/*

 *  Copyright 2009-present, Stephen Colebourne

 *

 *  Licensed under the Apache License, Version 2.0 (the "License");

 *  you may not use this file except in compliance with the License.

 *  You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 *  Unless required by applicable law or agreed to in writing, software

 *  distributed under the License is distributed on an "AS IS" BASIS,

 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 *  See the License for the specific language governing permissions and

 *  limitations under the License.

 */

package org.joda.money.format;

import java.io.IOException;

import java.util.ArrayList;

import java.util.List;

import java.util.Locale;

import org.joda.money.BigMoney;

import org.joda.money.CurrencyUnit;

import org.joda.money.IllegalCurrencyException;

/**

 * Provides the ability to build a formatter for monetary values.

 * <p>

 * This class is mutable and intended for use by a single thread.

 * A new instance should be created for each use.

 * The formatters produced by the builder are immutable and thread-safe.

 */

public final class MoneyFormatterBuilder {

    /**

     * The printers.

     */

    private final List<MoneyPrinter> printers = new ArrayList<>();

    /**

     * The parsers.

     */

    private final List<MoneyParser> parsers = new ArrayList<>();

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

    /**

     * Constructor, creating a new empty builder.

     */

    public MoneyFormatterBuilder() {

    }

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

    /**

     * Appends the amount to the builder using a standard format.

     * <p>

     * The format used is {@link MoneyAmountStyle#ASCII_DECIMAL_POINT_GROUP3_COMMA}.

     * The amount is the value itself, such as '12.34'.

     *

     * @return this, for chaining, never null

     */

    public MoneyFormatterBuilder appendAmount() {

        var pp = new AmountPrinterParser(MoneyAmountStyle.ASCII_DECIMAL_POINT_GROUP3_COMMA);

        return appendInternal(pp, pp);

    }

    /**

     * Appends the amount to the builder using a grouped localized format.

     * <p>

     * The format used is {@link MoneyAmountStyle#LOCALIZED_GROUPING}.

     * The amount is the value itself, such as '12.34'.

     *

     * @return this, for chaining, never null

     */

    public MoneyFormatterBuilder appendAmountLocalized() {

        var pp = new AmountPrinterParser(MoneyAmountStyle.LOCALIZED_GROUPING);

        return appendInternal(pp, pp);

    }

    /**

     * Appends the amount to the builder using the specified amount style.

     * <p>

     * The amount is the value itself, such as '12.34'.

     * <p>

     * The amount style allows the formatting of the number to be controlled in detail.

     * This includes the characters for positive, negative, decimal, grouping and whether

     * to output the absolute or signed amount.

     * See {@link MoneyAmountStyle} for more details.

     *

     * @param style  the style to use, not null

     * @return this, for chaining, never null

     */

    public MoneyFormatterBuilder appendAmount(MoneyAmountStyle style) {

        MoneyFormatter.checkNotNull(style, "MoneyAmountStyle must not be null");

        var pp = new AmountPrinterParser(style);

        return appendInternal(pp, pp);

    }

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

    /**

     * Appends the currency code to the builder.

     * <p>

     * The currency code is the three letter ISO code, such as 'GBP'.

     *

     * @return this, for chaining, never null

     */

    public MoneyFormatterBuilder appendCurrencyCode() {

        return appendInternal(Singletons.CODE, Singletons.CODE);

    }

    /**

     * Appends the currency code to the builder.

     * <p>

     * The numeric code is the ISO numeric code, such as '826' and is

     * zero padded to three digits.

     *

     * @return this, for chaining, never null

     */

    public MoneyFormatterBuilder appendCurrencyNumeric3Code() {

        return appendInternal(Singletons.NUMERIC_3_CODE, Singletons.NUMERIC_3_CODE);

    }

    /**

     * Appends the currency code to the builder.

     * <p>

     * The numeric code is the ISO numeric code, such as '826'.

     *

     * @return this, for chaining, never null

     */

    public MoneyFormatterBuilder appendCurrencyNumericCode() {

        return appendInternal(Singletons.NUMERIC_CODE, Singletons.NUMERIC_CODE);

    }

    /**

     * Appends the localized currency symbol to the builder.

     * <p>

     * The localized currency symbol is the symbol as chosen by the locale

     * of the formatter.

     * <p>

     * Symbols cannot be parsed.

     *

     * @return this, for chaining, never null

     */

        return appendInternal(SingletonPrinters.LOCALIZED_SYMBOL, null);

    }

    /**

     * Appends a literal to the builder.

     * <p>

     * The localized currency symbol is the symbol as chosen by the locale

     * of the formatter.

     *

     * @param literal  the literal to append, null or empty ignored

     * @return this, for chaining, never null

     */

    public MoneyFormatterBuilder appendLiteral(CharSequence literal) {

        if (literal == null || literal.length() == 0) {

            return this;

        }

        var pp = new LiteralPrinterParser(literal.toString());

        return appendInternal(pp, pp);

    }

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

    /**

     * Appends the printers and parsers from the specified formatter to this builder.

     * <p>

     * If the specified formatter cannot print, then the the output of this

     * builder will be unable to print. If the specified formatter cannot parse,

     * then the output of this builder will be unable to parse.

     *

     * @param formatter  the formatter to append, not null

     * @return this for chaining, never null

     */

    public MoneyFormatterBuilder append(MoneyFormatter formatter) {

        MoneyFormatter.checkNotNull(formatter, "MoneyFormatter must not be null");

        formatter.getPrinterParser().appendTo(this);

        return this;

    }

    /**

     * Appends the specified printer and parser to this builder.

     * <p>

     * If null is specified then the formatter will be unable to print/parse.

     *

     * @param printer  the printer to append, null makes the formatter unable to print

     * @param parser  the parser to append, null makes the formatter unable to parse

     * @return this for chaining, never null

     */

    public MoneyFormatterBuilder append(MoneyPrinter printer, MoneyParser parser) {

        return appendInternal(printer, parser);

    }

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

    /**

     * Appends the specified formatters, one used when the amount is positive,

     * and one when the amount is negative.

     * <p>

     * When printing, the amount is queried and the appropriate formatter is used.

     * <p>

     * When parsing, each formatter is tried, with the longest successful match,

     * or the first match if multiple are successful. If the negative parser is

     * matched, the amount returned will be negative no matter what amount is parsed.

     * <p>

     * A typical use case for this would be to produce a format like

     * '{@code ($123)}' for negative amounts and '{@code $123}' for positive amounts.

     * <p>

     * In order to use this method, it may be necessary to output an unsigned amount.

     * This can be achieved using {@link #appendAmount(MoneyAmountStyle)} and

     * {@link MoneyAmountStyle#withAbsValue(boolean)}.

     *

     * @param whenPositiveOrZero  the formatter to use when the amount is positive or zero

     * @param whenNegative  the formatter to use when the amount is negative

     * @return this for chaining, never null

     */

    public MoneyFormatterBuilder appendSigned(MoneyFormatter whenPositiveOrZero, MoneyFormatter whenNegative) {

        return appendSigned(whenPositiveOrZero, whenPositiveOrZero, whenNegative);

    }

    /**

     * Appends the specified formatters, one used when the amount is positive,

     * one when the amount is zero and one when the amount is negative.

     * <p>

     * When printing, the amount is queried and the appropriate formatter is used.

     * <p>

     * When parsing, each formatter is tried, with the longest successful match,

     * or the first match if multiple are successful. If the zero parser is matched,

     * the amount returned will be zero no matter what amount is parsed. If the negative

     * parser is matched, the amount returned will be negative no matter what amount is parsed.

     * <p>

     * A typical use case for this would be to produce a format like

     * '{@code ($123)}' for negative amounts and '{@code $123}' for positive amounts.

     * <p>

     * In order to use this method, it may be necessary to output an unsigned amount.

     * This can be achieved using {@link #appendAmount(MoneyAmountStyle)} and

     * {@link MoneyAmountStyle#withAbsValue(boolean)}.

     *

     * @param whenPositive  the formatter to use when the amount is positive

     * @param whenZero  the formatter to use when the amount is zero

     * @param whenNegative  the formatter to use when the amount is negative

     * @return this for chaining, never null

     */

    public MoneyFormatterBuilder appendSigned(MoneyFormatter whenPositive, MoneyFormatter whenZero, MoneyFormatter whenNegative) {

        MoneyFormatter.checkNotNull(whenPositive, "MoneyFormatter whenPositive must not be null");

        MoneyFormatter.checkNotNull(whenZero, "MoneyFormatter whenZero must not be null");

        MoneyFormatter.checkNotNull(whenNegative, "MoneyFormatter whenNegative must not be null");

        var pp = new SignedPrinterParser(whenPositive, whenZero, whenNegative);

        return appendInternal(pp, pp);

    }

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

    /**

     * Appends the specified printer and parser to this builder.

     * <p>

     * Either the printer or parser must be non-null.

     *

     * @param printer  the printer to append, null makes the formatter unable to print

     * @param parser  the parser to append, null makes the formatter unable to parse

     * @return this for chaining, never null

     */

    private MoneyFormatterBuilder appendInternal(MoneyPrinter printer, MoneyParser parser) {

        printers.add(printer);

        parsers.add(parser);

        return this;

    }

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

    /**

     * Builds the formatter from the builder using the default locale.

     * <p>

     * Once the builder is in the correct state it must be converted to a

     * {@code MoneyFormatter} to be used. Calling this method does not

     * change the state of this instance, so it can still be used.

     * <p>

     * This method uses the default locale within the returned formatter.

     * It can be changed by calling {@link MoneyFormatter#withLocale(Locale)}.

     *

     * @return the formatter built from this builder, never null

     */

    public MoneyFormatter toFormatter() {

        return toFormatter(Locale.getDefault());

    }

    /**

     * Builds the formatter from the builder setting the locale.

     * <p>

     * Once the builder is in the correct state it must be converted to a

     * {@code MoneyFormatter} to be used. Calling this method does not

     * change the state of this instance, so it can still be used.

     * <p>

     * This method uses the specified locale within the returned formatter.

     * It can be changed by calling {@link MoneyFormatter#withLocale(Locale)}.

     *

     * @param locale  the initial locale for the formatter, not null

     * @return the formatter built from this builder, never null

     */

    @SuppressWarnings("cast")

    public MoneyFormatter toFormatter(Locale locale) {

        MoneyFormatter.checkNotNull(locale, "Locale must not be null");

        var printersCopy = printers.toArray(new MoneyPrinter[printers.size()]);

        var parsersCopy = parsers.toArray(new MoneyParser[parsers.size()]);

        return new MoneyFormatter(locale, printersCopy, parsersCopy);

    }

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

    /**

     * Handles the singleton outputs.

     */

    private static enum Singletons implements MoneyPrinter, MoneyParser {

        CODE("${code}") {

            @Override

            public void print(MoneyPrintContext context, Appendable appendable, BigMoney money) throws IOException {

                appendable.append(money.getCurrencyUnit().getCode());

            }

            @Override

            public void parse(MoneyParseContext context) {

                var endPos = context.getIndex() + 3;

                if (endPos > context.getTextLength()) {

                    context.setError();

                } else {

                    var code = context.getTextSubstring(context.getIndex(), endPos);

                    try {

                        context.setCurrency(CurrencyUnit.of(code));

                        context.setIndex(endPos);

                    } catch (IllegalCurrencyException ex) {

                        context.setError();

                    }

                }

            }

        },

        NUMERIC_3_CODE("${numeric3Code}") {

            @Override

            public void print(MoneyPrintContext context, Appendable appendable, BigMoney money) throws IOException {

                appendable.append(money.getCurrencyUnit().getNumeric3Code());

            }

            @Override

            public void parse(MoneyParseContext context) {

                var endPos = context.getIndex() + 3;

                if (endPos > context.getTextLength()) {

                    context.setError();

                } else {

                    var code = context.getTextSubstring(context.getIndex(), endPos);

                    try {

                        context.setCurrency(CurrencyUnit.ofNumericCode(code));

                        context.setIndex(endPos);

                    } catch (IllegalCurrencyException ex) {

                        context.setError();

                    }

                }

            }

        },

        NUMERIC_CODE("${numericCode}") {

            @Override

            public void print(MoneyPrintContext context, Appendable appendable, BigMoney money) throws IOException {

                appendable.append(Integer.toString(money.getCurrencyUnit().getNumericCode()));

            }

            @Override

            public void parse(MoneyParseContext context) {

                var count = 0;

                for (; count < 3 && context.getIndex() + count < context.getTextLength(); count++) {

                    var ch = context.getText().charAt(context.getIndex() + count);

                    if (ch < '0' || ch > '9') {

                        break;

                    }

                }

                var endPos = context.getIndex() + count;

                var code = context.getTextSubstring(context.getIndex(), endPos);

                try {

                    context.setCurrency(CurrencyUnit.ofNumericCode(code));

                    context.setIndex(endPos);

                } catch (IllegalCurrencyException ex) {

                    context.setError();

                }

            }

        };

        private final String toString;

        private Singletons(String toString) {

            this.toString = toString;

        }

        @Override

        public String toString() {

            return toString;

        }

    }

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

    /**

     * Handles the singleton outputs.

     */

    private static enum SingletonPrinters implements MoneyPrinter {

        LOCALIZED_SYMBOL;

        @Override

        public void print(MoneyPrintContext context, Appendable appendable, BigMoney money) throws IOException {

            appendable.append(money.getCurrencyUnit().getSymbol(context.getLocale()));

        }

        @Override

        public String toString() {

            return "${symbolLocalized}";

        }

    }

}