hijackpoc.lua

local Event  = require('event')
local GPS    = require('gps')
local Point  = require('point')
local Socket = require('socket')
local Util   = require('util')

local os = _G.os

local hut1 = {
    { '     ', '     ', '     ', '     ', '  6  ' },
    { '33333', '14441', '14 41', '14 41', '11111' },
    { '34443', '4   4', '4   4', '4   4', '11111' },
    { '34443', '4   4', '5   5', '4   4', '11111' },
    { '34443', '4   4', '4   4', '4   4', '11111' },
    { '33333', '14441', '14541', '14441', '11111' },
}

local hut2 = {
    { '     ', '     ', '     ', '     ', '     ', '  6  ' },
    { '77777', '33333', '14441', '14 41', '14 41', '11111' },
    { '7   7', '34443', '4   4', '4   4', '4   4', '11111' },
    { '7   7', '39443', '4   4', '5   5', '4   4', '11111' },
    { '7   7', '38443', '48  4', '48  4', '48  4', '11111' },
    { '77777', '33333', '14441', '14541', '14441', '11111' },
}

local blocks = {
    [ '1' ] = { 'minecraft:cobblestone'   },
    [ '2' ] = { 'minecraft:oak_stairs',   },
    [ '3' ] = { 'minecraft:log',          Point.DOWN },
    [ '4' ] = { 'minecraft:planks'        },
    [ '5' ] = { 'minecraft:glass_pane'    },
    [ '6' ] = { 'minecraft:stone_stairs', Point.DOWN, Point.EAST, },
    [ '7' ] = { 'minecraft:fence',        nil,        nil,        Point.DOWN },
    [ '8' ] = { 'minecraft:ladder',       Point.EAST, nil,        Point.EAST },
    [ '9' ] = { 'minecraft:planks',       nil,        nil,        Point.EAST },
}

local spt = GPS.getPoint() or error('GPS failure')
local house = { }

local template = hut2
-- construct a simple schematic from the template
for x,plane in pairs(template) do
    for ry,row in pairs(plane) do
        local y = #plane - ry + 1
        for z = 1, #row do
            local b = row:sub(z, z)
            if blocks[b] then
                table.insert(house, {
                    x = x + spt.x,
                    y = y + spt.y - 1,
                    z = z + spt.z,
                    name       = blocks[b][1],
                    direction  = blocks[b][2], -- east, down, up, etc
                    heading    = blocks[b][3], -- n,s,e,w
                    dependency = blocks[b][4],
                })
            end
        end
    end
end

for _,b in pairs(house) do
    if b.dependency then
        local hi = Point.headings[b.dependency]
        local x,y,z = b.x + hi.xd, b.y + hi.yd, b.z + hi.zd
        for _,b2 in pairs(house) do
            if b2.x == x and b2.y == y and b2.z == z then
                b.dependency = b2
                break
            end
        end
    end
end

-- define a box the turtles should not path find out of
local height, width, length = #template[1], #template[1][1], #template
local box = {
    x = spt.x - 1,
    y = spt.y,
    z = spt.z - 1,
    ex = spt.x + length + 1,
    ey = spt.y + height + 1,
    ez = spt.z + width + 1,
}

local function hijackTurtle(remoteId)
    local socket, msg = Socket.connect(remoteId, 188)

    if not socket then
        error(msg)
    end

    socket:write('turtle')
    local methods = socket:read()

    local hijack = { }
    for _,method in pairs(methods) do
        hijack[method] = function(...)
            socket:write({ fn = method, args = { ... } })
            local resp = socket:read()
            if not resp then
                error('timed out')
            end
            return table.unpack(resp)
        end
    end

    return hijack
end

local args = { ... }
local turtleCount = #args
local turtles = { }

for _, id in pairs(args) do -- secondary channel
    table.insert(turtles, hijackTurtle(tonumber(id)))
end

for _, id in pairs(args) do
    Event.addRoutine(function()
        --os.sleep(1)
        local turtle = hijackTurtle(tonumber(id))
        os.sleep(1)
        turtle.resetState()
        turtle.enableGPS()
        local lastPoint = turtle.getPoint()
        turtle.setPersistent(true)
        turtle.pathfind(Point.closestPointInBox(lastPoint, box))
        turtle.setPathingBox(box)

        while true do
            -- get nearest point
            local pt
            local depends = { }
            while true do
                pt = Point.closest(turtle.getPoint(), house)
                if not pt then
                    break
                end
                Util.removeByValue(house, pt)

                if pt.dependency and not pt.dependency.placed then
                    table.insert(depends, pt)
                else
                    break
                end
            end
            if not pt then
                break
            end
            for _,b in pairs(depends) do
                table.insert(house, b)
            end

            -- try a couple times to place block in case a turtle is in the way
            for _ = 1, 3 do
                if turtle.placeAt(pt, pt.name) then
                    pt.placed = true
                    -- notify all turtles about this block
                    for _, t in pairs(turtles) do
                        t.addWorldBlock(pt)
                    end
                    break
                end
                os.sleep(.5)
            end
        end

        turtle.setPathingBox()
        turtle.pathfind(lastPoint)
        if turtleCount == 1 then
            Event.exitPullEvents()
        end
        turtleCount = turtleCount - 1
    end)
end

print('pulling')
Event.pullEvents()