#pragma once

/// \file errors.h
/// \author Folling <mail@folling.io>

#include <ikarus/macros.h>

/// \addtogroup errors Errors
/// \brief Error handling within libikarus
/// \details Functions in Ikarus may fail. To report the type of failure all functions have an out parameter for the error.
/// Upon erring the function will store relevant information about the error in
/// the out parameter. If the out parameter is null nothing will be stored. This
/// is not recommended as it essentially ignores errors. For the sake of
/// simplicity we have avoided mechanisms that "force" clients to handle errors.
/// @{

IKARUS_BEGIN_HEADER

/// \brief Delineates what caused an error.
/// \remark Note that this doesn't show responsibility. An error with source "SubSystem" could still be the
/// fault of libikarus, it just indicates where the error occurred.
enum IkarusErrorInfo {
	/// \brief No error occurred.
	IkarusErrorInfo_None = 0x0,
	/// \brief The client misused the API.
	/// Example: Accessing a resource that does not exist.
	IkarusErrorInfo_Client_Misuse = 0x01000001,
	/// \brief The client provided a null value for a parameter that must not be null.
	/// Example: Passing null for `ikarus_project_get_name`
	IkarusErrorInfo_Client_InvalidNull = 0x01000002,
	/// \brief The client provided a non-existent resource.
	/// Example: Passing an entity to a function after it has been deleted.
	IkarusErrorInfo_Client_NonExistent = 0x01000003,
	/// \brief The client provided a resource which exists but is not linked to the current context.
	/// Example: Passing a property that isn't linked to the current entity.
	IkarusErrorInfo_Client_NotLinked = 0x01000004,
	/// \brief The client provided an index that was out of bounds for some array.
	/// Example: Passing the index 3 for an `IkarusToggleValue` with size 3.
	IkarusErrorInfo_Client_IndexOutOfBounds = 0x01000005,
	/// \brief The client provided a numeric value that was out of bounds
	/// Example: Passing the value 2^32 to an i32 (might be passed as a string).
	IkarusErrorInfo_Client_ValueOutOfBounds = 0x01000006,
	/// \brief The client provided invalid input that doesn't fit in any of the other categories.
	/// Example: Passing an empty/blank string for a string that must be
	/// non-empty/-blank.
	IkarusErrorInfo_Client_InvalidInput = 0x01000007,
	/// \brief The client provided valid data in an invalid format.
	/// Example: Passing a malformed JSON string.
	IkarusErrorInfo_Client_InvalidFormat = 0x01000008,
	/// \brief The client violated a constraint.
	/// \details This error is most likely caused by clients.
	/// Example: A user tries to set the age of a character to a value outside
	/// its specified range.
	IkarusErrorInfo_Client_ConstraintViolated = 0x10000009,

	// 0x02 reserved for dependency errors

	/// \brief A file was not found.
	IkarusErrorInfo_Filesystem_NotFound = 0x03000001,
	/// \brief A file or directory already exists.
	IkarusErrorInfo_Filesystem_AlreadyExists = 0x03000002,
	/// \brief Missing permissions to access a file or directory.
	IkarusErrorInfo_Filesystem_MissingPermissions = 0x03000003,
	/// \brief Insufficient space to perform an operation.
	IkarusErrorInfo_Filesystem_InsufficientSpace = 0x03000004,
	/// \brief A path is invalid.
	IkarusErrorInfo_Filesystem_InvalidPath = 0x03000005,

	/// \brief A database connection failed.
	IkarusErrorInfo_Database_ConnectionFailed = 0x04000001,
	/// \brief A database query failed.
	IkarusErrorInfo_Database_QueryFailed = 0x04000002,
	/// \brief A database migration failed.
	IkarusErrorInfo_Database_MigrationFailed = 0x04000003,
	/// \brief A database is in an invalid state. This indicates a corrupt project.
	/// Example: An entity is linked to a non-existent blueprint.
	IkarusErrorInfo_Database_InvalidState = 0x04000004,

	/// \brief A system call failed.
	IkarusErrorInfo_OS_SystemCallFailed = 0x05000001,
	/// \brief A system call returned an invalid value.
	IkarusErrorInfo_OS_InvalidReturnValue = 0x05000002,
	/// \brief An OOM error occurred.
	IkarusErrorInfo_OS_InsufficientMemory = 0x05000003,

	/// \brief A datapoint within ikarus is invalid for the current state of the system.
	/// \details This differs from IkarusErrorInfo_Database_InvalidState in that the latter implies the database itself holds invalid state,
	/// whereas the former may imply that the state is ephemeral, e.g. data
	/// within a function.
	/// Example: The name of an object is found to be invalid UTF8.
	IkarusErrorInfo_LibIkarus_InvalidState = 0x06000001,
	/// \brief libikarus is unable to perform a certain operation that should succeed.
	IkarusErrorInfo_LibIkarus_CannotPerformOperation = 0x06000002,
	/// \brief libikarus is unable to perform a certain operation within a given timeframe.
	/// Example: A query takes longer than the timeout.
	IkarusErrorInfo_LibIkarus_Timeout = 0x06000003,
};

/// \brief The maximum length of an error message.
#define IKARUS_ERROR_DATA_MAX_MESSAGE_LIMIT 128

/// \brief The data stored for an error
struct IkarusErrorData {
	/// \brief The error type
	enum IkarusErrorInfo info;

	char message[IKARUS_ERROR_DATA_MAX_MESSAGE_LIMIT];
};

/// \brief Gets the name of an error info.
/// \param info The error info to get the name of.
/// \return The name of the error info.
/// \remark The returned pointer is valid for the lifetime of the program and must not be freed.
IKA_API char const * ikarus_error_info_get_name(enum IkarusErrorInfo info);

/// \brief Checks if an error data is a success.
/// \param data The error data to check.
/// \return True if the error data is a success, false otherwise.
IKA_API bool ikarus_error_data_is_success(IkarusErrorData const * data);
/// \brief Checks if an error data is an error.
/// \param data The error data to check.
/// \return True if the error data is an error, false otherwise.
IKA_API bool ikarus_error_data_is_error(IkarusErrorData const * data);

IKARUS_END_HEADER

/// @}