limapi

local cache = {} -- {["item:id"] = {["periph:id"] = {slot_n,slot_m...}}}
local mainChest = nil
local periphs = {} -- {["periph:id"] = true}
local debug = false

local function registerChests()
    periphs = {}
    local names = peripheral.getNames()

    for i = 1, #names do
        local name = names[i]
        if peripheral.hasType(name,"inventory") and name ~= mainChest then
            periphs[name] = true
        end
    end
end
local function loadCache(file)
    local f = fs.open(file,"r")
    if f == nil then return end
    cache = textutils.unserialise(f.readAll())
    f.close()
end
local function saveCache(file)
    local f = fs.open(file,"w")
    f.write(textutils.serialise(cache))
    f.close()
end
local function createCache()
    cache = {}
    for i in pairs(periphs) do
        if i ~= mainChest then
            local items = peripheral.call(i, "list")
            for slot, item in pairs(items) do
                cache[item.name] = cache[item.name] or {}
                cache[item.name][i] = cache[item.name][i] or {}
                cache[item.name][i][slot] = true
            end
        end
    end
end
local function setMainChest(name)
    if mainChest~=nil then periphs[mainChest]=true end
    mainChest = name
    periphs[name]=nil
end

local function pullItem(item, count)
    if item=="" or count==0 or cache[item]==nil then return 0 end
    local main = peripheral.wrap(mainChest)
    local remaining = count

    for periphName,slots in pairs(cache[item]) do
        local items = peripheral.call(periphName, "list")
        for slot in pairs(slots) do
            if slot == nil then break end
            if items[slot].count <= remaining then
                cache[item][periphName][slot]=nil
                local next = next
                if next(cache[item][periphName]) == nil then
                    cache[item][periphName] = nil
                    if next(cache[item]) == nil then
                        cache[item] = nil
                    end
                end
            end
            remaining = remaining - main.pullItems(periphName,slot,remaining)
            if remaining <= 0 then return count end
        end
    end

    return count-remaining
end
local function pushItemFromSlot(slot,item,count)
    -- this is a helper function and will do nothing if cached slots are full
    local remaining = count
    local main = peripheral.wrap(mainChest)
    for periphName,slots in pairs(cache[item]) do
        for i in pairs(slots) do
            remaining = remaining - main.pushItems(periphName,slot,remaining,i)
            if remaining<=0 then return count end
        end
    end
    return count-remaining
end
local function pushItem(item, count)
    if item=="" or count==0 then return 0 end
    local main = peripheral.wrap(mainChest)
    local items = main.list()
    local foundSlots = {}
    local totalFound = 0
    local maxSlot = 0
    cache[item] = cache[item] or {}

    for slot, it in pairs(items) do
        if slot > maxSlot then maxSlot = slot end
        if it.name == item then
            foundSlots[slot] = it.count
            totalFound = totalFound + it.count
        else
            foundSlots[slot] = 0
        end
    end

    if totalFound == 0 then return 0 end
    local toMove = math.min(count, totalFound)
    local remaining = toMove

    local recachePeriphs = {}
    local cachedPeriphs = cache[item] or {}
    for periphName in pairs(cachedPeriphs) do
        for slot = maxSlot, 1, -1 do
            if remaining <= 0 then break end
            local slotCount = foundSlots[slot] or 0
            if slotCount > 0 then
                local pushed = main.pushItems(periphName, slot, remaining)
                if pushed > 0 then
                    remaining = remaining - pushed
                    foundSlots[slot] = foundSlots[slot] - pushed
                    table.insert(recachePeriphs,periphName)
                end
            end
        end
    end

    if remaining > 0 then
        for periphName in pairs(periphs) do
            if not cachedPeriphs[periphName] then
                for slot = maxSlot, 1, -1 do
                    if remaining <= 0 then break end
                    local slotCount = foundSlots[slot] or 0
                    if slotCount > 0 then
                        local pushed = main.pushItems(periphName, slot, remaining)
                        if pushed > 0 then
                            cache[item] = cache[item] or {}
                            table.insert(recachePeriphs,periphName)
                            remaining = remaining - pushed
                            foundSlots[slot] = foundSlots[slot] - pushed
                        end
                    end
                end
            end
        end
    end

    for i=1,#recachePeriphs do
        local p = recachePeriphs[i]
        local l = peripheral.call(p,"list")
        for slot,it in pairs(l) do
            if it.name==item then
                cache[item][p] = cache[item][p] or {}
                cache[item][p][slot] = true
            end
        end
    end
    return toMove - remaining
end

--[[local function pushItem(item, count)
    if item=="" or count==0 then return 0 end
    local main = peripheral.wrap(mainChest)
    local items = main.list()
    local remaining = count
    local cachefull = false
    local keys = {}
    local index = 0

    cache[item] = cache[item] or {}

    for slot,it in pairs(items) do
        if it.name==item then
            if not cachefull then
                local pushed = pushItemFromSlot(slot,item,remaining)
                remaining = remaining - pushed
                if remaining<=0 then return count end
                if pushed==0 then cachefull = true end
            end
            if cachefull then
                index = index + 1
                keys[index] = {slot,it.count}
            end
        end
    end

    local function processPeriph(periphName)
        cache[item][periphName] = cache[item][periphName] or {}
        local chest = peripheral.wrap(periphName)
        local pushed = 1
        while pushed>0 and remaining>0 do
            if index==0 then return count - remaining end
            local slot = keys[index][1]
            pushed = main.pushItems(periphName,slot,remaining)
            if keys[index][2]<=pushed then
                index = index-1
            else
                keys[index][2] = keys[index][2] - pushed
            end
            remaining = remaining - pushed
        end
        local items = chest.list()
        for slot,it in pairs(items) do
            if it.name == item then
                cache[item][periphName][slot] = true
            end
        end
        if remaining==0 then return count end
    end
    for periphName in pairs(cache[item]) do
        local result = processPeriph(periphName)
        if result ~= nil then return result end
    end
    for periphName in pairs(periphs) do
        if cache[item][periphName] == nil then
            local result = processPeriph(periphName)
            if result ~= nil then return result end
        end
    end
    return count - remaining
end]]
local function returnItems()
    local l = peripheral.call(mainChest,"list")
    local c = {}
    local a = {}
    for slot,it in pairs(l) do
        c[it.name] = (c[it.name] or 0) + it.count
    end
    for name,count in pairs(c) do
        a[name] = pushItem(name,count)
    end
    return a
end
local function getCache()
    return cache,periphs
end
local function listItems()
    local keys = {}
    local ln = 0
    for k,v in pairs(cache) do
        ln=ln+1
        keys[ln]=k
    end
    return keys
end
local function countItem(item)
    if cache[item]==nil then return 0 end
    local c = 0
    for p,slots in pairs(cache[item]) do
        local items = peripheral.call(p,"list")
        for i in pairs(slots) do
            c=c+items[i].count
        end
    end
    if c == 0 or next(cache[item])==nil then cache[item]=nil end
    return c
end
local function listItemsWithCount()
    local l = listItems()
    local counted = {}
    for i=1,#l do
        counted[l[i]] = countItem(l[i])
    end
    return counted
end
local function restockMainChest()
    local m = peripheral.wrap(mainChest)
    for slot,item in pairs(m.list()) do
        pullItem(item.name,m.getItemDetail(slot).maxCount-item.count)
    end
end
local function sortChest(id)
    local c = peripheral.wrap(id)
    for slot,item in pairs(c.list()) do
        c.pushItems(id,slot)
    end
end
local function sortAllChests()
    for i in pairs(periphs) do
        sortChest(i)
    end
end
return {returnItems=returnItems,pushItem=pushItem,pullItem=pullItem,
    registerChests=registerChests,createCache=createCache,saveCache=saveCache,
    loadCache=loadCache,getCache=getCache,setDebugMode=setDebugMode,setMainChest=setMainChest,
    listItemsWithCount=listItemsWithCount,countItem=countItem,listItems=listItems,
    restockMainChest=restockMainChest,sortChest=sortChest,sortAllChests=sortAllChests}