/*
 * Copyright (c) 2017 Cisco and/or its affiliates.
 * 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.
 */

/**
 * @file parc_Varint.h
 * @ingroup datastructures
 * @brief A Variable Length Integer.
 *
 * A variable length integer.
 *
 *
 * Example:
 * @code
 * <#example#>
 * @endcode
 */
#ifndef libparc_parc_VarInt_h
#define libparc_parc_VarInt_h

#include <stdint.h>

#include <parc/algol/parc_Buffer.h>

/**
 * A variable length integer value.
 * <em>
 * This particular implementation is limited to a 64 bit value.
 * </em>
 */
struct parc_varint;
typedef struct parc_varint PARCVarint;


#define PARC_VARINT_INIT { 0 }

/**
 * Create a new instance of `PARCVarint`
 *
 * @return A `PARCVarint` pointer, which must be deallocated via {@link parcVarint_Destroy()}.
 *
 * Example:
 * @code
 * <#example#>
 * @endcode
 */
PARCVarint *parcVarint_Create(void);

/**
 * Decode an instance of {@link PARCBuffer} of length @p length into a new instance of `PARCVarInt`
 *
 * @param [in] buffer A pointer to a `PARCBuffer`.
 * @param [in] length The number of bytes to decode.
 * @return A `PARCVarint` pointer, which must be deallocated via {@link parcVarint_Destroy()}.
 *
 * Example:
 * @code
 * {
 *     <#example#>
 * }
 * @endcode */
PARCVarint *parcVarint_DecodeBuffer(PARCBuffer *buffer, size_t length);

/**
 * Decode an instance of {@link PARCBuffer} of length @p length into a new instance of `PARCVarInt`
 *
 * @param [in] buffer A pointer to a `PARCBuffer`.
 * @param [in] length The number of bytes to decode.
 * @return A `PARCVarint` pointer, which must be deallocated via {@link parcVarint_Destroy()}.
 *
 * Example:
 * @code
 * <#example#>
 * @endcode
 */
PARCVarint *parcVarint_DecodeElasticByteBuffer(const PARCBuffer *buffer, size_t length);

/**
 * Create a new `PARCVarint` from bytes in a {@link PARCBuffer}.
 *
 * @param [in] buffer A pointer to a `PARCBuffer`.
 * @return A `PARCVarint` pointer, which must be deallocated via {@link parcVarint_Destroy()}.
 *
 * Example:
 * @code
 * <#example#>
 * @endcode
 */
PARCVarint *parcVarint_FromElasticByteBuffer(const PARCBuffer *buffer);

/**
 * Create a `PARCVarint` with the value decoded from the given {@link PARCBuffer}
 * containing a UTF-8 string encoded number.
 *
 * @param [in] buffer A pointer to a `PARCBuffer` containing a UTF-8 string encoded number.
 * @return A `PARCVarint` pointer, which must be deallocated via {@link parcVarint_Destroy()}.
 *
 * Example:
 * @code
 * <#example#>
 * @endcode
 */
PARCVarint *parcVarint_FromUTF8Buffer(PARCBuffer *buffer);

/**
 * Create a `PARCVarint` with the value decoded from the given {@link PARCBuffer}
 * containing a UTF-8 string encoded number.
 *
 * @param [in] buffer A pointer to a `PARCBuffer` containing a UTF-8 string encoded number.
 * @return A `PARCVarint` pointer, which must be deallocated via {@link parcVarint_Destroy()}.
 *
 */
PARCVarint *parcVarint_FromUTF8ByteBuffer(const PARCBuffer *buffer);


extern PARCVarint *parcVarint_FromUint8(uint8_t uint);

extern PARCVarint *parcVarint_FromUint32(uint32_t uint);

extern PARCVarint *parcVarint_FromUint64(uint64_t uint);

extern PARCVarint *parcVarint_ShiftLeft(PARCVarint *varint, int bits);

extern PARCVarint *parcVarint_ShiftRight(PARCVarint *varint, int bits);

extern PARCVarint *parcVarint_And(PARCVarint *varint, PARCVarint *operand);

extern PARCVarint *parcVarint_AndUint8(PARCVarint *varint, uint8_t operand);

extern PARCVarint *parcVarint_AndUint16(PARCVarint *varint, uint16_t operand);

extern PARCVarint *parcVarint_AndUint32(PARCVarint *varint, uint32_t operand);

extern PARCVarint *parcVarint_AndUint64(PARCVarint *varint, uint64_t operand);

extern PARCVarint *parcVarint_Or(PARCVarint *varint, PARCVarint *operand);

extern PARCVarint *parcVarint_OrUint8(PARCVarint *varint, uint8_t operand);

extern PARCVarint *parcVarint_OrUint16(PARCVarint *varint, uint16_t operand);

extern PARCVarint *parcVarint_OrUint32(PARCVarint *varint, uint32_t operand);

extern PARCVarint *parcVarint_OrUint64(PARCVarint *varint, uint64_t operand);

/**
 * Determine if two `PARCVarint` instances are equal.
 *
 * The following equivalence relations on non-null `PARCVarint` instances are maintained:
 *
 *  * It is reflexive: for any non-null reference value x, `PARCVarint_Equals(x, x)`
 *      must return true.
 *
 *  * It is symmetric: for any non-null reference values x and y,
 *    `parcVarint_Equals(x, y)` must return true if and only if
 *        `parcVarint_Equals(y, x)` returns true.
 *
 *  * It is transitive: for any non-null reference values x, y, and z, if
 *        `parcVarint_Equals(x, y)` returns true and
 *        `parcVarint_Equals(y, z)` returns true,
 *        then  `parcVarint_Equals(x, z)` must return true.
 *
 *  * It is consistent: for any non-null reference values x and y, multiple
 *      invocations of `parcVarint_Equals(x, y)` consistently return true or
 *      consistently return false.
 *
 *  * For any non-null reference value x, `parcVarint_Equals(x, NULL)` must
 *      return false.
 *
 * @param varint A pointer to a `PARCVarint` instance.
 * @param operand A pointer to a `PARCVarint` instance.
 * @return true if the two `PARCVarint` instances are equal.
 *
 * Example:
 * @code
 * {
 *    PARCVarint *a = parcVarint_Create();
 *    PARCVarint *b = parcVarint_Create();
 *
 *    if (parcVarint_Equals(a, b)) {
 *        // true
 *    } else {
 *        // false
 *    }
 * }
 * @endcode
 */

extern int parcVarint_Equals(PARCVarint *varint, PARCVarint *operand);

/**
 * Determine if a `PARCVarint` instance is equal to a 64bit integer.
 *
 * The following equivalence relations on non-null `PARCVarint` instances are maintained:
 *
 *  * It is reflexive: for any non-null reference value x, `PARCVarint_Uint64Equals(x, x)`
 *      must return true.
 *
 *  * It is NOT symmetric: for any non-null reference values x and y,
 *    `parcVarint_Uint64Equals(x, y)` may not return true even if
 *        `parcVarint_Uint64Equals(y, x)` returns true.
 *
 *  * It is transitive: for any non-null reference values x, y, and z, if
 *        `parcVarint_Uint64Equals(x, y)` returns true and
 *        `parcVarint_Uint64Equals(y, z)` returns true,
 *        then  `parcVarint_Uint64Equals(x, z)` must return true.
 *
 *  * It is consistent: for any non-null reference values x and y, multiple
 *      invocations of `parcVarint_Uint64Equals(x, y)` consistently return true or
 *      consistently return false.
 *
 *  * For any non-null reference value x, `parcVarint_Uint64Equals(x, NULL)` must
 *      return false.
 *
 * @param [in] varint A pointer to a `PARCVarint` instance.
 * @param [in] value A pointer to a `uint64_t` instance.
 * @return true if the two instances are equal.
 *
 * Example:
 * @code
 * {
 *    PARCVarint *a = parcVarint_Create();
 *    uint64_t *b = 10; // some integer value
 *
 *    if (parcVarint_Uint64Equals(a, b)) {
 *        // true
 *    } else {
 *        // false
 *    }
 * }
 * @endcode
 */
extern int parcVarint_EqualsUint64(PARCVarint *varint, uint64_t value);

/**
 * Determine if a `PARCVarint` instance is equal to a 32 bit integer.
 *
 * The following equivalence relations on non-null `PARCVarint` instances are maintained:
 *
 *  * It is reflexive: for any non-null reference value x, `PARCVarint_Uint32Equals(x, x)`
 *      must return true.
 *
 *  * It is NOT symmetric: for any non-null reference values x and y,
 *    `parcVarint_Uint32Equals(x, y)` may not return true even if
 *        `parcVarint_Uint32Equals(y, x)` returns true.
 *
 *  * It is transitive: for any non-null reference values x, y, and z, if
 *        `parcVarint_Uint32Equals(x, y)` returns true and
 *        `parcVarint_Uint32Equals(y, z)` returns true,
 *        then  `parcVarint_Uint32Equals(x, z)` must return true.
 *
 *  * It is consistent: for any non-null reference values x and y, multiple
 *      invocations of `parcVarint_Uint32Equals(x, y)` consistently return true or
 *      consistently return false.
 *
 *  * For any non-null reference value x, `parcVarint_Uint32Equals(x, NULL)` must
 *      return false.
 *
 * @param [in] varint A pointer to a `PARCVarint` instance.
 * @param [in] value A pointer to a `uint32_t` instance.
 * @return true if the two instances are equal.
 *
 * Example:
 * @code
 * {
 *    PARCVarint *a = parcVarint_Create();
 *    uint32_t *b = 10; // some integer value
 *
 *    if (parcVarint_Uint32Equals(a, b)) {
 *        // true
 *    } else {
 *        // false
 *    }
 * }
 * @endcode
 */
extern int parcVarint_EqualsUint32(PARCVarint *varint, uint32_t value);

/**
 * Determine if a `PARCVarint` instance is equal to a 16 bit integer.
 *
 * The following equivalence relations on non-null `PARCVarint` instances are maintained:
 *
 *  * It is reflexive: for any non-null reference value x, `PARCVarint_Uint16Equals(x, x)`
 *      must return true.
 *
 *  * It is NOT symmetric: for any non-null reference values x and y,
 *    `parcVarint_Uint16Equals(x, y)` may not return true even if
 *        `parcVarint_Uint16Equals(y, x)` returns true.
 *
 *  * It is transitive: for any non-null reference values x, y, and z, if
 *        `parcVarint_Uint16Equals(x, y)` returns true and
 *        `parcVarint_Uint16Equals(y, z)` returns true,
 *        then  `parcVarint_Uint16Equals(x, z)` must return true.
 *
 *  * It is consistent: for any non-null reference values x and y, multiple
 *      invocations of `parcVarint_Uint16Equals(x, y)` consistently return true or
 *      consistently return false.
 *
 *  * For any non-null reference value x, `parcVarint_Uint16Equals(x, NULL)` must
 *      return false.
 *
 * @param [in] varint A pointer to a `PARCVarint` instance.
 * @param [in] value A pointer to a `uint16_t` instance.
 * @return true if the two instances are equal.
 *
 * Example:
 * @code
 * {
 *    PARCVarint *a = parcVarint_Create();
 *    uint16_t *b = 10; // some integer value
 *
 *    if (parcVarint_Uint16Equals(a, b)) {
 *        // true
 *    } else {
 *        // false
 *    }
 * }
 * @endcode
 */
extern int parcVarint_EqualsUint16(PARCVarint *varint, uint16_t value);

/**
 * Determine if a `PARCVarint` instance is equal to an 8 bit integer.
 *
 * The following equivalence relations on non-null `PARCVarint` instances are maintained:
 *
 *  * It is reflexive: for any non-null reference value x, `PARCVarint_Uint8Equals(x, x)`
 *      must return true.
 *
 *  * It is NOT symmetric: for any non-null reference values x and y,
 *    `parcVarint_Uint8Equals(x, y)` may not return true even if
 *        `parcVarint_Uint8Equals(y, x)` returns true.
 *
 *  * It is transitive: for any non-null reference values x, y, and z, if
 *        `parcVarint_Uint8Equals(x, y)` returns true and
 *        `parcVarint_Uint8Equals(y, z)` returns true,
 *        then  `parcVarint_Uint8Equals(x, z)` must return true.
 *
 *  * It is consistent: for any non-null reference values x and y, multiple
 *      invocations of `parcVarint_Uint8Equals(x, y)` consistently return true or
 *      consistently return false.
 *
 *  * For any non-null reference value x, `parcVarint_Uint8Equals(x, NULL)` must
 *      return false.
 *
 * @param [in] varint A pointer to a `PARCVarint` instance.
 * @param [in] value A pointer to a `uint8_t` instance.
 * @return true if the two instances are equal.
 *
 * Example:
 * @code
 * {
 *    PARCVarint *a = parcVarint_Create();
 *    uint8_t *b = 10; // some integer value
 *
 *    if (parcVarint_Uint8Equals(a, b)) {
 *        // true
 *    } else {
 *        // false
 *    }
 * }
 * @endcode
 */
extern int parcVarint_EqualsUint8(PARCVarint *varint, uint8_t value);

extern void parcVarint_Destroy(PARCVarint **varintP);

extern char *parcVarint_ToString(char **string, PARCVarint *varint);

extern uint8_t parcVarint_AsUint8(const PARCVarint *varint);

extern uint16_t parcVarint_AsUint16(const PARCVarint *varint);

extern uint32_t parcVarint_AsUint32(const PARCVarint *varint);

/**
 * Produce the 16 low-order bits of this `PARCVarint` as a `uint8_t`.
 *
 * @param [in] varint The inpu instance of `PARCVarint`
 * @return The 16 low-order bits as a `uint8_t`
 *
 * Example:
 * @code
 * <#example#>
 * @endcode
 */
uint64_t parcVarint_AsUint64(const PARCVarint *varint);

/**
 * Return the value of the given `PARCVarint` cast as a `size_t`
 *
 * @param [in] varint The `PARCVarint` to cast as a `size_t`
 *
 * @return The given `PARCVarint` cast as a `size_t`
 *
 * Example:
 * @code
 * <#example#>
 * @endcode
 */
size_t parcVarint_AsSize(const PARCVarint *varint);

/**
 * Set the value of the given `PARCVarint` to the given value.
 *
 * @param [in,out] varint The `PARCVarint` to be modified
 * @param [in] newValue The new value for the `PARCVarint`
 * @return The modified `PARCVarint`.
 */
PARCVarint *parcVarint_Set(PARCVarint *varint, uint64_t newValue);

/**
 * Multiply the `PARCVarint`
 *
 * @param [in,out] varint The `PARCVarint` to be multiplied by the @p multiplicand
 * @param [in] multiplicand The multiplicand to multiply by
 * @return The `PARCVarint` used as input.
 *
 * Example:
 * @code
 * <#example#>
 * @endcode
 */
PARCVarint *parcVarint_Multiply(PARCVarint *varint, int multiplicand);

/**
 * Divide the `PARCVarint` by a divisor
 *
 * @param [in,out] varint The `PARCVarint` to be divided by the @p divisor
 * @param [in] divisor The divisor to use
 * @return The `PARCVarint` used as input.
 *
 * Example:
 * @code
 * <#example#>
 * @endcode
 */
PARCVarint *parcVarint_Divide(PARCVarint *varint, int divisor);
/**
 * Multiply the `PARCVarint`
 *
 * @param [in,out] varint The `PARCVarint` to which the @p addend should be added
 * @param [in] addend The number to add to the `PARCVarint`
 * @return The `PARCVarint` used as input.
 *
 * Example:
 * @code
 * <#example#>
 * @endcode
 */
PARCVarint *parcVarint_Add(PARCVarint *varint, int addend);

/**
 * Subtract the @p subtrahend from the `PARCVarint`.
 *
 * @param [in,out] varint The `PARCVarint` from which to subtract the @p subtrahend
 * @param [in] subtrahend The number to subtract from the  `PARCVarint`
 * @return The `PARCVarint` used as input.
 *
 * Example:
 * @code
 * <#example#>
 * @endcode
 */
PARCVarint *parcVarint_Subtract(PARCVarint *varint, int subtrahend);
#endif // libparc_parc_VarInt_h