03")
            .put(" CLT", " −04")
            .put(" COST", " −04")
            .put(" COT", " −05")
            .put(" CST", " −06")
//            .put(" CST", " +08")
//            .put(" CST", " +09:30")
//            .put(" CST", " +10:30")
//            .put(" CST", " −05")
            .put(" CT", " +08")
            .put(" CVT", " −01")
            .put(" CWST", " +08:45")
            .put(" CXT", " +07")
            .put(" DAVT", " +07")
            .put(" DDUT", " +10")
            .put(" DFT", " +01")
            .put(" EASST", " −05")
            .put(" EAST", " −06")
            .put(" EAT", " +03")
//            .put(" ECT", " −04")
            .put(" ECT", " −05")
            .put(" EDT", " −04")
            .put(" EEDT", " +03")
            .put(" EEST", " +03")
            .put(" EET", " +02")
            .put(" EGST", " +00")
            .put(" EGT", " −01")
            .put(" EIT", " +09")
            .put(" EST", " −05")
//            .put(" EST", " +10")
            .put(" FET", " +03")
            .put(" FJT", " +12")
            .put(" FKST", " −03")
            .put(" FKT", " −04")
            .put(" FNT", " −02")
            .put(" GALT", " −06")
            .put(" GAMT", " −09")
            .put(" GET", " +04")
            .put(" GFT", " −03")
            .put(" GILT", " +12")
            .put(" GIT", " −09")
            .put(" GMT", " ")
//            .put(" GST", " −02")
            .put(" GST", " +04")
            .put(" GYT", " −04")
            .put(" HADT", " −09")
            .put(" HAEC", " +02")
            .put(" HAST", " −10")
            .put(" HKT", " +08")
            .put(" HMT", " +05")
            .put(" HOVT", " +07")
            .put(" HST", " −10")
            .put(" ICT", " +07")
            .put(" IDT", " +03")
            .put(" IOT", " +03")
            .put(" IRDT", " +08")
            .put(" IRKT", " +09")
            .put(" IRST", " +03:30")
            .put(" IST", " +05:30")
//            .put(" IST", " +01")
//            .put(" IST", " +02")
//            .put(" JST", " +09")
            .put(" KGT", " +06")
            .put(" KOST", " +11")
            .put(" KRAT", " +07")
            .put(" KST", " +09")
            .put(" LHST", " +10:30")
//            .put(" LHST", " +11")
            .put(" LINT", " +14")
            .put(" MAGT", " +12")
            .put(" MART", " −09:30")
            .put(" MAWT", " +05")
            .put(" MDT", " −06")
            .put(" MET", " +01")
            .put(" MEST", " +02")
            .put(" MHT", " +12")
            .put(" MIST", " +11")
            .put(" MIT", " −09:30")
            .put(" MMT", " +06:30")
            .put(" MSK", " +04")
//            .put(" MST", " +08")
            .put(" MST", " −07")
//            .put(" MST", " +06:30")
            .put(" MUT", " +04")
            .put(" MVT", " +05")
            .put(" MYT", " +08")
            .put(" NCT", " +11")
            .put(" NDT", " −02:30")
            .put(" NFT", " +11:30")
            .put(" NPT", " +05:45")
            .put(" NST", " −03:30")
            .put(" NT", " −03:30")
            .put(" NUT", " −11:30")
            .put(" NZDT", " +13")
            .put(" NZST", " +12")
            .put(" OMST", " +06")
            .put(" ORAT", " +05")
            .put(" PDT", " −07")
            .put(" PET", " −05")
            .put(" PETT", " +12")
            .put(" PGT", " +10")
            .put(" PHOT", " +13")
            .put(" PHT", " +08")
            .put(" PKT", " +05")
            .put(" PMDT", " −02")
            .put(" PMST", " −03")
            .put(" PONT", " +11")
            .put(" PST", " −08")
//            .put(" PST", " +08")
            .put(" RET", " +04")
            .put(" ROTT", " −03")
            .put(" SAKT", " +11")
            .put(" SAMT", " +04")
            .put(" SAST", " +02")
            .put(" SBT", " +11")
            .put(" SCT", " +04")
            .put(" SGT", " +08")
            .put(" SLT", " +05:30")
            .put(" SRT", " −03")
            .put(" SST", " −11")
//            .put(" SST", " +08")
            .put(" SYOT", " +03")
            .put(" TAHT", " −10")
            .put(" THA", " +07")
            .put(" TFT", " +05")
            .put(" TJT", " +05")
            .put(" TKT", " +14")
            .put(" TLT", " +09")
            .put(" TMT", " +05")
            .put(" TOT", " +13")
            .put(" TVT", " +12")
            .put(" UCT", " ")
            .put(" ULAT", " +08")
            .put(" UTC", " ")
            .put(" UYST", " −02")
            .put(" UYT", " −03")
            .put(" UZT", " +05")
            .put(" VET", " −04:30")
            .put(" VLAT", " +10")
            .put(" VOLT", " +04")
            .put(" VOST", " +06")
            .put(" VUT", " +11")
            .put(" WAKT", " +12")
            .put(" WAST", " +02")
            .put(" WAT", " +01")
            .put(" WEDT", " +01")
            .put(" WEST", " +01")
            .put(" WET", " ")
            .put(" WST", " +08")
            .put(" YAKT", " +09")
            .put(" YEKT", " +05")
            .build();
    
    /**
     * Try to guess the timezone code, and replace it with a timezone offset.
     * Note: JodaTime can guess a few codes already, they didn't include all codes since they are not standardized.
     * This method should only be used in last resort.
     * 
     * @param date Formated date, supposedly ending with a timezone code
     * @return Date with the code replaced by its offset if there is a match
     */
    public static String guessTimezoneOffset(String date) {
        for (Entry<String, String> entry : TIMEZONE_CODE_MAP.entrySet()) {
            String code = entry.getKey();
            String offset = entry.getValue();
            if (date.endsWith(code)) {
                return date.substring(0, date.length() - code.length()) + offset;
            }
        }
        return date;
    }
}