cutil

if not os.loadAPI("button") then
    error("Checkers util API requires the button API by minecraftwarlock to run")
end

mon = peripheral.wrap("left")

button.default()

xSize,ySize = mon.getSize()

turn = "white"
opponent = "black"
piecesInit = false
turnNum = 1
winner = false

function getKeys(tbl)
    local out = {}
    for k,v in pairs(tbl) do
        table.insert(out,k)
    end
    return out
end

function toggleTurn()
    if turn == "white" then
        turn = "black"
        opponent = "white"
    else
        turn = "white"
        opponent = "black"
    end
end

function isPresent(i,tbl)
    for k,v in ipairs(tbl) do
        if v == i then
            return true
        end
    end
    return false
end

function offset(x,coord)
    if string.lower(coord) == "x" then
        return math.floor(xSize / 2) + x
    elseif string.lower(coord) == "y" then
        return math.floor(ySize / 2) + x
    end
end

function onBoard(X,Y)
    if X < 1 or X > 8 or Y < 1 or Y > 8 then
        return false
    end
    return true
end

function getLength(tbl)
    local out = 0
    for i in ipairs(tbl) do
        out = out + 1
    end
end

boardX = offset(-3,"x")
boardY = offset(-3,"y")

pieces = {
    ["white"] = {
        ["piece1"] = {x = 7,y = 7,moves = 0,taken = 0,alive = true,king = false,color = colors.white},
        ["piece2"] = {x = 7,y = 5,moves = 0,taken = 0,alive = true,king = false,color = colors.white},
        ["piece3"] = {x = 7,y = 3,moves = 0,taken = 0,alive = true,king = false,color = colors.white},
        ["piece4"] = {x = 5,y = 3,moves = 0,taken = 0,alive = true,king = false,color = colors.white},
        ["piece5"] = {x = 5,y = 5,moves = 0,taken = 0,alive = true,king = false,color = colors.white},
        ["piece6"] = {x = 5,y = 7,moves = 0,taken = 0,alive = true,king = false,color = colors.white},
        ["piece7"] = {x = 3,y = 7,moves = 0,taken = 0,alive = true,king = false,color = colors.white},
        ["piece8"] = {x = 3,y = 5,moves = 0,taken = 0,alive = true,king = false,color = colors.white},
        ["piece9"] = {x = 3,y = 3,moves = 0,taken = 0,alive = true,king = false,color = colors.white},
        ["piece10"] = {x = 5,y = 3,moves = 0,taken = 0,alive = false,king = false,color = colors.white},
        ["piece11"] = {x = 3,y = 5,moves = 0,taken = 0,alive = false,king = false,color = colors.white},
        ["piece12"] = {x = 3,y = 7,moves = 0,taken = 0,alive = false,king = false,color = colors.white}
    },
    ["black"] = {
        ["piece13"] = {x = 6,y = 2,moves = 0,taken = 0,alive = false,king = false,color = colors.black},
        ["piece14"] = {x = 6,y = 4,moves = 0,taken = 0,alive = false,king = false,color = colors.black},
        ["piece15"] = {x = 6,y = 6,moves = 0,taken = 0,alive = false,king = false,color = colors.black},
        ["piece16"] = {x = 6,y = 8,moves = 0,taken = 0,alive = false,king = false,color = colors.black},
        ["piece17"] = {x = 7,y = 1,moves = 0,taken = 0,alive = false,king = false,color = colors.black},
        ["piece18"] = {x = 7,y = 3,moves = 0,taken = 0,alive = false,king = false,color = colors.black},
        ["piece19"] = {x = 7,y = 5,moves = 0,taken = 0,alive = false,king = false,color = colors.black},
        ["piece20"] = {x = 7,y = 7,moves = 0,taken = 0,alive = false,king = false,color = colors.black},
        ["piece21"] = {x = 8,y = 2,moves = 0,taken = 0,alive = false,king = false,color = colors.black},
        ["piece22"] = {x = 8,y = 4,moves = 0,taken = 0,alive = false,king = false,color = colors.black},
        ["piece23"] = {x = 8,y = 6,moves = 0,taken = 0,alive = false,king = false,color = colors.black},
        ["piece24"] = {x = 8,y = 8,moves = 0,taken = 0,alive = true,king = true,color = colors.black}
    }
}

alive = {["white"] = {},["black"] = {}}
dead = {["white"] = {},["black"] = {}}

function getAlive()
    for i in pairs(pieces) do
        for k,v in pairs(pieces[i]) do
            if v.alive and not isPresent(k,alive[i]) then
                table.insert(alive[i],k)
            elseif not v.alive then
                table.insert(dead[i],k)
                pieces[i][k].alive = "false"
            end
        end
    end
end

function getRealCoords(x,y)
    return boardX + x - 1,boardY + y - 1
end

function getBoardCoords(x,y)
    return x - boardX + 1,y - boardY + 1
end

function cntrdTxt(txt,x,y)
    mon.setBackgroundColor(colors.black)
    mon.setTextColor(colors.white)
    mon.setCursorPos(offset(-1 * (math.floor(string.len(txt) / 2 + x ) - 1),"x"),1 + x)
    mon.write(txt)
end

mods = {}

function drawRow(side,x,y,ln)
    mon.setCursorPos(x,y)
    for i=1,math.floor(ln / 2) do
        if side == 1 then
            mon.setBackgroundColor(colors.red)
            mon.write(" ")
            mon.setBackgroundColor(colors.black)
            mon.write(" ")
        elseif side == 2 then
            mon.setBackgroundColor(colors.black)
            mon.write(" ")
            mon.setBackgroundColor(colors.red)
            mon.write(" ")
        end
    end
end

function board(wdth,hgt)
    button.bg(boardX - 1,boardY - 1,10,10,colors.gray)
    local y = boardY
    for i=1,math.floor(hgt / 2) do
        drawRow(1,boardX,y,wdth)
        y = y + 1
        drawRow(2,boardX,y,wdth)
        y = y + 1
    end
end

function mainMenu()
    cntrdTxt("Checkers",0,0)
    button.define("lcl","Local",offset(-6,"x"),offset(-1,"y"),colors.white,colors.red,true)
    button.define("glbl","Globlal",offset(2,"x"),offset(-1,"y"),colors.lightGray,colors.gray,true)
    button.draw("all")
    button.deactivate("glbl")
    local pressed = button.click()
    button.deactivate("all")
    button.erase("all")
    return pressed
end

function findPlayer()
    local id = rednet.lookup("cg","cg")
    if type(x) == number then
        os.queueEvent("found_player",id)
    end
end
print("Checkers util API (by minecraftwarlock) loaded")

function definePieces()
    for k,v in pairs(pieces) do
        if not piecesInit then
            for key,value in pairs(pieces[k]) do
                local x1,y1 = getRealCoords(value.x,value.y)
                if not value.king then
                    button.define(key,"o",x1,y1,value.color,colors.red,false)
                else
                    button.define(key,"K",x1,y1,value.color,colors.red,false)
                end
            end
        else
            for key,value in ipairs(dead[k]) do
                button.delete(value)
            end
        end
    end
    dead = {white = {},black = {}}
end

function occupied(X,Y)
    for i in pairs(alive) do
        for k,v in ipairs(alive[i]) do
            if X == pieces[i][v].x and Y == pieces[i][v].y then
                return true,i,v
            end
        end
    end
    return false
end

function isJump(piece,x1,y1)
    local jumps = {}
    local X = pieces[turn][piece].x
    local Y = pieces[turn][piece].y
    if type(x1) == "number" and type(y1) == "number" then
        X,Y = x1,y1
    end
    local val,color,p = occupied(X - 1,Y + 1)
    local val2 = occupied(X - 2,Y + 2)
    if val and color == opponent and not val2 and onBoard(X - 2,Y + 2) then
        table.insert(jumps,{-2,2,p})
    end
    val,color,p = occupied(X - 1,Y - 1)
    val2 = occupied(X - 2,Y - 2)
    if val and color == opponent and not val2 and onBoard(X - 2,Y - 2) then
        table.insert(jumps,{-2,-2,p})
    end
    if pieces[turn][piece].king then
        val,color,p = occupied(X + 1,Y + 1)
        val2 = occupied(X + 2,Y + 2)
        if val and color == opponent and not val2 and onBoard(X + 2,Y + 2) then
            table.insert(jumps,{2,2,p})
        end
        val,color,p = occupied(X + 1,Y - 1)
        val2 = occupied(X + 2,Y - 2)
        if val and color == opponent and not val2 and onBoard(X + 2,Y - 2) then
            table.insert(jumps,{2,-2,p})
        end
    end
    return jumps
end

function getMoves(piece)
    local moves = {}
    local X = pieces[turn][piece].x
    local Y = pieces[turn][piece].y
    local val,color,p = occupied(X - 1,Y + 1)

    local x2,y2 = X,Y
    local jumps = isJump(piece)
    for k2,v2 in ipairs(jumps) do
        local x2,y2 = X + v2[1],Y + v2[2]
        local jumps2 = isJump(piece,x2,y2)
        table.insert(moves,{x2,y2,"jump",{v2[3]}})
        for k3,v3 in ipairs(jumps2) do
            local x3,y3 = x2 + v3[1],y2 + v3[2]
            local jumps3 = isJump(piece,x3,y3)
            table.insert(moves,{x3,y3,"jump",{v2[3],v3[3]}})
            for k4,v4 in ipairs(jumps3) do
                local x4,y4 = x3 + v4[1],y3 + v4[2]
                local jumps4 = isJump(piece,x4,y4)
                table.insert(moves,{x4,y4,"jump",{v2[3],v3[3],v4[3]}})
                for k5,v5 in ipairs(jumps4) do
                    local x5,y5 = x4 + v5[1],y4 + v5[2]
                    local jumps5 = isJump(piece,x5,y5)
                    table.insert(moves,{x5,y5,"jump",{v2[3],v3[3],v4[3],v5[3]}})
                    for k6,v6 in ipairs(jumps5) do
                        local x6,y6 = x5 + v6[1],y5 + v6[2]
                        local jumps6 = isJump(piece,x6,y6)
                        table.insert(moves,{x6,y6,"jump",{v2[3],v3[3],v4[3],v5[3],v6[3]}})
                        for k7,v7 in ipairs(jumps6) do
                            local x7,y7 = x6 + v7[1],y6 + v7[2]
                            local jumps7 = isJump(piece,x7,y7)
                            table.insert(moves,{x7,y7,"jump",{v2[3],v3[3],v4[3],v5[3],v6[3],v7[3]}})
                            for k8,v8 in ipairs(jumps7) do
                                local x8,y8 = x7 + v8[1],y7 + v8[2]
                                local jumps8 = isJump(piece,x8,y8)
                                table.insert(moves,{x8,y8,"jump",{v2[3],v3[3],v4[3],v5[3],v6[3],v7[3],v8[3]}})
                                for k9,v9 in ipairs(jumps8) do
                                    local x9,y9 = x8 + v9[1],y8 + v9[2]
                                    local jumps9 = isJump(piece,x9,y9)
                                    table.insert(moves,{x9,y9,"jump",{v2[3],v3[3],v4[3],v5[3],v6[3],v7[3],v8[3],v9[3]}})
                                    for k10,v10 in ipairs(jumps9) do
                                        local x10,y10 = x9 + v10[1],y9 + v10[2]
                                        table.insert(moves,{x10,y10,"jump",{v2[3],v3[3],v4[3],v5[3],v6[3],v7[3],v8[3],v9[3],v10[3]}})
                                    end
                                end
                            end
                        end
                    end
                end
            end
        end
    end

    if not val and onBoard(X - 1,Y + 1) then
        table.insert(moves,{X - 1,Y + 1,"move",{}})
    end
    val,color,p = occupied(X - 1,Y - 1)
    if not val and onBoard(X - 1,Y - 1) then
        table.insert(moves,{X - 1,Y - 1,"move",{}})
    end
    if pieces[turn][piece].king then
        val,color,p = occupied(X + 1,Y + 1)
        if not val and onBoard(X + 1,Y + 1) then
            table.insert(moves,{X + 1,Y + 1,"move",{}})
        end
        val,color,p = occupied(X + 1,Y - 1)
        if not val and onBoard(X + 1,Y - 1) then
            table.insert(moves,{X + 1,Y - 1,"move",{}})
        end
    end
    local hasJump = false
    for key,val in ipairs(moves) do
        if val[3] == "jump" then
            hasJump = true
        end
    end
    local newMoves = moves
    if hasJump then
        for key,val in ipairs(moves) do
            if val[3] == "move" then
                table.remove(newMoves,key)
            end
        end
    end
    return newMoves
end

function displayMoves(piece)
    button.color(piece,pieces[turn][piece].color,colors.lime)
    for k,v in ipairs(getMoves(piece)) do
        local X,Y = getRealCoords(v[1],v[2])
        button.define("move"..tostring(k)," ",X,Y,colors.white,colors.lime,false)
        button.draw("move"..tostring(k))
    end
end

function doMove()
    local going = true
    while going do
        local piece = button.click()
        local moves = getMoves(piece)
        displayMoves(piece)
        button.deactivate("all")
        button.activate(piece)
        local move = button.click()
        print("move initialized as "..move)
        if move == piece then
            print("move = piece")
            button.color(piece,colors.white,colors.red)
            mon.setBackgroundColor(colors.red)
            for key,value in ipairs(moves) do
                button.delete("move"..tostring(key))
            end
        else
            print("move = "..move)
            for k,v in ipairs(moves[move][4]) do
                pieces[opponent][v].alive = false
                pieces[turn][piece].taken = pieces[turn][piece].taken + 1
            end
            for key,value in ipairs(moves) do
                button.delete("move"..tostring(key))
            end
            local x,y = getRealCoords(moves[move][1],moves[move][2])
            button.move(piece,x,y)
            pieces[turn][piece].x = moves[move][1]
            pieces[turn][piece].y = moves[move][2]
            going = false
        end
    end
end

function nextTurn()
    toggleTurn()
    getAlive()
    definePieces()
    button.draw(alive[turn])
    button.draw(alive[opponent])
    button.deactivate(alive[opponent])
    doMove()
    turnNum = turnNum + 1
end

function noWinner()
    for k,v in pairs(alive) do
        if getLength(v) == 0 then
            winner = k
            return false
        end
    end
    return true
end