From 121643be455e33039d36cc5f02b778a82b6555ea Mon Sep 17 00:00:00 2001
From: Asger Gitz-Johansen <asger.gitz@hotmail.com>
Date: Sat, 3 Aug 2024 11:13:09 +0200
Subject: [PATCH] feat: add simple two-thread watch prototype

I feel like I'm crushing it today!
---
 Makefile      |  1 +
 README.md     |  2 +-
 include/cli.h |  4 ++++
 src/cli.c     | 14 ++++++++++++--
 src/main.c    | 50 +++++++++++++++++++++++++++++++++++++++++++-------
 5 files changed, 61 insertions(+), 10 deletions(-)

diff --git a/Makefile b/Makefile
index a673b9c..d4fdfeb 100644
--- a/Makefile
+++ b/Makefile
@@ -20,6 +20,7 @@ CFLAGS += -Wall -Werror -std=c23 -g
 # includes
 CFLAGS += -Iinclude
 # libraries
+CFLAGS += -lpthread
 
 .PHONY: all clean
 
diff --git a/README.md b/README.md
index b8f00fd..a8978fa 100644
--- a/README.md
+++ b/README.md
@@ -81,7 +81,7 @@ If you want `compile_commands.json` files, you should use [bear](https://github.
  - [x] First things first, let's implement something that reacts when some provided file changes (not poll please).
  - [x] Second things second, implement a simple logging system with differing levels of verbosity and configurable
        output file using cli options.
- - [ ] Third things third, implement a thing that simultaneously watches two different files (multithreading).
+ - [x] Third things third, implement a thing that simultaneously watches two different files (multithreading).
        it should be cancellable with ctrl+c, but it should just contiuously print event notifications.
  - [ ] Fourth things fourth, implement a prototype that reads a space-separated file and populates a struct.
 
diff --git a/include/cli.h b/include/cli.h
index 730a24a..9dbbdda 100644
--- a/include/cli.h
+++ b/include/cli.h
@@ -4,7 +4,11 @@
 #include "optional.h"
 
 typedef struct {
+    // prototyping
     optional_str file;
+    optional_str file2;
+
+    // actual
     int verbosity;
     bool help;
     bool version;
diff --git a/src/cli.c b/src/cli.c
index ae4b96f..ef764e8 100644
--- a/src/cli.c
+++ b/src/cli.c
@@ -9,6 +9,9 @@ cli_options new_options() {
     result.file.has_value = false;
     result.file.value = NULL;
 
+    result.file2.has_value = false;
+    result.file2.value = NULL;
+
     result.verbosity = 1;
 
     result.help = false;
@@ -29,10 +32,12 @@ cli_options new_options() {
 void free_options(cli_options v) {
     if(v.file.has_value)
         free(v.file.value);
+    if(v.file2.has_value)
+        free(v.file2.value);
 }
 
 //                                                         <max
-const char* optstring = "f:v:Cl:hV";
+const char* optstring = "f:F:v:Cl:hV";
 const char* help_msg = 
     "Usage: %s [-v level] [-C] [-l file] [-h] [-V]\n"
     "\n"
@@ -42,7 +47,8 @@ const char* help_msg =
     "ACTUALLY USEFUL YET\n"
     "\n"
     "OPTIONS:\n"
-    "  -f file     set file\n"
+    "  -f file     (WIP) set file\n"
+    "  -F file     (WIP) set another file\n"
     "  -v level    Set verbosity level [0-4]\n"
     "  -C          Force color output, ignoring $NO_COLOR\n"
     "  -l file     Set log to output to a file\n"
@@ -64,6 +70,10 @@ cli_options parse(int argc, char** argv) {
                 options.file.value = strdup(optarg);
                 options.file.has_value = true;
                 break;
+            case 'F':
+                options.file2.value = strdup(optarg);
+                options.file2.has_value = true;
+                break;
             case 'v':
                 options.verbosity = atoi(optarg);
                 break;
diff --git a/src/main.c b/src/main.c
index cc20d16..5f6c329 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,10 +1,13 @@
 #include "cli.h"
 #include "log.h"
 #include "notify.h"
+#include "util.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 
+#include <pthread.h>
+
 void on_event(struct inotify_event* const e) {
     const char* msg =
         "got an event:\n"
@@ -17,6 +20,12 @@ void on_event(struct inotify_event* const e) {
     log_info(msg, e->wd, e->mask, e->cookie, e->len, e->name);
 }
 
+void* listen_for_changes_thread(void* data) {
+    const char* f = (const char*)data;
+    listen_for_changes(f, &on_event);
+    return NULL;
+}
+
 int main(int argc, char** argv) {
     cli_options args = parse(argc, argv);
     log_settings settings;
@@ -29,19 +38,46 @@ int main(int argc, char** argv) {
         print_help(stdout, argv[0]);
         exit(EXIT_SUCCESS);
     }
-
     if(args.version) {
         fprintf(stdout, SCI_VERSION "\n");
         exit(EXIT_SUCCESS);
     }
 
-    if(args.file.has_value) {
-        if(access(args.file.value, F_OK) != 0) {
-            fprintf(stderr, "no such file or directory %s\n", args.file.value);
-            exit(EXIT_FAILURE);
-        }
-        listen_for_changes(args.file.value, &on_event);
+    if(!args.file.has_value) {
+        fprintf(stderr, "no file provided see -h for usage\n");
+        exit(EXIT_FAILURE);
     }
+    if(!args.file2.has_value) {
+        fprintf(stderr, "no second file provided see -h for usage\n");
+        exit(EXIT_FAILURE);
+    }
+
+    if(access(args.file.value, F_OK) != 0) {
+        fprintf(stderr, "no such file or directory %s\n", args.file.value);
+        exit(EXIT_FAILURE);
+    }
+    if(access(args.file2.value, F_OK) != 0) {
+        fprintf(stderr, "no such file or directory %s\n", args.file2.value);
+        exit(EXIT_FAILURE);
+    }
+
+
+    log_trace("spawning trigger thread for %s", args.file.value);
+    pthread_t file1_thread;
+    pthread_attr_t attr1;
+    ASSERT_SYSCALL_SUCCESS(pthread_attr_init(&attr1));
+    ASSERT_SYSCALL_SUCCESS(pthread_create(&file1_thread, &attr1, &listen_for_changes_thread, (void*)args.file.value));
+    ASSERT_SYSCALL_SUCCESS(pthread_attr_destroy(&attr1));
+
+    log_trace("spawning trigger thread for %s", args.file2.value);
+    pthread_t file2_thread;
+    pthread_attr_t attr2;
+    ASSERT_SYSCALL_SUCCESS(pthread_attr_init(&attr2));
+    ASSERT_SYSCALL_SUCCESS(pthread_create(&file2_thread, &attr1, &listen_for_changes_thread, (void*)args.file2.value));
+    ASSERT_SYSCALL_SUCCESS(pthread_attr_destroy(&attr2));
+
+    pthread_join(file1_thread, NULL);
+    pthread_join(file2_thread, NULL);
 
     free_options(args);
 }