// The C Plus Plus headers.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <ctype.h>
#include <stdarg.h>

// The other further headers.
#include "Header.h"
#include "amxxmodule.h"
#include "sqlite3.h"

// The definitions.
#define MAXIMUM_CHARACTERS_FOR_STRING	4096U
#define MAXIMUM_CHARACTERS_FOR_COLUMN	128U
#define MAXIMUM_ROWS_TO_SELECT			2048U
#define MAXIMUM_COLUMNS_TO_HAVE			64U

// The Database_Row class. Each row will contain 64 columns as long as 128 maximum characters.
class Database_Row
{
public:
	char Column[MAXIMUM_COLUMNS_TO_HAVE][MAXIMUM_CHARACTERS_FOR_COLUMN];
};

// The data used into the extension.
Database_Row g_Row[MAXIMUM_ROWS_TO_SELECT];

sqlite3 * g_Handle = NULL;

char g_String[MAXIMUM_CHARACTERS_FOR_STRING];

int g_Rows = 0U;
int g_Iterator = 0U;
int g_Length = 0U;

// The SQLite handlers.
int SQLite_SelectQueryHandler(void *, int Count, char ** Data, char **)
{
	if (g_Rows < MAXIMUM_ROWS_TO_SELECT)
	{
		for (g_Iterator = 0; g_Iterator < Count && g_Iterator < MAXIMUM_COLUMNS_TO_HAVE; g_Iterator++)
		{
			_snprintf(g_Row[g_Rows].Column[g_Iterator], MAXIMUM_CHARACTERS_FOR_COLUMN, "%s", \
				Data[g_Iterator] ? Data[g_Iterator] : "NULL");
		}
	}

	// Let this one to increment everytime. It will be usefull for getting the rows count from any table.
	g_Rows++;

	return 0U;
}

int SQLite_UpdateQueryHandler(void *, int, char **, char **)
{
	// Do nothing.
	return 0U;
}

// The AMX Mod X functions.
static cell AMX_NATIVE_CALL Query(AMX * Handle, cell * Parameters)
{
	g_Rows = 0U;

	sqlite3_exec(g_Handle, MF_GetAmxString(Handle, Parameters[1U], 0U, 0U), Parameters[2U] ? \
		SQLite_SelectQueryHandler : SQLite_UpdateQueryHandler, NULL, NULL);

	return g_Rows;
}

static cell AMX_NATIVE_CALL Get(AMX * Handle, cell * Parameters)
{
	// If the coder will fail, this won't log any error. Will just set the buffer as "NULL" and will return zero.
	if (Parameters[1U] >= 0U && Parameters[1U] < MAXIMUM_ROWS_TO_SELECT && Parameters[2U] >= 0U && \
		Parameters[2U] < MAXIMUM_COLUMNS_TO_HAVE)
	{
		MF_SetAmxString(Handle, Parameters[3U], g_Row[Parameters[1U]].Column[Parameters[2U]], Parameters[4U]);

		return (cell)atoi(g_Row[Parameters[1U]].Column[Parameters[2U]]);
	}

	MF_SetAmxString(Handle, Parameters[3U], "NULL", Parameters[4U]);

	return 0U;
}

static cell AMX_NATIVE_CALL Safe(AMX * Handle, cell * Parameters)
{
	// Run into an error whether coder wants to replace a bad character with another bad character.
	if (Parameters[2] == '\'' || Parameters[2] == '"' || Parameters[2] == '\\' || Parameters[2] == '`')
	{
		MF_LogError(Handle, AMX_ERR_NATIVE, \
			"Unable to replace a bad character with another bad character. Bad characters are \\, ', \" and `.");

		return 0U;
	}

	g_Length = _snprintf(g_String, MAXIMUM_CHARACTERS_FOR_STRING, "%s", MF_GetAmxString(Handle, Parameters[1U], 0U, 0U));

	// Check for each character.
	for (g_Iterator = 0; g_Iterator < g_Length; g_Iterator++)
	{
		if (g_String[g_Iterator] == '\'' || g_String[g_Iterator] == '"' || g_String[g_Iterator] == '\\' \
			|| g_String[g_Iterator] == '`')
		{
			// Replace bad character with the given one.
			g_String[g_Iterator] = Parameters[2U];
		}
	}

	MF_SetAmxString(Handle, Parameters[1U], g_String, g_Length);

	return 1U;
}

// Functions bundle.
const AMX_NATIVE_INFO g_Functions[] =
{
	{ "Database_Query", Query },
	{ "Database_Get", Get },
	{ "Database_Safe", Safe },

	{ NULL, NULL }
};

// AMX Mod X forwards.
void OnAmxxAttach(void)
{
	MF_AddNatives(g_Functions);

	sqlite3_open("Database.SQ3", &g_Handle);
}

void OnAmxxDetach(void)
{
	sqlite3_close(g_Handle);
}