-- Links material input pins of selected mesh nodes to the correspondingly named
-- output linkers of a Node Graph, where your materials are located.
-- If you prefer to copy the materials, just find the variable 'copy_materials' below and change to true
--
--  @description    Links selected mesh materials to matching outputs in a node graph
--  @author         Soft Office
--  @version        0.1
--  @shortcut       alt + l

-- options
local copy_materials = false

-- functions
function values (t)
  local i = 0
  return function ()  i = i + 1; return t[i]  end
end

function select_node_type(items, node_type)
    --returns all nodes in selection set matching given type
    selection = {}
        for i, n in pairs(items) do
            if n.nodeType == node_type then 
                table.insert(selection, n) 
            end
        end
    return selection
end

function find_first_graph(items, graph_type)
    --returns first graph in the selection set
    for n in values(items) do
        if n.graphType == graph_type then 
            return n 
        end
    end
    return nil
end

function select_pin_type(node, pin_type)
    --returns indexes of all pins matching given type
    pins = {}
    for i=1, node:getPinCount() do
        if node:getPinInfoIx(i).type == pin_type then table.insert(pins, node:getPinInfoIx(i).name) end
    end
    return pins
end

function print_table(table, str)
    --print a table plus an optional extra string
    for i,n in pairs(table) do
        print(i,n)
    end
    print(str)
end


--get selection
local sel = octane.project.getSelection()
--print("selection set:")
--print_table(sel, "\n")
if #sel == 0 then
    octane.gui.showError("Selection is empty!", "Material Linker")
    return nil
end--if

--get Node Graph
mat_graph = find_first_graph(sel, octane.GT_STANDARD)
--print("material graph:\n", mat_graph, "\n")
if mat_graph == nil then
    octane.gui.showError("Please include a (single) node graph in your selection", "Material Linker")
    return nil
end

--get Material Outputs
mat_outputs = mat_graph:findNodes(octane.NT_OUT_MATERIAL, false)
--print("material outputs:")
--print_table(mat_outputs, "\n")
if #mat_outputs == 0 then
    octane.gui.showError("Please include at least one material output in the node graph", "Material Linker")
    return nil
end

--get Mesh nodes
local geom_nodes = select_node_type(sel, octane.NT_GEO_MESH)
--print("geometry nodes:")
--print_table(geom_nodes, "\n")
if #geom_nodes == 0 then
    octane.gui.showError("Please include at least one mesh node in your selection", "Material Linker")
    return nil
end


for n in values(geom_nodes) do
    print("material pins for ", n, ":")
    for pinIx=1, n:getPinCount() do
        if n:getPinInfoIx(pinIx).type == octane.PT_MATERIAL then
            --match pin name to a material output name
            local src = nil
            for m in values(mat_outputs) do
                if n:getPinInfoIx(pinIx).name == m:getProperties().name then
                    src = copy_materials and m:getConnectedNodeIx(1) or m
                    break
                end--if
            end
            print("> ", n:getPinInfoIx(pinIx).name, " : ", src)
            if src then 
                if copy_materials then
                    n:copyFromIx(pinIx, src)
                else
                    n:connectToIx(pinIx, src)
                end--if
            end--if
        end--if
    end--for
    print(" ")
end--for