/**
 * @file m_flashrom.c
 * @brief Save game check and error handling functions.
 *
 * This file contains functions related to save game checks, error handling,
 * and related utility functions. The functions are responsible for verifying
 * save data integrity, managing error information, and displaying save data
 * check results and error information.
 *
 * Global Functions:
 *  - mFRm_set_msg_idx()         : Set the message index.
 *  - mFRm_get_msg_idx()         : Get the message index.
 *  - mFRm_ReturnCheckSum()      : Calculate the checksum of the given data.
 *  - mFRm_GetFlatCheckSum()     : Calculate the flat checksum for save data.
 *  - mFRm_CheckSaveData_ID()    : Check if the save data ID matches the expected ID.
 *  - mFRm_CheckSaveData_common(): Check the save data for various conditions.
 *  - mFRm_CheckSaveData()       : Perform a save data check.
 *  - mFRm_ClearSaveCheckData()  : Clear the save check data structure.
 *  - mFRm_SetSaveCheckData()    : Set the save check data structure.
 *  - mFRm_PrintSavedDebug()     : Print a debug indicator if saved debug data is found.
 *  - mFRm_clear_err_info()      : Clear the error information array.
 *  - mFRm_save_data_check()     : Perform a series of save data checks and store errors.
 *  - mFRm_display_errInfo()     : Display error information on the screen.
 *
 * File-local Functions:
 *  - mFRm_get_free_errInfo()    : Find a free slot in the error information array.
 *  - mFRm_set_errInfo()         : Set error information in the error information array.
 *  - mFRm_get_errInfoNum()      : Get the number of errors in the error information array.
 */

/* TODO: finish & include sChk_ZZZ files each programmer wrote */
/* TODO: A few removed functions need to be matched on N64 and included for proper .rodata layout */

#include "m_flashrom.h"

#include "m_common_data.h"
#include "m_time.h"
#include "m_land.h"
#include "zurumode.h"

static int l_mfrm_msg_idx;
static int l_mfrm_now_color;
static mFRm_err_info_c l_mfrm_err_info[mFRm_ERROR_INFO_NUM];
static int l_mfrm_err_debug[] = {0, 0, 0, 0, 0, 0};

/* Predeclaration for save check functions */
static int sChk_check_save_data();
static int sChk_check_save_gen();
static int sChk_CheckSaveData_MYK();
static int sChk_CheckSaveData_NSW();
static int sChk_check_save_take();
static int sChk_CheckSaveData_YSD();
static int sChk_CheckSaveData_komatu();

/**
 * @brief Set the current message index value.
 * 
 * This function sets the global message index value to the provided input.
 * 
 * @param idx The message index value to be set.
 */
extern void mFRm_set_msg_idx(int idx) {
  l_mfrm_msg_idx = idx;
}

/**
 * @brief Get the current message index value.
 * 
 * This function returns the global message index value.
 * 
 * @return int The current message index value.
 */
extern int mFRm_get_msg_idx() {
  return l_mfrm_msg_idx;
}

/**
 * @brief Calculate the checksum of the given data.
 * 
 * This function calculates the checksum of the provided data by adding
 * all the 16-bit data elements together.
 * 
 * @param data A pointer to the data buffer.
 * @param size The size of the data buffer in bytes.
 * @return u16 The calculated checksum.
 */
extern u16 mFRm_ReturnCheckSum(u16* data, int size) {
  u16 checksum = 0;

  // Check if the size is even
  if ((size & 1) == 0) {
    // Calculate the checksum by adding all 16-bit data elements
    while (size != 0) {
      checksum += *data;
      data++;
      size -= sizeof(u16);
    }
  }

  return checksum;
}

/**
 * @brief Calculate the flat checksum of the given data.
 * 
 * This function calculates the flat checksum of the provided data by
 * subtracting the current checksum from the calculated checksum and
 * then performing a bitwise complement and incrementing by 1.
 * 
 * @param data A pointer to the data buffer.
 * @param size The size of the data buffer in bytes.
 * @param now_checksum The current checksum of the data buffer.
 * @return u16 The calculated flat checksum.
 */
extern u16 mFRm_GetFlatCheckSum(u16* data, int size, u16 now_checksum) {
  // Calculate the checksum
  u16 checksum = mFRm_ReturnCheckSum(data, size) - now_checksum;

  // Perform bitwise complement and increment by 1
  return (u16)(((~checksum & 0xFFFF) + 1) & 0xFFFF);
}

/**
 * @brief Check if the save data ID is valid.
 * 
 * This function checks if the provided save_check structure contains a valid
 * save data ID.
 * 
 * @param save_check A pointer to the mFRm_chk_t structure containing the save data ID.
 * @return int Returns TRUE if the save data ID is valid, otherwise FALSE.
 */
extern int mFRm_CheckSaveData_ID(mFRm_chk_t* save_check) {
  int ret = FALSE;
  
  // Check if the save data ID is valid
  if ((save_check->code == mFRm_SAVE_ID)) {
    ret = TRUE;
  }
  
  return ret;
}

/**
 * @brief Check if the save data is valid.
 * 
 * This function checks if the provided save_check structure contains valid save data,
 * comparing the land ID with the provided land_id parameter.
 * 
 * @param save_check A pointer to the mFRm_chk_t structure containing the save data.
 * @param land_id The land ID to check against the save data.
 * @return int Returns TRUE if the save data is valid, otherwise FALSE.
 */
extern int mFRm_CheckSaveData_common(mFRm_chk_t* save_check, u16 land_id) {
  int ret = FALSE;

  // Check if the save data ID is valid and land IDs match
  if (mFRm_CheckSaveData_ID(save_check) != 0 &&
      mLd_CHECK_LAND_ID(save_check->land_id) &&
      save_check->land_id == land_id) {
    ret = TRUE;
  }

  return ret;
}

/**
 * @brief Check if the current save data is valid.
 * 
 * This function checks if the current save data is valid using mFRm_CheckSaveData_common.
 * 
 * @return int Returns TRUE if the save data is valid, otherwise FALSE.
 */
extern int mFRm_CheckSaveData() {
  return mFRm_CheckSaveData_common(Save_GetPointer(save_check), Save_Get(land_info.id));
}

/**
 * @brief Clear the save check data.
 * 
 * This function clears the provided save_check structure by setting its fields to their
 * default values.
 * 
 * @param save_check A pointer to the mFRm_chk_t structure to be cleared.
 */
extern void mFRm_ClearSaveCheckData(mFRm_chk_t* save_check) {
  // Set the save check data fields to their default values
  save_check->code = -1;
  save_check->land_id = 0xFFFF;
  bcopy((lbRTC_time_c*)&mTM_rtcTime_clear_code, &save_check->time, sizeof(lbRTC_time_c));
  save_check->checksum = 0;
}

/**
 * @brief Set the save check data.
 * 
 * This function sets the save check data fields based on the current save data
 * and real-time clock values.
 * 
 * @param save_check A pointer to the mFRm_chk_t structure to be set.
 */
extern void mFRm_SetSaveCheckData(mFRm_chk_t* save_check) {
  u16 land_id = Save_Get(land_info.id);

  // Set the save check data fields
  save_check->code = mFRm_SAVE_ID;
  save_check->land_id = land_id;
  lbRTC_TimeCopy(&save_check->time, &common_data.time.rtc_time);
}

/**
 * @brief Print the saved debug information.
 * 
 * This function prints an 'X' to the screen if the saved debug information is available.
 * 
 * @param gfxprint A pointer to the gfxprint_t structure for screen printing.
 */
extern void mFRm_PrintSavedDebug(gfxprint_t* gfxprint) {
  // Check if the saved debug information is available
  if (Save_Get(saved_rom_debug) == TRUE) {
    // Set the print color and location
    gfxprint_color(gfxprint, 50, 250, 100, 255);
    gfxprint_locate8x8(gfxprint, 29, 3);
    // Print an 'X' to the screen
    gfxprint_printf(gfxprint, "X");
  }
}

/**
 * @brief Clear the error information.
 * 
 * This function clears the error information by setting all error numbers
 * to mFRm_NO_ERROR_NO.
 */
extern void mFRm_clear_err_info() {
  int i;
  // Zero out the error information array
  bzero(l_mfrm_err_info, sizeof(mFRm_err_info_c) * mFRm_ERROR_INFO_NUM);

  // Set all error numbers to mFRm_NO_ERROR_NO
  for (i = 0; i < mFRm_ERROR_INFO_NUM; i++) {
    l_mfrm_err_info[i].err_no = mFRm_NO_ERROR_NO;
  }
}

/**
 * @brief Get a free error information slot.
 * 
 * This function returns a pointer to the first available error information slot.
 * 
 * @param err_info A pointer to the error information array.
 * @param count The number of error information slots.
 * @return mFRm_err_info_c* A pointer to the first available error information slot or NULL if none are available.
 */
static mFRm_err_info_c* mFRm_get_free_errInfo(mFRm_err_info_c* err_info, int count) {
  mFRm_err_info_c* ret = NULL;

  // Iterate through the error information slots
  while (count != 0) {
    // Check if the current slot is available
    if (err_info->err_no == mFRm_NO_ERROR_NO) {
      ret = err_info;
      break;
    }
    err_info++;
    count--;
  }
  return ret;
}

/**
 * @brief Set the error information for a specific process.
 * 
 * This function sets the error information for the specified process index and error number.
 * 
 * @param err_info A pointer to the error information array.
 * @param proc_idx The process index for which the error occurred.
 * @param err_no The error number to be set.
 */
static void mFRm_set_errInfo(mFRm_err_info_c* err_info, int proc_idx, int err_no) {
  // Get a free error information slot
  mFRm_err_info_c* free = mFRm_get_free_errInfo(err_info, mFRm_ERROR_INFO_NUM);

  // Set the error information if a free slot is available
  if (free != NULL) {
    free->err_no = err_no;
    free->proc_idx = proc_idx;
  }
}

/**
 * @brief Get the number of error information slots with errors.
 * 
 * This function returns the number of error information slots with error numbers
 * different from mFRm_NO_ERROR_NO.
 * 
 * @param err_info A pointer to the error information array.
 * @param count The number of error information slots.
 * @return int The number of error information slots with errors.
 */
static int mFRm_get_errInfoNum(mFRm_err_info_c* err_info, int count) {
  int ret = 0;

  // Loop through the error information slots
  while (count != 0) {
    // Increment the count if the error number is not mFRm_NO_ERROR_NO
    if (err_info->err_no != mFRm_NO_ERROR_NO) {
      ret++;
    }
    err_info++;
    count--;
  }
  return ret;
}

/**
 * @brief Perform save data checks.
 * 
 * This function performs save data checks for different procedures and
 * increments the color index upon each check.
 */
extern void mFRm_save_data_check() {
  // Define save data check procedures
  static save_check_proc* proc[] = {
    &sChk_check_save_data,     &sChk_check_save_gen,  &sChk_CheckSaveData_MYK,
    &sChk_CheckSaveData_NSW,   &sChk_check_save_take, &sChk_CheckSaveData_YSD,
    &sChk_CheckSaveData_komatu
  };

  int i = 0;
  mFRm_err_info_c* err_info = l_mfrm_err_info;
  l_mfrm_now_color = 0;

  // If zurumode_flag is greater or equal to 2 and scene_no is 7, perform save data checks
  if ((zurumode_flag >= 2) && (Save_Get(scene_no) == 7)) {
    // If there are no errors, perform the save data checks
    if (mFRm_get_errInfoNum(err_info, mFRm_ERROR_INFO_NUM) == 0) {
      while (i < 7) {
        (*proc[i])();
        l_mfrm_now_color++;
        i++;
      }
    }
  }
}

/* Color table for displaying error information */
static u32 l_mfrm_color_table[7][3] = {
  {  0,   0,   0}, /* Black */
  {255,   0,   0}, /* Red */
  {255, 255, 255}, /* White */
  {  0, 190,   0}, /* Green */
  {100, 100, 100}, /* Gray */
  {  0,   0, 255}, /* Blue */
  {255,   0, 255}  /* Magenta */
};

/* This needs pool_data on */
#pragma pool_data on
/**
 * @brief Display error information on the screen.
 * 
 * This function displays the error information on the screen if there are
 * any errors and if the zurumode_flag is greater than or equal to 2.
 * 
 * @param gfxprint A pointer to the gfxprint_t structure for screen printing.
 */
extern void mFRm_display_errInfo(gfxprint_t* gfxprint) {
  mFRm_err_info_c* err_info = l_mfrm_err_info;
  int i;

  // If zurumode_flag is greater or equal to 2 and scene_no is 7, display
  // error information
  if ((zurumode_flag >= 2) && (Save_Get(scene_no) == 7)) {
    gfxprint_locate8x8(gfxprint, 37, 17);
    gfxprint_color(gfxprint, 255, 255, 255, 255);
    gfxprint_printf(gfxprint, "-");

    // If there are errors, display them on the screen
    if (mFRm_get_errInfoNum(err_info, mFRm_ERROR_INFO_NUM) > 0) {
      for (i = 0; i < 10; i++) {
        gfxprint_locate8x8(gfxprint, 30, i + 18);

        // Break the loop if no error is found
        if (err_info->err_no == mFRm_NO_ERROR_NO) {
          break;
        }

        // Set the color for displaying the error information
        gfxprint_color(
          gfxprint,
          l_mfrm_color_table[err_info->err_no][0],
          l_mfrm_color_table[err_info->err_no][1],
          l_mfrm_color_table[err_info->err_no][2],
          255
        );

        // Display the error information
        gfxprint_printf(
          gfxprint,
          "x%dx %d",
          err_info->err_no,
          err_info->proc_idx
        );
        err_info++;
      }
    }
  }
}
#pragma pool_data reset