From 0a8f169064c61726f7474db816e0ea5e5e4c5fc4 Mon Sep 17 00:00:00 2001
From: Roberto Alsina <ralsina@netmanagers.com.ar>
Date: Wed, 5 Feb 2020 16:11:17 -0300
Subject: [PATCH] basic monitor parsing started

---
 xrandroll/monitor.py | 62 ++++++++++++++++++++++++++++++++++++++++++++
 xrandroll/xrandr.py  | 13 ++++++++--
 2 files changed, 73 insertions(+), 2 deletions(-)
 create mode 100644 xrandroll/monitor.py

diff --git a/xrandroll/monitor.py b/xrandroll/monitor.py
new file mode 100644
index 0000000..0d2af2a
--- /dev/null
+++ b/xrandroll/monitor.py
@@ -0,0 +1,62 @@
+"""An object that represents a monitor."""
+
+import re
+
+
+def _split_by_lines_matching(pattern, lines):
+    """Return a list of groups of lines, splitting on lines
+    matching the pattern. The line matching the pattern is
+    included in the SECOND group. Empty groups are removed."""
+    groups = [[]]
+    for l in lines:
+        if re.match(pattern, l):  # Start a new group
+            groups.append([])
+        groups[-1].append(l)
+
+    return [g for g in groups if g]
+
+
+class Field:
+    """One of the data fields for a monitor."""
+
+    def __init__(self, data):
+        """Initialize Field from xrandr data."""
+        self.name = data[0].split(":")[0].strip()
+        self.value = data[:]
+
+    def __repr__(self):
+        return f"{self.name}: {self.value}"
+
+
+class Mode:
+    """One of the modes for a monitor."""
+
+    def __init__(self, data):
+        """Initialize Mode from xrandr data."""
+        self.data = data
+        self.name = data[0].strip().split()[0]
+
+    def __repr__(self):
+        return self.data[0].strip()
+
+
+class Monitor:
+    """Object representing a monitor according to xrandr."""
+
+    def __init__(self, data):
+        """Initialize a monitor object out of data from xrandr --verbose.
+
+        data is a list of lines.
+        """
+
+        _ = data.pop(0)
+        modes_data = _split_by_lines_matching("^  [^ ]", data)
+        fields_data = _split_by_lines_matching(r"^\t[^ ]", modes_data.pop(0))
+
+        self.modes = {}
+        for m in (Mode(d) for d in modes_data):
+            self.modes[m.name] = m
+
+        self.fields = {}
+        for f in (Field(d) for d in fields_data):
+            self.fields[f.name] = f
diff --git a/xrandroll/xrandr.py b/xrandroll/xrandr.py
index 97269c1..a34f99a 100644
--- a/xrandroll/xrandr.py
+++ b/xrandroll/xrandr.py
@@ -2,10 +2,19 @@
 
 import subprocess
 
+from monitor import Monitor, _split_by_lines_matching
+
 
 def read_data():
-    data = subprocess.check_output(["xrandr", "--verbose"])
-    return data
+    data = subprocess.check_output(
+        ["xrandr", "--verbose"], encoding="utf-8"
+    ).splitlines()
+    # Going to pretend there can only be one screen because life is short.
+    screen = _split_by_lines_matching("^Screen ", data)[0]
+
+    result = []
+    for monitor_data in _split_by_lines_matching(r"^[^ \t].*", screen[1:]):
+        result.append(Monitor(monitor_data))
 
 
 def parse_data(data):