feat: implement pit tag command

pit-project/commands/__init__.py

@@ -19,3 +19,4 @@
 # from . import pull
 # from . import clone
 from . import stash
+from . import tag

pit-project/commands/checkout.py

@@ -36,14 +36,23 @@ def run(args):
     elif len(targets) == 1 and _is_branch(repo_root, targets[0]):
         handle_branch_checkout(repo_root, targets[0])
 
-    # Case 3: checkout <file>...
+    # Case 3: checkout <tag>
+    elif len(targets) == 1 and _is_tag(repo_root, targets[0]):
+        handle_tag_checkout(repo_root, targets[0])
+
+    # Case 4: checkout <file>...
     else:
         handle_file_restore(repo_root, targets)
 
 def _is_branch(repo_root, name):
     branches = repository.get_all_branches(repo_root)
     return name in branches
 
+def _is_tag(repo_root, name):
+    tags = repository.get_all_tags(repo_root)
+    return name in tags
+
+
 def handle_create_and_checkout(repo_root, branch_name):
     # 1. Check if branch already exists
     if _is_branch(repo_root, branch_name):
@@ -71,6 +80,42 @@ def handle_branch_checkout(repo_root, branch_name):
 
     perform_checkout(repo_root, branch_name)
 
+
+
+def handle_tag_checkout(repo_root, tag_name):
+    # Similar to branch checkout, but results in detached HEAD
+    # 1. Validate clean
+    if not is_clean(repo_root):
+        print("error: Your local changes would be overwritten by checkout.", file=sys.stderr)
+        sys.exit(1)
+
+    # 2. Get commit
+    commit_hash = repository.get_tag_commit(repo_root, tag_name)
+    if not commit_hash:
+        print(f"fatal: tag '{tag_name}' not found.", file=sys.stderr)
+        sys.exit(1)
+
+    # 3. Update Workdir & Index
+    # Reuse perform_checkout logic's parts
+    target_files = objects.get_commit_files(repo_root, commit_hash)
+    current_commit = repository.get_head_commit(repo_root)
+    # If in detached HEAD or initial state
+    current_files = objects.get_commit_files(repo_root, current_commit) if current_commit else {}
+
+    update_working_directory(repo_root, current_files, target_files)
+    update_index(repo_root, target_files)
+
+    # 4. Detached HEAD
+    head_path = os.path.join(repo_root, '.pit', 'HEAD')
+    with open(head_path, 'w') as f:
+        f.write(commit_hash)
+
+    print(f"Note: checking out '{tag_name}'.")
+    print("\nYou are in 'detached HEAD' state. You can look around, make experimental")
+    print("changes and commit them, and you can discard any commits you make in this")
+    print("state without impacting any branches by switching back to a branch.")
+    print(f"\nHEAD is now at {commit_hash[:7]}")
+
 def perform_checkout(repo_root, target_branch):
     # 1. Validate clean state
     if not is_clean(repo_root):
@@ -154,13 +199,23 @@ def is_clean(repo_root):
     return True
 
 def load_index(repo_root):
+
     index_path = os.path.join(repo_root, '.pit', 'index')
     index_files = {}
     if os.path.exists(index_path):
         with open(index_path, 'r') as f:
             for line in f:
-                hash_val, path = line.strip().split(' ', 1)
-                index_files[path] = hash_val
+                parts = line.strip().split(' ')
+                if len(parts) >= 4:
+                     # New format: hash mtime size path
+                     hash_val = parts[0]
+                     # mtime = parts[1], size = parts[2] - not used here
+                     path = " ".join(parts[3:])
+                     index_files[path] = hash_val
+                else:
+                     # Old format
+                     hash_val, path = line.strip().split(' ', 1)
+                     index_files[path] = hash_val
     return index_files
 
 def update_working_directory(repo_root, current_files, target_files):

pit-project/commands/tag.py

@@ -0,0 +1,51 @@
+# The command: pit tag [<name>]
+# What it does: Creates a lightweight tag ref pointing to the current HEAD, or lists existing tags.
+# How it does: To create a tag, it gets the HEAD commit hash and writes it to a file in `.pit/refs/tags/<name>`. To list, it reads that directory.
+# What data structure it uses: Files references (similar to branches).
+
+import os
+import sys
+from utils import repository
+
+def run(args):
+    repo_root = repository.find_repo_root()
+    if not repo_root:
+        print("fatal: not a pit repository", file=sys.stderr)
+        sys.exit(1)
+
+    if args.name:
+        create_tag(repo_root, args.name)
+    else:
+        list_tags(repo_root)
+
+def create_tag(repo_root, name):
+    # Validate tag name? (Simple check for now)
+    if not name or '/' in name or '\\' in name or name.startswith('.'):
+         print(f"fatal: Invalid tag name '{name}'", file=sys.stderr)
+         sys.exit(1)
+
+    head_commit = repository.get_head_commit(repo_root)
+    if not head_commit:
+        print("fatal: Failed to resolve 'HEAD' as a valid revision.", file=sys.stderr)
+        sys.exit(1)
+
+    tags_dir = os.path.join(repo_root, '.pit', 'refs', 'tags')
+    os.makedirs(tags_dir, exist_ok=True)
+
+    tag_path = os.path.join(tags_dir, name)
+    if os.path.exists(tag_path):
+        print(f"fatal: tag '{name}' already exists", file=sys.stderr)
+        sys.exit(1)
+
+    with open(tag_path, 'w') as f:
+        f.write(head_commit)
+
+    print(f"Created tag '{name}' at {head_commit[:7]}")
+
+def list_tags(repo_root):
+    tags = repository.get_all_tags(repo_root)
+    if not tags:
+        return
+
+    for tag in sorted(tags):
+        print(tag)

pit-project/pit.py

@@ -2,7 +2,7 @@
 from commands import (
     init, add, commit, log, status, config,
     branch, checkout, diff, merge, reset,
-    revert, clean,
+    revert, clean, stash, tag
     # remote, push, pull, clone
 )
 
@@ -87,6 +87,12 @@ def main():
     clean_parser.add_argument("-d", action="store_true", help="Remove untracked directories as well.")
     clean_parser.set_defaults(func=clean.run)
 
+    # Command: stash
+    stash_parser = subparsers.add_parser("stash", help="Stash the changes in a dirty working directory away.")
+    stash_parser.add_argument("action", nargs="?", choices=["push", "list", "pop", "show", "drop", "clear"], default="push", help="The action to perform (push, list, pop, show, drop, clear)")
+    stash_parser.add_argument("stash_arg", nargs="?", help="Stash index (e.g. stash@{0}) or message for push")
+    stash_parser.set_defaults(func=stash.run)
+
     # # Command: remote
     # remote_parser = subparsers.add_parser("remote", help="Manage remote repositories (HTTPS only)")
     # remote_parser.add_argument("subcommand", help="Subcommand: add, remove, list, set-url")
@@ -99,9 +105,9 @@ def main():
     # push_parser.add_argument("remote", help="Remote name")
     # push_parser.add_argument("branch", help="Branch to push")
     # push_parser.add_argument("-u", "--set-upstream", action="store_true",
-    # #                         help="Set upstream branch tracking")
+    #                         help="Set upstream branch tracking")
     # push_parser.add_argument("-f", "--force", action="store_true",
-    # #                         help="Force push (overwrite remote)")
+    #                         help="Force push (overwrite remote)")
     # push_parser.set_defaults(func=push.run)
 
     # # Command: pull
@@ -116,6 +122,11 @@ def main():
     # clone_parser.add_argument("directory", nargs="?", help="The name of the directory to clone into.")
     # clone_parser.set_defaults(func=clone.run)
 
+    # Command: tag
+    tag_parser = subparsers.add_parser("tag", help="Create, list, delete or verify a tag object signed with GPG.")
+    tag_parser.add_argument("name", nargs="?", help="The name of the tag to create.")
+    tag_parser.set_defaults(func=tag.run)
+
     # Parse the arguments
     args = parser.parse_args()
 

pit-project/utils/config.py

@@ -43,8 +43,8 @@ def write_config(key, value): # Sets a configuration key to a value and writes i
         raise FileNotFoundError("Not a Pit repository.")
 
     config_path = get_config_path(repo_root)
-os.makedirs(os.path.dirname(config_path), exist_ok=True)
-config = configparser.ConfigParser()
+    os.makedirs(os.path.dirname(config_path), exist_ok=True)
+    config = configparser.ConfigParser()
 
     if os.path.exists(config_path):
         config.read(config_path)

pit-project/utils/repository.py

@@ -61,4 +61,17 @@ def get_branch_commit(repo_root, branch_name): # Retrieves the commit hash that
     if not os.path.exists(branch_path):
         return None
     with open(branch_path, 'r') as f:
+        return f.read().strip()
+
+def get_all_tags(repo_root): # Lists all tag names by reading the refs/tags directory
+    tags_dir = os.path.join(repo_root, '.pit', 'refs', 'tags')
+    if not os.path.isdir(tags_dir):
+        return []
+    return [name for name in os.listdir(tags_dir) if not name.startswith('.')]
+
+def get_tag_commit(repo_root, tag_name): # Retrieves the commit hash that a given tag points to
+    tag_path = os.path.join(repo_root, '.pit', 'refs', 'tags', tag_name)
+    if not os.path.exists(tag_path):
+        return None
+    with open(tag_path, 'r') as f:
         return f.read().strip()