local robot = require("robot")
local component = require("component")
local sides = require("sides")
local event = require("event")
local term = require("term")
local nav = require("nav")

local geolyzer = component.geolyzer

local depth, width, crops = ...

if not depth or not width or not crops then
    print("Usage: farm <forward> <right> <crops>")
    return
end

depth = tonumber(depth)
width = tonumber(width)
crops = tonumber(crops)

print("Farming " .. crops .. " crops in a " .. depth .. "x" .. width .. " area")


local dir_forward = true
local dir_right = true

local pos_forward = 1
local pos_right = 1

local running = true

local function growth_to_char(growth)
    if growth <= 0.25 then
        return '.'
    elseif growth <= 0.50 then
        return '+'
    elseif growth <= 0.75 then
        return 'S'
    else
        return '#'
    end
end

local function move_width()
    if dir_right then
        if pos_right == width then
            dir_right = false
        end
    else
        if pos_right == 1 then
            dir_right = true
        end
    end

    if dir_right then
        robot.turnRight()
        nav.forward()
        robot.turnLeft()
        pos_right = pos_right + 1
    else
        robot.turnLeft()
        nav.forward()
        robot.turnRight()
        pos_right = pos_right - 1
    end
end

local function move_depth()
    if dir_forward then
        if pos_forward == depth then
            dir_forward = false
            move_width()
        else
            nav.forward()
            pos_forward = pos_forward + 1
        end
    else
        if pos_forward == 1 then
            dir_forward = true
            move_width()
        else
            nav.back()
            pos_forward = pos_forward - 1
        end
    end
end

local function plant()
    robot.select(pos_right % crops + 1)
    robot.placeDown()
    term.write(growth_to_char(0))
    term.setCursorBlink(true)
end

local function check_crop()
    if robot.detectDown() then
        local crop = geolyzer.analyze(sides.down)
        if not crop.growth then
            return -- ignore this block
        end
        if crop.growth >= 1.0 then
            robot.swingDown()
            plant()
        else
            term.write(growth_to_char(crop.growth))
            term.setCursorBlink(true)
        end
    else
        plant()
    end
end

local function handle_interrupt()
    if event.pull(0.1, "interrupted") then
        term.clear()
        print("Interrupted. Returning to original location...")
        robot.setLightColor(0xff0000)

        -- return to original location
        while pos_forward > 1 do
            nav.back()
            pos_forward = pos_forward - 1
        end

        robot.turnLeft()
        while pos_right > 1 do
            nav.forward()
            pos_right = pos_right - 1
        end
        robot.turnRight()

        running = false
    end
end

term.clear()
robot.setLightColor(0x00ff00)

while running do
    term.setCursor(pos_right, depth - pos_forward + 1)
    check_crop()
    move_depth()
    handle_interrupt()
end