local Public = {}

local shop_list = {
    ['coal'] = 1,
    ['copper-ore'] = 1,
    ['crude-oil-barrel'] = 7.5,
    ['empty-barrel'] = 5,
    ['iron-ore'] = 1,
    ['landfill'] = 2,
    ['raw-fish'] = 4.25,
    ['stone'] = 1,
    ['uranium-ore'] = 3,
    ['wood'] = 0.75
}

function Public.create_shopping_chest(surface, position, destructible)
    local entity = surface.create_entity({name = 'logistic-chest-requester', position = position, force = 'shopping_chests'})
    entity.minable = false
    if not destructible then
        entity.destructible = false
    end
end

function Public.create_dump_chest(surface, position, destructible)
    local entity = surface.create_entity({name = 'logistic-chest-passive-provider', position = position, force = 'shopping_chests'})
    entity.minable = false
    if not destructible then
        entity.destructible = false
    end
end

local function get_affordable_item_count(name, count)
    if global.credits >= count * shop_list[name] then
        return count
    end
    count = math.floor(global.credits / shop_list[name])
    return count
end

local function process_shopping_chest(k, chest)
    if not chest.valid then
        global.shopping_chests[k] = nil
        return
    end
    if global.credits <= 0 then
        return
    end
    local requested_item_stack = chest.get_request_slot(1)
    if not requested_item_stack then
        return
    end
    if not shop_list[requested_item_stack.name] then
        chest.surface.create_entity(
            {name = 'flying-text', position = {chest.position.x - 2, chest.position.y}, text = requested_item_stack.name .. ' is not for sale', color = {r = 200, g = 160, b = 30}}
        )
        return
    end
    local inventory = chest.get_inventory(defines.inventory.chest)
    --if not inventory.can_insert(requested_item_stack) then return end
    local current_count = inventory.get_item_count(requested_item_stack.name)
    if current_count >= requested_item_stack.count then
        return
    end
    local count = requested_item_stack.count - current_count
    count = get_affordable_item_count(requested_item_stack.name, count)
    if count < 1 then
        return
    end
    local inserted_amount = inventory.insert({name = requested_item_stack.name, count = count})
    if inserted_amount == 0 then
        return
    end
    local spent_credits = inserted_amount * shop_list[requested_item_stack.name]
    global.credits = global.credits - spent_credits
    chest.surface.create_entity({name = 'flying-text', position = chest.position, text = '-' .. spent_credits .. ' ø', color = {r = 200, g = 160, b = 30}})
end

local function process_dump_chest(key, chest)
    if not chest.valid then
        global.dump_chests[key] = nil
        return
    end
    local inventory = chest.get_inventory(defines.inventory.chest)
    if inventory.is_empty() then
        return
    end
    for k, _ in pairs(shop_list) do
        local removed = inventory.remove(k)
        if removed > 0 then
            local gain = removed * shop_list[k]
            global.credits = global.credits + gain
            chest.surface.create_entity({name = 'flying-text', position = chest.position, text = '+' .. gain .. ' ø', color = {r = 200, g = 160, b = 30}})
            return
        end
    end
end

local function gui()
    local tooltip = 'Trade goods: '
    for k, v in pairs(shop_list) do
        tooltip = tooltip .. k
        tooltip = tooltip .. ' '
        tooltip = tooltip .. v
        tooltip = tooltip .. ' | '
    end

    for _, player in pairs(game.connected_players) do
        if player.gui.top.credits_button then
            player.gui.top.credits_button.destroy()
        end
        local frame = player.gui.top.add({type = 'frame', name = 'credits_button'})
        frame.style.maximal_height = 38
        frame.style.top_padding = 0
        frame.style.left_padding = 0
        local element = frame.add({type = 'label', name = 'credits', caption = global.credits .. ' ø', tooltip = tooltip})
        local style = element.style
        style.minimal_height = 38
        style.maximal_height = 38
        style.minimal_width = 100
        style.horizontal_align = 'right'
        style.top_padding = 2
        style.left_padding = 2
        style.right_padding = 2
        style.bottom_padding = 2
        style.font_color = {r = 255, g = 215, b = 0}
        style.font = 'default-large-bold'
    end
end

local function on_gui_opened(event)
    if not event.entity then
        return
    end
    if event.entity.force.name ~= 'shopping_chests' then
        return
    end

    local index = event.entity.position.x .. '_'
    index = index .. event.entity.position.y
    if global.registerd_shopping_chests[index] then
        return
    end

    if event.entity.name == 'logistic-chest-passive-provider' then
        global.dump_chests[#global.dump_chests + 1] = event.entity
        global.registerd_shopping_chests[index] = true
        event.entity.surface.create_entity({name = 'flying-text', position = event.entity.position, text = 'Chest registered, shop active!', color = {r = 200, g = 160, b = 30}})
        return
    end
    if event.entity.name == 'logistic-chest-requester' then
        global.shopping_chests[#global.shopping_chests + 1] = event.entity
        global.registerd_shopping_chests[index] = true
        event.entity.surface.create_entity({name = 'flying-text', position = event.entity.position, text = 'Chest registered, shop active!', color = {r = 200, g = 160, b = 30}})
        return
    end
end

local function tick()
    for k, chest in pairs(global.shopping_chests) do
        process_shopping_chest(k, chest)
    end
    for k, chest in pairs(global.dump_chests) do
        process_dump_chest(k, chest)
    end
    gui()
end

local function on_init()
    global.shopping_chests = {}
    global.dump_chests = {}
    global.registerd_shopping_chests = {}
    global.credits = 0
    game.create_force('shopping_chests')
    game.forces.player.set_friend('shopping_chests', true)
    game.forces.shopping_chests.set_friend('player', true)
end

local Event = require 'utils.event'
Event.add(defines.events.on_gui_opened, on_gui_opened)
Event.on_nth_tick(120, tick)
Event.on_init(on_init)

return Public