Class.ttslua

---@class ge_tts__Class
local Class = {}

---@param object table
---@return nil | table
function Class.getClass(object)
    return (--[[---@type { __class: nil | table } ]] object).__class
end

---@param sourceClass table
---@param targetClass table
---@return boolean
local function isDescendentClass(sourceClass, targetClass)
    if sourceClass == targetClass then
        return true
    end

    local parentClass = (--[[---@type { __index: nil | table } ]] getmetatable(sourceClass)).__index
    return parentClass ~= nil and isDescendentClass(--[[---@not nil]] parentClass, targetClass)
end

---@type table<table, nil | table<table, nil | boolean>>
local descendentCache = {}

---@param sourceClass table
---@param targetClass table
---@return boolean
function Class.isDescendentClass(sourceClass, targetClass)
    if sourceClass == targetClass then
        return true
    end

    local sourceCache = descendentCache[sourceClass]

    if sourceCache then
        local isDescendent = (--[[---@not nil]] sourceCache)[targetClass]

        if isDescendent ~= nil then
            return --[[---@not nil]] isDescendent
        end
    else
        sourceCache = {}
        descendentCache[sourceClass] = sourceCache
    end

    local parentClass = (--[[---@type { __index: nil | table } ]] getmetatable(sourceClass)).__index
    local isDescendent = parentClass ~= nil and isDescendentClass(--[[---@not nil]] parentClass, targetClass)

    ;(--[[---@not nil]] sourceCache)[targetClass] = isDescendent

    return isDescendent
end

---@param object table
---@return boolean
function Class.isInstance(object, class)
    local objectClass = Class.getClass(object)
    return objectClass ~= nil and Class.isDescendentClass(--[[---@not nil]] Class.getClass(object), class)
end

---@generic AncestorClass
---@generic Class : AncestorClass
---@param descendent Class
---@param parent nil | AncestorClass
---@return AncestorClass
function Class.parentConstructor(descendent, parent)
    local metatable = --[[---@type { __call: function }]] getmetatable(parent)
    local call = metatable.__call
    local wrappedStaticParent = function(...)
        return call(descendent, ...)
    end
    return --[[---@type AncestorClass]] wrappedStaticParent
end

---@generic Class
---@param class Class
---@return { __class: Class }
function Class.rootConstructor(class)
    return { __class = class }
end

return Class