/*
 * util.h - Utility functions
 * Copyright (C) 2024  Alexander Rosenberg
 *
 * This program is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later
 * version. See the LICENSE file for more information.
 */
#ifndef INCLUDED_UTIL_H
#define INCLUDED_UTIL_H

#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
#include <time.h>
#include <stdbool.h>
#include <sys/types.h>
#include <libgpio.h>
#include <sqlite3.h>

typedef enum {
    TEMP_UNIT_F = 'F',
    TEMP_UNIT_C = 'C'
} TemperatureUnit;

typedef struct {
    char *config_path; // path to config file
    bool strict_config; // exit if unknown config options is found
    bool verbose; // be more verbose

    char *gpio_path; // path of GPIO device file to use
    gpio_pin_t en_pin;
    gpio_pin_t rs_pin;
    gpio_pin_t rw_pin;
    gpio_pin_t data_pins[8];
    gpio_pin_t bl_pin;
    char *database_location; // location of sqlite3 database
    char *temp_key; // sysctl key for temperature
    char *humid_key; // sysctl key for humidity
    char *fail_key; // sysctl key for number of fails
    uint32_t fail_limit; // limit for number of failures before exit
    uint32_t refresh_time; // time between temp and humid refresh

    // menu navigation pins
    gpio_pin_t up_pin;
    gpio_pin_t down_pin;
    gpio_pin_t back_pin;
    gpio_pin_t sel_pin;

    TemperatureUnit temp_unit;
} Options;
extern Options GLOBAL_OPTS;

/*
 * Cleanup an Options struct.
 */
void cleanup_options(Options *opts);

/*
 * Like malloc(3), except that if allocation fails, an error will be written to
 * standard error and abort(3) called
 */
void *malloc_checked(size_t n);

/*
 * Like realloc(3), except that if allocation fails, an error will be written to
 * standard error and abort(3) called
 */
void *realloc_checked(void *old_ptr, size_t n);

/*
 * Like strdup(3), except that if allocation fails, an error will be written to
 * standard error and abort(3) called
 */
void *strdup_checked(const char *str);

/*
 * Like free(3), but do nothing if P is NULL.
 */
#define FREE_CHECKED(p) if (p) {free(p);}

/*
 * Call fprintf(3) to stderr only if verbose mode was enabled.
 */
#define LOG_VERBOSE(...) if (GLOBAL_OPTS.verbose) {fprintf(stderr, __VA_ARGS__);}

/*
 * Return: the number of days in month M. 1 is January. Y is the year.
 */
int days_in_month(int m, int y);

/*
 * Initialize SQL queries used by this file.
 */
void initialize_util_queries(sqlite3 *db);

/*
 * Cleanup SQL queries used by this file.
 */
void cleanup_util_queries(void);

typedef struct {
    int64_t utc;
    int utc_year;
    int utc_month;
    int utc_day;
    int utc_hour;
    int utc_minute;
    int utc_second;
    int64_t local;
    int local_year;
    int local_month;
    int local_day;
    int local_hour;
    int local_minute;
    int local_second;
} UtilDate;

enum {
    PERIOD_HOUR = 0,
    PERIOD_DAY,
    PERIOD_WEEK,
    PERIOD_MONTH,
    PERIOD_YEAR,
};
typedef int UtilPeriod;
extern const char *PERIOD_LABELS[];
extern const size_t NPERIOD;

/*
 * Return the START of the first and END of the last PERIOD (ex. week) of DB.
 * Also get the hour, minute, and second limits for the first and last day.
 * Return: false if an error occurred, true otherwise.
 */
bool get_database_limits(sqlite3 *db, UtilPeriod period, UtilDate *start,
                         UtilDate *end);

typedef struct {
    int64_t npoints;
    int temp;
    int humid;
    int year;
    int month;
    int day;
    int hour;
    bool lower_bound;
    bool upper_bound;
} UtilAveragePeriod;

/*
 * Get the average temp. and humid. between YEAR-MONTH-DAY + COUNT * PERIOD and
 * YEAR-MONTH-DAY + (COUNT + 1) * PERIOD.
 * Return: false if an error occurred, true otherwise.
 */
bool get_average_for_period(sqlite3 *db, int year, int month, int day,
                           int64_t count, UtilPeriod period,
                           UtilAveragePeriod *data);

typedef struct {
    int64_t time;
    int temp;
    int humid;
    bool has_next;
    int64_t next_time;
    int next_temp;
    int next_humid;
    bool has_prev;
    int64_t prev_time;
    int prev_temp;
    int prev_humid;
} UtilDataPointInfo;

/*
 * Get the data, next point, and previous point for data point TIME. INFO must
 * not be NULL.
 * Return: false if an error occurred, true otherwise.
 */
bool get_data_point_info(sqlite3 *db, int64_t time, UtilDataPointInfo *info);

typedef struct {
    int64_t npoints;
    int temp;
    int humid;
} UtilAverageRange;

/*
 * Get the average DATA for the range of UTC times START to END (inclusive).
 * Return: false if an error occurred, true otherwise.
 */
bool get_average_for_range(sqlite3 *db, uint64_t start, uint64_t end,
                           UtilAverageRange *data);

/*
 * Convert the temperature in deciKelvin DK to either F or C.
 */
float convert_temperature(int dk);

#endif