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/**
 * @file datatop_helpers.c
 * @brief Contains functions which output data.
 *
 * Contains functions which are used for printing data to output streams.
 * Handles all formatting for data output. Also contains functions which
 * are responsible for data gathering and collection.
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <time.h>
#include <sys/time.h>
#include <string.h>
#include <errno.h>
#include "datatop_interface.h"
#include "datatop_linked_list.h"
#include "datatop_fileops.h"

/**
 * @brief Prints the name and prefix of a datapoint.
 *
 * @param dp Dp whose name and prefix is printed.
 * @param prefix Directory where dp is contained.
 * @param fw File to print the information to.
 * @return FILE_ERROR - Writing to file was unsuccessful.
 * @return FILE_SUCCESS - Writing to file was successful.
 */
static int dtop_format_dp_names(struct dtop_data_point *dp, const char
						*prefix, FILE *fw)
{
	if (dp->prefix) {
		if (fprintf(fw, "\"%s:%s:%s\",", prefix, dp->prefix,
							dp->name) < 0)
			return FILE_ERROR;
	} else {
		if (fprintf(fw, "\"%s::%s\",", prefix, dp->name) < 0)
			return FILE_ERROR;
	}
	return FILE_SUCCESS;
}

/**
 * @brief Prints the value of a datapoint.
 *
 * Checks the type of the value and will print it accordingly.
 *
 * @param dp Pointer to the data_point struct which holds the value that will
 *           be printed.
 * @param fw File to print the information to.
 * @return FILE_ERROR - Writing to file was unsuccessful.
 * @return FILE_SUCCESS - Writing to file was successful.
 */
static int dtop_format_dp_values(struct dtop_data_point *dp, FILE *fw)
{
	switch (dp->type) {
	case DTOP_ULONG:
		if (fprintf(fw, "%"PRIu64, dp->data.d_ulong) < 0)
			return FILE_ERROR;
	break;
	case DTOP_LONG:
		if (fprintf(fw, "%"PRId64, dp->data.d_long) < 0)
			return FILE_ERROR;
	break;
	case DTOP_UINT:
		if (fprintf(fw, "%d", dp->data.d_uint) < 0)
			return FILE_ERROR;
	break;
	case DTOP_INT:
		if (fprintf(fw, "%u", dp->data.d_uint) < 0)
			return FILE_ERROR;
	break;
	case DTOP_UCHAR:
		if (fprintf(fw, "%c,", dp->data.d_uchar) < 0)
			return FILE_ERROR;
		if (fprintf(fw, "(0x%02X)", dp->data.d_uchar) < 0)
			return FILE_ERROR;
	break;
	case DTOP_CHAR:
		if (fprintf(fw, "%c,", dp->data.d_char) < 0)
			return FILE_ERROR;
		if (fprintf(fw, "(%d)", dp->data.d_char) < 0)
			return FILE_ERROR;
	break;
	case DTOP_STR:
		if (fprintf(fw, "\"%s\"", dp->data.d_str) < 0)
			return FILE_ERROR;
	break;
	default:
		if (fprintf(fw, "UNKNOWN_TYPE") < 0)
			return FILE_ERROR;
	break;
	}
	return FILE_SUCCESS;
}

/**
 * @brief Prints the name and prefix of a dp, formatted appropriately.
 *
 * @param dpset data_point_gatherer used to access dp directory.
 * @param dp data_point used to get datapoint prefix if available.
 */
static void dtop_format_text_for_snapshot
	(struct dtop_data_point_gatherer *dpset, struct dtop_data_point dp)
{
	printf("%s:", dpset->prefix);
	if (dp.prefix)
		printf("%s:", dp.prefix);

	printf("%s::", dp.name);
}

/**
 * @brief Prints a datapoint value to a specified csv file.
 *
 * @param dp Datapoint that holds the value to be printed.
 * @param fw File to print to.
 * @return FILE_ERROR - Writing to file was unsuccessful.
 * @return FILE_SUCCESS - Writing to file was successful.
 */
static int dtop_print_dp_csv(struct dtop_data_point *dp, FILE *fw)
{
	if (dtop_format_dp_values(dp, fw) == FILE_ERROR)
		return FILE_ERROR;
	if (fprintf(fw, ",") < 0)
		return FILE_ERROR;
	return FILE_SUCCESS;
}

/**
 * @brief Prints a datapoint value to the terminal.
 *
 * @param dp Holds the value to be printed print.
 * @param prefix Used to print prefix of the data_point.
 */
static void dtop_print_dp(struct dtop_data_point *dp, const char *prefix)
{
	dtop_format_dp_names(dp, prefix, stdout);
	printf(" ");
	dtop_format_dp_values(dp, stdout);
	printf("\n");
}

/**
 * @brief Finds delta(value) of a datapoint.
 *
 * Function accounts for different types that values may be.
 *
 * @param dpset Pointer to a data_point used as another parameter for printing.
 * @param dp Datapoint which contains the value to find the difference of.
 */
static void dtop_handle_dp_type_for_snapshot(
	struct dtop_data_point_gatherer *dpset, struct dtop_data_point dp)
{
	int64_t int64;

	switch (dp.type) {
	case DTOP_ULONG:
	default:
		/* This is less than ideal. Replace with 128-bit ops later */
		int64 = (int64_t)dp.data.d_ulong
			- (int64_t)dp.initial_data.d_ulong;
		if (int64 != 0) {
			dtop_format_text_for_snapshot(dpset, dp);
			printf("%"PRId64"\n", int64);
		}
	break;

	case DTOP_LONG:
		/* This is less than ideal. Replace with 128-bit ops later */
		int64 = (int64_t)dp.data.d_long
			- (int64_t)dp.initial_data.d_long;
		if (int64 != 0) {
			dtop_format_text_for_snapshot(dpset, dp);
			printf("%"PRId64"\n", int64);
		}
	break;

	case DTOP_UINT:
		int64 = (int64_t)dp.data.d_uint
			- (int64_t)dp.initial_data.d_uint;
		if (int64 != 0) {
			dtop_format_text_for_snapshot(dpset, dp);
			printf("%"PRId64"\n", int64);
		}
	break;

	case DTOP_INT:
		int64 = (int64_t)dp.data.d_int
			- (int64_t)dp.initial_data.d_int;
		if (int64 != 0) {
			dtop_format_text_for_snapshot(dpset, dp);
			printf("%"PRId64"\n", int64);
		}
	break;
	}
}

/**
 * @brief Calls the dtop_print_dp_csv function for each data_point a dpg has access to.
 *
 * @param dpg A data_point_gatherer struct that is iterated through for each datapoint.
 * @param fw File to print datapoint values to.
 * @return FILE_ERROR - Writing to file was unsuccessful.
 * @return FILE_SUCCESS - Writing to file was successful.
 */
static int dtop_print_dpg_csv(struct dtop_data_point_gatherer *dpg, FILE *fw)
{
	int i;

	for (i = 0; i < dpg->data_points_len; i++)
		if (dtop_print_dp_csv(&(dpg->data_points[i]), fw) == FILE_ERROR)
			return FILE_ERROR;
	return FILE_SUCCESS;
}

/**
 * @brief Calls the dtop_format_dp_names function for each data_point a dpg has access to.
 *
 * @param dpg A data_point_gatherer struct that is iterated through for each datapoint.
 * @param fw File to printg datapoint names and prefixes to.
 * @return FILE_ERROR - Writing to file was unsuccessful.
 * @return FILE_SUCCESS - Writing to file was successful.
 */
int dtop_print_dpg_names_csv(struct dtop_data_point_gatherer *dpg, FILE *fw)
{
	int i;

	for (i = 0; i < dpg->data_points_len; i++)
		if (dtop_format_dp_names(&(dpg->data_points[i]),
		dpg->prefix, fw) == FILE_ERROR)
			return FILE_ERROR;

	return FILE_SUCCESS;
}

/**
 * @brief Prints all dp values to a specified file.
 *
 * This function is responsible for the printing of all data_point values
 * to a specified file. It will iterate through the linked list which contains
 * all of the dpgs and will print each dp value, being sure to flush the buffer.
 *
 * @param dpg_list Pointer to first node of linked list which contains all dpgs.
 * @param fw File that data prints to.
 * @return FILE_ERROR - Writing to file was unsuccessful.
 * @return FILE_SUCCESS - Writing to file was successful.
 */
int dtop_write_pollingdata_csv(struct dtop_linked_list *dpg_list, FILE *fw)
{
	struct dtop_linked_list *curr_ptr = dpg_list;
	struct dtop_data_point_gatherer *dpset;

	while (curr_ptr) {
		dpset = (struct dtop_data_point_gatherer *) curr_ptr->data;
		if (dtop_print_dpg_csv(dpset, fw) == FILE_ERROR)
			return FILE_ERROR;
		curr_ptr = curr_ptr->next_ptr;
		fflush(fw);
	}

	if (fprintf(fw, "\n") < 0)
		return FILE_ERROR;

	return FILE_SUCCESS;
}

/**
 * @brief Calls the dtop_print_dp function for each data_point a dpg has access to.
 *
 * @param dpg A data_point_gatherer struct that is iterated through for each datapoint.
 */
void dtop_print_dpg(struct dtop_data_point_gatherer *dpg)
{
	int i;
	for (i = 0; i < dpg->data_points_len; i++)
		dtop_print_dp(&(dpg->data_points[i]), dpg->prefix);
}

/**
 * @brief Stores the values for the datapoints and populates the initial value.
 *
 * @param dp A datapoint whose value will be stored.
 * @param str Str used for sscanf function call to find value of dp.
 */
void dtop_store_dp(struct dtop_data_point *dp, const char *str)
{
	switch (dp->type) {
	case DTOP_ULONG:
		sscanf(str, "%"PRIu64, &(dp->data.d_ulong));
		if (dp->initial_data_populated == NOT_POPULATED) {
			dp->initial_data.d_ulong = dp->data.d_ulong;
			dp->initial_data_populated = POPULATED;
		}
	break;
	case DTOP_LONG:
		sscanf(str, "%"PRId64, &(dp->data.d_long));
		if (dp->initial_data_populated == NOT_POPULATED) {
			dp->initial_data.d_long = dp->data.d_long;
			dp->initial_data_populated = POPULATED;
		}
	break;
	case DTOP_UINT:
		sscanf(str, "%u",  &(dp->data.d_uint));
		if (dp->initial_data_populated == NOT_POPULATED) {
			dp->initial_data.d_uint = dp->data.d_uint;
			dp->initial_data_populated = POPULATED;
		}
	break;
	case DTOP_INT:
		sscanf(str, "%d",  &(dp->data.d_int));
		if (dp->initial_data_populated == NOT_POPULATED) {
			dp->initial_data.d_int = dp->data.d_int;
			dp->initial_data_populated = POPULATED;
		}
	break;
	case DTOP_UCHAR:
		sscanf(str, "%c",  &(dp->data.d_uchar));
		if (dp->initial_data_populated == NOT_POPULATED) {
			dp->initial_data.d_uchar = dp->data.d_uchar;
			dp->initial_data_populated = POPULATED;
		}
	break;
	case DTOP_CHAR:
		sscanf(str, "%c",  &(dp->data.d_char));
		if (dp->initial_data_populated == NOT_POPULATED) {
			dp->initial_data.d_char = dp->data.d_char;
			dp->initial_data_populated = POPULATED;
		}
	break;
	case DTOP_STR:
		sscanf(str, "%s",  dp->data.d_str);
		if (dp->initial_data_populated == NOT_POPULATED) {
			memcpy(dp->initial_data.d_str, dp->data.d_str,
			       DTOP_DP_MAX_STR_LEN);
			dp->initial_data_populated = POPULATED;
		}
	break;
	default:
	break;
	}
}

/**
 * @brief Responsible for calculating and printing current time to file.
 *
 * Prints the time since 1970, in Seconds and Milliseconds.
 *
 * @param fw File that time is printed to.
 * @return FILE_ERROR - Writing to file was unsuccessful.
 * @return FILE_SUCCESS - Writing to file was successful.
 */
int dtop_print_time_at_poll(FILE *fw)
{
	struct timeval tv;
	gettimeofday(&tv, NULL);

	if (fprintf(fw, "%10ld", tv.tv_sec) < 0)
		return FILE_ERROR;

	if (fprintf(fw, ".%06ld,", tv.tv_usec) < 0)
		return FILE_ERROR;

	return FILE_SUCCESS;
}

/**
 * @brief Polls all dp values and updates each value.
 *
 * @param dpg_list Pointer to first node of linked list which contains all dpgs.
 */
void dtop_poll(struct dtop_linked_list *dpg_list)
{
	struct dtop_linked_list *curr_ptr = dpg_list;
	struct dtop_data_point_gatherer *dpset;

	while (curr_ptr) {
		dpset = (struct dtop_data_point_gatherer *) curr_ptr->data;
		dpset->poll(dpset);
		curr_ptr = curr_ptr->next_ptr;
	}
}

/**
 * @brief Prints the delta(value) of all data_points to terminal.
 *
 * @param dpg_list Pointer to first node of linked list which contains all dpgs.
 */
void dtop_print_snapshot_diff(struct dtop_linked_list *dpg_list)
{
	int i;

	struct dtop_linked_list *curr_ptr = dpg_list;
	struct dtop_data_point_gatherer *dpset;
	printf("\n");
	printf("Change In Datapoint Values\n");
	printf("---------------------------\n");
	while (curr_ptr) {
		dpset = (struct dtop_data_point_gatherer *) curr_ptr->data;
		for (i = 0; i < dpset->data_points_len; i++)
			dtop_handle_dp_type_for_snapshot(dpset,
					  dpset->data_points[i]);
		curr_ptr = curr_ptr->next_ptr;
	}
	printf("\n");
}

/**
 * @brief Resets the initial values of all data_points.
 *
 * @param dpg_list Pointer to first node of linked list which contains all dpgs.
 */
void dtop_reset_dp_initial_values(struct dtop_linked_list *dpg_list)
{
	int i;

	struct dtop_linked_list *curr_ptr = dpg_list;
	struct dtop_data_point_gatherer *dpset;

	while (curr_ptr) {
		dpset = (struct dtop_data_point_gatherer *) curr_ptr->data;
		for (i = 0; i < dpset->data_points_len; i++)
			dpset->data_points[i].initial_data_populated
							= NOT_POPULATED;
		curr_ptr = curr_ptr->next_ptr;
	}
}

/**
 * @brief Calls deconstructor method for all dpgs dynamically created.
 *
 * Checks to see if each dpg created has a deconstructor method. If not null,
 * function calls the appropiate deconstructor method to deallocate memory.
 *
 * @param dpg_list Pointer to first node of linked list which contains all dpgs.
 */
void deconstruct_dpgs(struct dtop_linked_list *dpg_list)
{
	struct dtop_linked_list *curr_ptr = dpg_list;
	struct dtop_data_point_gatherer *dpset;

	while (curr_ptr) {
		dpset = (struct dtop_data_point_gatherer *) curr_ptr->data;
		if (dpset->deconstruct)
			dpset->deconstruct(dpset);
		curr_ptr = curr_ptr->next_ptr;
	}
}