/**
 * Copyright (c) 2025 Dominic Masters
 * 
 * This software is released under the MIT License.
 * https://opensource.org/licenses/MIT
 */

#pragma once
#include "dusk.h"

typedef uint8_t errorcode_t;

typedef struct {
  errorcode_t code;
  char_t *message;
  char_t *lines;
} errorstate_t;

typedef struct {
  errorcode_t code;
  errorstate_t *state;
} errorret_t;

static const errorcode_t ERROR_OK = 0;
static const errorcode_t ERROR_NOT_OK = 1;

#define ERROR_STATE_INIT ((errorstate_t){ ERROR_OK, NULL, NULL })

static const char_t *ERROR_PRINT_FORMAT = "Error (%d): %s\n%s";
static const char_t *ERROR_LINE_FORMAT = "  at %s:%d in function %s\n";
static errorstate_t ERROR_STATE = ERROR_STATE_INIT;

/**
 * Sets the error state with the provided code and message.
 * 
 * @param state The error state to initialize.
 * @param code The error code to set.
 * @param file The file where the error occurred.
 * @param function The function where the error occurred.
 * @param line The line number where the error occurred.
 * @param message The error message.
 * @param args The arguments for the error message.
 * @return The error code.
 */
errorret_t errorThrowImpl(
  errorstate_t *state,
  errorcode_t code,
  const char_t *file,
  const char_t *function,
  const int32_t line,
  const char_t *message,
  ...
);

/**
 * Returns an error state with no error.
 * 
 * @return An error state with code ERROR_OK.
 */
errorret_t errorOkImpl();

/**
 * Chains an error state, allowing for error propagation.
 * 
 * @param retval The return value containing the error state.
 * @param file The file where the error occurred.
 * @param function The function where the error occurred.
 * @param line The line number where the error occurred.
 * @return The error code if an error occurred, otherwise continues execution.
 */
errorret_t errorChainImpl(
  const errorret_t retval,
  const char_t *file,
  const char_t *function,
  const int32_t line
);

/**
 * Catches an error and handles it.
 * 
 * @param retval The return value containing the error state.
 */
void errorCatch(const errorret_t retval);

/**
 * Prints the error state to the console.
 * 
 * @param retval The return value containing the error state.
 * @return Passed retval for chaining.
 */
errorret_t errorPrint(const errorret_t retval);

/**
 * Creates an error with a specific error state.
 * 
 * @param state The error state to set.
 * @param message The format string for the error message.
 * @param ... Additional arguments for the format string.
 * @return The error code.
 */
#define errorCreate(state, message, ... ) \
  errorThrowImpl(\
    (state), ERROR_NOT_OK, __FILE__, __func__, __LINE__, (message), \
    ##__VA_ARGS__ \
  )

/**
 * Throws an error with a specific error state.
 * 
 * @param state The error state to set.
 * @param message The format string for the error message.
 * @param ... Additional arguments for the format string.
 * @return The error code.
 */
#define errorThrowState(state, message, ... ) \
  return errorThrowImpl(\
    (state), ERROR_NOT_OK, __FILE__, __func__, __LINE__, (message), \
    ##__VA_ARGS__ \
  )

/**
 * Throws an error with a formatted message.
 * 
 * @param code The error code to throw.
 * @param message The format string for the error message.
 * @param ... Additional arguments for the format string.
 * @return The error code.
 */
#define errorThrowWithCode(code, message, ... ) \
  return errorThrowImpl(\
    &ERROR_STATE, (code), __FILE__, __func__, __LINE__, (message), \
    __VA_ARGS__ \
  )

/**
 * Throws an error with a default error code of ERROR_NOT_OK.
 * 
 * @param message The format string for the error message.
 * @param ... Additional arguments for the format string.
 * @return The error code.
 */
#define errorThrow(message, ...) \
  return errorThrowImpl(\
    &ERROR_STATE, ERROR_NOT_OK, __FILE__, __func__, __LINE__, (message), \
    ##__VA_ARGS__ \
  )

/**
 * Checks if a child method errored, and if it did, then send it up the chain.
 * @param retval The return value containing the error state.
 * @return The error code if an error occurred, otherwise continues execution.
 */
#define errorChain(retval) { \
  errorret_t errorChainRetval = (retval); \
  if (errorChainRetval.code != ERROR_OK) { \
    return errorChainImpl(errorChainRetval, __FILE__, __func__, __LINE__); \
  } \
}
  

/**
 * Returns without an error.
 */
#define errorOk() \
  return errorOkImpl()

// EOF