/*

 *  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.math.BigDecimal;

import java.text.ParsePosition;

import java.util.Locale;

import org.joda.money.BigMoney;

import org.joda.money.CurrencyUnit;

/**

 * Context used when parsing money.

 * <p>

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

 * A new instance is created for each parse.

 */

public final class MoneyParseContext {

    /**

     * The locale to parse using.

     */

    private Locale locale;

    /**

     * The text to parse.

     */

    private CharSequence text;

    /**

     * The text index.

     */

    private int textIndex;

    /**

     * The text error index.

     */

    private int textErrorIndex = -1;

    /**

     * The parsed currency.

     */

    private CurrencyUnit currency;

    /**

     * The parsed amount.

     */

    private BigDecimal amount;

    /**

     * Constructor.

     *

     * @param locale  the locale, not null

     * @param text  the text to parse, not null

     * @param index  the current text index

     */

    MoneyParseContext(Locale locale, CharSequence text, int index) {

        this.locale = locale;

        this.text = text;

        this.textIndex = index;

    }

    /**

     * Constructor.

     *

     * @param locale  the locale, not null

     * @param text  the text to parse, not null

     * @param index  the current text index

     * @param errorIndex  the error index

     * @param currency  the currency

     * @param amount  the parsed amount

     */

    MoneyParseContext(Locale locale, CharSequence text, int index, int errorIndex, CurrencyUnit currency, BigDecimal amount) {

        this.locale = locale;

        this.text = text;

        this.textIndex = index;

        this.textErrorIndex = errorIndex;

        this.currency = currency;

        this.amount = amount;

    }

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

    /**

     * Gets the locale.

     *

     * @return the locale, not null

     */

    public Locale getLocale() {

        return locale;

    }

    /**

     * Sets the locale.

     *

     * @param locale  the locale, not null

     */

    public void setLocale(Locale locale) {

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

        this.locale = locale;

    }

    /**

     * Gets the text being parsed.

     *

     * @return the text being parsed, never null

     */

    public CharSequence getText() {

        return text;

    }

    /**

     * Sets the text.

     *

     * @param text  the text being parsed, not null

     */

    public void setText(CharSequence text) {

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

        this.text = text;

    }

    /**

     * Gets the length of the text being parsed.

     *

     * @return the length of the text being parsed

     */

    public int getTextLength() {

        return text.length();

    }

    /**

     * Gets a substring of the text being parsed.

     *

     * @param start  the start index

     * @param end  the end index

     * @return the substring, not null

     */

    public String getTextSubstring(int start, int end) {

        return text.subSequence(start, end).toString();

    }

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

    /**

     * Gets the current parse position index.

     *

     * @return the current parse position index

     */

    public int getIndex() {

        return textIndex;

    }

    /**

     * Sets the current parse position index.

     *

     * @param index  the current parse position index

     */

    public void setIndex(int index) {

        this.textIndex = index;

    }

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

    /**

     * Gets the error index.

     *

     * @return the error index, negative if no error

     */

    public int getErrorIndex() {

        return textErrorIndex;

    }

    /**

     * Sets the error index.

     *

     * @param index  the error index

     */

    public void setErrorIndex(int index) {

        this.textErrorIndex = index;

    }

    /**

     * Sets the error index from the current index.

     */

    public void setError() {

        this.textErrorIndex = textIndex;

    }

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

    /**

     * Gets the parsed currency.

     *

     * @return the parsed currency, null if not parsed yet

     */

    public CurrencyUnit getCurrency() {

        return currency;

    }

    /**

     * Sets the parsed currency.

     *

     * @param currency  the parsed currency, may be null

     */

    public void setCurrency(CurrencyUnit currency) {

        this.currency = currency;

    }

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

    /**

     * Gets the parsed amount.

     *

     * @return the parsed amount, null if not parsed yet

     */

    public BigDecimal getAmount() {

        return amount;

    }

    /**

     * Sets the parsed currency.

     *

     * @param amount  the parsed amount, may be null

     */

    public void setAmount(BigDecimal amount) {

        this.amount = amount;

    }

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

    /**

     * Checks if the parse has found an error.

     *

     * @return whether a parse error has occurred

     */

    public boolean isError() {

        return textErrorIndex >= 0;

    }

    /**

     * Checks if the text has been fully parsed such that there is no more text to parse.

     *

     * @return true if fully parsed

     */

    public boolean isFullyParsed() {

        return textIndex == getTextLength();

    }

    /**

     * Checks if the context contains a currency and amount suitable for creating

     * a monetary value.

     *

     * @return true if able to create a monetary value

     */

    public boolean isComplete() {

        return currency != null && amount != null;

    }

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

    /**

     * Creates a child context.

     *

     * @return the child context, never null

     */

        return new MoneyParseContext(locale, text, textIndex, textErrorIndex, currency, amount);

    }

    /**

     * Merges the child context back into this instance.

     *

     * @param child  the child context, not null

     */

    void mergeChild(MoneyParseContext child) {

        setLocale(child.getLocale());

        setText(child.getText());

        setIndex(child.getIndex());

        setErrorIndex(child.getErrorIndex());

        setCurrency(child.getCurrency());

        setAmount(child.getAmount());

    }

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

    /**

     * Converts the indexes to a parse position.

     *

     * @return the parse position, never null

     */

    public ParsePosition toParsePosition() {

        var pp = new ParsePosition(textIndex);

        pp.setErrorIndex(textErrorIndex);

        return pp;

    }

    /**

     * Converts the context to a {@code BigMoney}.

     *

     * @return the monetary value, never null

     * @throws MoneyFormatException if either the currency or amount is missing

     */

    public BigMoney toBigMoney() {

        if (currency == null) {

            throw new MoneyFormatException("Cannot convert to BigMoney as no currency found");

        }

        if (amount == null) {

            throw new MoneyFormatException("Cannot convert to BigMoney as no amount found");

        }

        return BigMoney.of(currency, amount);

    }

}