JSON.mustache

{{>licenseInfo}}

package {{invokerPackage}};

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonParseException;
import com.google.gson.TypeAdapter;
import com.google.gson.internal.bind.util.ISO8601Utils;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonWriter;
import com.google.gson.JsonElement;
import io.gsonfire.GsonFireBuilder;
import io.gsonfire.TypeSelector;
{{#joda}}
import org.joda.time.DateTime;
import org.joda.time.LocalDate;
import org.joda.time.format.DateTimeFormatter;
import org.joda.time.format.DateTimeFormatterBuilder;
import org.joda.time.format.ISODateTimeFormat;
{{/joda}}

{{#models.0}}
import {{modelPackage}}.*;
{{/models.0}}
import okio.ByteString;

import java.io.IOException;
import java.io.StringReader;
import java.lang.reflect.Type;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.ParsePosition;
{{#jsr310}}
import java.time.LocalDate;
import java.time.OffsetDateTime;
import java.time.format.DateTimeFormatter;
{{/jsr310}}
import java.util.Date;
import java.util.Locale;
import java.util.Map;
import java.util.HashMap;

public class JSON {
    private Gson gson;
    private boolean isLenientOnJson = false;
    private DateTypeAdapter dateTypeAdapter = new DateTypeAdapter();
    private SqlDateTypeAdapter sqlDateTypeAdapter = new SqlDateTypeAdapter();
    {{#joda}}
    private DateTimeTypeAdapter dateTimeTypeAdapter = new DateTimeTypeAdapter();
    private LocalDateTypeAdapter localDateTypeAdapter = new LocalDateTypeAdapter();
    {{/joda}}
    {{#jsr310}}
    private OffsetDateTimeTypeAdapter offsetDateTimeTypeAdapter = new OffsetDateTimeTypeAdapter();
    private LocalDateTypeAdapter localDateTypeAdapter = new LocalDateTypeAdapter();
    {{/jsr310}}
    private ByteArrayAdapter byteArrayAdapter = new ByteArrayAdapter();

    @SuppressWarnings("unchecked")
    public static GsonBuilder createGson() {
        GsonFireBuilder fireBuilder = new GsonFireBuilder()
        {{#models}}
        {{#model}}
        {{#discriminator}}
                .registerTypeSelector({{classname}}.class, new TypeSelector<{{classname}}>() {
                    @Override
                    public Class<? extends {{classname}}> getClassForElement(JsonElement readElement) {
                        Map<String, Class> classByDiscriminatorValue = new HashMap<String, Class>();
                        {{#mappedModels}}
                        classByDiscriminatorValue.put("{{mappingName}}"{{^discriminatorCaseSensitive}}.toUpperCase(Locale.ROOT){{/discriminatorCaseSensitive}}, {{modelName}}.class);
                        {{/mappedModels}}
                        classByDiscriminatorValue.put("{{name}}"{{^discriminatorCaseSensitive}}.toUpperCase(Locale.ROOT){{/discriminatorCaseSensitive}}, {{classname}}.class);
                        return getClassByDiscriminator(classByDiscriminatorValue,
                                getDiscriminatorValue(readElement, "{{{propertyBaseName}}}"));
                    }
          })
        {{/discriminator}}
        {{/model}}
        {{/models}}
        ;
        GsonBuilder builder = fireBuilder.createGsonBuilder();
        {{#disableHtmlEscaping}}
        builder.disableHtmlEscaping();
        {{/disableHtmlEscaping}}
        return builder;
    }

    private static String getDiscriminatorValue(JsonElement readElement, String discriminatorField) {
        JsonElement element = readElement.getAsJsonObject().get(discriminatorField);
        if (null == element) {
            throw new IllegalArgumentException("missing discriminator field: <" + discriminatorField + ">");
        }
        return element.getAsString();
    }

    /**
     * Returns the Java class that implements the OpenAPI schema for the specified discriminator value.
     *
     * @param classByDiscriminatorValue The map of discriminator values to Java classes.
     * @param discriminatorValue The value of the OpenAPI discriminator in the input data.
     * @return The Java class that implements the OpenAPI schema
     */
    private static Class getClassByDiscriminator(Map classByDiscriminatorValue, String discriminatorValue) {
        Class clazz = (Class) classByDiscriminatorValue.get(discriminatorValue{{^discriminatorCaseSensitive}}.toUpperCase(Locale.ROOT){{/discriminatorCaseSensitive}});
        if (null == clazz) {
            throw new IllegalArgumentException("cannot determine model class of name: <" + discriminatorValue + ">");
        }
        return clazz;
    }

    public JSON() {
        gson = createGson()
            .registerTypeAdapter(Date.class, dateTypeAdapter)
            .registerTypeAdapter(java.sql.Date.class, sqlDateTypeAdapter)
            {{#joda}}
            .registerTypeAdapter(DateTime.class, dateTimeTypeAdapter)
            .registerTypeAdapter(LocalDate.class, localDateTypeAdapter)
            {{/joda}}
            {{#jsr310}}
            .registerTypeAdapter(OffsetDateTime.class, offsetDateTimeTypeAdapter)
            .registerTypeAdapter(LocalDate.class, localDateTypeAdapter)
            {{/jsr310}}
            .registerTypeAdapter(byte[].class, byteArrayAdapter)
            .create();
    }

    /**
     * Get Gson.
     *
     * @return Gson
     */
    public Gson getGson() {
        return gson;
    }

    /**
     * Set Gson.
     *
     * @param gson Gson
     * @return JSON
     */
    public JSON setGson(Gson gson) {
        this.gson = gson;
        return this;
    }

    /**
     * Configure the parser to be liberal in what it accepts.
     *
     * @param lenientOnJson Set it to true to ignore some syntax errors
     * @return JSON
     * @see <a href="https://www.javadoc.io/doc/com.google.code.gson/gson/2.8.5/com/google/gson/stream/JsonReader.html">https://www.javadoc.io/doc/com.google.code.gson/gson/2.8.5/com/google/gson/stream/JsonReader.html</a>
     */
    public JSON setLenientOnJson(boolean lenientOnJson) {
        isLenientOnJson = lenientOnJson;
        return this;
    }

    /**
     * Serialize the given Java object into JSON string.
     *
     * @param obj Object
     * @return String representation of the JSON
     */
    public String serialize(Object obj) {
        return gson.toJson(obj);
    }

    /**
     * Deserialize the given JSON string to Java object.
     *
     * @param <T>        Type
     * @param body       The JSON string
     * @param returnType The type to deserialize into
     * @return The deserialized Java object
     */
    @SuppressWarnings("unchecked")
    public <T> T deserialize(String body, Type returnType) {
        try {
            if (isLenientOnJson) {
                JsonReader jsonReader = new JsonReader(new StringReader(body));
                // see https://www.javadoc.io/doc/com.google.code.gson/gson/2.8.5/com/google/gson/stream/JsonReader.html
                jsonReader.setLenient(true);
                return gson.fromJson(jsonReader, returnType);
            } else {
                return gson.fromJson(body, returnType);
            }
        } catch (JsonParseException e) {
            // Fallback processing when failed to parse JSON form response body:
            // return the response body string directly for the String return type;
            if (returnType.equals(String.class)) {
                return (T) body;
            } else {
                throw (e);
            }
        }
    }

    /**
     * Gson TypeAdapter for Byte Array type
     */
    public class ByteArrayAdapter extends TypeAdapter<byte[]> {

        @Override
        public void write(JsonWriter out, byte[] value) throws IOException {
            if (value == null) {
                out.nullValue();
            } else {
                out.value(ByteString.of(value).base64());
            }
        }

        @Override
        public byte[] read(JsonReader in) throws IOException {
            switch (in.peek()) {
                case NULL:
                    in.nextNull();
                    return null;
                default:
                    String bytesAsBase64 = in.nextString();
                    ByteString byteString = ByteString.decodeBase64(bytesAsBase64);
                    return byteString.toByteArray();
            }
        }
    }

    {{#joda}}
    /**
     * Gson TypeAdapter for Joda DateTime type
     */
    public static class DateTimeTypeAdapter extends TypeAdapter<DateTime> {

        private DateTimeFormatter formatter;

        public DateTimeTypeAdapter() {
            this(new DateTimeFormatterBuilder()
                .append(ISODateTimeFormat.dateTime().getPrinter(), ISODateTimeFormat.dateOptionalTimeParser().getParser())
                .toFormatter());
        }

        public DateTimeTypeAdapter(DateTimeFormatter formatter) {
            this.formatter = formatter;
        }

        public void setFormat(DateTimeFormatter dateFormat) {
            this.formatter = dateFormat;
        }

        @Override
        public void write(JsonWriter out, DateTime date) throws IOException {
            if (date == null) {
                out.nullValue();
            } else {
                out.value(formatter.print(date));
            }
        }

        @Override
        public DateTime read(JsonReader in) throws IOException {
            switch (in.peek()) {
                case NULL:
                    in.nextNull();
                    return null;
                default:
                    String date = in.nextString();
                    return formatter.parseDateTime(date);
            }
        }
    }

    /**
     * Gson TypeAdapter for Joda LocalDate type
     */
    public class LocalDateTypeAdapter extends TypeAdapter<LocalDate> {

        private DateTimeFormatter formatter;

        public LocalDateTypeAdapter() {
            this(ISODateTimeFormat.date());
        }

        public LocalDateTypeAdapter(DateTimeFormatter formatter) {
            this.formatter = formatter;
        }

        public void setFormat(DateTimeFormatter dateFormat) {
            this.formatter = dateFormat;
        }

        @Override
        public void write(JsonWriter out, LocalDate date) throws IOException {
            if (date == null) {
                out.nullValue();
            } else {
                out.value(formatter.print(date));
            }
        }

        @Override
        public LocalDate read(JsonReader in) throws IOException {
            switch (in.peek()) {
                case NULL:
                    in.nextNull();
                    return null;
                default:
                    String date = in.nextString();
                    return formatter.parseLocalDate(date);
            }
        }
    }

    public JSON setDateTimeFormat(DateTimeFormatter dateFormat) {
        dateTimeTypeAdapter.setFormat(dateFormat);
        return this;
    }

    public JSON setLocalDateFormat(DateTimeFormatter dateFormat) {
        localDateTypeAdapter.setFormat(dateFormat);
        return this;
    }

    {{/joda}}
    {{#jsr310}}
    /**
     * Gson TypeAdapter for JSR310 OffsetDateTime type
     */
    public static class OffsetDateTimeTypeAdapter extends TypeAdapter<OffsetDateTime> {

        private DateTimeFormatter formatter;

        public OffsetDateTimeTypeAdapter() {
            this(DateTimeFormatter.ISO_OFFSET_DATE_TIME);
        }

        public OffsetDateTimeTypeAdapter(DateTimeFormatter formatter) {
            this.formatter = formatter;
        }

        public void setFormat(DateTimeFormatter dateFormat) {
            this.formatter = dateFormat;
        }

        @Override
        public void write(JsonWriter out, OffsetDateTime date) throws IOException {
            if (date == null) {
                out.nullValue();
            } else {
                out.value(formatter.format(date));
            }
        }

        @Override
        public OffsetDateTime read(JsonReader in) throws IOException {
            switch (in.peek()) {
                case NULL:
                    in.nextNull();
                    return null;
                default:
                    String date = in.nextString();
                    if (date.endsWith("+0000")) {
                        date = date.substring(0, date.length()-5) + "Z";
                    }
                    return OffsetDateTime.parse(date, formatter);
            }
        }
    }

    /**
     * Gson TypeAdapter for JSR310 LocalDate type
     */
    public class LocalDateTypeAdapter extends TypeAdapter<LocalDate> {

        private DateTimeFormatter formatter;

        public LocalDateTypeAdapter() {
            this(DateTimeFormatter.ISO_LOCAL_DATE);
        }

        public LocalDateTypeAdapter(DateTimeFormatter formatter) {
            this.formatter = formatter;
        }

        public void setFormat(DateTimeFormatter dateFormat) {
            this.formatter = dateFormat;
        }

        @Override
        public void write(JsonWriter out, LocalDate date) throws IOException {
            if (date == null) {
                out.nullValue();
            } else {
                out.value(formatter.format(date));
            }
        }

        @Override
        public LocalDate read(JsonReader in) throws IOException {
            switch (in.peek()) {
                case NULL:
                    in.nextNull();
                    return null;
                default:
                    String date = in.nextString();
                    return LocalDate.parse(date, formatter);
            }
        }
    }

    public JSON setOffsetDateTimeFormat(DateTimeFormatter dateFormat) {
        offsetDateTimeTypeAdapter.setFormat(dateFormat);
        return this;
    }

    public JSON setLocalDateFormat(DateTimeFormatter dateFormat) {
        localDateTypeAdapter.setFormat(dateFormat);
        return this;
    }

    {{/jsr310}}
    /**
     * Gson TypeAdapter for java.sql.Date type
     * If the dateFormat is null, a simple "yyyy-MM-dd" format will be used
     * (more efficient than SimpleDateFormat).
     */
    public static class SqlDateTypeAdapter extends TypeAdapter<java.sql.Date> {

        private DateFormat dateFormat;

        public SqlDateTypeAdapter() {}

        public SqlDateTypeAdapter(DateFormat dateFormat) {
            this.dateFormat = dateFormat;
        }

        public void setFormat(DateFormat dateFormat) {
            this.dateFormat = dateFormat;
        }

        @Override
        public void write(JsonWriter out, java.sql.Date date) throws IOException {
            if (date == null) {
                out.nullValue();
            } else {
                String value;
                if (dateFormat != null) {
                    value = dateFormat.format(date);
                } else {
                    value = date.toString();
                }
                out.value(value);
            }
        }

        @Override
        public java.sql.Date read(JsonReader in) throws IOException {
            switch (in.peek()) {
                case NULL:
                    in.nextNull();
                    return null;
                default:
                    String date = in.nextString();
                    try {
                        if (dateFormat != null) {
                            return new java.sql.Date(dateFormat.parse(date).getTime());
                        }
                        return new java.sql.Date(ISO8601Utils.parse(date, new ParsePosition(0)).getTime());
                    } catch (ParseException e) {
                        throw new JsonParseException(e);
                    }
            }
        }
    }

    /**
     * Gson TypeAdapter for java.util.Date type
     * If the dateFormat is null, ISO8601Utils will be used.
     */
    public static class DateTypeAdapter extends TypeAdapter<Date> {

        private DateFormat dateFormat;

        public DateTypeAdapter() {}

        public DateTypeAdapter(DateFormat dateFormat) {
            this.dateFormat = dateFormat;
        }

        public void setFormat(DateFormat dateFormat) {
            this.dateFormat = dateFormat;
        }

        @Override
        public void write(JsonWriter out, Date date) throws IOException {
            if (date == null) {
                out.nullValue();
            } else {
                String value;
                if (dateFormat != null) {
                    value = dateFormat.format(date);
                } else {
                    value = ISO8601Utils.format(date, true);
                }
                out.value(value);
            }
        }

        @Override
        public Date read(JsonReader in) throws IOException {
            try {
                switch (in.peek()) {
                    case NULL:
                        in.nextNull();
                        return null;
                    default:
                        String date = in.nextString();
                        try {
                            if (dateFormat != null) {
                                return dateFormat.parse(date);
                            }
                            return ISO8601Utils.parse(date, new ParsePosition(0));
                        } catch (ParseException e) {
                            throw new JsonParseException(e);
                        }
                }
            } catch (IllegalArgumentException e) {
                throw new JsonParseException(e);
            }
        }
    }

    public JSON setDateFormat(DateFormat dateFormat) {
        dateTypeAdapter.setFormat(dateFormat);
        return this;
    }

    public JSON setSqlDateFormat(DateFormat dateFormat) {
        sqlDateTypeAdapter.setFormat(dateFormat);
        return this;
    }

}