--
-- Minetest lurkcoin mod - ATMs
--
-- © 2019 by luk3yx
--

local open_atms = {}

local function e(text)
    return minetest.formspec_escape(tostring(text))
end

local formspecs = {}

lurkcoin.formspec_prepend = 'style_type[image_button;bgimg=;bgimg_pressed=]'

-- 0.4 compatibility
if minetest.global_exists('default') and default.gui_bg and
        default.gui_bg_img and default.gui_slots then
    lurkcoin.formspec_prepend = default.gui_bg .. default.gui_bg_img ..
        default.gui_slots .. lurkcoin.formspec_prepend
end

local function centre_label(pos, label)
    return 'image_button[' .. pos .. ';blank.png;;' .. e(label) ..
        ';true;false;]'
end

local formspec_img = 'blank.png'
if minetest.registered_items['default:mese_crystal'] then
    formspec_img = 'default_mese_crystal.png'
elseif minetest.registered_items['default:gold_ingot'] or
        minetest.registered_items['mcl_core:gold_ingot'] then
    formspec_img = 'default_gold_ingot.png'
end

-- The formspec code is based on something I did in 2017(?) for lurkcoinV1,
-- formspecs are weird and I somehow got it right then.
local function get_formspec(name, page, params)
    -- The formspec template
    local formspec = 'size[8,9]' .. lurkcoin.formspec_prepend ..
        'label[0.5,1.75;Your balance: ' ..
            e(lurkcoin.bank.getbal(name)) .. 'cr.]' ..
        centre_label('1,0.55;6,0.5', 'Welcome to a ' .. lurkcoin.server_name ..
            ' ATM!') ..
        'label[0.5,2.25;Exchange rate: \194\1641.00 is equal to ' ..
            e(lurkcoin.exchange_rate) .. 'cr.]' ..
        centre_label('1.75,1.05;4.5,0.5', 'Your account: ' .. name) ..
        'image[0.5,0.5;1,1;' .. formspec_img .. ']' ..
        'image[6.5,0.5;1,1;' .. formspec_img .. ']'

    -- Get the page formspec
    page = formspecs[page] or formspecs.main
    if type(page) == 'string' then
        formspec = formspec .. page
    elseif type(page) == 'function' then
        formspec = formspec .. page(name, params)
    end

    -- Return the generated formspec
    return formspec
end

-- The formspecs (depending on installed mods)
local withdrawls = false

-- Payment screen
function formspecs.pay(name, fields)
    fields = fields or {}
    local formspec =
        'field[0.8,3.5;7,1;user;User to pay;' .. e(fields.user or '') .. ']' ..
        'field_close_on_enter[user;false]' ..
        'field[0.8,4.8;7,1;server;Server the user is on;' ..
            e(fields.server or lurkcoin.server_name) .. ']' ..
        'field_close_on_enter[server;false]' ..
        'field[0.8,6.15;7,1;amount;Amount to pay (in cr);' ..
            e(fields.amount or '5.00') .. ']' ..
        'field_close_on_enter[amount;false]'

    if fields._err then
        formspec = formspec ..
            'label[0.5,7;' .. e(fields._err) .. ']' ..
            'button[0.5,8;3.5,1;payuser;Cancel]' ..
            'button[4,8;3.5,1;paysubmit;Try again]'
    elseif fields.paysubmit then
        formspec = formspec ..
            'label[0.5,7;Please confirm the above values.'
        if fields.server ~= lurkcoin.server_name then
            local exc = -1
            if type(fields._exchange_rate) == 'number' then
                exc = fields._exchange_rate
            end

            if exc < 0 then
                lurkcoin.get_exchange_rate(fields.amount, fields.server or
                        lurkcoin.server_name, function(data, msg)
                    if not data then
                        fields._err = msg
                    end
                    fields._exchange_rate = data
                    return lurkcoin.show_atm(name, 'pay', fields)
                end)
                return formspec .. '\n' .. fields.amount .. 'cr is equal to' ..
                    ' ...\n\n(Calculating...)]'
            end

            exc = tostring(math.floor(exc * 100) / 100)
            formspec = formspec .. '\n' .. fields.amount .. 'cr is ' ..
                'equal to ' .. exc .. '.'
        end
        formspec = formspec .. ']' ..
            'button[0.5,8;3.5,1;payuser;Cancel]' ..
            'button[4,8;3.5,1;payconfirm;Confirm and pay]'
    else
        formspec = formspec ..
            'button[0.5,7;7,1;paysubmit;Pay the user!]'

        if withdrawls then
            formspec = formspec ..
                'button[0.5,8;3.5,1;home;Go back]' ..
                'button_exit[4,8;3.5,1;quit;Quit]'
        else
            formspec = formspec ..
                'button_exit[0.5,8;7,1;quit;Quit]'
        end
    end
    return formspec
end

-- The main formspec
if minetest.get_modpath('currency') then
    formspecs.main =
        'button[0.5,3.25;7,1;deposit;Deposit money]' ..
        'field[0.8,4.87;6,1;withdraw;Withdraw money (in Mg);5.00]' ..
        'field_close_on_enter[withdraw;false]' ..
        'button[6.5,4.55;1,1;wd;Next >]' ..
        'field[0.8,6.12;6,1;user;Pay someone;]' ..
        'field_close_on_enter[user;false]' ..
        'button[6.5,5.8;1,1;payuser;Next >]' ..
        'button_exit[0.5,8;7,1;quit;Quit]'

    -- Create a withdrawls list with available currency.
    withdrawls = {
        [0.05] = 'currency:minegeld_cent_5',
        [0.10] = 'currency:minegeld_cent_10',
        [0.25] = 'currency:minegeld_cent_25',
        [1]    = 'currency:minegeld',
        [5]    = 'currency:minegeld_5',
        [10]   = 'currency:minegeld_10',
        [20]   = 'currency:minegeld_20', -- The original mod now has 20Mg notes.
        [50]   = 'currency:minegeld_50',
        [100]  = 'currency:minegeld_100',
    }

    -- Remove non-registered notes
    local remove = {}
    for id, note in pairs(withdrawls) do
        if not minetest.registered_items[note] then
            table.insert(remove, id)
        end
    end
    for _, id in ipairs(remove) do
        withdrawls[id] = nil
    end
    assert(#withdrawls > 0, 'The "currency" mod did not register any notes!')

    -- Create a detached inventory for depositing
    local inv = minetest.create_detached_inventory('lurkcoin:atm_deposit', {
        on_put = function(inv, listname, _, stack, player)
            local name = stack:get_name()
            if name:sub(1, 17) == 'currency:minegeld' then
                local m = name:sub(19)
                if #m > 0 then
                    if m:sub(1, 5) == 'cent_' then
                        m = tonumber(m:sub(6))
                        if m then m = m / 100 end
                    elseif m == 'bundle' then
                        m = 0.05 * 9
                    else
                        m = tonumber(m)
                    end
                else
                    m = 1
                end

                if type(m) == 'number' and m == m then
                    m = m * stack:get_count()
                    local pname = player:get_player_name()
                    if not lurkcoin.bank.add(pname, m, 'Deposit') then
                        player:get_inventory():add_item('main', stack)
                    end
                    minetest.log('action', 'Player ' .. pname ..
                        ' deposits ' .. tostring(m) .. 'Mg (' ..
                        stack:to_string() .. ') into a lurkcoin ATM.')
                end
            end
            inv:set_list(listname, {})
            lurkcoin.show_atm(player:get_player_name(), 'deposit')
        end,

        allow_put = function(_, _, _, stack, _)
            local name = stack:get_name()
            if name:sub(1, 17) == 'currency:minegeld' then
                return stack:get_count()
            else
                return 0
            end
        end,

        allow_take = function() return 0 end,
    })
    inv:set_size("lurkcoin", 1)

    -- Depositing
    formspecs.deposit =
        'list[current_player;main;0,4.85;8,1;]'  ..
        'list[current_player;main;0,6.08;8,3;8]' ..
        'list[detached:lurkcoin:atm_deposit;lurkcoin;3.5,3;1,1;]' ..
        'listring[]' ..
        centre_label('0,3;3.5,1', 'Deposit money here →') ..
        'button[5.25,3;2,1;home;Finish]'
else
    -- When there is no physical currency, the only thing you can do is pay
    --  others.
    formspecs.main = formspecs.pay
end

-- "Transaction accepted" screen
function formspecs.success(_, text)
    return 'image[2.1,3;4.5,4.5;lurkcoin_success.png]' ..
        centre_label('1,7;6,1', text or 'Transaction sent!') ..
        'button[0.5,8;3.5,1;home;Go back]' ..
        'button_exit[4,8;3.5,1;quit;Quit]'
end

-- "Transaction failed" screen
function formspecs.error(_, text)
    return 'image[2.1,3;4.5,4.5;lurkcoin_error.png]' ..
        centre_label('1,7;6,1', text or 'An error has occurred!') ..
        'button[0.5,8;3.5,1;home;Go back]' ..
        'button_exit[4,8;3.5,1;quit;Quit]'
end

-- Processing screen
formspecs.processing =
    'image[2.1,3;4.5,4.5;lurkcoin_processing.png]' ..
    centre_label('1,7;6,1', 'Processing your transaction...') ..
    centre_label('1,8;6,1', 'This should only take a few seconds.')

-- A wrapper function
function lurkcoin.show_atm(name, page, params)
    minetest.show_formspec(name, 'lurkcoin:atm', get_formspec(name,
        page, params))
end

minetest.register_on_player_receive_fields(function(player, formname, raw)
    if formname ~= 'lurkcoin:atm' then return end

    local name = player:get_player_name()

    -- Do a shallow copy in case some other mod relies on "fields" not changing.
    local fields = {}
    for k, v in pairs(raw) do
        if type(k) == 'string' and k:sub(1, 1) ~= '_' then
            fields[k] = v
        end
    end

    if withdrawls then
        if fields.deposit then
            return lurkcoin.show_atm(name, 'deposit')
        elseif fields.wd then
            local amount = tonumber(fields.withdraw)
            if not amount or amount ~= amount or amount <= 0 then
                return lurkcoin.show_atm(name, 'error',
                    'ERROR: Invalid number!')
            end
            local bal = lurkcoin.bank.getbal(name)
            if amount > bal then
                return lurkcoin.show_atm(name, 'error',
                    'ERROR: You cannot afford to do that!')
            end

            local note
            for id, item in pairs(withdrawls) do
                -- HACK: Multiply both amount and id by 1000 to avoid
                -- floating-point bugs.
                if (not note or id > note) and
                        (amount * 1000) % (id * 1000) == 0 then
                    local def = minetest.registered_items[item]
                    if def and amount / id <= (def.stack_max or 99) then
                        note = id
                    end
                end
            end

            if not note then
                return lurkcoin.show_atm(name, 'error',
                    'ERROR: I cannot store that amount of\nmoney in a ' ..
                    'single stack of notes/coins!')
            end

            local stack = ItemStack({
                name  = withdrawls[note],
                count = (amount * 1000) / (note * 1000),
            })
            local inv = player:get_inventory()
            if not inv:room_for_item('main', stack) then
                return lurkcoin.show_atm(name, 'error',
                    'ERROR: You do not have enough inventory space!')
            end

            minetest.log('action', 'Player ' .. name .. ' withdraws ' ..
                tostring(amount) .. 'Mg (' .. stack:to_string() ..
                ') from a lurkcoin ATM.')
            lurkcoin.bank.subtract(name, amount)
            inv:add_item('main', stack)

            return lurkcoin.show_atm(name, 'success')
        end
    end

    if fields.payconfirm and open_atms[name] and open_atms[name].pay then
        local data = open_atms[name]
        for k, v in pairs(data) do
            if type(v) == 'number' then fields[k] = tonumber(fields[k]) end
            if k ~= 'pay' and fields[k] ~= v then
                if k ~= 'amount' then
                    k = 'target ' .. k
                end
                fields._err = 'The ' .. k ..
                    ' was modified before pressing confirm!'
                lurkcoin.show_atm(name, 'pay', fields)
                return
            end
        end
        lurkcoin.show_atm(name, 'processing')
        lurkcoin.pay(name, data.user, data.server, data.amount,
            function(success, msg)
                local page = success and 'success' or 'error'
                return lurkcoin.show_atm(name, page, msg)
            end
        )
    elseif fields.payuser or fields.paysubmit or fields.payconfirm then
        if fields.paysubmit then
            local amount = tonumber(fields.amount)
            if not amount or amount ~= amount or amount <= 0 then
                fields._err = 'Invalid number!'
                lurkcoin.show_atm(name, 'pay', fields)
                return
            elseif lurkcoin.bank.getbal(name) - amount < 0 then
                fields._err = 'You cannot afford to do that!'
                lurkcoin.show_atm(name, 'pay', fields)
                return
            elseif fields.server then
                fields.server = fields.server:trim()
            end

            if fields.user then
                fields.user = fields.user:trim()
            end

            if not fields.server or fields.server == '' then
                fields.server = lurkcoin.server_name
            end

            open_atms[name] = {
                pay    = true,
                user   = fields.user or '',
                server = fields.server,
                amount = amount,
            }
            if open_atms[name].user == '' or (
                    fields.server == lurkcoin.server_name and
                    not lurkcoin.bank.user_exists(open_atms[name].user)
                    ) then
                fields._err = 'That user does not exist!'
                lurkcoin.show_atm(name, 'pay', fields)
                return
            end
        end
        lurkcoin.show_atm(name, 'pay', fields)
    elseif fields.home then
        lurkcoin.show_atm(name, 'main')
    elseif fields.quit then
        open_atms[name] = nil
    end
end)

minetest.register_on_leaveplayer(function(player)
    open_atms[player:get_player_name()] = nil
end)