Farm_proc

--[[main script for farming procedure]]

--load functions responsible for positioning/repositioning/farming
os.loadAPI("APIS/positioners");
os.loadAPI("APIS/farmers");

--action turtle start farming condition
assert(positioners.check_start_pos(), "Could not initialise the turtle for the farming procedure\nCould not identify it's starting location\n(are there birch planks directly above and beneath it?");

--check Netherrack can be found from start block, declare 'dir' also as local
local init_result, dir = positioners.find_next_neth()
assert(init_result, "Could not find the appropriate direction to travel in from\n the turtle starting position, is the farm set up correctly?");


local loop_vars = {["count"] = 0, ["blockId"] = nil, ["dir"] = nil, ["prevManvr"] = nil, ["action"] = ""};

--**input** assertion tests for required fuel level and seed requirements
assert(turtle.getFuelLevel() > 50, "Fuel level is below required level to start farming, - terminating");

--given 'result' == true can start farming
turtle.forward();

print("Gone forwards!");

--open log file (overwrite) and save to io class handle
log = io.open("logs/proc_log", "w");
print("Opened log!");

--start main farming process loop
while turtle.getFuelLevel() > 0 do

  print("entered loop");
  --reset action variable
  loop_vars["action"] = "";

  --sort log variables
  loop_vars["count"] = loop_vars["count"] + 1;

  --identify the block above (returns inv slot(1-4) it matches with or false if it doesn't)
  loop_vars["blockId"] = positioners.id();

  if blockId == 1 then
    loop_vars["action"] = "Netherrack above ";

    if loop_vars["dir"] == nil then
      print("Netherrack found, planting");

      farmers.plant();

      --shift turtle forward such that it can evaluate a new block. Ensure that moves forward in case of obstruction
      assert(turtle.forward(), "The turtle is impeded from moving forwards in farming route");

      --log statement
      loop_vars["action"] = loop_vars["action"].."plant and move forward";

    else
      --initiate change in direction procedure
      assert(positioners.change_direction(loop_vars["dir"]), "Failed to complete turtle change direction procedure");

      --reset dir
      loop_vars["dir"] = nil;

      loop_vars["action"] = loop_vars["action"].." actioned 'positioners.change_position(dir)'.";
    end;

  elseif blockId == 3 then

    turtle.forward();
    --log statement
    loop_vars["action"] = "Proceeding past marble block";

  elseif blockId == false then
    print("Finding next Netherrack block.");

    --retrace back to the most recent 'legitimate' block");
    turtle.back();

    --call function to reposition turtle for next farming line
    result, loop_vars["dir"] = positioners.find_next_neth(loop_vars["prevMan"]);
    assert(result, "A new netherrack block could not be found in any direction.");

    --assign dir result to prevMan (information for next positioners.change_position() call
    loop_vars["prevMan"] = loop_vars["dir"];

    --log statement
    loop_vars["action"] = "No 'legitimate' block above, 'positioners.find_next_neth() successful,\nassigning dir accordingly.";

  else
    --log statement
   log.write("Unhandled exception in farm_proc main loop");
    log.close();

   error("positioners.find_next_neth() did not find an appropriate block above it.");
  end;

  print("farm_proc loop");

  --write current turn to log file
  --log.write("Turn no: "..loop_vars["count"].."\n    Id()== "..tostring(loop_vars["blockId"]).."\n    Action: "..loop_vars["action"].."\n    Previous maneuver: "..loop_vars["prevMan"].."\n\n");
end;

--updating log
log.write("Error - turtle ran out of fuel\n");
log.close();

error("Turtle ran out of fuel whilst planting - terminated");