SudokuGen SUCCESS :D

----------------------------------------------MISC FUNCS
if fs.exists("console") then
    shell.run("delete console")
end


local debug = false
local h = fs.open("console","a")
function log(t)
    if debug then
  if type(t) == "table" then
    for i,v in pairs(t) do
      h.write("i = ")
      h.write(i)
      h.write(" v = ")
      h.write(v)
      h.write("\n")
    end

  else
    h.write(t)
    h.write("\n")
  end
  h.flush()
  end
end

function logBoard(board, currentPos, futurePos)
    if debug then
        for y = 1, 9 do
        term.setCursorPos(1, y + math.ceil(y/3) - 1)
            for x = 1, 9 do
                if tonumber(board[y][x]) then
                    term.setTextColor(colors.red)
                    write(board[y][x])
                else
                    term.setTextColor(colors.white)
                    write("0")
                end
                if x == 3 or x == 6 then
                    write(" ")
                end
            end
        end
        if currentPos then
            term.setTextColor(colors.orange)
            term.setCursorPos(currentPos[1] + math.floor((currentPos[1]-1)/3), currentPos[2] + math.floor((currentPos[2]-1)/3))
            term.write(board[currentPos[2]][currentPos[1]])
        end
        if futurePos then
            term.setTextColor(colors.lime)
            term.setCursorPos(futurePos[1] + math.floor((futurePos[1]-1)/3), currentPos[2] + math.floor((futurePos[2]-1)/3))
            term.write("*")
            os.pullEvent("mouse_click")
        end
        print("")
        sleep(.1)
    end
end

local chrono = 0
function printBoard(board, num, str, override, lineTab, isoTab)
    if (debug and num) or override then
        for y = 1, 9 do
            term.setCursorPos(1, y + math.ceil(y/3))
            term.setBackgroundColor(colors.black)
            term.setTextColor(colors.white)
            write("|")
            for x = 1, 9 do
                if tonumber(board[y][x]) then
                    term.setTextColor(colors.blue)
                    write(board[y][x])
                elseif board[y][x][num] == 1 then
                    term.setTextColor(colors.lime)
                    write(num)
                else
                    term.setTextColor(colors.lightGray)
                    write("0")
                end
                if x == 3 or x == 6 then
                    term.setTextColor(colors.white)
                    write("|")
                end
            end
            term.setTextColor(colors.white)
            write("|")
        end
        if lineTab then
            for i = 1, #lineTab do
                term.setCursorPos(lineTab[i][1] + math.ceil(lineTab[i][1]/3), lineTab[i][2] + math.ceil(lineTab[i][2]/3))
                if lineTab[i][3] then
                    term.setBackgroundColor(colors.red)
                    if lineTab[i][4] == 1 then
                        term.setTextColor(colors.black)
                        write(num)
                    else
                        term.setTextColor(colors.gray)
                        write("0")
                    end
                else
                    term.setBackgroundColor(colors.black)
                    if lineTab[i][4] == 1 then
                        term.setTextColor(colors.yellow)
                        write(num)
                    else
                        term.setTextColor(colors.lightGray)
                        write("0")
                    end
                end
            end
        end
        if isoTab then
            for i = 2, #isoTab do
                term.setBackgroundColor(colors.orange)
                term.setCursorPos(isoTab[i][1] + math.ceil(isoTab[i][1]/3), isoTab[i][2] + math.ceil(isoTab[i][2]/3))
                if isoTab[i][3] == 1 then
                    term.setTextColor(colors.black)
                    write(num)
                else
                    term.setTextColor(colors.gray)
                    write("0")
                end
            end
            term.setBackgroundColor(colors.green)
            term.setTextColor(colors.lime)
            term.setCursorPos(isoTab[1][1] + math.ceil(isoTab[1][1]/3), isoTab[1][2] + math.ceil(isoTab[1][2]/3))
            write(num)
        end
        term.setBackgroundColor(colors.black)
        term.setTextColor(colors.white)
        term.setCursorPos(1, 1)
        write("-------------")
        term.setCursorPos(1, 5)
        write("|---+---+---|")
        term.setCursorPos(1, 9)
        write("|---+---+---|")
        term.setCursorPos(1, 13)
        write("-------------")
        term.setCursorPos(1, 14)
    elseif not num then
        for y = 1, 9 do
            term.setCursorPos(1, y + math.ceil(y/3))
            term.setTextColor(colors.white)
            write("|")
            for x = 1, 9 do
                local c = 0
                for i = 1, 9 do
                    if board[y][x][i] == 1 then
                        if c ~= 0 then
                            c = 0
                            break;
                        end
                        c = i
                    end
                end
                if c ~= 0 then
                    term.setTextColor(colors.yellow)
                    write(c)
                else
                    term.setTextColor(colors.lightGray)
                    write("0")
                end
                if x == 3 or x == 6 then
                    term.setTextColor(colors.white)
                    write("|")
                end
            end
            term.setTextColor(colors.white)
            write("|")
        end
        term.setCursorPos(1, 1)
        write("-------------")
        term.setCursorPos(1, 5)
        write("|---+---+---|")
        term.setCursorPos(1, 9)
        write("|---+---+---|")
        term.setCursorPos(1, 13)
        write("-------------")
        term.setCursorPos(1, 14)
    end
    if debug then
        if str then
            term.clearLine()
            write(str)
        end
        os.pullEvent()
    end
    chrono = chrono + 1
    if chrono >= 100 then
        sleep(.005)
        chrono = 0
    end
end

----------------------------------------------GENERATION
function initializeBoard(board)
    for y = 1, 9 do
        board[y] = {}
        for x = 1, 9 do
            board[y][x] = {1, 1, 1, 1, 1, 1, 1, 1, 1}
        end
    end
end

function generatePuzzle(board)
    local scanRef = {}
    --log("-=-=-=-=-=-=-=-Starting Generation Algorithm-=-=-=-=-=-=-=-")
    for n = 1, 9 do
        --log("Filling in " .. n .. " --------------")
        scanRef = {{1, 1, 1, 1, 1, 1, 1, 1, 1}, {1, 1, 1, 1, 1, 1, 1, 1, 1}}
        for q = 1, 9 do
            --log("Quadrant " .. q .. "...")
            scanRef, changed = scanPatterns(board, q, n, scanRef)
            --if debug and changed then
                printBoard(board, n, "Scanned")
            --end
            if scanRef[2][q] == 1 then
                local cells = getAvailableCells(board, q, n)
                local c = cells[math.random(1, #cells)]
                isolateNumber(board, c[1], c[2], n, " -=-random-=-")
                scanRef[2][q] = 0
            end
            --printBoard(board, n, "Reverting cycle...")
            --log("Quadrant " .. q .. " isolated>>")
        end
    end
    --finalizeBoard(board)
end

function isolateNumber(board, x, y, num, comment)
    comment = comment or ""
    local logTab = {}
    if debug then
        table.insert(logTab, {x, y, 1})
        for i = 1, 9 do
            if not tonumber(board[i][x]) then table.insert(logTab, {x, i, board[i][x][num]}) end
            if not tonumber(board[y][i]) then table.insert(logTab, {i, y, board[y][i][num]}) end
            if not tonumber(board[(math.ceil(y/3)-1)*3+math.ceil(i/3)][(math.ceil(x/3)-1)*3+(i-1)%3+1]) then
                table.insert(logTab, {(math.ceil(x/3)-1)*3+(i-1)%3+1, (math.ceil(y/3)-1)*3+math.ceil(i/3), board[(math.ceil(y/3)-1)*3+math.ceil(i/3)][(math.ceil(x/3)-1)*3+(i-1)%3+1][num]})
            end
        end
    end
    for i = 1, 9 do
        if not tonumber(board[i][x]) then board[i][x][num] = 0 end--whole row
        if not tonumber(board[y][i]) then board[y][i][num] = 0 end--whole column
        if not tonumber(board[(math.ceil(y/3)-1)*3+math.ceil(i/3)][(math.ceil(x/3)-1)*3+(i-1)%3+1]) then
            board[(math.ceil(y/3)-1)*3+math.ceil(i/3)][(math.ceil(x/3)-1)*3+(i-1)%3+1][num] = 0
        end
        --log("-->" .. (math.ceil(y/3)-1)*3+(i-1)%3+1 .. ":" .. (math.ceil(x/3)-1)*3+(i-1)%3+1)
                             --whole box (holy crap! what a line of code!)
    end
    --for i = 1, 9 do
    --  board[y][x][i] = 0
    --end
    board[y][x] = num
    printBoard(board, num, "Isolated: " .. x .. ":" .. y .. comment, _, _, logTab)
end

function scanPatterns(board, qStart, num, refTab)
    local flag = true
    local altered = false
    while flag do
        flag = false
        for i = qStart, 9 do
            local cells = getAvailableCells(board, i, num)
            if #cells < 1 then
                --convertBoard(board)
                printBoard(board, num, _, true)
                error("ERROR: No avilable places for number " .. num .. " in quadrant " .. i)
            elseif #cells == 1 and refTab[2][i] == 1 then
                isolateNumber(board, cells[1][1], cells[1][2], num)
                refTab[2][i] = 0
                flag = true
                altered = true
                break;
            elseif #cells > 1 and #cells <= 3 and refTab[1][i] == 1 then

                    local rays = detectLine(cells)
                    for _, v in ipairs(rays) do
                        --log("Row?: " .. tostring(v[1]) .. " Slice:" .. v[2] .. "  | Q" .. i)
                        eliminateLine(board, v[1], v[2], i, num)
                    end
                refTab[1][i] = 0
                flag = true
                altered = true
                break;
            end
        end
    end
    return refTab, altered
end

function getAvailableNum(board, quadrant, num)
    local cells = {}
    for i = 1, 3 do
        for j = 1, 3 do
            if board[(math.ceil(quadrant/3)-1)*3 + i][(quadrant-1)%3 + j][num] == 1 then
                table.insert(cells, {(quadrant-1)%3 + j, (math.ceil(quadrant/3)-1)*3 + i})
            end
        end
    end
    return cells
end

function detectLine(cells)
    local xList = {}
    local yList = {}
    for i, v in ipairs(cells) do
        table.insert(xList, v[1])
        table.insert(yList, v[2])
    end
    local rays = {}
    table.sort(xList)
    table.sort(yList)
    if xList[1] == xList[#xList] then
        table.insert(rays, {false, xList[1]})
    end
    if yList[1] == yList[#yList] then
        table.insert(rays, {true, yList[1]})
    end
    return rays
end

function eliminateLine(board, row, slice, homeQuadrant, num) --num: the current number
    --int[][][]board: the board, boolean row: whether it is a row or a column
    --int slice: row/col being altered, homeQuadrant: unnaffected quadrant
    local logTab = {}
    if row then
        for i = 1, 9 do
            if not tonumber(board[slice][i]) then
                table.insert(logTab, {i, slice, math.ceil(i/3) ~= (homeQuadrant-1)%3 + 1, board[slice][i][num]})
                if math.ceil(i/3) ~= (homeQuadrant-1)%3 + 1 then
                    board[slice][i][num] = 0
                end
            end
        end
    else
        for i = 1, 9 do
            if not tonumber(board[i][slice]) then
                table.insert(logTab, {slice, i, math.ceil(i/3) ~= math.ceil(homeQuadrant/3), board[i][slice][num]})
                if math.ceil(i/3) ~= math.ceil(homeQuadrant/3) then
                    board[i][slice][num] = 0
                end
            end
        end
    end
    printBoard(board, num, "Line Eliminated: Q" .. homeQuadrant .. ", " .. tostring(row) .. ", " .. slice, _, logTab)
end

function convertBoard(board)
    for y = 1, 9 do
        for x = 1, 9 do
            local num = 0
            for i = 1, 9 do
                if board[y][x][i] == 1 then
                    if num ~= 0 then
                        --error("ERROR: Multiple answers at " .. x .. ":" .. y)
                        board[y][x] = 0
                        break;
                    else
                        num = i
                    end
                end
            end
            if num == 0 then
                --error("ERROR: No answers at " .. x .. ":" .. y)
                board[y][x] = {}
            else
                board[y][x] = num
            end
        end
    end
end

function finalizeBoard(board)
    for y = 1, 9 do
        for x = 1, 9 do
            local num = 0
            for i = 1, 9 do
                if board[y][x][i] == 1 then
                    if num ~= 0 then
                        error("ERROR: Multiple answers at " .. x .. ":" .. y)
                    end
                    num = i
                end
            end
            if num == 0 then
                error("ERROR: No answers at " .. x .. ":" .. y)
            end
            board[y][x] = num
        end
    end
end

function getAvailableCells(board, quadrant, num)
    local result = {}
    for y = (math.ceil(quadrant/3)-1)*3 + 1, (math.ceil(quadrant/3)-1)*3 + 3 do
        for x = ((quadrant-1)%3)*3 + 1, ((quadrant-1)%3)*3 + 3 do
            if board[y][x] == num or (not tonumber(board[y][x]) and board[y][x][num] == 1) then
                table.insert(result, {x, y})
            end
        end
    end
    return result
end

function iLocate(i, quadrantX, quadrantY, board)
    for y =  1, 3 do
        for x = 1, 3 do
            if board[y + (quadrantY-1)*3][x + (quadrantX-1)*3] == i then
                return {x, y}, {x + (quadrantX-1)*3, y + (quadrantY-1)*3}
            end
        end
    end
    printBoard(board)
    error("iLocate Failed")
end
----------------------------------------------SOLUTION

----------------------------------------------ENGINE
local tArgs = {...}
term.setBackgroundColor(colors.black)
term.setTextColor(colors.white)
term.clear()

if #tArgs == 0 then
    term.setCursorPos(1, 1)
    print("Usage: ".. shell.getRunningProgram() .." gen <view>")
    print("adding <view> will show the process")
    print("algorithm works about 40% of the time\n")
    print("Usage: ".. shell.getRunningProgram() .." solve [puzzleFile] <view>")
    print("input the sudoku puzzle file into puzzleFile")
    print("adding <view> will show the process")
    print("coming soon...")
else
    if tArgs[1] == "generate" or tArgs[1] == "gen" or tArgs[1] == "g" then
        if tArgs[2] == "view" then debug = true end
        local board = {}
        initializeBoard(board)
        generatePuzzle(board)
        printBoard(board)
    elseif tArgs[1] == "solve" or tArgs[1] == "s" then
        if tArgs[3] == "view" then debug = true end
    end
end