1 files changed, 64 insertions, 0 deletions
diff --git a/activity.lua b/activity.lua
new file mode 100644
index 0000000..1be6e93
--- /dev/null
+++ b/activity.lua
@@ -0,0 +1,64 @@
+local activity = {}
+
+
+function activity.days (year)
+	if year % 4 ~= 0 or year % 100 == 0 and year % 400 ~= 0 then
+		return 365
+	end
+	return 366
+end
+
+
+function activity.this_year ()
+	return os.date"%Y"
+end
+
+
+function activity.first_week_day (year)
+	year = year or activity.this_year()
+	return os.date("*t", os.time{year=year, month=1, day=1}).wday
+end
+
+
+function activity.generate_table (year)
+	year = year or activity.this_year()
+
+	local function spot ()
+		return [[<td>]]
+	end
+
+	local function day (level)
+		return ([[<td data-activity-level="%d">]]):format(level)
+	end
+
+	local function cell (exists)
+		if not exists then
+			return spot
+		end
+		return day
+	end
+
+	local function row (weekday, first, last)
+		first = cell(first)
+		last = cell(last)
+		local row = ([[<tr><td class="activity-chart-label"><span>%s</span>]]):format(weekday)
+		row = row .. first(math.random(0, 4))
+		for _=1,51 do
+			row = row .. day(math.random(0, 4))
+		end
+		row = row .. last(math.random(0, 4)) .. "\n"
+		return row
+	end
+
+	local rows = ""
+	local weekdays = {"", "Mon", "", "Wed", "", "Fri", ""}
+	local start_from = activity.first_week_day(year)
+	local end_at = (start_from + activity.days(year) - 1) % 7
+	for index, weekday in pairs(weekdays) do
+		rows = rows .. row(weekday, index >= start_from, index <= end_at)
+	end
+	return [[<table class="activity-chart">]] .. "\n" .. rows .. "</table>"
+end
+
+
+return activity