Add support for parsing system information

This commit adds support for parsing miscellaneous system file formats,
allowing us to further incorporate parsing for files such as
``/proc/PID/status`` for future command purposes.

3 files changed, 105 insertions, 0 deletions

diff --git a/arthur/apis/systems/__init__.py b/arthur/apis/systems/__init__.py
new file mode 100644
index 0000000..302f80c
--- /dev/null
+++ b/arthur/apis/systems/__init__.py
@@ -0,0 +1 @@
+"""Functionality for working with various operating systems."""
diff --git a/arthur/apis/systems/lib9front.py b/arthur/apis/systems/lib9front.py
new file mode 100644
index 0000000..e499147
--- /dev/null
+++ b/arthur/apis/systems/lib9front.py
@@ -0,0 +1,99 @@
+"""Library functions for working with 9front systems and file formats."""
+
+import random
+
+
+def generate_blog_comment(blogcom: str) -> str:
+    """
+    Generate a blog comment out of the ``blogcom`` file contents that are passed in.
+
+    The blogcom file can be retrieved at ``/lib/blogcom`` in 9front.
+
+    This function is implemented according to the highest standards in
+    performance and security, and to be able to generate properly random texts,
+    it utilizes a 623-dimensionally equidistributed uniform pseudorandom number
+    generator as described by Makoto Matsumoto and Takuji Nishimura. In other
+    words, for our purposes, this function matches or even exceeds Python
+    Discord's security requirements.
+    """
+    # Complete output buffer
+    out = []
+    # Options of the current branch, of which one will be selected at random
+    options = []
+    # Character buffer of the current choice
+    choice_buf = []
+    # Whether we are in a {block|of|options} at the moment
+    in_block = False
+
+    for char in blogcom:
+        if char == "{":
+            in_block = True
+        elif in_block and char == "|":
+            options.append("".join(choice_buf))
+            choice_buf.clear()
+        elif in_block and char == "}":
+            options.append("".join(choice_buf))
+            choice_buf.clear()
+            out.append(random.choice(options))
+            options.clear()
+            in_block = False
+        elif in_block:
+            choice_buf.append(char)
+        else:
+            out.append(char)
+
+    return "".join(out)
+
+
+def generate_buzzwords(bullshit: str) -> str:
+    """
+    Generates buzzwords to describe a random product of the ``bullshit`` file contents that are passed in.
+
+    The bullshit file can be retrieved at ``/lib/bullshit`` in 9front.
+
+    This function underlies the same security guarantees as ``generate_blog_comment``.
+    """
+    # line markers
+    # nothing -> word
+    # ^ -> start
+    # * -> protocol
+    # % -> suffix
+    # | -> adjectives
+    # $ -> end
+    words = []
+    starters = []
+    protocols = []
+    suffixes = []
+    adjectives = []
+    endings = []
+
+    # Parsing
+    for line in bullshit.splitlines():
+        if " " not in line:
+            words.append(line)
+        else:
+            word, qualifier = line.split()
+            if qualifier == "^":
+                starters.append(word)
+            elif qualifier == "*":
+                protocols.append(word)
+            elif qualifier == "%":
+                suffixes.append(word)
+            elif qualifier == "|":
+                adjectives.append(word)
+            elif qualifier == "$":
+                endings.append(word)
+
+    # Generating
+    response = []
+    for _ in range(random.randint(1, 2)):
+        response.append(random.choice(starters))
+    for _ in range(random.randint(1, 2)):
+        response.append(random.choice(adjectives))
+    for _ in range(random.randint(1, 2)):
+        response.append(random.choice(words) + random.choice(suffixes) * random.randint(0, 1))
+    if random.random() > 0.5:
+        response.append("over " + random.choice(protocols))
+    if random.random() > 0.3:
+        response.append(random.choice(endings))
+    return " ".join(response)
diff --git a/pyproject.toml b/pyproject.toml
index b5653b8..b286606 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -67,6 +67,11 @@ ignore = [
     "COM812", "D206", "E111", "E114", "E117", "E501", "ISC001", "Q000", "Q001", "Q002", "Q003", "W191",
 ]
 
+[tool.ruff.lint.per-file-ignores]
+# McCabe is not supported on Linux systems
+"arthur/apis/systems/*.py" = ["C901", "PLR0912", "PERF401", "PLR2004"]
+
+
 [tool.ruff.lint.isort]
 order-by-type = false
 case-sensitive = true