feat: git version control for backup

makefile

@@ -4,9 +4,9 @@ VERSION := $(shell git describe --tags --always --dirty)
 
 CFLAGS := -Wall -Wextra -Werror -O2 \
 		  -DVERSION=\"$(VERSION)\" \
-	      $(shell pkg-config --cflags libcjson ncurses)
+	      $(shell pkg-config --cflags libcjson ncurses libgit2)
 
-LDFLAGS := $(shell pkg-config --libs libcjson ncurses)
+LDFLAGS := $(shell pkg-config --libs libcjson ncurses libgit2)
 
 SRC := src/main.c src/ui.c src/utils.c src/notes.c
 TARGET := notewrapper

src/main.c

@@ -96,7 +96,19 @@ int main(int argc, char *argv[]) {
     debug("Parsing the JSON config");
 
     cJSON *json = cJSON_Parse(data);
+
   if (!json) {
+      const char *error_ptr = cJSON_GetErrorPtr();
+  
+      if (error_ptr) {
+          error(
+              1,
+              "program",
+              "JSON parse error near: %.30s",
+              error_ptr
+          );
+      }
+  
       free(data);
   }
     error(!json, "program", "JSON parse error");
@@ -210,6 +222,9 @@ int main(int argc, char *argv[]) {
     char **backupDirectoriesArray = malloc(numDirectories * sizeof(char *));
     char **rsyncArgs = NULL;
     int rsyncArgsNumber = 0;
+    int gitEnabled = 0;
+    char *gitSignatureName = NULL;
+    char *gitSignatureEmail = NULL;
     cJSON *backupJSON = cJSON_GetObjectItem(json, "backup");
     if (backupJSON && cJSON_IsObject(backupJSON)) {
         cJSON *doesBackupJSON = cJSON_GetObjectItem(backupJSON, "enable");
@@ -285,11 +300,36 @@ int main(int argc, char *argv[]) {
                       "value is from an unexpected type",
                       configPath);
             }
+
+            // Configure Git backup
+            cJSON *gitJSON = cJSON_GetObjectItem(backupJSON, "git");
+            
+            if (gitJSON && cJSON_IsObject(gitJSON)) {
+                cJSON *gitEnableJSON = cJSON_GetObjectItem(gitJSON, "enable");
+                cJSON *gitNameJSON = cJSON_GetObjectItem(gitJSON, "name");
+                cJSON *gitEmailJSON = cJSON_GetObjectItem(gitJSON, "email");
+            
+                error(!gitEnableJSON || !cJSON_IsBool(gitEnableJSON), "user", "Entry \"git.enable\" in %s must be a bool.", configPath);
+                error(!gitNameJSON || !cJSON_IsString(gitNameJSON), "user", "Entry \"git.name\" in %s must be a string.", configPath);
+                error(!gitEmailJSON || !cJSON_IsString(gitEmailJSON), "user", "Entry \"git.email\" in %s must be a string.", configPath);
+            
+                gitEnabled = cJSON_IsTrue(gitEnableJSON) ? 1 : 0;
+            
+                if (gitEnabled) {
+                    gitSignatureName = strdup(cJSON_GetStringValue(gitNameJSON));
+                    gitSignatureEmail = strdup(cJSON_GetStringValue(gitEmailJSON));
+            
+                    error(gitSignatureName == NULL || gitSignatureEmail == NULL, "program", "malloc failed");
+            
+                    debug("git in %s is enabled with name \"%s\" and email \"%s\"", configPath, gitSignatureName, gitSignatureEmail);
                 } else {
-            error(1, "user",
+                    debug("git in %s is disabled", configPath);
-                  "%s did not contained a enable value inside the backup section or the value is "
+                }
-                  "from an unexpected type",
+            } else {
-                  configPath);
+                error(1, "user", "Entry \"git\" in %s must be an object containing \"enable\", \"name\", and \"email\".", configPath);
+            }
+        } else {
+            error(1, "user", "%s did not contained a enable value inside the backup section or the value is from an unexpected type", configPath);
         }
         // handle rsyncs array of arguments.
         cJSON *rsyncArgsJSON = cJSON_GetObjectItem(backupJSON, "rsyncArgs");
@@ -314,9 +354,7 @@ int main(int argc, char *argv[]) {
                   configPath);
         }
     } else {
-        debug("In %s, \"backup\" wasn't set or we encountered a abnormal type. Defaulting to "
+        debug("In %s, \"backup\" wasn't set or we encountered a abnormal type. Defaulting to {\"enable\": false}.", configPath);
-              "{\"enable\": false}.",
-              configPath);
     }
 backup_config_end:
 
@@ -541,6 +579,12 @@ backup_config_end:
 
     initscr(); // initialize ncurses
 
+    // initialized libgit2
+    if (gitEnabled) {
+      int libgit2InitializationTimes = git_libgit2_init();
+      error(libgit2InitializationTimes != 1, "program", "libgit2 has been initialized %d times (instead of one)", libgit2InitializationTimes);
+    }
+
     int shouldExit = 0;
     while (!shouldExit) {
         // this loop is the vault selector
@@ -620,6 +664,11 @@ backup_config_end:
             int shouldChangeVault = 0;
             // we must find the directory from which the vault comes again.
             char *notesDirectoryString = getDirectoryFromVault(vaultSelected, vaultsArray, vaultsCount, vaultsCountForEachDirectory, directoriesArray, numDirectories, shouldDebug);
+
+            if (gitEnabled) { // we check if we need to git init the vault each time we enter it
+                  ensureGitDirectory(notesDirectoryString, vaultSelected, gitSignatureName, gitSignatureEmail, shouldDebug);
+            }
+
             while (!shouldExit && !shouldChangeVault) {
                 // this loop is the note selector
                 int filesCount = 0;
@@ -712,6 +761,14 @@ backup_config_end:
                         appendToFile(fullPath, "\n", shouldDebug);
                     }
                     openEditor(fullPath, editorToOpen, shouldRender, shouldJumpToEnd, shouldDebug);
+                    if (gitEnabled) { // After closing a file, we need to update the git repo (if git is enable
+                      char *date = getDateAndTime();
+                      char *commitMsg = malloc(29);
+                      snprintf(commitMsg, 29, "Update - %s", date);
+                      gitBackupUpdate(notesDirectoryString, vaultSelected, gitSignatureName, gitSignatureEmail, commitMsg, shouldDebug);
+                      free(date);
+                      free(commitMsg);
+                    }
                     free(fullPath);
                 } else if (strcmp(noteSelected, "Create new note") == 0) {
                 note_creation:

src/utils.c

@@ -113,6 +113,185 @@ static void ensureDir(const char *path, const int shouldDebug) {
     }
 }
 
+void ensureGitDirectory(const char *path, const char *vault, const char *signatureName, const char *signatureEmail, const int shouldDebug) {
+  git_repository *repo = NULL;
+  char *fullPath = malloc(PATH_MAX);
+  snprintf(fullPath, PATH_MAX, "%s/%s", path, vault);
+
+  int git_repo_error_code = git_repository_open(&repo, fullPath);
+  if (git_repo_error_code) { // error (most probably that the git repo wasn't initialized)
+    int git_init_error_code = git_repository_init(&repo, fullPath, 0); // the 0 indicates that the directory isn't bare. See https://libgit2.org/docs/reference/main/repository/git_repository_init.html
+    error(git_init_error_code, "program", "git initialization didn't worked. Error code : %d\nSee https://libgit2.org/docs/reference/main/repository/git_repository_init.html for documentation\n\n%s", git_init_error_code, git_error_last()->message);
+    debug("git repo %s was initialized.", fullPath);
+    
+    // we need to setup the .gitignore
+    char *gitignorePath = malloc(PATH_MAX);
+    snprintf(gitignorePath, PATH_MAX, "%s/.gitignore", fullPath);
+    FILE *gitignore = fopen(gitignorePath, "a");
+    error(gitignore == NULL, "program", "failed to open/create %s\n%s", gitignorePath, git_error_last()->message);
+    fputs("*\n", gitignore);
+    fputs("!*/\n", gitignore);
+    fputs("!*.md\n", gitignore);
+    fclose(gitignore);
+    debug("Succesfully wrote .gitignore to %s", gitignorePath);
+    git_repository_free(repo); // we free to be able to open it in gitBackupUpdate()
+    char *date = getDateAndTime();
+    char *commitMsg = malloc(37);
+    snprintf(commitMsg, 37, "Initial commit - %s", date);
+    gitBackupUpdate(path, vault, signatureName, signatureEmail, commitMsg, shouldDebug);
+    free(date);
+    free(commitMsg);
+  } else { // the git repo already exists
+    debug("%s is already a git repo. Skipping initialization...", fullPath);
+    git_repository_free(repo);
+  }
+
+  free(fullPath);
+}
+
+void gitBackupUpdate(const char *path, const char *vault, const char *signatureName, const char *signatureEmail, const char *commitMsg, const int shouldDebug) {
+    git_repository *repo = NULL;
+    git_index *index = NULL;
+    git_tree *tree = NULL;
+    git_tree *head_tree = NULL;
+    git_commit *head_commit = NULL;
+    git_signature *signature = NULL;
+    git_diff *diff = NULL;
+
+    git_oid tree_id;
+    git_oid commit_id;
+
+    char *fullPath = malloc(PATH_MAX);
+    
+    error(fullPath == NULL, "program", "Failed to allocate path");
+
+    snprintf(fullPath, PATH_MAX, "%s/%s", path, vault);
+
+    /* Open repository */
+    int return_code = git_repository_open(&repo, fullPath);
+
+    error(return_code, "program", "Failed to open Git repository\n%s", git_error_last()->message);
+
+    /* Get the index */
+    return_code = git_repository_index(&index, repo);
+    error(return_code, "program", "Failed to get Git index\n%s", git_error_last()->message);
+
+    /* git add . */
+    return_code = git_index_add_all(index, NULL, 0, NULL, NULL);
+    error(return_code, "program", "Failed to add files\n%s", git_error_last()->message);
+
+    return_code = git_index_write(index);
+    error(return_code, "program", "Failed to write index\n%s", git_error_last()->message);
+
+    /*
+     * Check whether there are changes to commit.
+     *
+     * For a new repository there is no HEAD yet, so the index
+     * itself tells us whether there is anything to commit.
+     */
+    int has_changes = 0;
+
+    if (git_repository_head_unborn(repo)) {
+        has_changes = git_index_entrycount(index) > 0;
+    } else {
+        git_oid head_oid;
+
+        return_code = git_reference_name_to_id(
+            &head_oid,
+            repo,
+            "HEAD"
+        );
+        error(return_code, "program", "Failed to get HEAD\n%s", git_error_last()->message);
+
+        return_code = git_commit_lookup(
+            &head_commit,
+            repo,
+            &head_oid
+        );
+        error(return_code, "program", "Failed to lookup HEAD commit\n%s", git_error_last()->message);
+
+        return_code = git_commit_tree(
+            &head_tree,
+            head_commit
+        );
+        error(return_code, "program", "Failed to get HEAD tree\n%s", git_error_last()->message);
+
+        return_code = git_diff_tree_to_index(
+            &diff,
+            repo,
+            head_tree,
+            index,
+            NULL
+        );
+
+        error(return_code, "program", "Failed to create diff\n%s", git_error_last()->message);
+
+        has_changes = git_diff_num_deltas(diff) > 0;
+    }
+
+    /* Nothing changed, so don't create a commit */
+    if (!has_changes) {
+        debug("No changes to commit in %s", fullPath);
+        goto cleanup;
+    }
+
+    /* index → tree */
+    return_code = git_index_write_tree(&tree_id, index);
+    error(return_code, "program", "Failed to write tree\n%s", git_error_last()->message);
+
+    return_code = git_tree_lookup(&tree, repo, &tree_id);
+    error(return_code, "program", "Failed to lookup tree\n%s", git_error_last()->message);
+
+    /* Author/committer */
+    return_code = git_signature_now(
+        &signature,
+        signatureName,
+        signatureEmail
+    );
+    error(return_code, "program", "Failed to create signature\n%s", git_error_last()->message);
+
+    /* Create commit */
+    if (git_repository_head_unborn(repo)) {
+        return_code = git_commit_create_v(
+            &commit_id,
+            repo,
+            "HEAD",
+            signature,
+            signature,
+            NULL,
+            commitMsg,
+            tree,
+            0
+        );
+    } else {
+        return_code = git_commit_create_v(
+            &commit_id,
+            repo,
+            "HEAD",
+            signature,
+            signature,
+            NULL,
+            commitMsg,
+            tree,
+            1,
+            head_commit
+        );
+    }
+    error(return_code, "program", "Failed to create commit\n%s", git_error_last()->message);
+
+    debug("Created commit %s in %s", commitMsg, fullPath);
+
+cleanup:
+    git_diff_free(diff);
+    git_signature_free(signature);
+    git_tree_free(tree);
+    git_tree_free(head_tree);
+    git_commit_free(head_commit);
+    git_index_free(index);
+    git_repository_free(repo);
+    free(fullPath);
+}
+
 void initAppFilesAndDirs(const char *home, const int shouldDebug) {
     // sometimes .cache and .config doesn't exist. Such as with github actions machines
     char config_dir[PATH_MAX];
@@ -159,13 +338,28 @@ void initAppFilesAndDirs(const char *home, const int shouldDebug) {
             "       \"~/Documents/\": \"path/to/backup/\"\n"
             "    },\n"
             "    \"interval\": \"weekly\",\n"
-            "    \"rsyncArgs\": [\"-Lqah\", \"--update\"]\n"
+            "    \"rsyncArgs\": [\"-Lqah\", \"--update\"],\n"
+            "    \"git\": {\n"
+            "      \"enable\": false,\n"
+            "      \"email\": \"mail@example.com\",\n"
+            "      \"name\": \"Example Example\"\n"
+            "    }\n"
             "  }\n"
             "}\n");
 
     fclose(w);
 }
 
+char *getDateAndTime() {
+  char *return_value = malloc(20);
+  time_t now = time(NULL);
+  struct tm tm_now;
+  localtime_r(&now, &tm_now);
+
+  strftime(return_value, sizeof(return_value), "%Y-%m-%%d %H:%M:%%S", &tm_now);
+  return return_value;
+}
+
 void handleBackups(char **sourceDirectoryArray, const int sourceNumber, char **destinationDirectoryArray, const char *homeDir, const int interval, const char **rsyncArguments, const int rsyncArgumentsNumber,
                    const int forceBackup, int *backupMessage, const int shouldDebug) {
     int shouldBackup = 0;

src/utils.h

@@ -17,6 +17,8 @@
 #include <sys/wait.h>
 #include <time.h>
 #include <unistd.h>
+#include <git2.h>
+
 #ifndef VERSION
 #define VERSION "dev"
 #endif
@@ -85,4 +87,12 @@ will be added in the function.
 backupMessage will be set to 1 if a backup was launched.*/
 void handleBackups(char **sourceDirectoryArray, const int sourceDirectoryNumber, char **destinationDirectoryArray, const char *homeDir, const int interval, const char **rsyncArgs, const int rsyncArgsNumber,
                    const int forceBackup, int *backupMessage, const int shouldDebug);
+/*Equivalent of git init.
+If the directory wasn't git initialized. We do it.*/
+void ensureGitDirectory(const char *path, const char *vault, const char *signatureName, const char *signatureEmail, const int shouldDebug);
+/*Configures git, stages everything, commits everything*/
+void gitBackupUpdate(const char *path, const char *vault, const char *signatureName, const char *signatureEmail, const char *commitMsg, const int shouldDebug);
+// yyyy-mm-dd hh:mm:ss
+// Don't forget to free the pointer.
+char *getDateAndTime();
 #endif