Module:DropRateCalc

Need to test if Larran's keys are buffed, specifically for Template:CallistoDrops and the other bosses like that.

---

local p = {}

-- Donator rank drop rate bonuses, shown in the "My drop bonuses" bar (MediaWiki:VoteBoostToggle.js)
local RANK_REDUCTION = { royal = 0.40, divine = 0.45 }

-- somewhat matches osrs wiki
local function getColor(rate)
    if rate == 1 then
        return "#0b5884"  -- always
    elseif rate <= 16 then
        return "#3c780a"  -- common
    elseif rate <= 64 then
        return "#a48900"  -- uncommon
    elseif rate <= 256 then
        return "#b55e0c"  -- rare
    elseif rate <= 999 then
        return "#9f261e"  -- very rare
    else
        return "#5c1a1a"  -- extremely rare
    end
end

-- pass rank like {{DropRateCalc|512||d}} or {{DropRateCalc|512||r}}.  The two || between rate and rank are necessary, otherwise the arg is matched as noboost.
-- fallback to title to save edits on all pre-existing div pages (hopefully)
local function npcRank(frame)
    local f = frame.args[3] and frame.args[3]:lower() or ""
    if f == "d" then return "divine" end
    if f == "r" then return "royal" end
    local title = mw.title.getCurrentTitle().text:lower()
    if title:find("divine", 1, true) then return "divine" end
    if title:find("royal", 1, true) then return "royal" end
end

-- One drop rate cell. Monsters that need a Royal or Divine rank start at that rank's rate;
-- the bar then applies the reader's own rank and bonuses.
function p.calc(frame)
    local base = tonumber(frame.args[1])
    if not base then return "Invalid base rate" end
    local noboost = frame.args[2] == "noboost"
    local rank = npcRank(frame)
    local rate = base
    if not noboost and rank then
        rate = math.floor(base * (1 - RANK_REDUCTION[rank]))
    end
    local attrs = ' data-baserate="' .. base .. '" data-reduction="0"'
    if rank then attrs = attrs .. ' data-npcrank="' .. rank .. '"' end
    if noboost then attrs = attrs .. ' data-noboost="1"' end
    return '<td' .. attrs
        .. ' style="background-color:' .. getColor(rate) .. '; color:#ffffff; text-align:center;"'
        .. '>1/' .. rate .. '</td>'
end

return p