Roblox Minesweeper [WIP]

local realBoard = {}    -- true/false = mine/no mine
local myBoard = {}
local gameState = {}    -- 0 = undiscovered / 1 = discovered / 2 = flag / 3 = ?

--[[
local realBoard = {}    -- stores positions of mines
local gameBoard = {}    -- stores numbers of adjacent mines
local liveBoard = {}    -- stores current state of each board tile (unknown ,found, flagged, and marked)
local gamePieces = {}   -- physical game pieces
--]]

-- settings:
local width = 9     -- board width
local height = 9        -- board height
local density = 0.123   -- avg mines/tile (nil to ignore) [0.123 = beginner / 0.156 = intermediate / 0.206 = expert]
local mines = 10        -- mine count
if density then mines = width*height*density end
local deterministic = false -- avoid 50/50 guess cases (currently unimplemented)
local openFirstMove = true  -- ensure first move lands on a tile with 0 surrounding mines

--[[    default board settings:
    beginner : 9x9/10
    intermediate : 16x16/40
    expert : 30x16/99
--]]

local function shuffle(table)
    local buffer
    for i = #table, 1, -1 do
        local r = math.random(1,i)
        buffer = table[i]
        table[i] = table[r]
        table[r] = buffer
    end
end

local function isValid(x, y)
    return x>0 and x<=width and y>0 and y<=height
end

local function getNeighbors(i)  -- gets neighbor indexes
    local neighbors = {}
    local x = (i-1)%width + 1
    local y = math.floor((i-1)/width)+1

    for ix = x-1, x+1 do
        for iy = y-1, y+1 do
            if isValid(ix, iy) then
                table.insert(neighbors, ix+(iy-1)*width)
            end
        end
    end

    return neighbors
end

local function countNearbyMines(i)
    local total = 0
    for _, i in ipairs(getNeighbors(i)) do
        if realBoard[i] then total += 1 end
    end
    return total
end

local function labelTiles()
    for i, bomb in ipairs(realBoard) do
        if not bomb then return end
        for _, n in ipairs(getNeighbors(i)) do
            if not realBoard[n] then
                myBoard[n] = myBoard[n]+1
            else
                myBoard[n] = "X"
            end
        end
    end
end

local function getGameState()   -- 0 = in progress / -1 = lost / 1 = won
    local win = true
    for i, v in ipairs(realBoard) do
        if v and gameState[i] == 1 then
            return -1
        end
        if win and not v and gameState[i] ~= 1 then
            win = false
        end
    end
    if win then return 1 end
    return 0
end

local function win()    -- does stuff when you win
end

local function lose()   -- does stuff when you lost
end

local function update()
    -- add visual updates to the board here
    local state = getGameState()
    if state == -1 then return lose() end
    if state == 1 then return win() end
end

local function open(x,y)
    local i = x+(y-1)*width
    if not isValid(x, y) then return end
    if not gameState[i] == 0 then return end
    gameState[i] = 1
    if myBoard[i] == 0 then
        cord(x,y)
    end
    update()
end

local function cord(x,y)
    local state = gameState[x+(y-1)*width]
    local nearbyFlags = 0
    for _, i in ipairs(getNeighbors(x+(y-1)*width)) do
        if gameState[i] == 2 then
            nearbyFlags += 1
        end
    end

    if nearbyFlags == myBoard[t] and (state == 1 or state == 3) then
        for ix = x-1, x+1 do
            for iy = y-1, y+1 do
                open(ix,iy)
            end
        end
    end
    update()
end

local function flag(x,y)
    local i = x+(y-1)*width
    local state = gameState[i]
    if state == 0 then
        gameState[i] = 2
    elseif state == 2 then
        gameState[i] = 3
    elseif state = 3 then
        gameState[i] = 0
    end
end

local function firstMove(x,y)
    local i = x+(y-1)*width
    if realBoard[i] then
        local newPos = 1
        while realBoard[newPos] do
            newPos += 1
        end
        realBoard[newPos] = true
        realBoard[i] = false
    end
    if openFirstMove then
        local shift = 1
        while countNearbyMines(i) > 0 and shift < width*height do
            local buffer = realBoard[1]
            for s = 1, #realBoard-1 do
                realBoard[s] = realBoard[s+1]
            end
            realBoard[#realBoard] = buffer
            shift = shift + 1
        end
        if countNearbyMines(i) > 0 then
            shuffle(realBoard)
            firstMove(x,y)
        end
    end
    labelTiles()
    open(x,y)
end

local function buildBoard() -- creates physical game board
end

local function setupBoard()
    realBoard = {}
    myBoard = {}
    gameState = {}

    mines = clamp(mines, 1, width*height-1)
    for i = 1, width*height do
        gameState[i] = 0
        myBoard[i] = 0
        realBoard[i] = false
        if i <= mines then
            realBoard[i] = true
        end
    end

    shuffle(realBoard)
    buildBoard()
end

setupBoard()
firstMove(math.floor(width/2), math.floor(height/2))