# -*- coding: utf-8 -*-
#
# Copyright © Spyder Project Contributors
# Licensed under the terms of the MIT License
# (see spyder/__init__.py for details)

"""Spyder run container."""

# Standard library imports
import functools
import os.path as osp
from typing import Callable, List, Dict, Tuple, Set, Optional
from uuid import uuid4
from weakref import WeakSet, WeakValueDictionary

# Third-party imports
from qtpy.QtGui import QIcon
from qtpy.QtCore import Qt, Signal
from qtpy.QtWidgets import QAction

# Local imports
from spyder.api.plugins import Plugins
from spyder.api.widgets.main_container import PluginMainContainer
from spyder.api.translations import _
from spyder.plugins.run.api import (
    RunActions, StoredRunExecutorParameters, RunContext, RunExecutor,
    RunResultFormat, RunConfigurationProvider, RunResultViewer, OutputFormat,
    SupportedExecutionRunConfiguration, RunConfigurationMetadata,
    StoredRunConfigurationExecutor, ExtendedRunExecutionParameters,
    RunExecutionParameters, WorkingDirOpts, WorkingDirSource,
    SupportedExtensionContexts)
from spyder.plugins.run.models import (
    RunExecutorParameters, RunExecutorListModel, RunConfigurationListModel)
from spyder.plugins.run.widgets import RunDialog, RunDialogStatus
from spyder.utils.sourcecode import camel_case_to_snake_case


class RunContainer(PluginMainContainer):
    """Non-graphical container used to spawn dialogs and creating actions."""

    sig_run_action_created = Signal(str, bool, str)
    sig_open_preferences_requested = Signal()

    # ---- PluginMainContainer API
    # -------------------------------------------------------------------------
    def setup(self):
        self.current_working_dir: Optional[str] = None

        self.parameter_model = RunExecutorParameters(self)
        self.executor_model = RunExecutorListModel(self)
        self.metadata_model = RunConfigurationListModel(
            self, self.executor_model)

        self.run_metadata_provider: WeakValueDictionary[
            str, RunConfigurationProvider] = WeakValueDictionary()
        self.run_executors: WeakValueDictionary[
            str, RunExecutor] = WeakValueDictionary()
        self.viewers: WeakValueDictionary[
            str, RunResultViewer] = WeakValueDictionary()

        self.executor_use_count: Dict[str, int] = {}
        self.viewers_per_output: Dict[str, Set[str]] = {}

        self.run_action = self.create_action(
            RunActions.Run,
            _('&Run'),
            self.create_icon('run'),
            tip=_("Run file"),
            triggered=functools.partial(
                self.run_file, selected_uuid=None,
                selected_executor=None
            ),
            register_shortcut=True,
            shortcut_context='_',
            context=Qt.ApplicationShortcut
        )

        self.configure_action = self.create_action(
            RunActions.Configure,
            _('&Configuration per file'),
            self.create_icon('run_settings'),
            tip=_('Run settings'),
            triggered=functools.partial(
                self.edit_run_configurations,
                display_dialog=True,
                disable_run_btn=True,
                selected_executor=None
            ),
            register_shortcut=True,
            shortcut_context='_',
            context=Qt.ApplicationShortcut
        )

        self.create_action(
            RunActions.GlobalConfigurations,
            _("&Global presets"),
            triggered=self.sig_open_preferences_requested
        )

        self.re_run_action = self.create_action(
            RunActions.ReRun,
            _('Re-run &last file'),
            self.create_icon('run_again'),
            tip=_('Run again last file'),
            triggered=self.re_run_file,
            register_shortcut=True,
            shortcut_context='_',
            context=Qt.ApplicationShortcut
        )

        self.re_run_action.setEnabled(False)

        self.current_input_provider: Optional[str] = None
        self.current_input_extension: Optional[str] = None

        self.context_actions: Dict[
            Tuple[str, str, str], Tuple[QAction, Callable]] = {}
        self.re_run_actions: Dict[
            Tuple[str, str, str], Tuple[QAction, Callable]] = {}
        self.run_executor_actions: Dict[
            Tuple[str, str], Tuple[QAction, Callable]] = {}

        # 'File' is the only super context we support for now. It needs to be
        # set here so that run actions for files in different plugins (e.g.
        # 'Debug file') are declared correctly at startup.
        # Fixes spyder-ide/spyder#23694
        self.super_contexts: Set[str] = {RunContext.File}
        self.supported_extension_contexts: Dict[str, Set[Tuple[str, str]]] = {}

        self.last_executed_file: Optional[str] = None
        self.last_executed_per_context: Set[Tuple[str, str]] = set()
        self._last_executed_configuration: Optional[str] = None
        self._save_last_configured_executor: bool = True

    def update_actions(self):
        pass

    # ---- Public API
    # -------------------------------------------------------------------------
    def gen_anonymous_execution_run(
        self,
        context: str,
        extra_action_name: Optional[str] = None,
        context_modificator: Optional[str] = None,
        re_run: bool = False,
        last_executor_name: Optional[str] = None
    ) -> Callable:

        def anonymous_execution_run():
            if self.currently_selected_configuration is None:
                return

            # We save the last executed configuration in case we need it to
            # re-run the last action with the same parameters.
            # This is necessary for spyder-ide/spyder#23076
            if not re_run:
                uuid = self.currently_selected_configuration
                self._last_executed_configuration = (
                    self.currently_selected_configuration
                )
            else:
                uuid = self._last_executed_configuration

                # If nothing has been executed so far, we can't re-run it.
                if uuid is None:
                    return

            # Get run configuration
            input_provider = self.run_metadata_provider[uuid]
            if context in self.super_contexts:
                run_conf = input_provider.get_run_configuration(uuid)
            else:
                run_conf = input_provider.get_run_configuration_per_context(
                    context,
                    extra_action_name,
                    context_modificator,
                    re_run=re_run,
                )

            if run_conf is None:
                return

            # Get last executor
            super_metadata = self.metadata_model[uuid]
            extension = super_metadata['input_extension']

            last_executor = last_executor_name or self._get_default_executor(
                extension
            )
            if last_executor is None:
                last_executor = self.get_last_used_executor_parameters(uuid)
                last_executor = last_executor['executor']

            run_comb = (extension, context)
            if (
                last_executor is None
                or not self.executor_model.executor_supports_configuration(
                    last_executor, run_comb
                )
            ):
                last_executor = self.executor_model.get_default_executor(
                    run_comb)

            # Get execution params
            if context in self.super_contexts:
                # This applies to super contexts because we save run conf
                # params only for them (we handle just one super context for
                # now: "file").

                # Get last used params
                all_params = (
                    self.metadata_model.get_run_configuration_parameters(
                        uuid, last_executor
                    )["params"]
                )

                last_params_uuid = self.get_last_used_execution_params(
                    uuid, last_executor
                )

                if last_params_uuid in all_params:
                    # Use the last params set by the user in RunDialog.
                    # Fixes spyder-ide/spyder#22496
                    exec_params = all_params[last_params_uuid]["params"]
                else:
                    # If no custom params have been set, use the default ones
                    for stored_params in all_params.values():
                        if stored_params.get("default", False):
                            exec_params = stored_params["params"]
            else:
                # This is necessary for subcontexts (e.g. cell and selection).
                # Although they can have conf widgets (which is also tested),
                # that functionality is not exposed in the UI at the moment.
                path = super_metadata['path']
                dirname = osp.dirname(path)

                executor_metadata = self.executor_model[
                    ((extension, context), last_executor)
                ]
                ConfWidget = executor_metadata['configuration_widget']

                conf = {}
                if ConfWidget is not None:
                    conf = ConfWidget.get_default_configuration()

                working_dir = WorkingDirOpts(
                    source=WorkingDirSource.ConfigurationDirectory,
                    path=dirname
                )

                exec_params = RunExecutionParameters(
                    working_dir=working_dir, executor_params=conf
                )

            # Perform execution
            ext_exec_params = ExtendedRunExecutionParameters(
                uuid=None, name=None, params=exec_params)
            executor = self.run_executors[last_executor]
            executor.exec_run_configuration(run_conf, ext_exec_params)

            # Save metadata and set state of re-run actions
            self.last_executed_per_context |= {(uuid, context)}

            if (
                (context, extra_action_name, context_modificator)
                in self.re_run_actions
            ):
                act, _ = self.re_run_actions[
                    (context, extra_action_name, context_modificator)]
                act.setEnabled(True)

        return anonymous_execution_run

    def run_file(
        self, selected_uuid=None, selected_executor=None, rerun=False
    ):
        if not isinstance(selected_uuid, bool) and selected_uuid is not None:
            self.switch_focused_run_configuration(selected_uuid, rerun)

        self.edit_run_configurations(
            display_dialog=False,
            selected_executor=selected_executor
        )

    def edit_run_configurations(
        self,
        display_dialog=True,
        disable_run_btn=False,
        selected_executor=None
    ):
        self.dialog = RunDialog(
            self,
            self.metadata_model,
            self.executor_model,
            self.parameter_model,
            disable_run_btn=disable_run_btn
        )

        self.dialog.setup()
        self.dialog.finished.connect(self.process_run_dialog_result)
        self.dialog.sig_delete_config_requested.connect(
            self.delete_executor_configuration_parameters
        )

        # If the file is going to be executed (not configured) and the executor
        # is not provided, check if it has a default one.
        if not display_dialog and selected_executor is None:
            metadata = self.metadata_model.get_selected_metadata()
            if metadata is not None:
                extension = metadata["input_extension"]
                selected_executor = self._get_default_executor(extension)

        if selected_executor is not None:
            self.dialog.select_executor(selected_executor)

        if display_dialog:
            self.dialog.open()
        else:
            self.dialog.run_btn_clicked()

    def process_run_dialog_result(self, result):
        status = self.dialog.status

        if status == RunDialogStatus.Close:
            return

        uuid, executor_name, ext_params = self.dialog.get_configuration()

        if (status & RunDialogStatus.Save) == RunDialogStatus.Save:
            exec_uuid = ext_params['uuid']

            # Default parameters should already be saved in our config system.
            # So, there is no need to save them again here.
            if exec_uuid is not None and not ext_params["default"]:

                info = self.metadata_model.get_metadata_context_extension(uuid)
                context, ext =  info
                context_name = context['name']
                context_id = getattr(RunContext, context_name)
                all_exec_params = self.get_executor_configuration_parameters(
                    executor_name,
                    ext,
                    context_id
                )
                exec_params = all_exec_params['params']
                exec_params[exec_uuid] = ext_params

                self.set_executor_configuration_parameters(
                    executor_name,
                    ext,
                    context_id,
                    all_exec_params,
                )

            last_used_conf = StoredRunConfigurationExecutor(
                executor=executor_name, selected=ext_params['uuid']
            )

            if self._save_last_configured_executor:
                self._set_last_configured_executor(uuid, executor_name)

            # Reset this attribute to the default for next time
            self._save_last_configured_executor = True

            self.set_last_used_execution_params(uuid, last_used_conf)

        if (status & RunDialogStatus.Run) == RunDialogStatus.Run:
            provider = self.run_metadata_provider[uuid]
            executor = self.run_executors[executor_name]
            run_conf = provider.get_run_configuration(uuid)
            working_dir_opts = ext_params['params']['working_dir']
            working_dir_source = working_dir_opts['source']
            if working_dir_source == WorkingDirSource.ConfigurationDirectory:
                fname = run_conf['metadata']['path']
                dirname = osp.dirname(fname)
            elif working_dir_source == WorkingDirSource.CurrentDirectory:
                dirname = self.current_working_dir
            else:
                dirname = working_dir_opts['path']

            working_dir_opts['path'] = dirname

            self.last_executed_file = uuid
            self.re_run_action.setEnabled(True)

            executor.exec_run_configuration(run_conf, ext_params)

    def re_run_file(self):
        self.run_file(
            self.last_executed_file, selected_executor=None, rerun=True
        )

    @property
    def currently_selected_configuration(self):
        return self.metadata_model.get_current_run_configuration()

    def switch_focused_run_configuration(
        self, uuid: Optional[str], rerun: bool = False
    ):
        uuid = uuid or None

        # We need the first check to correctly update the run and context
        # actions when the config is None.
        # Fixes spyder-ide/spyder#22607
        if uuid is not None and uuid == self.currently_selected_configuration:
            return

        self.metadata_model.set_current_run_configuration(uuid)

        # For now, the default executor for run_action is the IPython console,
        # so we check if it's enabled to enable the action too.
        # TODO: Fix this when we make the executor configurable.
        if uuid is not None and self._plugin.is_plugin_enabled(
            Plugins.IPythonConsole
        ):
            self.run_action.setEnabled(True)
            self.configure_action.setEnabled(True)

            metadata = self.metadata_model[uuid]
            self.current_input_provider = metadata['source']
            self.current_input_extension = metadata['input_extension']

            if not rerun:
                input_provider = self.run_metadata_provider[uuid]
                input_provider.focus_run_configuration(uuid)

            self.set_actions_status()

            return

        self.run_action.setEnabled(False)
        self.configure_action.setEnabled(False)

        for context, act, mod in self.context_actions:
            action, __ = self.context_actions[(context, act, mod)]
            action.setEnabled(False)

        for context, act, mod in self.re_run_actions:
            action, __ = self.re_run_actions[(context, act, mod)]
            action.setEnabled(False)

        for context_name, executor_name in self.run_executor_actions:
            action, __ = self.run_executor_actions[
                (context_name, executor_name)]
            action.setEnabled(False)

    def set_actions_status(self):
        if self.current_input_provider is None:
            return

        if self.currently_selected_configuration is None:
            return

        if (
            self.current_input_provider
            not in self.supported_extension_contexts
        ):
            return

        input_provider_ext_ctxs = self.supported_extension_contexts[
            self.current_input_provider]

        for context, act, mod in self.context_actions:
            key = (self.current_input_extension, context)
            status = key in self.executor_model
            status = status and key in input_provider_ext_ctxs
            action, __ = self.context_actions[(context, act, mod)]
            action.setEnabled(status)

        for context, act, mod in self.re_run_actions:
            key = (self.current_input_extension, context)
            status = key in self.executor_model
            status = status and key in input_provider_ext_ctxs

            last_run_exists = (
                (self.currently_selected_configuration,
                 context) in self.last_executed_per_context)

            action, __ = self.re_run_actions[(context, act, mod)]
            action.setEnabled(status and last_run_exists)

        for context_name, executor_name in self.run_executor_actions:
            status = self.executor_model.executor_supports_configuration(
                executor_name,
                (self.current_input_extension, context_name))
            key = (self.current_input_extension, context_name)
            status = status and key in input_provider_ext_ctxs

            action, __ = self.run_executor_actions[
                (context_name, executor_name)]
            action.setEnabled(status)

    def set_current_working_dir(self, path: str):
        self.current_working_dir = path

    def create_run_button(
        self,
        context_name: str,
        text: str,
        icon: Optional[QIcon] = None,
        tip: Optional[str] = None,
        shortcut_context: Optional[str] = None,
        register_shortcut: bool = False,
        extra_action_name: Optional[str] = None,
        context_modificator: Optional[str] = None,
        re_run: bool = False
    ) -> QAction:
        """
        Create a run or a "run and do something" button for a specific run
        context.

        Parameters
        ----------
        context_name: str
            The identifier of the run context.
        text: str
           Localized text for the action
        icon: Optional[QIcon]
            Icon for the action when used in menu or toolbar.
        tip: Optional[str]
            Tooltip to define for action on menu or toolbar.
        shortcut_context: Optional[str]
            Set the `str` context of the shortcut.
        register_shortcut: bool
            If True, main window will expose the shortcut in Preferences.
            The default value is `False`.
        extra_action_name: Optional[str]
            The name of the action to execute on the run input provider
            after requesting the run input.
        context_modificator: Optional[str]
            The name of the modification to apply to the action, e.g. run
            selection <up to line>.
        re_run: bool
            If True, then the button will act as a re-run button instead of
            a run one.

        Returns
        -------
        action: SpyderAction
            The corresponding action that was created.

        Notes
        -----
        1. The context passed as a parameter must be a subordinate of the
        context of the current focused run configuration that was
        registered via `register_run_configuration_metadata`. For instance,
        Cell can be used if and only if the file was registered.

        2. The button will be registered as `run <context>` or
        `run <context> <context_modificator> and <extra_action_name>`
        on the action registry.

        3. The created button will operate over the last focused run input
        provider.

        4. If the requested button already exists, this method will not do
        anything, which implies that the first registered shortcut will be the
        one to be used. For the built-in run contexts (file, cell and
        selection), the editor will register their corresponding icons and
        shortcuts.
        """
        dict_actions = self.re_run_actions if re_run else self.context_actions

        if (
            (context_name, extra_action_name, context_modificator)
            in dict_actions
        ):
            action, __ = self.context_actions[
                (context_name, extra_action_name, context_modificator)]
            return action

        prefix = 're-' if re_run else ''
        action_name = f'{prefix}run {context_name}'
        if context_modificator is not None:
            action_name = f'{action_name} {context_modificator}'
        if extra_action_name is not None:
            action_name = f'{action_name} and {extra_action_name}'

        func = self.gen_anonymous_execution_run(
            context_name, extra_action_name, context_modificator,
            re_run=re_run, last_executor_name=None)

        action = self.create_action(
            action_name,
            text,
            icon,
            tip=tip,
            triggered=func,
            register_shortcut=register_shortcut,
            shortcut_context=shortcut_context,
            context=Qt.WidgetShortcut,
        )

        if re_run:
            self.re_run_actions[
                (context_name, extra_action_name, context_modificator)] = (
                action, func)
            action.setEnabled(False)
        else:
            self.context_actions[
                (context_name, extra_action_name, context_modificator)] = (
                action, func)

        self.sig_run_action_created.emit(action_name, register_shortcut,
                                         shortcut_context)
        return action

    def create_run_in_executor_button(
        self,
        context_name: str,
        executor_name: str,
        text: str,
        icon: Optional[QIcon] = None,
        tip: Optional[str] = None,
        shortcut_context: Optional[str] = None,
        register_shortcut: bool = False,
        shortcut_widget_context: int = Qt.WidgetShortcut
    ) -> QAction:
        """
        Create a "run <context> in <provider>" button for a given run context
        and executor.

        Parameters
        ----------
        context_name: str
            The identifier of the run context.
        executor_name: str
            The identifier of the run executor.
        text: str
           Localized text for the action
        icon: Optional[QIcon]
            Icon for the action when used in a menu or toolbar.
        tip: Optional[str]
            Tooltip to define for action on menu or toolbar.
        shortcut_context: Optional[str]
            Set the `str` context of the shortcut.
        register_shortcut: bool
            If True, main window will expose the shortcut in Preferences.
            The default value is `False`.

        Returns
        -------
        action: SpyderAction
            The corresponding action that was created.

        Notes
        -----
        1. The context passed as a parameter must be a subordinate of the
        context of the current focused run configuration that was
        registered via `register_run_configuration_metadata`. For instance,
        Cell can be used if and only if the file was registered.

        2. The button will be registered as `run <context> in <provider>` on
        the action registry.

        3. The created button will operate over the last focused run input
        provider.

        4. If the requested button already exists, this method will not do
        anything, which implies that the first registered shortcut will be the
        one to be used.
        """
        if (context_name, executor_name) in self.run_executor_actions:
            action, __ = self.run_executor_actions[
                (context_name, executor_name)]
            return action

        action_name = f'run {context_name} in {executor_name}'

        func = lambda: None
        if context_name in self.super_contexts:
            func = functools.partial(self.run_file,
                                     selected_executor=executor_name)
        else:
            func = self.gen_anonymous_execution_run(
                context_name, re_run=False,
                last_executor_name=executor_name)

        action = self.create_action(
            action_name,
            text,
            icon,
            tip=tip,
            triggered=func,
            register_shortcut=register_shortcut,
            shortcut_context=shortcut_context,
            context=shortcut_widget_context
        )

        self.run_executor_actions[(context_name, executor_name)] = (
            action, func)

        self.sig_run_action_created.emit(action_name, register_shortcut,
                                         shortcut_context)
        return action

    def register_run_configuration_provider(
        self,
        provider_name: str,
        supported_extensions_contexts: List[SupportedExtensionContexts]
    ):
        """
        Register the supported extensions and contexts that a
        `RunConfigurationProvider` supports.

        Parameters
        ----------
        provider_name: str
            The identifier of the :class:`RunConfigurationProvider` instance
            that is registering the set of supported contexts per extension.
        supported_extensions_contexts: List[SupportedExtensionContexts]
            A list containing the supported contexts per file extension
            supported.
        """
        provider_extensions_contexts = self.supported_extension_contexts.get(
            provider_name, set({}))

        for supported_extension_contexts in supported_extensions_contexts:
            for ext_context in supported_extension_contexts['contexts']:
                context = ext_context['context']
                is_super = ext_context['is_super']
                context_name = context['name']
                context_identifier = context.get('identifier', None)
                if context_identifier is None:
                    context_identifier = camel_case_to_snake_case(context_name)
                    context['identifier'] = context_identifier
                setattr(RunContext, context_name, context_identifier)
                ext_list = supported_extension_contexts['input_extension']
                if not isinstance(ext_list, list):
                    ext_list = [ext_list]
                for ext in ext_list:
                    provider_extensions_contexts |= {(ext, context_identifier)}
                if is_super:
                    self.super_contexts |= {context_identifier}

        self.supported_extension_contexts[
            provider_name] = provider_extensions_contexts

        self.set_actions_status()

    def deregister_run_configuration_provider(
        self,
        provider_name: str,
        unsupported_extensions_contexts: List[SupportedExtensionContexts]
    ):
        """
        Deregister the extensions and contexts that a
        `RunConfigurationProvider` no longer supports.

        Parameters
        ----------
        provider_name: str
            The identifier of the :class:`RunConfigurationProvider` instance
            that is deregistering the set of formerly supported contexts
            per extension.
        unsupported_extensions_contexts: List[SupportedExtensionContexts]
            A list containing the formerly supported contexts per
            file extension.
        """
        provider_extensions_contexts = self.supported_extension_contexts.get(
            provider_name, set({}))

        for unsupported_extension_contexts in unsupported_extensions_contexts:
            ext = unsupported_extension_contexts['input_extension']
            for ext_context in unsupported_extension_contexts['contexts']:
                context = ext_context['context']
                context_name = context['name']
                context_id = getattr(RunContext, context_name)
                provider_extensions_contexts -= {(ext, context_id)}

        if provider_extensions_contexts:
            self.supported_extension_contexts[
                provider_name] = provider_extensions_contexts
        else:
            self.supported_extension_contexts.pop(provider_name, set({}))

    def register_run_configuration_metadata(
        self,
        provider: RunConfigurationProvider,
        metadata: RunConfigurationMetadata
    ):
        """
        Register the metadata for a run configuration.

        Parameters
        ----------
        provider: RunConfigurationProvider
            A :class:`SpyderPluginV2` instance that implements the
            :class:`RunConfigurationProvider` interface and will register
            and own a run configuration.
        metadata: RunConfigurationMetadata
            The metadata for a run configuration that the provider is able to
            produce.
        """
        context = metadata['context']
        context_name = context['name']
        context_identifier = context.get('identifier', None)

        if context_identifier is None:
            context_identifier = camel_case_to_snake_case(context_name)
            context['identifier'] = context_identifier
        setattr(RunContext, context_name, context_identifier)

        run_id = metadata['uuid']
        self.run_metadata_provider[run_id] = provider
        self.metadata_model[run_id] = metadata

    def deregister_run_configuration_metadata(self, uuid: str):
        """
        Deregister a given run configuration by its unique identifier.

        Parameters
        ----------
        uuid: str
            Unique identifier for a run configuration metadata that will not
            longer exist. This id should have been registered using
            `register_run_configuration_metadata`.
        """
        self.metadata_model.pop(uuid)
        self.run_metadata_provider.pop(uuid)

        if uuid == self.last_executed_file:
            self.last_executed_file = None
            self.re_run_action.setEnabled(False)

        to_remove = set({})
        for (opened_uuid, context) in self.last_executed_per_context:
            if opened_uuid == uuid:
                to_remove |= {(opened_uuid, context)}

        self.last_executed_per_context -= to_remove

    def register_executor_configuration(
        self,
        executor: RunExecutor,
        configuration: List[SupportedExecutionRunConfiguration]
    ):
        """
        Register a :class:`RunExecutorProvider` instance to indicate its
        support for a given set of run configurations.

        Parameters
        ----------
        provider: RunExecutor
            A :class:`SpyderPluginV2` instance that implements the
            :class:`RunExecutor` interface and will register execution
            input type information.
        configuration: List[SupportedExecutionRunConfiguration]
            A list of input configurations that the provider is able to
            produce. Each configuration specifies the input extension
            identifier as well as the available execution context for that
            type.
        """
        executor_id = executor.NAME
        executor_name = executor.get_name()
        self.run_executors[executor_id] = executor
        executor_count = self.executor_use_count.get(executor_id, 0)

        for config in configuration:
            context = config['context']
            context_name = context['name']
            context_id = context.get('identifier', None)
            if context_id is None:
                context_id = camel_case_to_snake_case(context_name)
            setattr(RunContext, context_name, context_id)

            output_formats = []
            for out in config['output_formats']:
                output_name = out['name']
                output_id = out.get('identifier', None)
                if not output_id:
                    output_id = camel_case_to_snake_case(output_name)
                setattr(RunResultFormat, output_name, output_id)
                updated_out = {'name': output_name, 'identifier': output_id}
                output_formats.append(updated_out)

            config['output_formats'] = output_formats
            ext_list = config['input_extension']
            if not isinstance(ext_list, list):
                ext_list = [ext_list]
            for ext in ext_list:
                self.executor_model.add_input_executor_configuration(
                    ext, context_id, executor_id, config)
                executor_count += 1

                # Save default configs to our config system so that they are
                # displayed in the Run confpage
                config_widget = config["configuration_widget"]
                default_conf = (
                    config_widget.get_default_configuration()
                    if config_widget
                    else {}
                )
                self._save_default_graphical_executor_configuration(
                    executor_id,
                    ext,
                    context_id,
                    default_conf
                )

        self.executor_use_count[executor_id] = executor_count
        self.executor_model.set_executor_name(executor_id, executor_name)
        self.set_actions_status()

    def deregister_executor_configuration(
        self,
        executor: RunExecutor,
        configuration: List[SupportedExecutionRunConfiguration]
    ):
        """
        Deregister a :class:`RunExecutor` instance from providing a set
        of run configurations that are no longer supported by it.

        Parameters
        ----------
        executor: RunExecutor
            A :class:`SpyderPluginV2` instance that implements the
            :class:`RunExecutor` interface and will deregister execution
            input type information.
        configuration: List[SupportedExecutionRunConfiguration]
            A list of input configurations that the executor wants to
            deregister. Each configuration specifies the input extension
            identifier as well as the available execution context for that
            type.
        """
        executor_id = executor.NAME

        for config in configuration:
            ext = config['input_extension']
            context = config['context']
            context_name = context['name']
            context_id = getattr(RunContext, context_name)
            self.executor_model.remove_input_executor_configuration(
                ext, context_id, executor_id)
            self.executor_use_count[executor_id] -= 1

        if self.executor_use_count[executor_id] <= 0:
            self.run_executors.pop(executor_id)

        self.set_actions_status()

    def register_viewer_configuration(
        self,
        viewer: RunResultViewer,
        formats: List[OutputFormat]
    ):
        """
        Register a :class:`RunResultViewer` instance to indicate its support
        for a given set of output run result formats.

        Parameters
        ----------
        provider: RunResultViewer
            A :class:`SpyderPluginV2` instance that implements the
            :class:`RunResultViewer` interface and will register
            supported output formats.
        formats: List[OutputFormat]
            A list of output formats that the viewer is able to display.
        """
        for out_format in formats:
            format_name = out_format['name']
            format_id = out_format.get('identifier', None)
            if format_id is None:
                format_id = camel_case_to_snake_case(format_name)
            setattr(RunResultFormat, format_name, format_id)

            viewers_set = self.viewers.get(format_id, WeakSet())
            viewers_set.add(viewer)
            self.viewers[format_id] = viewers_set

    def deregister_viewer_configuration(
        self,
        viewer: RunResultViewer,
        formats: List[OutputFormat]
    ):
        """
        Deregister a :class:`RunResultViewer` instance from supporting a set of
        output formats that are no longer supported by it.

        Parameters
        ----------
        provider: RunResultViewer
            A :class:`SpyderPluginV2` instance that implements the
            :class:`RunResultViewer` interface and will deregister
            output format support.
        formats: List[OutputFormat]
            A list of output formats that the viewer wants to deregister.
        """
        for out_format in formats:
            format_name = out_format['name']
            format_id = getattr(RunResultFormat, format_name)
            if format_id in self.viewers:
                viewer_set = self.viewers[format_id]
                viewer_set.discard(viewer)

    def get_executor_configuration_parameters(
        self,
        executor_name: str,
        extension: str,
        context_id: str
    ) -> StoredRunExecutorParameters:
        """
        Retrieve the stored parameters for a given executor `executor_name`
        using context `context_id` with file extension `extension`.

        Parameters
        ----------
        executor_name: str
            The identifier of the run executor.
        extension: str
            The file extension to register the configuration parameters for.
        context_id: str
            The context to register the configuration parameters for.

        Returns
        -------
        config: StoredRunExecutorParameters
            A dictionary containing the run executor parameters for the given
            run configuration.
        """

        all_execution_params: Dict[
            str,
            Dict[Tuple[str, str], StoredRunExecutorParameters]
        ] = self.get_conf('parameters', default={})

        executor_params = all_execution_params.get(executor_name, {})
        params = executor_params.get(
            (extension, context_id),
            StoredRunExecutorParameters(params={})
        )

        return params

    def set_executor_configuration_parameters(
        self,
        executor_name: str,
        extension: str,
        context_id: str,
        params: StoredRunExecutorParameters
    ):
        """
        Update and save the list of configuration parameters for a given
        executor on a given pair of context and file extension.

        Parameters
        ----------
        executor_name: str
            The identifier of the run executor.
        extension: str
            The file extension to register the configuration parameters for.
        context_id: str
            The context to register the configuration parameters for.
        params: StoredRunExecutorParameters
            A dictionary containing the run configuration parameters for the
            given executor.
        """
        all_execution_params: Dict[
            str,
            Dict[Tuple[str, str], StoredRunExecutorParameters]
        ] = self.get_conf('parameters', default={})

        executor_params = all_execution_params.get(executor_name, {})
        ext_ctx_params = executor_params.get((extension, context_id), {})

        if ext_ctx_params:
            # Update current parameters in case the user has already saved some
            # before.
            ext_ctx_params['params'].update(params['params'])
        else:
            # Create a new entry of executor parameters in case there isn't any
            executor_params[(extension, context_id)] = params

        all_execution_params[executor_name] = executor_params

        self.set_conf('parameters', all_execution_params)

    def delete_executor_configuration_parameters(
        self,
        executor_name: str,
        extension: str,
        context_id: str,
        uuid: str
    ):
        """
        Delete an executor parameter set from our config system.

        Parameters
        ----------
        executor_name: str
            The identifier of the run executor.
        extension: str
            The file extension of the configuration parameters to delete.
        context_id: str
            The context of the configuration parameters to delete.
        uuid: str
            The run configuration identifier.
        """
        all_execution_params: Dict[
            str,
            Dict[Tuple[str, str], StoredRunExecutorParameters]
        ] = self.get_conf('parameters', default={})

        executor_params = all_execution_params[executor_name]
        ext_ctx_params = executor_params[(extension, context_id)]['params']

        for params_id in ext_ctx_params:
            if params_id == uuid:
                # Prevent to remove default parameters
                if ext_ctx_params[params_id]["default"]:
                    return

                ext_ctx_params.pop(params_id, None)
                break

        executor_params[(extension, context_id)]['params'] = ext_ctx_params
        all_execution_params[executor_name] = executor_params

        self.set_conf('parameters', all_execution_params)

    def get_last_used_executor_parameters(
        self,
        uuid: str
    ) -> StoredRunConfigurationExecutor:
        """
        Retrieve the last used execution parameters for a given
        run configuration.

        Parameters
        ----------
        uuid: str
            The run configuration identifier.

        Returns
        -------
        last_used_params: StoredRunConfigurationExecutor
            A dictionary containing the last used executor and parameters
            for the given run configuration.
        """
        last_executor = self._get_last_configured_executor(uuid)
        default = StoredRunConfigurationExecutor(executor=None, selected=None)

        if last_executor is None:
            return default
        else:
            mru_executors_uuids: Dict[
                str, List[StoredRunConfigurationExecutor]
            ] = self.get_conf('last_used_parameters_per_executor', default={})

            all_params = mru_executors_uuids.get(uuid, [])

            last_used_params = default
            for params in all_params:
                if params["executor"] == last_executor:
                    last_used_params = params

            return last_used_params

    def get_last_used_execution_params(
        self,
        uuid: str,
        executor_name: str
    ) -> Optional[str]:
        """
        Retrieve the last used execution parameters for a given pair of run
        configuration identifier and executor name.

        Parameters
        ----------
        uuid: str
            The run configuration identifier.
        executor_name: str
            The identifier of the run executor.

        Returns
        -------
        last_used_params: Optional[str]
            The identifier of the last used parameters for the given
            run configuration on the given executor. None if the executor has
            not executed the run configuration.
        """

        mru_executors_uuids: Dict[
            str,
            List[StoredRunConfigurationExecutor]
        ] = self.get_conf('last_used_parameters_per_executor', default={})

        default = StoredRunConfigurationExecutor(
            executor=executor_name,
            selected=None
        )
        all_params = mru_executors_uuids.get(uuid, [default])

        last_used_params = None
        for params in all_params:
            if params['executor'] == executor_name:
                last_used_params = params['selected']

        return last_used_params

    def set_last_used_execution_params(
        self,
        uuid: str,
        params: StoredRunConfigurationExecutor
    ):
        """
        Store the list of last used executors and their parameters for a given
        run configuration.

        Parameters
        ----------
        uuid: str
            The run configuration identifier.
        params: StoredRunConfigurationExecutor
            Dictionary containing the last used executor and run parameters
            used.
        """
        mru_executors_uuids: Dict[
            str,
            List[StoredRunConfigurationExecutor]
        ] = self.get_conf('last_used_parameters_per_executor', default={})

        if uuid in mru_executors_uuids:
            new_params = []
            params_added = False
            for saved_params in mru_executors_uuids[uuid]:
                # Discard saved params for the executor and use the new ones
                # instead. We need to do this when the executor was configured
                # before
                if params["executor"] == saved_params["executor"]:
                    new_params.append(params)
                    params_added = True
                else:
                    # Add params for all other executors
                    new_params.append(saved_params)

            # If the executor hasn't been configured yet, we simply need to add
            # its new params to the list.
            if not params_added:
                new_params.append(params)

            # Replace current params with the new ones
            mru_executors_uuids[uuid] = new_params
        else:
            mru_executors_uuids[uuid] = [params]

        self.set_conf('last_used_parameters_per_executor', mru_executors_uuids)

    # ---- Private API
    # -------------------------------------------------------------------------
    def _save_default_graphical_executor_configuration(
        self,
        executor_name: str,
        extension: str,
        context_id: str,
        default_conf: dict,
    ):
        """
        Save a default executor configuration to our config system.

        Parameters
        ----------
        executor_name: str
            The identifier of the run executor.
        extension: str
            The file extension to register the configuration parameters for.
        context_id: str
            The context to register the configuration parameters for.
        default_conf: dict
            A dictionary containing the run configuration parameters for the
            given executor.
        """
        # Check if there's already a default parameter config to not do this
        # because it's not necessary.
        current_params = self.get_executor_configuration_parameters(
            executor_name,
            extension,
            context_id
        )

        for param in current_params["params"].values():
            if param["default"]:
                return

        # Id for this config
        uuid = str(uuid4())

        # Build config
        cwd_opts = WorkingDirOpts(
            source=WorkingDirSource.ConfigurationDirectory,
            path=None
        )

        exec_params = RunExecutionParameters(
            working_dir=cwd_opts, executor_params=default_conf
        )

        ext_exec_params = ExtendedRunExecutionParameters(
            uuid=uuid,
            name=_("Default"),
            params=exec_params,
            file_uuid=None,
            default=True,
        )

        store_params = StoredRunExecutorParameters(
            params={uuid: ext_exec_params}
        )

        # Save config
        self.set_executor_configuration_parameters(
            executor_name,
            extension,
            context_id,
            store_params,
        )

    def _get_last_configured_executor(self, uuid: str) -> Optional[str]:
        """
        Get the last executor configured in RunDialog for a given file.

        Parameters
        ----------
        uuid: str
            Unique id associated to a file.
        """
        mru_uuids_to_executor_names: Dict[
            str, str,
        ] = self.get_conf('last_configured_executor', default={})

        return mru_uuids_to_executor_names.get(uuid, None)

    def _set_last_configured_executor(self, uuid: str, executor_name: str):
        """
        Set the last executor configured in RunDialog for a given file.

        Parameters
        ----------
        uuid: str
            Unique id associated to a file.
        """
        mru_uuids_to_executor_names: Dict[
            str, str,
        ] = self.get_conf('last_configured_executor', default={})

        mru_uuids_to_executor_names[uuid] = executor_name
        self.set_conf('last_configured_executor', mru_uuids_to_executor_names)

    def _get_default_executor(self, extension: str) -> Optional[str]:
        """
        Get the default for a given file extension.

        Parameters
        ----------
        extension: str
            The file extension

        Returns
        -------
        executor_name: Optional[str]
            The default executor name or None if there isn't one for the given
            extension.

        Notes
        -----
        - This is necessary in case a file has multiple executors so that the
          Run file, cell and selection buttons use this executor by default.
        - We need to implement an API and UI for this so that a default
          executor can be declared for other file types.
        """
        executor_name = None

        if extension in ["py", "ipy", "pyx"]:
            # This is the most intuitive executor for Python-like files and it
            # was also the default in Spyder 5.
            executor_name = Plugins.IPythonConsole

        # This avoids changing the last executor selected in RunDialog when
        # using the default one.
        self._save_last_configured_executor = False

        return executor_name
