package com.fasterxml.jackson.databind.deser.std;

import java.io.*;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URL;
import java.nio.charset.Charset;
import java.util.Currency;
import java.util.Locale;
import java.util.TimeZone;
import java.util.regex.Pattern;

import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.core.util.VersionUtil;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.exc.InvalidFormatException;
import com.fasterxml.jackson.databind.util.ClassUtil;

Base class for simple deserializers that serialize values from String representation: this includes JSON Strings and other Scalar values that can be coerced into text, like Numbers and Booleans). Simple JSON String values are trimmed using String.trim. Partial deserializer implementation will try to first access current token as a String, calls _deserialize(String,DeserializationContext) and returns return value. If this does not work (current token not a simple scalar type), attempts are made so that: 

Embedded values (JsonToken.VALUE_EMBEDDED_OBJECT) are returned as-is if they are of compatible type 
Arrays may be "unwrapped" if (and only if) DeserializationFeature.UNWRAP_SINGLE_VALUE_ARRAYS is enabled, and array contains just a single scalar value that can be deserialized (for example, JSON Array with single JSON String element). 


Special handling includes:

Null values (JsonToken.VALUE_NULL) are handled by returning value returned by JsonDeserializer.getNullValue(DeserializationContext): default implementation simply returns Java `null` but this may be overridden. 
Empty String (after trimming) will result in _deserializeFromEmptyString getting called, and return value being returned as deserialization: default implementation simply returns `null`. 

/**
 * Base class for simple deserializers that serialize values from String
 * representation: this includes JSON Strings and other Scalar values that
 * can be coerced into text, like Numbers and Booleans).
 * Simple JSON String values are trimmed using {@link java.lang.String#trim}.
 * Partial deserializer implementation will try to first access current token as
 * a String, calls {@code _deserialize(String,DeserializationContext)} and
 * returns return value.
 * If this does not work (current token not a simple scalar type), attempts
 * are made so that:
 *<ul>
 * <li>Embedded values ({@link JsonToken#VALUE_EMBEDDED_OBJECT}) are returned as-is
 *    if they are of compatible type
 *  </li>
 * <li>Arrays may be "unwrapped" if (and only if) {@link DeserializationFeature#UNWRAP_SINGLE_VALUE_ARRAYS}
 *    is enabled, and array contains just a single scalar value that can be deserialized
 *    (for example, JSON Array with single JSON String element).
 *  </li>
 * </ul>
 *<p>
 * Special handling includes:
 * <ul>
 * <li>Null values ({@link JsonToken#VALUE_NULL}) are handled by returning value
 *   returned by {@link JsonDeserializer#getNullValue(DeserializationContext)}: default
 *   implementation simply returns Java `null` but this may be overridden.
 *  </li>
 * <li>Empty String (after trimming) will result in {@link #_deserializeFromEmptyString}
 *   getting called, and return value being returned as deserialization: default implementation
 *   simply returns `null`.
 *  </li>
 * </ul>
 */
@SuppressWarnings("serial")
public abstract class FromStringDeserializer<T> extends StdScalarDeserializer<T>
{
    public static Class<?>[] types() {
        return new Class<?>[] {
            File.class,
            URL.class,
            URI.class,
            Class.class,
            JavaType.class,
            Currency.class,
            Pattern.class,
            Locale.class,
            Charset.class,
            TimeZone.class,
            InetAddress.class,
            InetSocketAddress.class,
            StringBuilder.class,
        };
    }
    
    /*
    /**********************************************************
    /* Deserializer implementations
    /**********************************************************
     */
    
    protected FromStringDeserializer(Class<?> vc) {
        super(vc);
    }

    
Factory method for trying to find a deserializer for one of supported
types that have simple from-String serialization.
/**
     * Factory method for trying to find a deserializer for one of supported
     * types that have simple from-String serialization.
     */
    public static Std findDeserializer(Class<?> rawType)
    {
        int kind = 0;
        if (rawType == File.class) {
            kind = Std.STD_FILE;
        } else if (rawType == URL.class) {
            kind = Std.STD_URL;
        } else if (rawType == URI.class) {
            kind = Std.STD_URI;
        } else if (rawType == Class.class) {
            kind = Std.STD_CLASS;
        } else if (rawType == JavaType.class) {
            kind = Std.STD_JAVA_TYPE;
        } else if (rawType == Currency.class) {
            kind = Std.STD_CURRENCY;
        } else if (rawType == Pattern.class) {
            kind = Std.STD_PATTERN;
        } else if (rawType == Locale.class) {
            kind = Std.STD_LOCALE;
        } else if (rawType == Charset.class) {
            kind = Std.STD_CHARSET;
        } else if (rawType == TimeZone.class) {
            kind = Std.STD_TIME_ZONE;
        } else if (rawType == InetAddress.class) {
            kind = Std.STD_INET_ADDRESS;
        } else if (rawType == InetSocketAddress.class) {
            kind = Std.STD_INET_SOCKET_ADDRESS;
        } else if (rawType == StringBuilder.class) {
            kind = Std.STD_STRING_BUILDER;
        } else {
            return null;
        }
        return new Std(rawType, kind);
    }
    
    /*
    /**********************************************************
    /* Deserializer implementations
    /**********************************************************
     */

    @SuppressWarnings("unchecked")
    @Override
    public T deserialize(JsonParser p, DeserializationContext ctxt) throws IOException
    {
        // Let's get textual value, possibly via coercion from other scalar types
        String text = p.getValueAsString();
        if (text != null) { // has String representation
            if (text.length() == 0 || (text = text.trim()).length() == 0) {
                // Usually should become null; but not always
                return _deserializeFromEmptyString();
            }
            Exception cause = null;
            try {
                // 19-May-2017, tatu: Used to require non-null result (assuming `null`
                //    indicated error; but that seems wrong. Should be able to return
                //    `null` as value.
                return _deserialize(text, ctxt);
            } catch (IllegalArgumentException | MalformedURLException e) {
                cause = e;
            }
            // note: `cause` can't be null
            String msg = "not a valid textual representation";
            String m2 = cause.getMessage();
            if (m2 != null) {
                msg = msg + ", problem: "+m2;
            }
            // 05-May-2016, tatu: Unlike most usage, this seems legit, so...
            JsonMappingException e = ctxt.weirdStringException(text, _valueClass, msg);
            e.initCause(cause);
            throw e;
            // nothing to do here, yet? We'll fail anyway
        }
        JsonToken t = p.currentToken();
        // [databind#381]
        if (t == JsonToken.START_ARRAY) {
            return _deserializeFromArray(p, ctxt);
        }
        if (t == JsonToken.VALUE_EMBEDDED_OBJECT) {
            // Trivial cases; null to null, instance of type itself returned as is
            Object ob = p.getEmbeddedObject();
            if (ob == null) {
                return null;
            }
            if (_valueClass.isAssignableFrom(ob.getClass())) {
                return (T) ob;
            }
            return _deserializeEmbedded(ob, ctxt);
        }
        return (T) ctxt.handleUnexpectedToken(_valueClass, p);
    }
        
    protected abstract T _deserialize(String value, DeserializationContext ctxt) throws IOException;

    protected T _deserializeEmbedded(Object ob, DeserializationContext ctxt) throws IOException {
        // default impl: error out
        ctxt.reportInputMismatch(this,
                "Don't know how to convert embedded Object of type %s into %s",
                ob.getClass().getName(), _valueClass.getName());
        return null;
    }

    protected T _deserializeFromEmptyString() throws IOException {
        return null;
    }

    /*
    /**********************************************************
    /* A general-purpose implementation
    /**********************************************************
     */

    
"Chameleon" deserializer that works on simple types that are deserialized
from a simple String.
Since:
2.4/**
     * "Chameleon" deserializer that works on simple types that are deserialized
     * from a simple String.
     * 
     * @since 2.4
     */
    public static class Std extends FromStringDeserializer<Object>
    {
        private static final long serialVersionUID = 1;

        public final static int STD_FILE = 1;
        public final static int STD_URL = 2;
        public final static int STD_URI = 3;
        public final static int STD_CLASS = 4;
        public final static int STD_JAVA_TYPE = 5;
        public final static int STD_CURRENCY = 6;
        public final static int STD_PATTERN = 7;
        public final static int STD_LOCALE = 8;
        public final static int STD_CHARSET = 9;
        public final static int STD_TIME_ZONE = 10;
        public final static int STD_INET_ADDRESS = 11;
        public final static int STD_INET_SOCKET_ADDRESS = 12;
        public final static int STD_STRING_BUILDER = 13;

        protected final int _kind;
        
        protected Std(Class<?> valueType, int kind) {
            super(valueType);
            _kind = kind;
        }

        @Override
        protected Object _deserialize(String value, DeserializationContext ctxt) throws IOException
        {
            switch (_kind) {
            case STD_FILE:
                return new File(value);
            case STD_URL:
                return new URL(value);
            case STD_URI:
                return URI.create(value);
            case STD_CLASS:
                try {
                    return ctxt.findClass(value);
                } catch (Exception e) {
                    return ctxt.handleInstantiationProblem(_valueClass, value,
                            ClassUtil.getRootCause(e));
                }
            case STD_JAVA_TYPE:
                return ctxt.getTypeFactory().constructFromCanonical(value);
            case STD_CURRENCY:
                // will throw IAE if unknown:
                return Currency.getInstance(value);
            case STD_PATTERN:
                // will throw IAE (or its subclass) if malformed
                return Pattern.compile(value);
            case STD_LOCALE:
                {
                    int ix = _firstHyphenOrUnderscore(value);
                    if (ix < 0) { // single argument
                        return new Locale(value);
                    }
                    String first = value.substring(0, ix);
                    value = value.substring(ix+1);
                    ix = _firstHyphenOrUnderscore(value);
                    if (ix < 0) { // two pieces
                        return new Locale(first, value);
                    }
                    String second = value.substring(0, ix);
                    return new Locale(first, second, value.substring(ix+1));
                }
            case STD_CHARSET:
                return Charset.forName(value);
            case STD_TIME_ZONE:
                return TimeZone.getTimeZone(value);
            case STD_INET_ADDRESS:
                return InetAddress.getByName(value);
            case STD_INET_SOCKET_ADDRESS:
                if (value.startsWith("[")) {
                    // bracketed IPv6 (with port number)

                    int i = value.lastIndexOf(']');
                    if (i == -1) {
                        throw new InvalidFormatException(ctxt.getParser(),
                                "Bracketed IPv6 address must contain closing bracket",
                                value, InetSocketAddress.class);
                    }

                    int j = value.indexOf(':', i);
                    int port = j > -1 ? Integer.parseInt(value.substring(j + 1)) : 0;
                    return new InetSocketAddress(value.substring(0, i + 1), port);
                }
                int ix = value.indexOf(':');
                if (ix >= 0 && value.indexOf(':', ix + 1) < 0) {
                    // host:port
                    int port = Integer.parseInt(value.substring(ix+1));
                    return new InetSocketAddress(value.substring(0, ix), port);
                }
                // host or unbracketed IPv6, without port number
                return new InetSocketAddress(value, 0);
            case STD_STRING_BUILDER:
                return new StringBuilder(value);
            }
            VersionUtil.throwInternal();
            return null;
        }

        @Override
        protected Object _deserializeFromEmptyString() throws IOException {
            // As per [databind#398], URI requires special handling
            if (_kind == STD_URI) {
                return URI.create("");
            }
            // As per [databind#1123], Locale too
            if (_kind == STD_LOCALE) {
                return Locale.ROOT;
            }
            if (_kind == STD_STRING_BUILDER) {
                return new StringBuilder();
            }
            return super._deserializeFromEmptyString();
        }

        protected int _firstHyphenOrUnderscore(String str)
        {
            for (int i = 0, end = str.length(); i < end; ++i) {
                char c = str.charAt(i);
                if (c == '_' || c == '-') {
                    return i;
                }
            }
            return -1;
        }
    }
}