from threading import Thread

from asciimatics.exceptions import NextScene
from asciimatics.widgets import Frame, Layout, Button, Divider, Label

from ..operation_strings import descriptions as op_desc
from ..utils import generic_handle_stream_response
from .TUIStreamResponseHandler import TUIStreamResponseHandler


class TransactionView(Frame):
    def __init__(self, screen, width, height, model):
        super().__init__(
            screen,
            height,
            width,
            can_scroll=False,
            on_load=self._on_load,
            title='Running Transaction',
        )
        self._model = model
        # map operation names to label widgets
        self._labels = {}
        # this is an ugly hack to get around the fact that _on_load()
        # will be called again when we reset() in the TUIStreamResponseHandler
        self._loaded = False

    def _add_buttons(self):
        layout = Layout([100])
        self.add_layout(layout)
        layout.add_widget(Divider())

        layout = Layout([1, 1])
        self.add_layout(layout)
        self._next_btn = Button('Next', self._next)
        self._next_btn.disabled = True
        layout.add_widget(self._next_btn, 1)

    def _add_line(self, text: str = ''):
        layout = Layout([100])
        self.add_layout(layout)
        layout.add_widget(Label(text, align='^'))

    def _on_load(self):
        if self._loaded:
            return
        self._loaded = True
        
        for _ in range(2):
            self._add_line()
        for operation in self._model.operations:
            desc = op_desc[operation]
            layout = Layout([10, 1, 10])
            self.add_layout(layout)
            layout.add_widget(Label(desc + '...', align='>'), 0)
            desc_label = Label('', align='<')
            layout.add_widget(desc_label, 2)
            self._labels[operation] = desc_label
        self._add_line()
        self._msg_layout = Layout([100])
        self.add_layout(self._msg_layout)
        self.add_layout(Layout([100], fill_frame=True))

        self._add_buttons()
        self.fix()
        Thread(target=self._do_txn).start()

    def _do_txn(self):
        resp = self._model.deferred_req()
        handler = TUIStreamResponseHandler(
            model=self._model,
            labels=self._labels,
            next_btn=self._next_btn,
            msg_layout=self._msg_layout,
            frame=self,
        )
        generic_handle_stream_response(resp, self._model.operations, handler)

    def _next(self):
        self._model.scene_stack.clear()
        raise NextScene('Welcome')