SGPS

--UPDATE SGPS
local towerdata = http.get("http://pastebin.com/raw.php?i=MCCNBq1a").readAll()
local fl = fs.open("data/twrs", "w")
fl.write(towerdata)
fl.close()
local fl = fs.open("data/twrs", "r")
local towers = textutils.unserialize(fl.readAll())
fl.close()
--END UPDATE SGPS

local funcargs = {...}

local function printWithFormat(...)
        local s = "&1"
        for k, v in ipairs(arg) do
                s = s .. v
        end
        s = s .. "&0"

        local fields = {}
        local lastcolor, lastpos = "0", 0
        for pos, clr in s:gmatch"()&(%x)" do
                table.insert(fields, {s:sub(lastpos + 2, pos - 1), lastcolor})
                lastcolor, lastpos = clr , pos
        end

        for i = 2, #fields do
                term.setTextColor(2 ^ (tonumber(fields[i][2], 16)))
                io.write(fields[i][1])
        end
end

local x, y, z = gps.locate(5)
local you = vector.new(x,y,z)

local function printUsage()
    print("Usage:")
    print("sgps distance x y z")
    print("sgps navdistance x y z")
    print("sgps loc\nor sgps locate")
end

if(funcargs[1]=="update")then
    shell.run("rm","sgps")
    shell.run("pastebin","get","zDQP9G99","sgps")
    printWithFormat("&5Updated!\n")
    return
elseif(funcargs[1]=="distance") then
    if(#funcargs<2) then
        print("Use 'sgps distance x y z'!")
        return
    end
    local there = vector.new(tonumber(funcargs[2]),tonumber(funcargs[3]),tonumber(funcargs[4]))
    local dist = you-there
    printWithFormat("&1Distance is "..dist:length().."\n&2Navigation Distance:\n&4"..tostring(dist).."\n")
    return
elseif(funcargs[1]=="navdistance") then
    if(#funcargs<2) then
        print("Use 'sgps navdistance x y z'!")
        return
    end
    while true do
        local x, y, z = gps.locate(5)
        local you = vector.new(x,y,z)
        term.clear()
        term.setCursorPos(1,1)
        local there = vector.new(tonumber(funcargs[2]),tonumber(funcargs[3]),tonumber(funcargs[4]))
        local dist = you-there
        printWithFormat("&1Distance is "..dist:length().."\n&2Navigation Distance:\n&4"..tostring(dist).."\n")
        sleep(1)
    end
elseif(funcargs[1]=="locate" or funcargs[1]=="loc")then
    local x, y, z = gps.locate(5)
    local you = vector.new(x,y,z)
    for k,v in pairs(towers) do
        local sat = vector.new(v[1],v[2],v[3])
        local distance = you - sat
        local argstext = v[1]..", "..v[2]..", "..v[3]
        printWithFormat("<TOWER> &3"..k.."\n&4@"..argstext.."\n".."+/- &7"..distance:length().."\n")
    end

    if(not x) then
        printWithFormat("&4Couldn't get location!\nLearn how to do trilateration!\n")
    else
        local loctext = x..", "..y..", "..z
        printWithFormat("&2Your location is:\n&4@"..loctext.."\n")
    end
elseif(#funcargs<1) then
    printUsage()
end