Dumped recent refueling history into a repository

Yes, currently it only dumps into the standard output. There's too
little data especially on LPG to make any good estimates at this
point. Later on, this format will allow the data to be dumped anywhere
for any kind of analysis or calculations to be done within this
codebase.

Or something like that.

2 files changed, 37 insertions, 0 deletions

diff --git a/dump.lua b/dump.lua
new file mode 100755
index 0000000..4fb3d77
--- /dev/null
+++ b/dump.lua
@@ -0,0 +1,7 @@
+#!/usr/bin/env -S lua -l fuel
+local f = fuel.fill
+local r = fuel.relative
+f("O", "2023-12-28", "17:55", 202230.0, "95", 100.21, 15.37)
+f("O", "2024-02-23", "12:05", r(119.2), "lpg", 74.14, 23.61)
+f("O", "2024-02-23", "12:18", 202350.9, "95", 100.02, 14.95)
+f("O", "2024-04-05", "12:27", r(279.2), "95", 100.16, 14.86)
diff --git a/fuel.lua b/fuel.lua
new file mode 100644
index 0000000..c10b205
--- /dev/null
+++ b/fuel.lua
@@ -0,0 +1,30 @@
+local fmts = {
+	["zł"] = "%.2f %s",
+	l = "%.2f %s",
+	km = "%.1f %s",
+}
+
+
+local function fmt (value, unit)
+	return (fmts[unit] or "%.1f"):format(value, unit)
+end
+
+
+local last_milage = 0
+
+
+local function relative (kilometres)
+	return last_milage + kilometres
+end
+
+
+local function fill (id, date, time, milage, fuel, cost, volume)
+	if last_milage > milage then
+		error "new milage may not be less than the previous"
+	end
+	last_milage = milage
+	print(id, date, time, fmt(last_milage, "km"), fuel, fmt(cost, "zł"), fmt(volume, "l"))
+end
+
+
+return {fill=fill, relative=relative}