local component = require("component")
local robot = require("robot")
local sides = require("sides")

local crafting = component.crafting
local inventory = component.inventory_controller

RESULT_SLOT = 4

local iron_pickaxe_recipe = {
    result = {
        name = 'minecraft:iron_pickaxe',
        count = 1,
    },
    ingredients = {
        'minecraft:iron_ingot', 'minecraft:iron_ingot', 'minecraft:iron_ingot',
        nil, 'minecraft:stick', nil,
        nil, 'minecraft:stick', nil,
    }
}

-- robots inventory is 4 wide and crafting uses the top left portion
local slot_map = {
    1,2,3,
    5,6,7,
    9,10,11
}

-- Search the facing chest for "item" and take "count" items and place them in "slot"
-- Returns number of items fetched
local function fetch_item(item, output_slot)
    robot.select(output_slot)
    local size = inventory.getInventorySize(sides.forward)
    if not size then
        print('Not facing a chest')
        return false
    end

    for slot = 1, size do
        local stack = inventory.getStackInSlot(sides.forward, slot)
        if stack then
            if stack.name == item then
                inventory.suckFromSlot(sides.forward, slot, 1)
                return true
            end
        end
    end

    print('Missing ' .. item)
    return false
end

-- accepts a recipe table containing result and ingredients
local function craft_recipe(recipe)
    for i, ingredient in pairs(recipe.ingredients) do
        print('Fetching ' .. ingredient)
        fetch_item(ingredient, slot_map[i])
    end

    -- select slot for the result
    robot.select(RESULT_SLOT)

    -- craft the resulting item
    local crafted = crafting.craft(1)

    if not crafted then
        print('Crafting failed')
    end
end

-- local target = ...

-- if not target then
--     print("Usage: craft <item>")
--     return
-- end

craft_recipe(iron_pickaxe_recipe)