#!/usr/bin/env python
# License: GPLv3 Copyright: 2020, Kovid Goyal <kovid at kovidgoyal.net>

import os
from base64 import standard_b64decode, standard_b64encode
from io import BytesIO
from typing import TYPE_CHECKING, Optional

from kitty.types import AsyncResponse
from kitty.utils import is_png

from .base import (
    MATCH_WINDOW_OPTION,
    SUPPORTED_IMAGE_FORMATS,
    ArgsType,
    Boss,
    CmdGenerator,
    ImageCompletion,
    PayloadGetType,
    PayloadType,
    RCOptions,
    RemoteCommand,
    ResponseType,
    Window,
)

if TYPE_CHECKING:
    from kitty.cli_stub import SetWindowLogoRCOptions as CLIOptions


class SetWindowLogo(RemoteCommand):
    protocol_spec = __doc__ = '''
    data+/str: Chunk of PNG data, base64 encoded no more than 2048 bytes. Must send an empty chunk to indicate end of image. \
    Or the special value :code:`-` to indicate image must be removed.
    position/str: The logo position as a string, empty string means default
    alpha/float: The logo alpha between :code:`0` and :code:`1`. :code:`-1` means use default
    match/str: Which window to change the logo in
    self/bool: Boolean indicating whether to act on the window the command is run in
    '''

    short_desc = 'Set the window logo'
    desc = (
        'Set the logo image for the specified windows. You must specify the path to an image that'
        ' will be used as the logo. If you specify the special value :code:`none` then any existing logo will'
        ' be removed. Supported image formats are: '
    ) + ', '.join(SUPPORTED_IMAGE_FORMATS)

    options_spec = MATCH_WINDOW_OPTION + '''\n
--self
type=bool-set
Act on the window this command is run in, rather than the active window.


--position
The position for the window logo. See :opt:`window_logo_position`.


--alpha
type=float
default=-1
The amount the window logo should be faded into the background.
See :opt:`window_logo_position`.


--no-response
type=bool-set
default=false
Don't wait for a response from kitty. This means that even if setting the image
failed, the command will exit with a success code.
'''
    args = RemoteCommand.Args(spec='PATH_TO_PNG_IMAGE', count=1, json_field='data', special_parse='!read_window_logo(io_data, args[0])',
                              completion=ImageCompletion)
    reads_streaming_data = True

    def message_to_kitty(self, global_opts: RCOptions, opts: 'CLIOptions', args: ArgsType) -> PayloadType:
        if len(args) != 1:
            self.fatal('Must specify path to exactly one PNG image')
        path = os.path.expanduser(args[0])
        import secrets
        ret = {
            'match': opts.match,
            'self': opts.self,
            'alpha': opts.alpha,
            'position': opts.position,
            'stream_id': secrets.token_urlsafe(),
        }
        if path.lower() == 'none':
            ret['data'] = '-'
            return ret
        if not is_png(path):
            self.fatal(f'{path} is not a PNG image')

        def file_pipe(path: str) -> CmdGenerator:
            with open(path, 'rb') as f:
                while True:
                    data = f.read(512)
                    if not data:
                        break
                    ret['data'] = standard_b64encode(data).decode('ascii')
                    yield ret
            ret['data'] = ''
            yield ret
        return file_pipe(path)

    def response_from_kitty(self, boss: Boss, window: Optional[Window], payload_get: PayloadGetType) -> ResponseType:
        data = payload_get('data')
        alpha = float(payload_get('alpha', '-1'))
        position = payload_get('position') or ''
        if data == '-':
            path = ''
            tfile = BytesIO()
        else:
            q = self.handle_streamed_data(standard_b64decode(data) if data else b'', payload_get)
            if isinstance(q, AsyncResponse):
                return q
            import hashlib
            path = '/from/remote/control/' + hashlib.sha1(q.getvalue()).hexdigest()
            tfile = q

        for window in self.windows_for_match_payload(boss, window, payload_get):
            if window:
                window.set_logo(path, position, alpha, tfile.getvalue())
        return None


set_window_logo = SetWindowLogo()
