From f3060c080671445bf3b432c7f820886089a314c7 Mon Sep 17 00:00:00 2001
From: Tony Breeds <tony@bakeyournoodle.com>
Date: Wed, 7 Jun 2023 09:29:33 -0500
Subject: [PATCH] [iCal] Add an iCal file route.

Add a handler that converts the existing slot data into an ICS file.
This .ics file can be global ".../ptg.ics" or per track ".../ironic.ics"

Right now each block deafults to 60 minutes if there isn't a 'duration'
field in the slot entry.

Change-Id: I7a67ba777c004e57206976aca377fe3f41956db0
---
 ptgbot/ics.py    | 66 ++++++++++++++++++++++++++++++++++++++++++++++++
 ptgbot/web.py    | 11 ++++++++
 requirements.txt |  1 +
 3 files changed, 78 insertions(+)
 create mode 100644 ptgbot/ics.py

diff --git a/ptgbot/ics.py b/ptgbot/ics.py
new file mode 100644
index 0000000..370486f
--- /dev/null
+++ b/ptgbot/ics.py
@@ -0,0 +1,66 @@
+
+import datetime
+import icalendar
+
+
+def json2ical(db, include_teams="ALL"):
+    teams = slots = {}
+
+    # FIXME: The unused label and the _slots here are irritating.
+    for label, _slots in db["slots"].items():
+        for slot in _slots:
+            slots[slot["name"]] = slot
+
+    for location, schedule in db["schedule"].items():
+        for slot in schedule:
+            team = schedule[slot]
+            # FIXME: This is possibly wrong as teams can globally override the
+            # VC url and ignore the setting in the room/slot/table
+            if slot == "url" or team == "":
+                continue
+            teams.setdefault(team, []).append((location, slot))
+
+    if include_teams in ["ALL", "ptg"]:
+        include_teams = list(teams.keys())
+    if isinstance(include_teams, str):
+        include_teams = [include_teams]
+
+    c = icalendar.Calendar()
+    c.add("prodid", "-//Opendev PTGBot//ptg.opendev.org//")
+    c.add("version", "2.0")
+
+    for team in include_teams:
+        for booking in teams.get(team, []):
+            location, slot = booking
+            url = db["schedule"].get(location, {}).get("url", "")
+            etherpad = db["etherpads"].get(team, "")
+            time = slots.get(slot, {}).get("realtime")
+            # TODO(tonyb): 60 mins is a default picked to make the existing
+            # DB work unchanged.  We can leave this as is or pick another
+            # number. Longer term we could also potentially add a
+            # 'default_duration' to the DB as a per-event not hard-coded
+            # value to save adding a 'duration' to each slot.
+            duration = slots.get(slot, {}).get("duration", 60)
+            dtstart = datetime.datetime.fromisoformat(time)
+            name = summary = "[PTG] " + team
+            desc = "Etherpad: " + etherpad + "\n"
+            uid = (dtstart.strftime("%Y%m%d%H%M") + "/" + location +
+                   "@ptg.opendev.org")
+
+            e = icalendar.Event()
+            e.add("name", name)
+            e.add("summary", summary)
+            e.add("description", desc)
+            e.add("dtstart", dtstart)
+            e.add("dtend", dtstart + datetime.timedelta(mins=duration))
+            e.add("priority", 0)
+
+            # FIXME: Why the change in format
+            # FIXME: Check for empty url?  it shouldn't happen due to the
+            # way we build the the teams/bookings lists
+            e["location"] = icalendar.vText(url)
+            e["uid"] = uid
+
+            c.add_component(e)
+
+    return c.to_ical()
diff --git a/ptgbot/web.py b/ptgbot/web.py
index 938f3ba..b5b276c 100644
--- a/ptgbot/web.py
+++ b/ptgbot/web.py
@@ -8,6 +8,9 @@ import os
 import pkg_resources
 import socketserver
 
+import ptgbot.ics
+
+
 CONFIG = {}
 
 
@@ -19,6 +22,14 @@ class RequestHandler(http.server.SimpleHTTPRequestHandler):
                 self.send_header('Content-type', 'application/json')
                 self.end_headers()
                 self.wfile.write(fp.read())
+        elif self.path.endswith('.ics'):
+            team = os.path.basename(self.path)[:-4]
+            with open(CONFIG['db_filename'], 'rb') as fp:
+                ics = ptgbot.ics.json2ical(json.load(fp), team)
+            self.send_response(200)
+            self.send_header('Content-type', 'text/calendar')
+            self.end_headers()
+            self.wfile.write(ics)
         else:
             http.server.SimpleHTTPRequestHandler.do_GET(self)
 
diff --git a/requirements.txt b/requirements.txt
index 9147466..9ae2beb 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,3 +3,4 @@ irc==15.1.1
 python-daemon >= 1.6
 ib3
 requests
+icalendar >= 5.0.0