GreenhouseTurtle

local COAL, COMPOST, SOIL, BROWN, RED = "quark:charcoal_block", "farmersdelight:organic_compost", "farmersdelight:rich_soil", "minecraft:brown_mushroom", "minecraft:red_mushroom"
local CHESTS = {
    COAL={x=-419, y=71, z=-532, heading=1},
    COMPOST={x=-419, y=71, z=-533, heading=1},
    SOIL={x=-419, y=71, z=-534, heading=1},
    BROWN={x=-419, y=72, z=-534, heading=1},
    RED={x=-419, y=73, z=-534, heading=1}
}
local LANES = {
    {x=-420, y=71, z=-533, heading=3, length=24, left=true, right=true},
    {x=-420, y=71, z=-530, heading=3, length=24, right=true},
    {x=-420, y=71, z=-536, heading=3, length=24, left=true}
}
local LANES_LENGTH = 3
local laneIndex = 1

function calculatePositionHeading()
    write("Calculating position... ")
    local curX, curY, curZ = gps.locate()
    print("Done!")

    write("Calculating compass heading... ")
    local turns = 0 -- How many right turns the turtle just did to find an empty spot.
    while turtle.detect() do
        turtle.turnRight()
        turns = turns + 1
    end
    turtle.forward()
    local newX, _, newZ = gps.locate()

    -- Calculates heading.
    local heading
    if newZ < curZ then heading = 0
    elseif newX > curX then heading = 1
    elseif newZ > curZ then heading = 2
    elseif newX < curX then heading = 3 end

    -- Returns to old position and heading.
    turtle.back()
    for _=1, turns % 4 do
        turtle.turnLeft()
    end
    heading = (heading - turns) % 4

    print("Done!")
    return {x=curX, y=curY, z=curZ, heading=heading}
end

local pos = calculatePositionHeading()

function setOffset(distance)
    if pos.heading == 0 then pos.z = pos.z - distance
    elseif pos.heading == 1 then pos.x = pos.x + distance
    elseif pos.heading == 2 then pos.z = pos.z + distance
    elseif pos.heading == 3 then pos.x = pos.x - distance end
end
function offsetForward(newPos)
    if pos.heading == 0 then return pos.z - newPos.z
    elseif pos.heading == 1 then return newPos.x - pos.x
    elseif pos.heading == 2 then return newPos.z - pos.z
    elseif pos.heading == 3 then return pos.x - newPos.x end
end
function offsetSide(newPos) -- TODO: Re-use code better.
    if pos.heading == 0 then return pos.x - newPos.x
    elseif pos.heading == 1 then return pos.z - newPos.z
    elseif pos.heading == 2 then return newPos.x - pos.x
    elseif pos.heading == 3 then return newPos.z - pos.z end
end
function forward()
    local moved = turtle.forward()
    if moved then setOffset(1) end
    return moved
end
function back()
    local moved = turtle.forward()
    if moved then setOffset(-1) end
    return moved
end
function up()
    local moved = turtle.up()
    if moved then pos.y = pos.y + 1 end
    return moved
end
function down()
    local moved = turtle.down()
    if moved then pos.y = pos.y - 1 end
    return moved
end
function turnRight()
    local moved = turtle.turnRight()
    if moved then pos.heading = (pos.heading + 1) % 4 end
    return moved
end
function turnLeft()
    local moved = turtle.turnLeft()
    if moved then pos.heading = (pos.heading - 1) % 4 end
    return moved
end
function turnToward(newPos)
    local moved = false
    if offsetSide(newPos) > 0 then moved = turnLeft()
    else moved = turnRight() end
    return moved
end
function turnTo(newHeading)
    if (pos.heading - newHeading) % 4 == 1 then turnLeft()
    else while pos.heading ~= newHeading do turnRight() end end
end

function goTo(newPos)
    while true do
        while offsetForward(newPos) > 0 do if not forward() then break end end
        if pos.x == newPos.x and pos.y == newPos.y and pos.z == newPos.z then break end
        turnToward(newPos)
        while pos.y < newPos.y do if not up() then break end end
        while pos.y > newPos.y do if not down() then break end end
        while offsetForward(newPos) < 0 do turnToward(newPos) end
    end
end
function goToChest(chest)
    goTo(chest)
    turnTo(chest.heading)
end

function selectItem(name)
    for i=1, 16 do
        local item = turtle.getItemDetail(i)
        if item ~= nil and item.name == name then
            turtle.select(i)
            return true
        end
    end
    return false
end
function countItem(name)
    local sum = 0
    for i=1, 16 do
        local item = turtle.getItemDetail(i)
        if item ~= nil and item.name == name then
            sum = sum + item.count
        end
    end
    return sum
end

function tendBlock()
    local exists, block = turtle.inspect()
    if block.name == SOIL then
        write("Found rich soil... ")
        selectItem(SOIL)
        turtle.dig()
        exists = false
    end
    if not exists then
        if not selectItem(COMPOST) then
            print("No organic compost!")
            return
        end
        turtle.place()
        print("Placed organic compost!")
        if countItem(BROWN) >= 1 then
            up()
            local slot = turtle.getSelectedSlot() + 1
            if slot <= 16 then turtle.select(slot) end
            local item = turtle.getItemDetail()
            if item == nil or item.name ~= BROWN then
                selectItem(BROWN)
                print("Found mushroom")
            end
            turtle.place()
            down()
        end
    end
end

while true do
    goTo({x=-419, y=71, z=-529})
    if countItem(SOIL) > 0 then
        write("Dumping rich soil... ")
        goToChest(CHESTS.SOIL)
        selectItem(SOIL)
        turtle.drop()
        print("Done!")
    end
    if countItem(BROWN) > 32 then
        write("Dumping rich brown mushrooms... ")
        goToChest(CHESTS.BROWN)
        selectItem(BROWN)
        turtle.drop()
        print("Done!")
    end
    if turtle.getFuelLevel() < 10000 then
        selectItem(COAL)
        turtle.refuel()
    end
    if countItem(COAL) < 32 then
        write("Refueling coal... ")
        goToChest(CHESTS.COAL)
        selectItem(COAL)
        turtle.suck(turtle.getItemSpace())
        print("Done!")
    end
    if countItem(COMPOST) < 32 then
        write("Refueling organic compost... ")
        goToChest(CHESTS.COMPOST)
        selectItem(COMPOST)
        turtle.suck(64 - countItem(COMPOST))
        print("Done!")
    end
    local lane = LANES[laneIndex]
    write("Moving to lane "..laneIndex.."... ")
    goTo(lane)
    print("Done!")
    turnTo(lane.heading)
    print("Tending to lane "..laneIndex.."... ")
    for _=1, lane.length do
        if lane.left then
            turnLeft()
            tendBlock()
            turnRight()
        end
        if lane.right then
            turnRight()
            tendBlock()
            turnLeft()
        end
        if not forward() then
            write("Aborted (blocked)")
            break
        end
    end
    laneIndex = (laneIndex % LANES_LENGTH) + 1
end