From 81ce5812a6087e04586b0701830c004bfd58b391 Mon Sep 17 00:00:00 2001
From: hygienic-books <hygienic-books@tentic.net>
Date: Wed, 23 Mar 2022 23:38:25 +0100
Subject: [PATCH] Account for situations where a state file does not (yet)
 exist

---
 mvw-dl.py | 42 +++++++++++++++++++++++++++---------------
 1 file changed, 27 insertions(+), 15 deletions(-)

diff --git a/mvw-dl.py b/mvw-dl.py
index f9d997f..bc2859d 100644
--- a/mvw-dl.py
+++ b/mvw-dl.py
@@ -89,6 +89,7 @@ JSONType = t.Union[str, int, float, bool, None, t.Dict[str, t.Any], t.List[t.Any
 # 3: No search results to download
 # 4: State file already exists, has more than 0 bytes size but doesn't contain usable JSON
 # 5: State file lock cannot be acquired within file_lock_timeout
+# 6: Unable to create state directory
 
 
 class CONST(object):
@@ -461,12 +462,19 @@ def get_state_file_abs_path(
         config_obj: configparser.ConfigParser()) -> str:
 
     state_dir = config_obj.get(section_name, "state_files_dir")
-    state_file = \
-        config_obj.get(section_name, "state_file_name_prefix") + \
-        section_name + \
-        config_obj.get(section_name, "state_file_name_suffix")
-    state_file_abs_path = os.path.join(state_dir, state_file)
-    return state_file_abs_path
+    try:
+        os.makedirs(state_dir, exist_ok=True)
+    except OSError:
+        log.error(f"Unable to create '[{section}]' state directory '{state_dir}'. "
+                  f"We're not going to be able to log state information. Exiting 6 ...")
+        sys.exit(6)
+    else:
+        state_file = \
+            config_obj.get(section_name, "state_file_name_prefix") + \
+            section_name + \
+            config_obj.get(section_name, "state_file_name_suffix")
+        state_file_abs_path = os.path.join(state_dir, state_file)
+        return state_file_abs_path
 
 
 def state_file_none_or_valid_json(
@@ -534,7 +542,8 @@ def log_successful_download(
 
     with lock:
         state_file_none_or_valid_json(state_file_abs_path)
-        with open(state_file_abs_path, "r+", encoding="utf-8") as state_file:
+        state_file_open_mode = "r+" if os.path.exists(state_file_abs_path) else "w+"
+        with open(state_file_abs_path, state_file_open_mode, encoding="utf-8") as state_file:
             try:
                 json_state = json.load(state_file)
             except json.JSONDecodeError:
@@ -651,14 +660,17 @@ def get_content_length(
 
 def get_json_state(
         state_file_abs_path: str) -> json.loads:
-
-    with open(state_file_abs_path, "r", encoding="utf-8") as state_file:
-        try:
-            json_state = json.load(state_file)
-        except json.JSONDecodeError:
-            return []
-        else:
-            return json_state
+    try:
+        with open(state_file_abs_path, "r", encoding="utf-8") as state_file:
+            try:
+                json_state = json.load(state_file)
+            except json.JSONDecodeError:
+                return []
+            else:
+                return json_state
+    except FileNotFoundError:
+        log.debug(f"State file does not exist (yet), assuming no previous downloads have ever happened ...")
+        return []
 
 
 def is_already_downloaded(