local MINFUELLEVEL = 4000
local tunnelLength = 0
local torches = false
local garbage = {
    ["minecraft:cobblestone"] = true,
    ["minecraft:dirt"] = true,
    ["minecraft:gravel"] = true,
    ["minecraft:stone"] = true,
    ["minecraft:sand"] = true
}





local args = {...}

local sides = {"left", "right"}
local equipment = {left = nil, right = nil}
local tools = {["minecraft:compass"] = true, ["plethora:module"] = true, ["minecraft:diamond_pickaxe"] = true}
local inventory = {} -- {itemName = {slot1, slot2, slot3}}
local pos = vector.new(0, 0, 0)
local heading = vector.new(1, 0, 0)
local directions = {NORTH = vector.new(0, 0, -1), EAST = vector.new(1, 0, 0), SOUTH = vector.new(0, 0, 1), WEST = vector.new(-1, 0, 0)}
local orientations = {[vector.new(0, 0, -1):tostring()] = 0, [vector.new(1, 0, 0):tostring()] = 1, [vector.new(0, 0, 1):tostring()] = 2, [vector.new(-1, 0, 0):tostring()] = 3}
local home = vector.new(0, 0, 0)
local startingHeading
-- init
function init()

    if args then
        if args[1] then
            tunnelLength = args[1]
        end

        if args[2] then
            torches = args[2]
        end
    end

    heading = getFacing()
    startingHeading = heading
    print(heading)
    for _, side in pairs(sides) do
        local tool = peripheral.getType(side) 
        if tool then
            equipment[side] = tool
        end
    end

    for side, tool in pairs(equipment) do
        print(side .. ": " .. tool)
    end

    scanInventory()
end

-- inventory functions
function scanInventory()
    inventory = {}

    for i = 1, 16 do
        local data = turtle.getItemDetail(i)
        if data then
            if inventory[data.name] then
                table.insert(inventory[data.name], i)
            else
                inventory[data.name] = {i}
            end
        end
    end
end

function selectItem(itemName)
    scanInventory()
    if not inventory[itemName] then return false end

    turtle.select(inventory[itemName][1])
    return true
end

function equipItem(itemName, side)
    side = side or "right"
    scanInventory()
    if not inventory[itemName] then return false end
    turtle.select(inventory[itemName][1])

    if side == "right" then
        turtle.equipRight()
    else
        turtle.equipLeft()
    end
end

function purgeInv()
    for i = 1, 16 do
        local data = turtle.getItemDetail(i)
        if data then
            if garbage[data.name] then
                turtle.select(i)
                turtle.dropUp()
            end

            for b = 1, i-1 do
                local d = turtle.getItemDetail(b)
                if d then
                    if d.name == data.name then
                        turtle.select(i)
                        turtle.transferTo(b)
                    end
                end
            end
        end
    end
end

function refuel()
    scanInventory()
    if inventory["minecraft:coal"] then
        turtle.select(inventory["minecraft:coal"][1])
        turtle.refuel()
    end
end

function emptyInventory()
    purgeInv()

    for i = 1, 16 do
        local data = turtle.getItemDetail(i)
        if data then
            if not tools[data.name] then
                turtle.select(i)
                turtle.drop()
            end
        end
    end
end

function getEmptySpace()
    local emptySpace = 0

    for i = 1, 16 do
        local count = turtle.getItemCount(i)
        if count == 0 then
            emptySpace = emptySpace + 1
        end
    end
    return emptySpace
end
-- navigation
function getFacing()
    equipItem("minecraft:compass")
    local facing = peripheral.call("right", "getFacing")
    return directions[string.upper(facing)]
end

function compareVectors(vec1, vec2)
    if vec1.x == vec2.x and vec1.y == vec2.y and vec1.z == vec2.z then
        return true
    else
        return false
    end
end

function turnRight()
    turtle.turnRight()

    if compareVectors(heading, vector.new(1, 0, 0)) then
        heading = vector.new(0, 0, 1)
    elseif compareVectors(heading, vector.new(-1, 0, 0)) then
        heading = vector.new(0, 0, -1)
    elseif compareVectors(heading, vector.new(0, 0, 1)) then
        heading = vector.new(-1, 0, 0)
    elseif compareVectors(heading, vector.new(0, 0, -1)) then
        heading = vector.new(1, 0, 0)
    end

    return true
end

function turnLeft()
    turtle.turnLeft()
 
    if compareVectors(heading, vector.new(1, 0, 0)) then
        heading = vector.new(0, 0, -1)
    elseif compareVectors(heading, vector.new(-1, 0, 0)) then
        heading = vector.new(0, 0, 1)
    elseif compareVectors(heading, vector.new(0, 0, 1)) then
        heading = vector.new(1, 0, 0)
    elseif compareVectors(heading, vector.new(0, 0, -1)) then
        heading = vector.new(-1, 0, 0)
    end

    return true
end

function forward()
    local tries = 0
    repeat 
        if tries > 50 then return false end
        tries = tries + 1
        turtle.dig() 
    until turtle.forward()
    pos = pos + heading
    return true
end

function back()
    if not turtle.back() then
        turnRight()
        turnRight()
        forward()
        turnLeft()
        turnLeft()
    else
        pos = pos - heading
    end

    return true
end

function up()
    repeat turtle.digUp() until turtle.up() 

    pos = pos + vector.new(0, 1, 0)
    return true
end

function down()
    local tries = 0
    repeat
        if tries > 50 then return false end
        tries = tries + 1
        turtle.digDown()
    until turtle.down() 

    pos = pos + vector.new(0, -1, 0)
    return true
end

function turnToHeading(newHeading)
    if compareVectors(newHeading, heading) then
        return true
    end

    if compareVectors(newHeading, -heading) then
        turnRight()
        turnRight()
        return true
    end

    if orientations[newHeading:tostring()] == 0 and orientations[heading:tostring()] == 3 then
        turnRight()
        return true
    end

    if orientations[newHeading:tostring()] == 3 and orientations[heading:tostring()] == 0 then
        turnLeft()
        return true
    end


    if orientations[newHeading:tostring()] > orientations[heading:tostring()] then
        turnRight()
    else
        turnLeft()
    end
end

function goto(newPos)
    if newPos.x > pos.x then
        turnToHeading(vector.new(1, 0, 0))
        while newPos.x > pos.x do
            if not forward() then return false end
        end
    end

    if newPos.x < pos.x then
        turnToHeading(vector.new(-1, 0, 0))
        while newPos.x < pos.x do
            if not forward() then return false end
        end
    end

    if newPos.z > pos.z then
        turnToHeading(vector.new(0, 0, 1))
        while newPos.z > pos.z do
            if not forward() then return false end
        end
    end

    if newPos.z < pos.z then
        turnToHeading(vector.new(0, 0, -1))
        while newPos.z < pos.z do
            if not forward() then return false end
        end
    end

    while newPos.y > pos.y do
        up()
    end

    while newPos.y < pos.y do
        if not down() then return false end
    end
end


-- mining functions
function isOreBlock(name)
    if string.find(name, "ore")  and string.find(name, "minecraft") then return true end
    if string.find(name, "ore")  and string.find(name, "thermal") then return true end
    return false
end

function scanArea()
    if equipment.right ~= "plethora:scanner" then
        equipItem("plethora:module")
    end

    local data = peripheral.call("right", "scan")
    local ores = {}

    for _, block in pairs(data) do
        if isOreBlock(block.name) then
            block.x = block.x + pos.x
            block.y = block.y + pos.y
            block.z = block.z + pos.z
            table.insert(ores, block)
        end
    end

    return ores
end

function getDistance(pos1, pos2)
    local x = math.abs(pos1.x - pos2.x)
    local y = math.abs(pos1.y - pos2.y)
    local z = math.abs(pos1.z - pos2.z)
    return (x + y + z)
end

function createMiningPath(ores)
    local unassignedOres = ores
    local assignedOres = {}

    local lowestScore = 999
    local lowestIndex = 1
    for i = 1, #unassignedOres do
        local dis = getDistance(unassignedOres[i], pos)
        if dis < lowestScore then
            lowestIndex = i
            lowestScore = dis
        end
    end

    table.insert(assignedOres, unassignedOres[lowestIndex])
    table.remove(unassignedOres, lowestIndex)

    while #unassignedOres > 0 do

        local lowestScore = 999
        local lowestIndex = 1
        for i = 1, #unassignedOres do
            local dis = getDistance(unassignedOres[i], assignedOres[#assignedOres])
            if dis < lowestScore then
                lowestIndex = i
                lowestScore = dis
            end
        end 
        table.insert(assignedOres, unassignedOres[lowestIndex])
        table.remove(unassignedOres, lowestIndex)
    end

    print(#assignedOres)
    return assignedOres
end

function scanAndMine()
    local ores = scanArea()
    equipItem("minecraft:diamond_pickaxe")
    local path = createMiningPath(ores)

    print(#path)
    for i = 1, #path do
        if i % 5 == 0 then
            purgeInv()
            if getEmptySpace() < 3 then
                dumpItems()
            end
        end

        goto(vector.new(path[i].x, path[i].y, path[i].z))
    end
end

function dumpItems()
    local thisPos = pos
    local thisHeading = heading
    goto(home)
    turnToHeading(-startingHeading)
    emptyInventory()

    goto(thisPos)
    turnToHeading(thisHeading)
end

function main()
    equipItem("minecraft:diamond_pickaxe")
    for i = 1, 5 do
        turtle.digUp()
        forward()
    end
    for i = 1, tunnelLength/8 do
        equipItem("minecraft:diamond_pickaxe")
        for b = 1, 8 do
            turtle.digUp()
            forward()
        end

        local curPos = pos
        local curHeading = heading
        scanAndMine()
        goto(curPos)
        turnToHeading(curHeading)
        purgeInv()

        if turtle.getFuelLevel() < MINFUELLEVEL then
            refuel()
        end
    end
    goto(home)
    turnToHeading(-startingHeading)
    emptyInventory()
end

init()
main()