Feat: Selector (#59)

* selector init

* fixes

* recalculate set weights on add/update

Author: DemiAutomatic

imports/selector/shared.lua

@@ -0,0 +1,175 @@
+---@alias OxSelectorItem {[1]: number, [2]: any}
+---@alias OxSelectorSet OxSelectorItem[]
+
+---@class OxSelector: OxClass
+---@field private sets OxSelectorSet | table<string, OxSelectorItem[]>
+---@field private totalWeights table<string, number>
+local OxSelector = lib.class("OxSelector")
+
+local DEFAULT_SET = 'default'
+local deepClone = lib.table.deepclone
+
+
+local function calculateTotalWeight(set)
+    local total = 0
+    for i = 1, #set do
+        local item = set[i]
+        assert(type(item) == "table", "Each OxSelectorItem must be a table")
+        local weight = item[1]
+        assert(type(weight) == "number" and weight >= 0, "weight must be 0 or more")
+        total += weight
+    end
+    return total
+end
+
+
+---@param sets OxSelectorSet | table<string, OxSelectorItem[]>
+function OxSelector:constructor(sets)
+    if type(sets) ~= "table" then
+        lib.print.error("Invalid sets provided to OxSelector constructor")
+    end
+
+    if lib.table.type(sets) == "array" then
+        sets = { [DEFAULT_SET] = sets }
+    end
+
+    self.private.totalWeights = {}
+    self.private.sets = {}
+
+    for setName, set in pairs(sets) do
+        assert(type(set) == "table" and lib.table.type(set) == "array", "Each set must be an array of OxSelectorItem")
+        assert(#set > 0, "Each set must contain at least one OxSelectorItem")
+
+        self.private.totalWeights[setName] = calculateTotalWeight(set)
+    end
+
+    self.private.sets = sets
+end
+
+--- Get a random non-weighted item from a specific set
+---@param setName? string
+---@return OxSelectorItem?
+function OxSelector:getRandom(setName)
+    local set = (setName and self.private.sets[setName]) or self.private.sets[DEFAULT_SET]
+    if not set then return nil end
+    local item = set[math.random(#set)][2]
+
+    return type(item) == "table" and deepClone(item) or item
+end
+
+--- Get a random weighted item from a specific set
+---@param setName? string
+---@return OxSelectorItem?
+function OxSelector:getRandomWeighted(setName)
+    local set = (setName and self.private.sets[setName]) or self.private.sets[DEFAULT_SET]
+    if not set then return nil end
+
+    local totalWeight = self.private.totalWeights[setName or DEFAULT_SET]
+    if totalWeight == 0 then return nil end
+
+    local randomWeight = math.random() * totalWeight
+    local cumulativeWeight = 0
+
+    for i = 1, #set do
+        cumulativeWeight = cumulativeWeight + set[i][1]
+        if randomWeight <= cumulativeWeight then
+            local item = set[i][2]
+            return type(item) == "table" and deepClone(item) or item
+        end
+    end
+
+    return nil
+end
+
+--- get multiple non-weighted random items from a specific set
+---@param setName? string
+---@param count number
+---@return OxSelectorItem[]
+function OxSelector:getRandomAmount(setName, count)
+    assert(type(count) == "number" and count > 0, "Count must be a positive number")
+    local items = {}
+    for _ = 1, count do
+        local item = self:getRandom(setName)
+        if item then
+            table.insert(items, item)
+        end
+    end
+    return items
+end
+
+--- get multiple weighted random items from a specific set
+---@param setName? string
+---@param count number
+---@return OxSelectorItem[]
+function OxSelector:getRandomWeightedAmount(setName, count)
+    assert(type(count) == "number" and count > 0, "Count must be a positive number")
+    local items = {}
+    for _ = 1, count do
+        local item = self:getRandomWeighted(setName)
+        if item then
+            table.insert(items, item)
+        end
+    end
+    return items
+end
+
+--- get all items from a specific set
+---@param setName? string
+---@return OxSelectorItem[]
+function OxSelector:getSet(setName)
+    return deepClone((setName and self.private.sets[setName]) or self.private.sets[DEFAULT_SET])
+end
+
+--- get all sets
+---@return table<string, OxSelectorItem[]>
+function OxSelector:getAllSets()
+    return deepClone(self.private.sets)
+end
+
+--- add a new set
+---@param setName string
+---@param items OxSelectorItem[]
+function OxSelector:addSet(setName, items)
+    assert(type(setName) == "string", "setName must be a string")
+
+    if self.private.sets[setName] then
+        lib.print.error("Selector set '" .. setName .. "' already exists.")
+        return
+    end
+
+    assert(type(items) == "table" and lib.table.type(items) == "array", "items must be an array")
+    assert(#items > 0, "set must contain at least one OxSelectorItem")
+
+    self.private.totalWeights[setName] = calculateTotalWeight(items)
+    self.private.sets[setName] = items
+end
+
+--- update an existing set
+---@param setName string
+---@param newItems OxSelectorItem[]
+function OxSelector:updateSet(setName, newItems)
+    assert(type(setName) == "string", "setName must be a string")
+
+    if not self.private.sets[setName] then
+        lib.print.error("Selector set '" .. setName .. "' does not exist.")
+        return
+    end
+
+    assert(type(newItems) == "table" and lib.table.type(newItems) == "array", "newItems must be an array")
+    assert(#newItems > 0, "set must contain at least one OxSelectorItem")
+
+    self.private.totalWeights[setName] = calculateTotalWeight(newItems)
+    self.private.sets[setName] = newItems
+end
+
+--- remove a set
+---@param setName string
+function OxSelector:removeSet(setName)
+    assert(type(setName) == "string", "setName must be a string")
+
+    self.private.totalWeights[setName] = nil
+    self.private.sets[setName] = nil
+end
+
+lib.selector = OxSelector
+return lib.selector