#ifndef DYNET_C_MODEL_H_
#define DYNET_C_MODEL_H_

#include <dynet_c/define.h>
#include <dynet_c/devices.h>
#include <dynet_c/dim.h>
#include <dynet_c/param-init.h>
#include <dynet_c/tensor.h>

/**
 * Opaque type of Parameter.
 */
typedef struct dynetParameter dynetParameter_t;

/**
 * Opaque type of LookupParameter.
 */
typedef struct dynetLookupParameter dynetLookupParameter_t;

/**
 * Opaque type of ParameterCollection.
 */
typedef struct dynetParameterCollection dynetParameterCollection_t;

/**
 * Creates a new Parameter object.
 * @param newobj Pointer to receive a handler.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetCreateParameter(dynetParameter_t **newobj);

/**
 * Deletes the Parameter object.
 * @param param Pointer of a handler.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetDeleteParameter(dynetParameter_t *param);

/**
 * Fills the Parameter with zero values.
 * @param param Pointer of a handler.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetFillParameterWithZeros(dynetParameter_t *param);

/**
 * Returns dim of the parameter.
 * @param param Pointer of a handler.
 * @param newobj Pointer to receive a Dim object.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetGetParameterDim(
    const dynetParameter_t *param, dynetDim_t **newobj);

/**
 * Retrieves internal values in the parameter as a tensor.
 * @param param Pointer of a handler.
 * @param tensor Pointer to receive a tensor of the internal values.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetGetParameterValues(
    dynetParameter_t *param, dynetTensor_t **tensor);

/**
 * Retrieves internal gradients in the parameter as a tensor.
 * @param param Pointer of a handler.
 * @param tensor Pointer to receive a tensor of the internal gradients.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetGetParameterGradients(
    dynetParameter_t *param, dynetTensor_t **tensor);

/**
 * Sets update status of the parameter.
 * @param param Pointer of a handler.
 * @param b Update status value.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetSetParameterUpdated(
    dynetParameter_t *param, DYNET_C_BOOL b);

/**
 * Returns update status of the parameter.
 * @param param Pointer of a handler.
 * @param retval Pointer to receive an update status value.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetIsParameterUpdated(
    const dynetParameter_t *param, DYNET_C_BOOL *retval);

/**
 * Creates a new LookupParameter object.
 * @param newobj Pointer to receive a handler.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetCreateLookupParameter(
    dynetLookupParameter_t **newobj);

/**
 * Deletes the LookupParameter object.
 * @param param Pointer of a handler.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetDeleteLookupParameter(
    dynetLookupParameter_t *param);

/**
 * Initializes one paticular column of the values in the LookupParameter.
 * @param param Pointer of a handler.
 * @param index Index of the column to be initialized/
 * @param value List of initial values.
 * @param n Number of values.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetInitializeLookupParameter(
    dynetLookupParameter_t *param, uint32_t index, const float *value,
    size_t n);

/**
 * Fills the LookupParameter with zero values.
 * @param param Pointer of a handler.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetFillLookupParameterWithZeros(
    dynetLookupParameter_t *param);

/**
 * Returns dim of the parameter.
 * @param param Pointer of a handler.
 * @param newobj Pointer to receive a Dim object.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetGetLookupParameterDim(
    const dynetLookupParameter_t *param, dynetDim_t **newobj);

/**
 * Retrieves internal values in the parameter as an array of tensors.
 * @param param Pointer of a handler.
 * @param tensors Pointer to receive a list of the internal values.
 * @param size Pointer to receive the length of the array.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetGetLookupParameterValues(
    dynetLookupParameter_t *param, dynetTensor_t **tensors, size_t *size);

/**
 * Sets update status of the parameter.
 * @param param Pointer of a handler.
 * @param b Update status value.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetSetLookupParameterUpdated(
    dynetLookupParameter_t *param, DYNET_C_BOOL b);

/**
 * Sets update status of the parameter.
 * @param param Pointer of a handler.
 * @param retval Pointer to receive an update status value.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetIsLookupParameterUpdated(
    const dynetLookupParameter_t *param, DYNET_C_BOOL *retval);

/**
 * Creates a new ParameterCollection object.
 * @param newobj Pointer to receive a handler.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetCreateParameterCollection(
    dynetParameterCollection_t **newobj);

/**
 * Deletes the ParameterCollection object.
 * @param pc Pointer of a handler.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetDeleteParameterCollection(
    dynetParameterCollection_t *pc);

/**
 * Gets the L2 norm of the gradient in the ParameterCollection.
 * @param pc Pointer of a handler.
 * @param retval Pointer to receive the L2 norm value.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetGetParameterCollectionGradientL2Norm(
    const dynetParameterCollection_t *pc, float *retval);

/**
 * Sets weight decay coefficient for parameters in the ParameterCollection.
 * @param pc Pointer of a handler.
 * @param lambda Weight decay coefficient.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetSetParameterCollectionWeightDecayLambda(
    dynetParameterCollection_t *pc, float lambda);

/**
 * Gets weight decay coefficient for parameters in the ParameterCollection.
 * @param pc Pointer of a handler.
 * @param retval Pointer to receive the weight decay coefficient.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetGetParameterCollectionWeightDecayLambda(
    const dynetParameterCollection_t *pc, float *retval);

/**
 * Adds a parameter to the ParameterCollection.
 * @param pc Pointer of a handler.
 * @param d Pointer of a dim.
 * @param init Pointer of an initializer.
 * @param name Name of the parameter.
 * @param device Pointer of a device.
 * @param newobj Pointer to receive a Parameter object.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetAddParametersToParameterCollection(
    dynetParameterCollection_t *pc, const dynetDim_t *d,
    const dynetParameterInit_t *init, const char *name, dynetDevice_t *device,
    dynetParameter_t **newobj);

/**
 * Adds a lookup parameter to the ParameterCollection.
 * @param pc Pointer of a handler.
 * @param n Number of lookup indices.
 * @param d Pointer of a dim.
 * @param init Pointer of an initializer.
 * @param name Name of the parameter.
 * @param device Pointer of a device.
 * @param newobj Pointer to receive a LookupParameter object.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetAddLookupParametersToParameterCollection(
    dynetParameterCollection_t *pc, uint32_t n, const dynetDim_t *d,
    const dynetParameterInit_t *init, const char *name, dynetDevice_t *device,
    dynetLookupParameter_t **newobj);

/**
 * Adds a subcollection to the ParameterCollection.
 * @param pc Pointer of a handler.
 * @param name Name of a subcollection.
 * @param newobj Pointer to receive a ParameterCollection object.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetAddSubcollectionToParameterCollection(
    dynetParameterCollection_t *pc, const char *name,
    dynetParameterCollection_t **newobj);

/**
 * Gets the total number of tunable parameters in the ParameterCollection.
 * @param pc Pointer of a handler.
 * @param retval Pointer to receive the total number of tunable parameters.
 * @return Status code.
 */
DYNET_C_API DYNET_C_STATUS dynetGetParameterCollectionParameterCount(
    const dynetParameterCollection_t *pc, size_t *retval);

#endif  // DYNET_C_MODEL_H_