local rChan = 7322
local sChan = 7321
local modem = peripheral.wrap("right")
modem.open(rChan)
local slot = 1
turtle.select(1)
local function select(s)
    slot = s
    turtle.select(s)
end
-- TODO: Check if it really IS a modem

local function send(msg)
    modem.transmit(sChan, rChan, msg)
end

local dir = 0
local dirs = {
    up = 0,
    right = 1,
    down = 2,
    left = 3
}

local function turnRight()
    dir = dir + 1
    if dir == 4 then dir = 0 end
    turtle.turnRight()
    send("right")
end

local function turnLeft()
    dir = dir - 1
    if dir == -1 then dir = 3 end
    turtle.turnLeft()
    send("left")
end


local function faceDirection(d)
    if d == dir then return
    else
        if (d == 0 and dir == 3) or (d > dir and not (d == 3 and dir == 0)) then
            while d ~= dir do
                turnRight()
            end
        else
            while d ~= dir do
                turnLeft()
            end
        end
    end
end

local function quickLook()
    local found = turtle.detect()
    if found == true then found = 0 else found = -1 end
    send("block " .. found)
end

local function identifyLook()
    if turtle.detect() == false then return end
    for i=9,16 do
        select(i)
        -- turtle.compare() returns true if comparing nothing with nothing, we don't want that.
        if turtle.compare() and turtle.getItemCount(slot) > 0 then
            send("iblock " .. slot)
            return
        end
    end
    quickLook()
end

local function search()
    for i=1,4 do quickLook() turnRight()
    end
end

local function identifySearch()
    for i=1,4 do
        identifyLook()
        turnRight()
    end
end

local function forward()
    quickLook()
    if turtle.forward() then
        send("forward")
        quickLook()
    end
end

local function mine()
    for i=9,16 do
        select(i)
        if turtle.getItemSpace(i) ~= 0 and (turtle.getItemCount(i) == 0 or turtle.compare() == true) then
            if turtle.dig() then
                send("mine " .. slot .. " " .. turtle.getItemCount(slot))
                quickLook()
            else
                send("cantmine")
            end
            return
        end
    end
    send("nospace")
end

local function place(sl)
    if turtle.getItemCount(sl) == 0 then
        send("emptyslot")
        return
    end
    select(sl)

    if turtle.place() then
        send("place")
        identifyLook()
    else
        send("cantplace")
    end
end

local commands = {
    search = search,
    isearch = identifySearch,
    up = function()
        faceDirection(0)
        forward()
    end,
    down = function()
        faceDirection(2)
        forward()
    end,
    left = function()
        faceDirection(3)
        forward()
    end,
    right = function()
        faceDirection(1)
        forward()
    end,
    mine = mine,
    place = function(args)
        place(tonumber(args[2]))
    end
}

local function split(str)
    ret = {}
    for i in string.gmatch(str, "%S+") do
        table.insert(ret, i)
    end
    return ret
end

term.clear()
term.setCursorPos(1, 1)
write([[Welcome to the turtle "Roguelike"

Run the other program on an advanced computer in order to control this turtle.

The computer needs to have a modem attached at the top.

(Modem channels 7322 and 7311 are used)


To quit, press 'q'.]])

while true do
    local ev, side, c, rc, msg, dist = os.pullEvent()
    if ev == "modem_message" then
        local smsg = split(msg)
        if commands[smsg[1]] ~= nil then
            commands[smsg[1]](smsg)
        end
    elseif ev == "char" and side == "q" then
        term.clear()
        term.setCursorPos(1, 1)
        return
    end
end