From b457c60f75ed195628095a418594ae23fc087cae Mon Sep 17 00:00:00 2001
From: "Alexander \"Arav\" Andreev" <me@arav.top>
Date: Sat, 25 Dec 2021 23:27:53 +0400
Subject: [PATCH] [main.c] Structure arguments_t removed. Use ptrs to vars
 instead. `parse_arguments` now returns status codes instead of printing stuff
 and closing program. `to_wattpersecond` is now `to_wattspersecond`. Fixed
 typo in usage, capitalised `options` word. Rephrased `print_version` text.
 Removed unnecessary check from `interval_to_seconds` (former `to_seconds`)
 function.

---
 src/main.c | 130 +++++++++++++++++++++++++----------------------------
 1 file changed, 62 insertions(+), 68 deletions(-)

diff --git a/src/main.c b/src/main.c
index 218d336..b34d8fd 100644
--- a/src/main.c
+++ b/src/main.c
@@ -5,91 +5,85 @@
 #include "main.h"
 
 int main(int argc, char **argv) {
-    arguments_t * args = parse_arguments(argc, argv);
+    price_t price;
+    wattage_t wattage;
+    interval_t interval = 0;
 
-    printf("%.2Lf\n", (args->price * args->wattage) * args->interval);
-
-    free(args);
-    return 0;
-}
-
-arguments_t * parse_arguments(int argc, char **argv) {
-    if (argc == 1) {
-        print_usage();
+    int res = parse_arguments(argc, argv, &price, &wattage, &interval);
+    if (res != 0) {
+        if (res == 1)
+            print_usage();
+        else if (res == 2)
+            print_version();
         exit(0);
     }
 
-    arguments_t *args = (arguments_t *)calloc(1, sizeof(arguments_t));
-    int pos_args_pos = 0;
+    printf("%.2Lf\n", (price * wattage) * interval);
 
-    for (int i = 1; i < argc; ++i) {
+    return 0;
+}
+
+int parse_arguments(int argc, char **argv, price_t *price, wattage_t *wattage, interval_t *interval) {
+    if (argc < 2) return 1;
+
+    for (int i = 1, pos = 0; i < argc; ++i)
         if (argv[i][0] == '-') {
-            if (argv[i][1] == 'h' || argv[i][2] == 'h') {
-                print_usage();
-                exit(0);
-            } else if (argv[i][1] == 'v' || argv[i][2] == 'v') {
-                print_version();
-                exit(0);
-            }
-        } else if (pos_args_pos == 0) {
-            args->price = to_wattpersecond((price_t)atof(argv[i]));
-            pos_args_pos++;
-        } else if (pos_args_pos == 1) {
-            args->wattage = atof(argv[i]);
-            pos_args_pos++;
-        } else if (pos_args_pos > 1) {
-            args->interval += to_seconds(argv[i]);
-            pos_args_pos++;
-        }
-    }
+            if (argv[i][1] == 'h' || argv[i][2] == 'h')
+                return 1;
+            else if (argv[i][1] == 'v' || argv[i][2] == 'v')
+                return 2;
+        } else if (argc < 4) {
+            return 1;
+        } else if (pos == 0) {
+            *price = to_wattspersecond((price_t)atof(argv[i]));
+            ++pos;
+        } else if (pos == 1) {
+            *wattage = (wattage_t)atof(argv[2]);
+            ++pos;
+        } else
+            *interval += (interval_t)interval_to_seconds(argv[i]);
 
-    if (pos_args_pos < 3) {
-        print_usage();
-        exit(1);
-    }
-
-    return args;
+    return 0;
 }
 
-interval_t to_seconds(char *interval) {
+inline interval_t interval_to_seconds(char *interval) {
     interval_t intrvl = (interval_t)atol(interval);
-    char unit = interval[strlen(interval) - 1];
 
-    if (!(unit >= '0' && unit <= '9'))
-        switch (unit) {
-            case 'm':
-            case 'M':
-                return intrvl * 60;
-            case 'h':
-            case 'H':
-                return intrvl * 60 * 60;
-            case 'd':
-            case 'D':
-                return intrvl * 60 * 60 * 24;
-        }
-    return intrvl;
+    switch (interval[strlen(interval) - 1]) {
+        case 'm':
+        case 'M':
+            return intrvl * 60;
+        case 'h':
+        case 'H':
+            return intrvl * 60 * 60;
+        case 'd':
+        case 'D':
+            return intrvl * 60 * 60 * 24;
+        default:
+            return intrvl;
+    }
 }
 
-inline price_t to_wattpersecond(price_t price) {
+inline price_t to_wattspersecond(price_t price) {
     return price / 1000.f / 3600.f;
 }
 
-void print_version() {
+inline void print_version() {
     puts("kwh-cost Ver. " VERSION "\n"
-           "Copyright (C) 2021 Alexander \"Arav\" Andreev <me@arav.top>. All rights reserved.\n"
-           "License for this program is stored in /usr/share/licenses/kwh-cost/LICENSE.");
+         "Copyright (C) 2021 Alexander \"Arav\" Andreev <me@arav.top>. All rights reserved.\n"
+         "You can see a license for this program in /usr/share/licenses/kwh-cost/LICENSE.");
 }
 
-void print_usage() {
-    puts("Usage: kwh-cost [options] price wattage interval [interval ...]\n"
-           "Options:\n"
-           "  --help, -h    Display this usage information.\n"
-           "  --version, -v Display program version.\n"
-           "Arguments:\n"
-           "  price    Price per kWh.\n"
-           "  wattage  Specify power usage in Watts.\n"
-           "  interval Time interval in seconds total cost to be calculated for.\n"
-           "           You may specify other time units such as:\n"
-           "           m'imute, h'our, d'ay. Example: 5d 3h.\n"
-           "           All given intervals will be summed up.");
+inline void print_usage() {
+    puts("Usage: kwh-cost [OPTIONS] price wattage interval [interval ...]\n"
+         "Options:\n"
+         "  --help, -h    Display this usage information.\n"
+         "  --version, -v Display program version.\n"
+         "Arguments:\n"
+         "  price    Price per kWh.\n"
+         "  wattage  Specify power usage in Watts.\n"
+         "  interval Time interval in seconds total cost to be calculated for.\n"
+         "           You may specify other time units such as:\n"
+         "           m'inute, h'our, d'ay. Example: 5d 3h.\n"
+         "           All given intervals will be summed up.");
 }