Slippery Square

local events, lost, won
local w, h = term.getSize()
local midW, midH = math.floor(w/2), math.floor(h/2)
local map = {}
local flood = {}
for i = 1, 15 do
    flood[i] = {}
end
local pos = {
    x = 8,
    y = 8
}
local dirsTab = {
    {-1, 0},
    {0, 1},
    {1, 0},
    {0, -1}
}

local function clearScreen()
    term.setBackgroundColor(colors.black)
    term.clear()
    term.setCursorPos(1, 1)
end

local function genMap()
    for y = 1, 15 do
        map[y] = {}
        for x = 1, 15 do
            if not (y == 8 and x == 8) then
                map[y][x] = math.random(1, 10) == 1 and true or false
            end
        end
    end
end

local function floodFill(yPos, xPos)
    for y = 1, 15 do
        for x = 1, 15 do
            flood[y][x] = 225
        end
    end
    flood[yPos][xPos] = 0
    local flag = false
    for i = 1, 225 do
        flag = true
        for y = 1, 15 do
            for x = 1, 15 do
                if flood[y][x] < 225 then
                    if y > 1 and not map[y - 1][x] and flood[y - 1][x] == 225 then
                        flood[y - 1][x] = flood[y][x] + 1
                    end
                    if x < 15 and not map[y][x + 1] and flood[y][x + 1] == 225 then
                        flood[y][x + 1] = flood[y][x] + 1
                    end
                    if y < 15 and not map[y + 1][x] and flood[y + 1][x] == 225 then
                        flood[y + 1][x] = flood[y][x] + 1
                    end
                    if x > 1 and not map[y][x - 1] and flood[y][x - 1] == 225 then
                        flood[y][x - 1] = flood[y][x] + 1
                    end
                elseif not map[y][x] then
                    flag = false
                end
            end
        end
        if flag then break end
    end
end

local function findPath()
    floodFill(pos.y, pos.x)
    local min = 225
    local minPos = {}
    for i = 2, 14 do
        if not map[1][i] and min > flood[1][i] then
            min = flood[1][i]
            minPos = {1, i}
        end
        if not map[i][1] and min > flood[i][1] then
            min = flood[i][1]
            minPos = {i, 1}
        end
        if not map[i][15] and min > flood[i][15] then
            min = flood[i][15]
            minPos = {i, 15}
        end
        if not map[15][i] and min > flood[15][i] then
            min = flood[15][i]
            minPos = {15, i}
        end
    end
    if min < 225 then
        floodFill(minPos[1], minPos[2])
        return false
    end
    return true
end

local function moveSquare()
    local min = 225
    local dir = 0
    if pos.y > 1 and not map[pos.y - 1][pos.x] and min > flood[pos.y - 1][pos.x] then --up
        min = flood[pos.y - 1][pos.x]
        dir = 1
    end
    if pos.x < 15 and not map[pos.y][pos.x + 1] and min > flood[pos.y][pos.x + 1] then --right
        min = flood[pos.y][pos.x + 1]
        dir = 2
    end
    if pos.y < 15 and not map[pos.y + 1][pos.x] and min > flood[pos.y + 1][pos.x] then --down
        min = flood[pos.y + 1][pos.x]
        dir = 3
    end
    if pos.x > 1 and not map[pos.y][pos.x - 1] and min > flood[pos.y][pos.x - 1] then --left
        min = flood[pos.y][pos.x - 1]
        dir = 4
    end

    if pos.y > 1 and pos.x < 15 and not map[pos.y - 1][pos.x + 1] and not (map[pos.y - 1][pos.x]  and map[pos.y][pos.x + 1]) and min > flood[pos.y - 1][pos.x + 1] then --up right
        min = flood[pos.y - 1][pos.x + 1]
        dir = 5
    end
    if pos.y < 15 and pos.x < 15 and not map[pos.y + 1][pos.x + 1] and not (map[pos.y + 1][pos.x]  and map[pos.y][pos.x + 1]) and min > flood[pos.y + 1][pos.x + 1] then --down right
        min = flood[pos.y + 1][pos.x + 1]
        dir = 6
    end
    if pos.y < 15 and pos.x > 1 and not map[pos.y + 1][pos.x - 1] and not (map[pos.y + 1][pos.x]  and map[pos.y][pos.x - 1]) and min > flood[pos.y + 1][pos.x - 1] then --down left
        min = flood[pos.y + 1][pos.x - 1]
        dir = 7
    end
    if pos.y > 1 and pos.x > 1 and not map[pos.y - 1][pos.x - 1] and not (map[pos.y - 1][pos.x]  and map[pos.y][pos.x - 1]) and min > flood[pos.y - 1][pos.x - 1] then --up left
        min = flood[pos.y - 1][pos.x - 1]
        dir = 8
    end

    if pos.x == 1 or pos.x == 15 or pos.y == 1 or pos.y == 15 then
        return true
    end
    if dir == 1 then
        pos.y = pos.y - 1
    elseif dir == 2 then
        pos.x = pos.x + 1
    elseif dir == 3 then
        pos.y = pos.y + 1
    elseif dir == 4 then
        pos.x = pos.x - 1
    elseif dir == 5 then
        pos.x = pos.x + 1
        pos.y = pos.y - 1
    elseif dir == 6 then
        pos.x = pos.x + 1
        pos.y = pos.y + 1
    elseif dir == 7 then
        pos.x = pos.x - 1
        pos.y = pos.y + 1
    elseif dir == 8 then
        pos.x = pos.x - 1
        pos.y = pos.y - 1
    end
end

local function updateScreen()
    for y = 1, 15 do
        for x = 1, 15 do
            if map[y][x] then
                if map[y][x] == "#" then
                  term.setBackgroundColor(colors.red)
                else
                  term.setBackgroundColor(colors.cyan)
                end
            elseif x == pos.x and y == pos.y and not lost then
                term.setBackgroundColor(colors.orange)
            elseif x % 2 == y % 2 then
                term.setBackgroundColor(colors.blue)
            else
                term.setBackgroundColor(colors.lightBlue)
            end
            term.setCursorPos(midW - 7 + x, midH - 7 + y)
            write(" ")
        end
    end
end

clearScreen()
genMap()
updateScreen()
while true do
    repeat
        events = {coroutine.yield("mouse_click")}
    until (events[3] >= midW - 6 and events[3] <= midW + 8 and events[4] >= midH - 6 and events[4] <= midH + 8) and not map[events[4] - midH + 7][events[3] - midW + 7] and not (events[4] - midH + 7 == pos.y and events[3] - midW + 7 == pos.x)
    map[events[4] - midH + 7][events[3] - midW + 7] = true
    updateScreen()
    sleep(.2)
    won = findPath()
    if won then break end
    lost = moveSquare()
    updateScreen()
    if lost then break end
end

local endTime = os.startTimer(math.random(1, 10)/10)
term.setBackgroundColor(colors.black)
term.setCursorPos(midW - 3, 1)
if won then
    term.setTextColor(colors.green)
    write("YOU WON")
    floodFill(pos.y, pos.x)
    local trapTab = {}
    for y = 1, 15 do
        for x = 1, 15 do
            if flood[y][x] < 225 then
                trapTab[#trapTab + 1] = {y, x}
            end
        end
    end
    term.setBackgroundColor(colors.red)
    for i = 1, #trapTab do
      for n = 1, 4 do
        if map[trapTab[i][1] + dirsTab[n][2]][trapTab[i][2] + dirsTab[n][1]] then
          map[trapTab[i][1] + dirsTab[n][2]][trapTab[i][2] + dirsTab[n][1]] = "#"
        end
      end
    end
    while true do
        local choice = trapTab[math.random(1, #trapTab)]
        pos.y, pos.x = choice[1], choice[2]
        updateScreen()
        repeat
            events = {os.pullEvent()}
        until (events[1] == "timer" and events[2] == endTime) or events[1] == "key"
        if events[1] == "timer" then
            endTime = os.startTimer(math.random(1, 10)/10)
        elseif events[1] == "key" then break end
    end
elseif lost then
    term.setTextColor(colors.red)
    write("YOU LOST")
    while true do
        for y = 1, 15 do
            for x = 1, 15 do
                if map[y][x] and math.random(1, 10) == 1 then
                    map[y][x] = false
                end
            end
        end
        updateScreen()
        repeat
            events = {os.pullEvent()}
        until (events[1] == "timer" and events[2] == endTime) or events[1] == "key"
        if events[1] == "timer" then
            endTime = os.startTimer(math.random(1, 10)/10)
        elseif events[1] == "key" then break end
    end
end

sleep(.1)
clearScreen()