goto

args = {...}

if not fs.isDir("locations") then
    fs.makeDir("locations")
end

local function getDirection()
    local f = 0
    local x, y, z = gps.locate(5,false)
    y = nil
    if args[1] == "special" then
        if turtle.detect() then
            if not turtle.dig() then
                error("Tried to dig bedrock.")
            end
        end
        while not turtle.forward() do
            turtle.attack()
        end
    else
        if not turtle.forward() then
            error("I am against a wall.")
        end
    end
    local newx, newy, newz = gps.locate(5,false)
    newy = nil
    turtle.back()
    if newz > z then
        f = 0
    elseif newx < x then
        f = 1
    elseif newz < z then
        f = 2
    elseif newx > x then
        f = 3
    end
    return f
end
local function gotox(x,newx,f)
    if f == 0 then
        turtle.turnRight()
    elseif f == 2 then
        turtle.turnLeft()
    elseif f == 3 then
        turtle.turnRight()
        turtle.turnRight()
    end
    if newx < x then
        local j = x - newx
        for i=1,j do
            if args[1] == "special" then
                local i = 0
                while not turtle.forward() do
                    if not turtle.dig() then
                        i = i + 1
                        turtle.attack()
                        if i == 30 then
                            error("Path blocked.")
                        end
                    end
                end
            else
                if not turtle.forward() then
                    error("Path blocked.")
                end
            end
        end
    elseif newx > x then
        local j = newx - x
        turtle.turnRight()
        turtle.turnRight()
        for i=1,j do
            if args[1] == "special" then
                local i = 0
                while not turtle.forward() do
                    if not turtle.dig() then
                        i = i + 1
                        turtle.attack()
                        if i == 30 then
                            error("Path blocked.")
                        end
                    end
                end
            else
                if not turtle.forward() then
                    error("Path blocked.")
                end
            end
        end
        turtle.turnLeft()
        turtle.turnLeft()
    end
        if f == 0 then
        turtle.turnLeft()
    elseif f == 2 then
        turtle.turnRight()
    elseif f == 3 then
        turtle.turnLeft()
        turtle.turnLeft()
    end
end
local function gotoy(y,newy)
    if newy > y then
        local j = newy - y
        for i=1,j do
            if args[1] == "special" then
                local i = 0
                while not turtle.up() do
                    if not turtle.digUp() then
                        i = i + 1
                        turtle.attackUp()
                        if i == 30 then
                            error("Path blocked.")
                        end
                    end
                end
            else
                if not turtle.up() then
                    error("Path blocked.")
                end
            end
        end
    elseif newy < y then
        local j = y - newy
        for i=1,j do
            if args[1] == "special" then
                local i = 0
                while not turtle.down() do
                    if not turtle.digDown() then
                        i = i + 1
                        turtle.attackDown()
                        if i == 30 then
                            error("Path blocked.")
                        end
                    end
                end
            else
                if not turtle.down() then
                    error("Path blocked.")
                end
            end
        end
    end
end
local function gotoz(z,newz,f)
    if f == 1 then
        turtle.turnLeft()
    elseif f == 2 then
        turtle.turnLeft()
        turtle.turnLeft()
    elseif f == 3 then
        turtle.turnRight()
    end
    if newz > z then
        local j = newz - z
        for i=1,j do
            if args[1] == "special" then
                local i = 0
                while not turtle.forward() do
                    if not turtle.dig() then
                        i = i + 1
                        turtle.attack()
                        if i == 30 then
                            error("Path blocked.")
                        end
                    end
                end
            else
                if not turtle.forward() then
                    error("Path blocked.")
                end
            end
        end
    elseif newz < z then
        turtle.turnRight()
        turtle.turnRight()
        local j = z - newz
        for i=1,j do
            if args[1] == "special" then
                local i = 0
                while not turtle.forward() do
                    if not turtle.dig() then
                        i = i + 1
                        turtle.attack()
                        if i == 30 then
                            error("Path blocked.")
                        end
                    end
                end
            else
                if not turtle.forward() then
                    error("Path blocked.")
                end
            end
        end
        turtle.turnLeft()
        turtle.turnLeft()
    end
    if f == 1 then
        turtle.turnRight()
    elseif f == 2 then
        turtle.turnRight()
        turtle.turnRight()
    elseif f == 3 then
        turtle.turnLeft()
    end
end
local function findDistance(x,y,z,newx,newy,newz)
    local distance = 0
    local xDist = 0
    local yDist = 0
    local zDist = 0
    if x > newx then
        xDist = x - newx
    elseif x < newx then
        xDist = newx - x
    end
    if y > newy then
        yDist = y - newy
    elseif x < newx then
        yDist = newy - y
    end
    if z > newz then
        zDist = z - newz
    elseif z < newz then
        zDist = newz - z
    end
    distance = xDist + yDist + zDist
    return distance
end

if args[1] ~= "special" then
    rednet.open("left")
end

x, y, z, f, newx, newy, newz, newf = 0, 0, 0, 0, 0, 0, 0, 0

if #args == 1 then
    local location = args[1]
    if fs.exists("locations/"..location) then
        local fLocation = fs.open("locations/"..location,"r")
        newx = tonumber(fLocation.readLine())
        newy = tonumber(fLocation.readLine())
        newz = tonumber(fLocation.readLine())
        fLocation.close()
        print("Going to "..location.."...")
    else
        error("Unknown location.")
    end
elseif #args == 2 and tonumber(args[1]) and tonumber(args[2]) then
    newx, newz = tonumber(args[1]), tonumber(args[2])
    print("Going to x: "..newx..", z: "..newz.."...")
elseif #args == 3 and tonumber(args[1]) and tonumber(args[2]) and tonumber(args[3])then
    newx, newy, newz = tonumber(args[1]), tonumber(args[2]), tonumber(args[3])
    print("Going to x: "..newx..", y: "..newy..", z: "..newz.."...")
elseif #args == 4 and tonumber(args[1]) and tonumber(args[2]) and tonumber(args[3]) and tonumber(args[4]) then
    newx, newy, newz, newf = tonumber(args[1]), tonumber(args[2]), tonumber(args[3]), tonumber(args[4])
    print("Going to x: "..newx..", y: "..newy..", z: "..newz..", f: "..newf.."...")
elseif #args == 9 and args[1] == "special" and tonumber(args[2]) and tonumber(args[3]) and tonumber(args[4]) and tonumber(args[5]) and tonumber(args[6]) and tonumber(args[6]) and tonumber(args[7]) and tonumber(args[8]) and tonumber(args[9]) then
    newx, newy, newz, newf = tonumber(args[2]), tonumber(args[3]), tonumber(args[4]), tonumber(args[5])
    x, y, z, f = tonumber(args[6]), tonumber(args[7]), tonumber(args[8]), tonumber(args[9])
elseif #args == 5 and args[1] == "add" and tonumber(args[3]) and tonumber(args[4]) and tonumber(args[5]) then
    local location, xname, yname, zname = args[2], args[3], args[4], args[5]
    if not fs.exists("locations/"..location) then
        local fLocation = fs.open("locations/"..location,"w")
        fLocation.writeLine(xname)
        fLocation.writeLine(yname)
        fLocation.writeLine(zname)
        fLocation.close()
        print("Location \""..location.."\" added.")
    else
        print("This location already exists. Would you like to replace it?\n\(y/n\)")
        while true do
            event, character = os.pullEvent()
            if event == "char" and character == "y" then
                local fLocation = fs.open("locations/"..location,"w")
                fLocation.writeLine(xname)
                fLocation.writeLine(yname)
                fLocation.writeLine(zname)
                fLocation.close()
                print("Location changed.")
                break
            elseif event == "char" and character == "n" then
                print("Location not changed.")
                break
            end
        end
    end
    error()
else
    print("To goto coords, use: \"goto <x> <z>\" or \"goto <x> <y> <z>\"")
    print("To goto a set location, use: \"goto <name>\"")
    print("To set a new location, use: \"goto add <name> <x> <y> <z>\"")
    error()
end

if args[1] ~= "special" then
    x, y, z = gps.locate(5,false)
end
if not x or not y or not z then
    error("Out of GPS range")
end
local distance = findDistance(x,y,z,newx,newy,newz)
local fuelLevel = turtle.getFuelLevel()
if type(fuelLevel) == "string" then
    fuelLevel = 9001e9001
end
if distance > fuelLevel then
    error("Not enough fuel to travel so far!")
end


if args[1] ~= "special" then
    turtle.up()
    turtle.up()
    turtle.up()
    f = getDirection()
end

if newy > y then
    gotoy(y,newy)
end
if newx ~= x then
    gotox(x,newx,f)
end
if newz ~= z then
    gotoz(z,newz,f)
end
if newy < y then
    gotoy(y,newy)
end
if newf ~= f then
    if f == 1 then
        turtle.turnLeft()
    elseif f == 2 then
        turtle.turnLeft()
        turtle.turnLeft()
    elseif f == 3 then
        turtle.turnRight()
    end
    if newf == 1 then
        turtle.turnRight()
    elseif newf == 2 then
        turtle.turnLeft()
        turtle.turnLeft()
    elseif newf == 3 then
        turtle.turnLeft()
    end
end

if args[1] ~= "special" then
    turtle.down()
    turtle.down()
    turtle.down()
    print("Done traveling!")
end

if args[1] ~= "special" then
    rednet.close("left")
end
args, x, y, z, f, newx, newy, newz, newf = nil, nil, nil, nil, nil, nil, nil, nil, nil