from collections.abc import MutableSequence

u32_le = lambda i: i.to_bytes(length=4, byteorder='little')

class Rating:
    EC = 0
    E = 1
    E10 = 2
    T = 3
    M = 4
    AO = 5
    RP = 6


class GuideMode:
    N = 0x11   # nothing
    B = 0x13   # buttons only
    T = 0x15   # touch only
    BT = 0x17  # buttons + touch


class Button:
    START = 0
    SELECT = 1
    A = 2
    B = 3
    X = 4
    Y = 5
    L = 6
    R = 7
    DPAD = 8


class DemoMenu(MutableSequence):
    def __init__(self):
        self.entries: list[DemoMenu.DemoMenuEntry] = []


    def encode(self) -> bytes:
        return b''.join([
            u32_le(len(self.entries)),
            b''.join(entry.encode() for entry in self.entries),
            u32_le(0)
        ])

    __bytes__ = encode


    def __getitem__(self, index):
        return self.entries[index]


    def __setitem__(self, index, value):
        self.entries[index] = value


    def __delitem__(self, index):
        del self.entries[index]


    def __len__(self):
        return len(self.entries)


    def insert(self, index, value):
        self.entries.insert(index, value)


    class DemoMenuEntry:
        def __init__(self, data: bytes|None = None):
            if data is None:
                self.banner_image = bytes(0x200)
                self.banner_palette = bytes(0x20)
                self.banner_text = [''] * 2
                self.rating = Rating.E
                self.guide_mode = GuideMode.N
                self.buttons_text = [''] * 9
                self.unknown_text = [''] * 3
                self.touch_text = [''] * 2
                self.padding = bytes(0x40)
                self.internal_name = ''
                return
            self.banner_image = data[:0x200]
            self.banner_palette = data[0x200:0x220]
            self.banner_text = [
                data[i:i+0x80].decode('latin-1').rstrip('\0')
                for i in range(0x220, 0x320, 0x80)
            ]
            self.rating = data[0x320]
            self.guide_mode = data[0x321]
            self.buttons_text = [
                data[i:i+0x20].decode('latin-1').rstrip('\0')
                for i in range(0x322, 0x442, 0x20)
            ]
            self.unknown_text = [
                data[i:i+0x20].decode('latin-1').rstrip('\0')
                for i in range(0x442, 0x4a2, 0x20)
            ]
            self.touch_text = [
                data[i:i+0x20].decode('latin-1').rstrip('\0')
                for i in range(0x4a2, 0x4e2, 0x20)
            ]
            self.padding = data[0x4e2:0x522]
            self.internal_name = data[0x522:0x52c].decode('latin-1').rstrip('\0')


        def encode(self) -> bytes:
            return b''.join([
                self.banner_image,
                self.banner_palette,
                b''.join(
                    text.ljust(0x80, '\0').encode('latin-1')
                    for text in self.banner_text
                ), self.rating.to_bytes(1),
                self.guide_mode.to_bytes(1),
                b''.join(
                    text.ljust(0x20, '\0').encode('latin-1')
                    for text in self.buttons_text
                ), b''.join(
                    text.ljust(0x20, '\0').encode('latin-1')
                    for text in self.unknown_text
                ), b''.join(
                    text.ljust(0x20, '\0').encode('latin-1')
                    for text in self.touch_text
                ), self.padding,
                self.internal_name.ljust(0xa, '\0').encode('latin-1')
            ])

        __bytes__ = encode


        def __len__(self):
            return 0x52c