Sudoku 100% (pcall)

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

local w, h = term.getSize()

local debug = false
local diagnostics = false
--local handle = fs.open("console","a")
function log(t)
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.lightBlue)
                    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)
                    elseif lineTab[i][5] then
                        term.setTextColor(colors.white)
                        write(lineTab[i][5])
                    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)
                    elseif lineTab[i][5] then
                        term.setTextColor(colors.lightBlue)
                        write(lineTab[i][5])
                    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)
                elseif isoTab[i][4] then
                    term.setTextColor(colors.white)
                    write(isoTab[i][4])
                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
                term.setTextColor(colors.yellow)
                if tonumber(board[y][x]) then
                    write(board[y][x])
                else write ("_") 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
            local logString = ""
            for i = 1, 2 do
                for n = 1, 9 do
                    logString = logString .. scanRef[i][n] .. ", "
                end
                logString = logString:sub(1, -3)
                logString = logString .. "\n"
            end
                printBoard(board, n, "ScanRef:\n" .. logString)
            --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]}) else table.insert(logTab, {x, i, 0, board[i][x]}) end
            if not tonumber(board[y][i]) then table.insert(logTab, {i, y, board[y][i][num]}) else table.insert(logTab, {i, y, 0, board[y][i]}) 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]})
            else
                table.insert(logTab, {(math.ceil(x/3)-1)*3+(i-1)%3+1, (math.ceil(y/3)-1)*3+math.ceil(i/3), 0, board[(math.ceil(y/3)-1)*3+math.ceil(i/3)][(math.ceil(x/3)-1)*3+(i-1)%3+1]})
            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)
                if not diagnostics then
                    printBoard(board, num, _, true)
                end
                error("ERROR: No avilable places for number " .. num .. " in quadrant " .. i .. " ("..num..":"..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 detected, rays = detectLine(cells)
                if detected then
                    refTab[1][i] = 0
                    flag = true
                    altered = true
                    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
                    break;
                end
            end
        end
    end
    return refTab, altered
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 > 0, 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                                                           -- or board[slice][i]
                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
            else
                table.insert(logTab, {i, slice, math.ceil(i/3) ~= (homeQuadrant-1)%3 + 1, 0, board[slice][i]})
            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
            else
                table.insert(logTab, {slice, i, math.ceil(i/3) ~= math.ceil(homeQuadrant/3), 0, board[i][slice]})
            end
        end
    end
    printBoard(board, num, "Line Eliminated: Q" .. homeQuadrant .. ", " .. tostring(row) .. ", " .. slice, _, logTab)
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

----------------------------------------------SOLUTION

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

local seed = math.random(1, 100000)
math.randomseed(seed)
log(seed)

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...\n")
    print("Usage: ".. shell.getRunningProgram() .." test [g or s]")
    print("Analyzes the current algorithm and compiles results")
    print("g for generation, s for solution (WIP)")
else
    if tArgs[1] == "generate" or tArgs[1] == "gen" or tArgs[1] == "g" then
        if tArgs[2] == "view" then debug = true end
        local board = {}
        diagnostics=true
        initializeBoard(board)
        if not debug then
            local ok, err = pcall(generatePuzzle, board)
            while not ok do
                initializeBoard(board)
                ok, err = pcall(generatePuzzle, board)
                printBoard(board)
            end
        else
            generatePuzzle(board)
            printBoard(board)
        end
    elseif tArgs[1] == "solve" or tArgs[1] == "s" then
        if tArgs[3] == "view" then debug = true end
    elseif tArgs[1] == "test" then
        diagnostics = true
        local board = {}
        if tArgs[2] == "g" then
            local s = 0
            local f = 0
            local errors = {}
            for i = 1, 9 do
                errors[i] = 0
            end
            while f < 100 do
                initializeBoard(board)
                ok, err = pcall(generatePuzzle, board)
                if not ok then
                    errors[tonumber(err:sub(#err-3, -4))] = errors[tonumber(err:sub(#err-3, -4))] + 1
                    f = f + 1
                    term.setCursorPos(1, h-1)
                    term.setBackgroundColor(colors.black)
                    term.clearLine()
                    write("Generating errors...")
                    term.setCursorPos(w-#tostring(f), h-1)
                    write(f .. "%")
                    term.setBackgroundColor(colors.red)
                    term.setCursorPos(1, h)
                    write(string.rep(" ", math.floor((f/100)*w)))
                else
                    s = s + 1
                end
            end
            --printBoard(board)
            term.setBackgroundColor(colors.black)
            term.clear()
            term.setCursorPos(1, 1)
            print("Results:")
            print("1  2  3  4  5  6  7  8  9")
            print("-------------------------")
            for i, v in ipairs(errors) do
                term.setCursorPos(3*(i-1) + 1, 4)
                write(v)
            end
            print("\n")
            print("Puzzles generated: " .. s+f)
            print("Success rate: " .. string.sub(tostring(s/(s+f)*100), 1, 5) .. "%")
        elseif tArgs[2] == "s" then

        end
    end
end