Dragon finder

-- ......
local args = { ... }

local DEBUG = false
local ITEM_NOT_FOUND = -1
local PERIPHERAL_SIDE = "left"
local PROTOCOL_STR = "gpsl"
local LOG_FILE = "lastrun.txt"
local DRAGONS_FILE = "dragons_found.txt"

local TURTLE_ID = 16
local RECV_ID = 7

local STRIDE = 32
local STRIDES_TO_DO = 32
local LATERAL_STRIDE = 32 -- default sensor range = 16
local STRIPS = 32
local FW_DIRECTION = 1    -- 1 foward, -1 back
local BK_DIRECTION = -1

local COAL_FUEL_V = 80
local REFUEL_THRESHOLD = 1000

local TURTLE_INV_SZ = 16
--local WIRELESS_MODEM = "computercraft:peripheral" range limitations
local WIRELESS_MODEM = "computercraft:advanced_modem"

local PICKAXE = "minecraft:diamond_pickaxe"
local SENSOR = "plethora:module"
local CHUNK_AWAKER = "walkingchunks:chunk_awaker"
local ENDER_CHEST = "enderstorage:ender_storage"
local COAL = "minecraft:coal"

-- peripheral type string returned by getType
local peripheral_type = {}
peripheral_type[WIRELESS_MODEM] = "modem"
peripheral_type[SENSOR] = "plethora:sensor"
peripheral_type[PICKAXE] = "pickaxe" -- not really it's type name, special case

local to_skip_list = { WIRELESS_MODEM, PICKAXE, SENSOR, ENDER_CHEST }

-- foward declare
local msg_houston
local fmt_gps_to_str
local get_gps_pos

local function log_to_file(msg, log_file)
    local handle = fs.open(log_file, "a")
    if handle then
        handle.write(msg .. '\n')
        handle.close()
    end
end

local function log_msg(msg)
    if (DEBUG) then
        print("logging..\n " .. msg)
    end

    log_to_file(msg, LOG_FILE)

    local tmp = log_msg
    log_msg = function(msg_p)
    end                           --avoid recursion
    msg_houston(msg)
    log_msg = tmp
end

local function skip_item(item)
    for i = 1, #to_skip_list, 1 do
        if item.name == to_skip_list[i] then
            return true
        end
    end
    return false
end

local function find_item_slot(item_name)
    --log_msg("Finding item slot for " .. item_name)
    for i = 1, TURTLE_INV_SZ, 1 do
        turtle.select(i)
        local item = turtle.getItemDetail()
        if item and item.name == item_name then
            return i
        end
    end

    return ITEM_NOT_FOUND
end

local function empty_inv()
    log_msg("Empting inventory...")
    for i = 1, TURTLE_INV_SZ, 1 do
        turtle.select(i)
        local item = turtle.getItemDetail()
        if item and (not skip_item(item)) then
            turtle.drop()
        end
    end
end

local function find_free_slot()
    for i = 1, TURTLE_INV_SZ, 1 do
        turtle.select(i)
        local item = turtle.getItemDetail()
        if not item then
            return i
        end
    end

    for i = 1, TURTLE_INV_SZ, 1 do
        turtle.select(i)
        local item = turtle.getItemDetail()
        if not skip_item(item) then
            turtle.drop()
            return i
        end
    end

    return -1
end

local function equip_peripheral(p_name)
    --local log = log_func or log_msg -- special case to avoid recursion
    --log_msg("Equiping " .. peripheral_type[p_name])
    if peripheral.getType(PERIPHERAL_SIDE) == peripheral_type[p_name] and p_name ~= PICKAXE then
        --log_msg(peripheral_type[p_name] .. " already equiped, skipping search...")
        return true
    end

    local item_slot = find_item_slot(p_name)
    if item_slot == ITEM_NOT_FOUND then
        log_msg("Could not find item " .. p_name)
        return false
    end

    --log_msg("Found " .. peripheral_type[p_name] .. "in slot " .. tostring(item_slot))
    turtle.select(item_slot)
    turtle.equipLeft()
    return true
end

local function refuel()
    log_msg("Refueling at pos " .. fmt_gps_to_str(get_gps_pos()))
    local has_equiped = equip_peripheral(PICKAXE)
    local fuel_chest_slot = find_item_slot(ENDER_CHEST)
    if fuel_chest_slot == ITEM_NOT_FOUND then
        return false
    end

    if turtle.detectDown() then
        turtle.digDown()
    end
    turtle.select(fuel_chest_slot)
    turtle.placeDown()
    local free_slot = find_free_slot()
    turtle.select(free_slot)
    turtle.suckDown()
    turtle.refuel()
    turtle.digDown()
    -- for i = 1, chest.size(), 1 do
    --     local item = chest.getItemMeta(i)
    --     ifitem.name == coal then
    --         free_slot = find_free_slot()
    --         chest.
    --     end
    -- end
end

local function check_and_refuel()
    local fuel_level = turtle.getFuelLevel()
    log_msg("Current fuel level " .. tostring(turtle.getFuelLevel()))
    if fuel_level < REFUEL_THRESHOLD then
        refuel()
    end
end

msg_houston = function(msg)
    local has_equiped = equip_peripheral(WIRELESS_MODEM)
    rednet.open(PERIPHERAL_SIDE)
    rednet.send(RECV_ID, msg, PROTOCOL_STR)
    rednet.close()
end

get_gps_pos = function()
    local has_equiped = equip_peripheral(WIRELESS_MODEM)
    return gps.locate(5)
end

fmt_gps_to_str = function(x, y, z)
    return tostring(x) .. " " .. tostring(y) .. " " .. tostring(z)
end

local function ez_gps_pos()
    return fmt_gps_to_str(get_gps_pos())
end

local function save_dragon(msg)
    log_to_file(msg, DRAGONS_FILE)
end

local function notify_houston()
    local x, y, z = get_gps_pos()
    local msg = "*** Dragon found around: " .. fmt_gps_to_str(x, y, z) .. " ***"
    log_msg(msg)
    save_dragon(msg)
end

local function scan_for_dragons()
    log_msg("Scanning for Dragons at " .. fmt_gps_to_str(get_gps_pos()))
    local has_equiped = equip_peripheral(SENSOR)
    local ss = peripheral.wrap(PERIPHERAL_SIDE)
    local entities = ss.sense()
    log_msg(tostring(#entities) .. " Entities found")
    for i = 1, #entities, 1 do
        if string.find(entities[i].name, "dragon") then
            return true
        end
    end
    return false
end

local function move_foward()
    turtle.dig()
    turtle.forward()
    turtle.digDown()
end

local function dig_stride(stride)
    stride = stride or STRIDE
    --log_msg("Starting a dig stride..")
    local has_equiped = equip_peripheral(PICKAXE)
    for i = 1, stride, 1 do
        move_foward()
    end
end

local function change_strip(direction, skip_strip)
    local turn = direction == FW_DIRECTION and function() turtle.turnRight() end or function() turtle.turnLeft() end
    local strides = skip_strip and (LATERAL_STRIDE * 2) or LATERAL_STRIDE
    turn()
    dig_stride(strides)
    turn()
    local dir_str = direction == FW_DIRECTION and "forward" or "back"
    log_msg("Changed strip, going " .. dir_str)
    local msg = "T:" .. fmt_gps_to_str(get_gps_pos())
    log_msg(msg)
end

local function run()
    local direction = FW_DIRECTION
    local strips_left = STRIPS % 2 == 0 and STRIPS or (STRIPS + 1)
    local skip_strip = false
    for i = 1, strips_left, 1 do
        for j = 1, STRIDES_TO_DO, 1 do
            check_and_refuel()
            dig_stride()
            if scan_for_dragons() then
                notify_houston()
                --log_msg("Stopping search... Beam me up, Scotty!")
                local strides_left = STRIDES_TO_DO - j
                if strides_left > 0 then
                    for k = 1, strides_left, 1 do -- lazy workaround to skip the same dragon, probably..
                        dig_stride()
                    end
                    j = j + strides_left
                    skip_strip = true
                end
            end
            if turtle.select(TURTLE_INV_SZ) and turtle.getItemDetail() then
                empty_inv()
            end
        end

        change_strip(direction, skip_strip)
        skip_strip = false
        direction = -direction
    end
    local msg = "Finished search for dragons at " .. fmt_gps_to_str(get_gps_pos())
    log_msg(msg)
end

local function debug_wireless()
    for i = 1, 30, 1 do
        log_msg("Sending coords " .. ez_gps_pos())
        sleep(3)
    end
end

run()
--debug_wireless()