local db = require("stratumBackend")
local completion = require("cc.completion")
local total_items = {}
local printer = peripheral.find("printer")
local monitor = peripheral.find("monitor")
local price_map = {}
local unit_name = nil
local full_item_qoute
local dirtied = false
term.clear()
if monitor then monitor.clear() end
local function tallyUpItems(price)
    local items = {}
    local currencies = db.getCurrencies()
    local worthmap = {}
    local worths = {}
    local minimum = 999
    for k,v in ipairs(currencies) do
        worthmap[db.getCurrencyWorth(v)] = v 
        worths[#worths+1] = db.getCurrencyWorth(v)
        minimum = math.min(db.getCurrencyWorth(v),minimum)
    end
    table.sort(worths, function (a, b)
        return a > b
    end)
    price = math.ceil(price/minimum)*minimum
    for _,i in ipairs(worths) do
        local subcount = math.floor(price/i)
        if subcount > 0 then
            items[worthmap[i]] = (items[worthmap[i]] or 0)+subcount
            price = price - subcount*1
        end
    end
    return items
end

local function printTotal()
    print("printing total...")
    if not printer then print("no printer found") return end
    if not printer.newPage() then print("not enough ink/pages") end
    printer.setPageTitle("Receipt")
    printer.write("Material Cost:")
    local x,y = printer.getCursorPos()
    printer.setCursorPos(1,y+2)
    local total = 0
    for k,v in pairs(total_items) do
        printer.write("- "..tostring(k).." x"..tostring(v))
        local x,y = printer.getCursorPos()
        printer.setCursorPos(1,y+1)
        total = total + (( db.getPrice(k) or 0)*v)
    end
    local x,y = printer.getCursorPos()
    printer.setCursorPos(1,y+1)
    printer.write("Total cost: "..tostring(math.floor(total*100+0.5)/100).." "..tostring(db.getCurrencyUnit()))
    local x,y = printer.getCursorPos()
    printer.setCursorPos(1,y+2)
    printer.write("Price in items:")
    local x,y = printer.getCursorPos()
    printer.setCursorPos(1,y+2)
    full_item_qoute = tallyUpItems(total)
    for k,v in pairs(full_item_qoute) do
        printer.write("- "..tostring(k).." x"..tostring(v))
        local x,y = printer.getCursorPos()
        printer.setCursorPos(1,y+1)
        total = total + (( db.getPrice(k) or 0)*v)
    end
    printer.endPage()
    print("printed the total!")
end

local function input()
    while true do
        local event = {os.pullEvent()}
        if event[1] == "key" then
            if event[2] == keys.a then
                sleep(0)
                local added_item_name = nil
                local added_item_count = nil
                local x,y = term.getSize()
                term.setCursorPos(1,y)
                term.write("item name > ")
                local materials = db.getMaterials()
                added_item_name = read(nil,nil, function(text) return completion.choice(text, materials) end)
                if added_item_name == "" then
                    added_item_name = nil
                else
                    repeat
                    term.write("item count > ")
                    added_item_count = tonumber(read())
                    until added_item_count ~= nil
                    if added_item_count <= 0 then
                        added_item_name = nil
                        added_item_count = nil
                    else
                        if not db.getPrice(added_item_name) then
                            print("item not found... define a price?")
                            print("price in items per 1 "..unit_name)
                            local new_price = nil
                            repeat
                                term.write("item price > ")
                                new_price = 1/tonumber(read())
                            until new_price ~= nil
                            ---@cast new_price number
                            if new_price > 0 then
                                db.setPrice(added_item_name,new_price)
                            end
                        end
                        total_items[added_item_name] = (total_items[added_item_name] or 0 ) + added_item_count
                        price_map[added_item_name] = db.getPrice(added_item_name)
                    end
                    dirtied = true
                end
            elseif event[2] == keys.l then
                for k,v in pairs(total_items) do
                    print(tostring(k).." x"..tostring(v))
                end
            elseif event[2] == keys.t then
                if not unit_name then
                    unit_name = db.getCurrencyUnit()
                end
                local total = 0
                for k,v in pairs(total_items) do
                    total = total + (( price_map[k] or 0)*v)
                end
                print("total: "..tostring(math.floor(total*100+0.5)/100).." "..tostring(unit_name))
            elseif event[2] == keys.f then
                if not unit_name then
                    unit_name = db.getCurrencyUnit()
                end
                sleep(0)
                local total = 0
                for k,v in pairs(total_items) do
                    print(tostring(k).." x"..tostring(v))
                    total = total + (( price_map[k] or 0)*v)
                end
                print("total: "..tostring(math.floor(total*100+0.5)/100).." "..tostring(unit_name))

                print("\nprice in items:")
                full_item_qoute = tallyUpItems(total)
                dirtied = true
                for k,v in pairs(full_item_qoute) do
                    print(tostring(k).." x"..tostring(v))
                    total = total + (( price_map[k] or 0)*v)
                end
                term.write("print receipt? (Y/n)")
                local resp = read()
                if string.find("n", string.lower(resp)) == nil or resp == "" then
                    printTotal()
                end
                term.write("finish order? (Y/n)")
                local resp = read()
                if string.find("n", string.lower(resp)) == nil or resp == "" then
                    total_items = {}
                    print("finished order..")
                end
                dirtied = true
                full_item_qoute = nil
            elseif event[2] == keys.d then
                sleep(0)
                local removed_item_name = nil
                local x,y = term.getSize()
                term.setCursorPos(1,y)
                term.write("item name > ")
                local materials = db.getMaterials()
                removed_item_name = read(nil,nil, function(text) return completion.choice(text, materials) end)
                if removed_item_name == "" then
                    removed_item_name = nil
                else
                    if total_items[removed_item_name] then
                        total_items[removed_item_name] = nil
                        print("removed item")
                    end
                end
                dirtied = true
            elseif event[2] == keys.n then
                sleep(0)
                term.setCursorPos(1,y)
                term.write("unit name > ")
                local unit_namel = read()
                if unit_namel ~= "" then
                    db.setCurrencyUnit(unit_namel)
                    unit_name = unit_namel
                    print("set currency unit")
                end
                dirtied = true
            elseif event[2] == keys.c then
                sleep(0)
                local added_currency_name = nil
                local added_currency_worth = nil
                local x,y = term.getSize()
                term.setCursorPos(1,y)
                term.write("currency name > ")
                added_currency_name = read()
                if added_currency_name == "" then
                    added_currency_name = nil
                else
                    repeat
                    term.write("currency worth > ")
                    added_currency_worth = tonumber(read())
                    until added_currency_worth ~= nil
                    if added_currency_worth <= 0 then
                        added_currency_name = nil
                        added_currency_worth = nil
                    else
                        ---@cast added_currency_worth number
                        db.setWorth(added_currency_name,added_currency_worth)
                    end
                end
                dirtied = true
            elseif event[2] == keys.i then
                sleep(0)
                local added_item_name = nil
                local added_item_price = nil
                local x,y = term.getSize()
                term.setCursorPos(1,y)
                term.write("item name > ")
                local materials = db.getMaterials()
                added_item_name = read(nil,nil, function(text) return completion.choice(text, materials) end)
                if added_item_name == "" then
                    added_item_name = nil
                else
                    repeat
                        print("price in items per 1 "..unit_name)
                        term.write("item price > ")
                        added_item_price = 1/tonumber(read())
                    until added_item_price ~= nil
                    if added_item_price <= 0 then
                        added_item_name = nil
                        added_item_price = nil
                    else
                        ---@cast added_item_price number
                        db.setPrice(added_item_name,added_item_price)
                        price_map[added_item_name] = db.getPrice(added_item_name)
                    end
                end
                dirtied = true
            end
        end
    end
end

local function render_monitor()
    while true do
        sleep(0)
        if monitor and dirtied then
            if not full_item_qoute then
                if not unit_name then
                    unit_name = db.getCurrencyUnit()
                end
                monitor.clear()
                local x,y = monitor.getSize()
                local total = 0
                for k,v in pairs(total_items) do
                    monitor.setCursorPos(1,y)
                    monitor.write(tostring(k).." x"..tostring(v).."")
                    monitor.scroll(1)
                    total = total + (( price_map[k] or 0)*v)
                end
                monitor.setCursorPos(1,y)
                monitor.write("total: "..tostring(math.floor(total*100+0.5)/100).." "..tostring(unit_name))
            else
                if not unit_name then
                    unit_name = db.getCurrencyUnit()
                end
                monitor.clear()
                local x,y = monitor.getSize()
                local total = 0
                for k,v in pairs(total_items) do
                    total = total + (( price_map[k] or 0)*v)
                end
                for k,v in pairs(full_item_qoute) do
                    monitor.setCursorPos(1,y)
                    monitor.write(tostring(k).." x"..tostring(v).."")
                    monitor.scroll(1)
                end
                monitor.setCursorPos(1,1)
                monitor.write("Full Item Quote:")
                monitor.setCursorPos(1,y)
                monitor.write("total: "..tostring(math.floor(total*100+0.5)/100).." "..tostring(unit_name))
            end
            dirtied = false
        end
    end
end
local loops = {input,render_monitor}
if db.loop then loops[#loops+1] = db.loop end
for k,v in ipairs(loops) do
    ---@cast loops thread[]
    loops[k] = coroutine.create(v)
    coroutine.resume(loops[k])
end
term.setCursorPos(1,1)
print([[Welcome to the cash register!
Controls are:
a to add an item to the order.
d to delete an item from the order.
l to list current items in the order.
t to get the total in the terminal.
(not listing items)
f to finalize the transaction.
(and optionally print the receipt)
i to add or set the price of an item to the database.
c to add or set the worth of a currency to the database.
n to set the displayed currency unit.
(default is cr for credits)
]])
local x,y = term.getSize()
term.setCursorPos(1,y)
while true do
    local event = {os.pullEvent()}
    for _,v in ipairs(loops) do
        if coroutine.status(v) ~= "dead" then
            local succ, err = coroutine.resume(v, table.unpack(event))
            if not succ then
                print(err)
            end
        end
    end
end