import sys
import shutil

class Menu:
    def __init__(self, items, cursor=0, head={}):
        self.head = head
        self.items = items
        self.cursor = cursor
        self.marked = []
        self.draw()

    def setHead(self, head):
        self.head = head
        self.draw()

    def setItems(self, items, cursor=0):
        self.__init__(items, cursor)

    def toggleMark(self):
        if self.cursor in self.marked:
            self.marked.remove(self.cursor)
        else:
            self.marked.append(self.cursor)
        self.draw()

    def setMarked(self, marked):
        self.marked = [i for i in range(len(self.items)) if self.items[i] in marked]
        self.draw()

    def isCurrentMarked(self):
        return self.cursor in self.marked

    def isMarked(self, item):
        return item in [self.items[i] for i in self.marked]

    def next(self):
        self.cursor += 1
        if self.cursor >= len(self.items):
            self.cursor = len(self.items) - 1
        self.draw()

    def prev(self):
        self.cursor -= 1
        if self.cursor < 0:
            self.cursor = 0
        self.draw()

    def selected(self):
        return self.items[self.cursor]

    def draw(self):
        size = shutil.get_terminal_size((80, 20))
        w = size[0]

        # Heading
        for i in range(size[1]):
            sys.stdout.write(f'\x1b[{i + 1};{w//2 + 1}H'+' '*(w//2))
        for row, key in enumerate(self.head):
            sys.stdout.write(f'\x1b[{row + 1};{w//2 + 1}H {key}: {self.head[key][:w//2 - len(key) - 3]}\x1b[0m')

        offset = len(self.head) + 2
        if offset == 2:
            offset = 1
        h = size[1] - offset
        first = 0
        if len(self.items) > h:
            if self.cursor > (h - offset)/2:
                first = self.cursor - h//2 - 1
                if first < 0:
                    first = 0
                elif len(self.items) - first < h + 1:
                    first = len(self.items) - h - 1

        for row, item in enumerate(self.items[first:h + first + 1]):
            mark = '\x1b[44m+' if row + first in self.marked else ' '
            text = mark+item[:w//2 - 1]+' '*(w//2 - 1 - len(item))
            if self.cursor == row + first:
                sys.stdout.write(f'\x1b[{row + offset};{w//2 + 1}H\x1b[7m{text}\x1b[0m')
            else:
                sys.stdout.write(f'\x1b[{row + offset};{w//2 + 1}H{text}\x1b[0m')