package org.embulk.config;

import javax.validation.Validation;
import org.apache.bval.jsr303.ApacheValidationProvider;
import com.google.inject.Inject;
import com.google.inject.Injector;
import com.google.common.base.Throwables;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.node.ObjectNode;

public class ModelManager
{
    private final Injector injector;
    private final ObjectMapper objectMapper;
    private final ObjectMapper configObjectMapper;  // configObjectMapper uses different TaskDeserializer
    private final TaskValidator taskValidator;

    @Inject
    public ModelManager(Injector injector, ObjectMapper objectMapper)
    {
        this.injector = injector;
        this.objectMapper = objectMapper;
        this.configObjectMapper = objectMapper.copy();
        this.taskValidator = new TaskValidator(
                Validation.byProvider(ApacheValidationProvider.class).configure().buildValidatorFactory().getValidator());

        objectMapper.registerModule(new TaskSerDe.TaskSerializerModule(objectMapper));
        objectMapper.registerModule(new TaskSerDe.TaskDeserializerModule(objectMapper, this));
        objectMapper.registerModule(new DataSourceSerDe.SerDeModule(this));
        configObjectMapper.registerModule(new TaskSerDe.TaskSerializerModule(configObjectMapper));
        configObjectMapper.registerModule(new TaskSerDe.ConfigTaskDeserializerModule(configObjectMapper, this));
        configObjectMapper.registerModule(new DataSourceSerDe.SerDeModule(this));
    }

    public <T> T readObject(Class<T> valueType, String json)
    {
        try {
            return objectMapper.readValue(json, valueType);
        } catch (Exception ex) {
            throw Throwables.propagate(ex);
        }
    }

    public <T> T readObject(Class<T> valueType, JsonParser parser)
    {
        try {
            return objectMapper.readValue(parser, valueType);
        } catch (Exception ex) {
            throw Throwables.propagate(ex);
        }
    }

    public <T> T readObjectWithConfigSerDe(Class<T> valueType, String json)
    {
        T t;
        try {
            t = configObjectMapper.readValue(json, valueType);
        } catch (Exception ex) {
            Throwables.propagateIfInstanceOf(ex, ConfigException.class);
            throw new ConfigException(ex);
        }
        validate(t);
        return t;
    }

    public <T> T readObjectWithConfigSerDe(Class<T> valueType, JsonParser parser)
    {
        T t;
        try {
            t = configObjectMapper.readValue(parser, valueType);
        } catch (Exception ex) {
            Throwables.propagateIfInstanceOf(ex, ConfigException.class);
            throw new ConfigException(ex);
        }
        validate(t);
        return t;
    }

    public String writeObject(Object object)
    {
        try {
            return objectMapper.writeValueAsString(object);
        } catch (Exception ex) {
            throw Throwables.propagate(ex);
        }
    }

    public void validate(Object object)
    {
        taskValidator.validateModel(object);
    }

    // visible for DataSource.set
    JsonNode writeObjectAsJsonNode(Object v)
    {
        String json = writeObject(v);
        try {
            return objectMapper.readValue(json, JsonNode.class);
        } catch (Exception ex) {
            throw Throwables.propagate(ex);
        }
    }

    // visible for TaskInvocationHandler.invokeDump
    ObjectNode writeObjectAsObjectNode(Object v)
    {
        String json = writeObject(v);
        try {
            return objectMapper.readValue(json, ObjectNode.class);
        } catch (Exception ex) {
            throw Throwables.propagate(ex);
        }
    }

    // visible for TaskSerDe.set
    // TODO create annotation calss and get its instance at the 2nd argument
    <T> T getInjectedInstance(Class<T> type)
    {
        return injector.getInstance(type);
    }
}