feat: add OWM condition id to icon mapping

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

1 files changed, 62 insertions, 0 deletions

diff --git a/lib/weather.lua b/lib/weather.lua
new file mode 100644
index 0000000..4eab3ac
--- /dev/null
+++ b/lib/weather.lua
@@ -0,0 +1,62 @@
+-- OpenWeatherMap domain knowledge and cache parsing.
+--
+-- Separate from lib/data.lua: that reads /proc and /sys, this reads a cached
+-- HTTP response and carries its own tables. Same testable shape though, every
+-- function takes a string or numbers and returns a value, so the tests need no
+-- filesystem and no network.
+--
+-- Nothing here raises. A Lua error in this project is a blank screen, so every
+-- parse path returns nil and lets the widget draw its "no data" state.
+
+local M = {}
+
+-- Nerd Font codepoints, all present in Inconsolata Nerd Font (card.FONT_MONO).
+-- Verified by rendering the glyphs and looking at them, not by fontconfig
+-- alone: a missing glyph draws as an invisible blank rather than an error.
+M.ICON = {
+  thunder_day       = '\u{E30F}',
+  thunder_night     = '\u{E32A}',
+  drizzle_day       = '\u{E306}',
+  drizzle_night     = '\u{E326}',
+  drizzle_heavy_day = '\u{E308}',
+  drizzle_heavy_night = '\u{E325}',
+  rain_day          = '\u{E308}',
+  rain_night        = '\u{E325}',
+  snow              = '\u{E31A}',
+  fog               = '\u{E313}',
+  tornado           = '\u{E351}',
+  clear_day         = '\u{E30D}',
+  clear_night       = '\u{E32B}',
+  few_day           = '\u{E302}',
+  few_night         = '\u{E379}',
+  overcast          = '\u{E312}',
+  unknown           = '\u{E374}',
+  sunrise           = '\u{E34C}',
+  sunset            = '\u{E34D}',
+}
+
+-- Condition id to icon, by upper bound. Ported from the polybar script's
+-- accumulated knowledge; the ranges are not round hundreds.
+-- `now`, `sunrise` and `sunset` are unix timestamps and pick the day or night
+-- face for the conditions that have both.
+function M.icon(id, now, sunrise, sunset)
+  if type(id) ~= 'number' then return M.ICON.unknown end
+  local day = true
+  if sunrise and sunset then day = (now >= sunrise and now <= sunset) end
+  local function pick(d, n) return day and d or n end
+
+  if id <= 232 then return pick(M.ICON.thunder_day, M.ICON.thunder_night)
+  elseif id <= 311 then return pick(M.ICON.drizzle_day, M.ICON.drizzle_night)
+  elseif id <= 321 then return pick(M.ICON.drizzle_heavy_day, M.ICON.drizzle_heavy_night)
+  elseif id <= 531 then return pick(M.ICON.rain_day, M.ICON.rain_night)
+  elseif id <= 622 then return M.ICON.snow
+  elseif id <= 771 then return M.ICON.fog
+  elseif id == 781 then return M.ICON.tornado
+  elseif id == 800 then return pick(M.ICON.clear_day, M.ICON.clear_night)
+  elseif id == 801 then return pick(M.ICON.few_day, M.ICON.few_night)
+  elseif id <= 804 then return M.ICON.overcast
+  end
+  return M.ICON.unknown
+end
+
+return M