Support new file creation

Now we test if the passed-in file exists. If it does, the decrypt ->
edit -> encrypt process is followed. If it does not exist, the
decryption process is skipped. Also added a check for an empty recipient
linked list to prevent attempting to edit files when no recipients are
specified.

2 files changed, 42 insertions, 24 deletions

diff --git a/TODO.adoc b/TODO.adoc
index fa8dec8..d3f69a7 100644
--- a/TODO.adoc
+++ b/TODO.adoc
@@ -12,5 +12,5 @@ Implement
 * [ ] Argument parser (eg: -r,--recipient)
 * [x] Recipient addition beyond the list already in the file
 * [ ] Recipient removal from existing file
-* [ ] New file creation (at least one recipient required)
+* [x] New file creation (at least one recipient required)
 * [x] Helptext
diff --git a/src/main.c b/src/main.c
index 2ddae06..03f4381 100644
--- a/src/main.c
+++ b/src/main.c
@@ -82,38 +82,56 @@ int main(int argc, char* argv[]) {
   gpgme_error_t err;
   struct gpgedit_config* config;
 
-  if(argc == 1) {
-    printf("Please specify a gpg encrypted file to edit\n");
-    return 1;
-  }
-
   config = gpgedit_config_new();
   parseargs(argc, argv, config);
 
-  // Initialize decryption context, create tmp file to write decrypted contents
-  // to, and run decryption operation.
-  err = init_gpg(&decctx, GPGME_PROTOCOL_OPENPGP);
-  if(err != GPG_ERR_NO_ERROR) {
-    printf("Error: %s\n", gpgme_strerror(err));
+  if(config->file == NULL) {
+    printf("Please specify a gpg encrypted file to edit\n");
     return 1;
   }
 
-  mkstemp(tmpfile);
-  gpgme_decrypt_result_t res = gpg_decrypt_file(config->file, tmpfile, decctx);
-  // Get keyids array from recipients list
-  gpgedit_config_recip_from_gpgme_recip(config, res->recipients);
-  // Freedom!
-  gpgme_release(decctx);
 
-  // Open the system editor
-  system_edit(tmpfile);
+  // Check if fd opened. If not, the specified file doesn't exist, so we need
+  // to create it.
+  FILE* fd = fopen(config->file, "r");
+  if(!fd) {
+    printf("File '%s' does not exist. Creating.\n", config->file);
+    mkstemp(tmpfile);
+  } else {
+    // File exists, close the fd for testing existance
+    fclose(fd);
+
+    // Initialize decryption context, create tmp file to write decrypted contents
+    // to, and run decryption operation.
+    err = init_gpg(&decctx, GPGME_PROTOCOL_OPENPGP);
+    if(err != GPG_ERR_NO_ERROR) {
+      printf("Error: %s\n", gpgme_strerror(err));
+      return 1;
+    }
+
+    mkstemp(tmpfile);
+    gpgme_decrypt_result_t res = gpg_decrypt_file(config->file, tmpfile, decctx);
+    // Get keyids array from recipients list
+    gpgedit_config_recip_from_gpgme_recip(config, res->recipients);
+    // Freedom!
+    gpgme_release(decctx);
+  }
 
-  printf("Recipients:\n");
-  strll_dump(config->recipients);
+  // We can't do anything if the recipient list is empty (eg: new file but no
+  // recipients specified).
+  if(config->recipients->str == NULL) {
+    printf("Recipient list empty. Cannot proceed.\n");
+  } else {
+    // Open the system editor
+    system_edit(tmpfile);
 
-  // Re-encrypt the plaintext tmp file
-  //printf("Re-encrypting file '%s' -> '%s'\n", tmpfile, config->file);
-  gpg_encrypt_file(tmpfile, config->file, config->recipients);
+    printf("Recipients:\n");
+    strll_dump(config->recipients);
+
+    // Re-encrypt the plaintext tmp file
+    //printf("Re-encrypting file '%s' -> '%s'\n", tmpfile, config->file);
+    gpg_encrypt_file(tmpfile, config->file, config->recipients);
+  }
 
   // Clean up tmpfile
   gpgedit_config_release(config);