import * as electronRemote from '@electron/remote';
const electronConsole = electronRemote.getGlobal('console') as Console;
import Logger from '../../../../logger/logger';
const LOG = Logger.create(__filename, electronConsole);

import { ReactNode } from 'react';
import { atom, selector } from 'recoil';
import { Channel, GuildMetadata, Member, Message } from '../../data-types';
import CombinedGuild from '../../guild-combined';
import GuildsManager from '../../guilds-manager';

export type WithUnloadedValue = {
	value: undefined;
	hasValueError: false;
	valueError: undefined;
};
export type WithLoadedValue<T> = T extends undefined ? never : {
	value: T;
	hasValueError: false;
	valueError: undefined;
};
export type WithFailedValue = {
	value: undefined;
	hasValueError: true;
	valueError: unknown;
};
export type WithLoadableValue<T> = WithUnloadedValue | WithLoadedValue<T> | WithFailedValue;

// NOTE: Should not extend this type. It is for type guards

export type GuildWithValue<T> = WithLoadedValue<T> & { guild: CombinedGuild };
export type GuildWithErrorableValue<T> = WithLoadableValue<T> & { guild: CombinedGuild };
export type ChannelWithErrorableValue<T> = WithLoadableValue<T> & { channel: Channel };

// Devoid is when we don't have a selected guild yet.
export function isDevoid<T>(state: NonNullable<T> | null): state is null {
	return state === null;
}
// NOTE: Using "pended" instead of "pending" since it has 6 letters like the rest of these functions. It will make the code look nicer :)
export function isPended<T>(withLoadableValue: WithLoadableValue<T>): withLoadableValue is WithUnloadedValue {
	return withLoadableValue.value === undefined && withLoadableValue.hasValueError === false;
}
export function isLoaded<T>(withLoadableValue: WithLoadableValue<T>): withLoadableValue is WithLoadedValue<T> {
	return withLoadableValue.value !== undefined;
}
export function isFailed<T>(withLoadableValue: WithLoadableValue<T>): withLoadableValue is WithFailedValue {
	return withLoadableValue.hasValueError;
}

// WARNING: This must NOT be used in a place that could prevent hooks from running
// NOTE: This is useful to skip rendering elements that require an atom if its value is not available yet. Using this in the parent element will prevent the child eleemnt from
// needing to implement the complexity of loading without a value
export function isDevoidPendedOrFailed<T>(withNullableLoadableValue: WithLoadableValue<T> | null): withNullableLoadableValue is null | WithUnloadedValue | WithFailedValue {
	return withNullableLoadableValue === null || isPended(withNullableLoadableValue) || isFailed(withNullableLoadableValue);
}

export const overlayState = atom<ReactNode>({
	key: 'overlayState',
	default: null
});

export const guildsManagerState = atom<GuildsManager | null>({
	key: 'guildsManagerState',
	default: null,
	// Allow mutability so that we can have changes to internal guild stuff
	// We will still listen to new/update/delete/conflict events to maintain the UI's state
	dangerouslyAllowMutability: true
});

export const guildsState = atom<GuildWithErrorableValue<GuildMetadata>[] | null>({
	key: 'guildsState',
	default: null,
	dangerouslyAllowMutability: true
});

export const selectedGuildIdState = atom<number | null>({
	key: 'selectedGuildIdState',
	default: null
});

export const selectedGuildWithMetaState = selector<GuildWithErrorableValue<GuildMetadata> | null>({
	key: 'selectedGuildWithMetaState',
	get: ({ get }) => {
		const guildsWithMeta = get(guildsState);
		if (guildsWithMeta === null) return null;

		const guildId = get(selectedGuildIdState);
		if (guildId === null) return null;

		return guildsWithMeta.find(guildWithMeta => guildWithMeta.guild.id === guildId) ?? null;
	},
	dangerouslyAllowMutability: true
});

// Note: You likely want selectedGuildWithMetaState
export const selectedGuildState = selector<CombinedGuild | null>({
	key: 'selectedGuildState',
	get: ({ get }) => {
		const guildWithMeta = get(selectedGuildWithMetaState);
		if (isDevoid(guildWithMeta)) return null;

		return guildWithMeta.guild;
	},
	dangerouslyAllowMutability: true
});

export const selectedGuildWithMembersState = atom<GuildWithErrorableValue<Member[]> | null>({
	key: 'selectedGuildWithMembersState',
	default: null,
	dangerouslyAllowMutability: true
});

export const selectedGuildWithSelfMemberState = selector<GuildWithErrorableValue<Member> | null>({
	key: 'selectedGuildWithSelfMemberState',
	get: ({ get }) => {
		const guildWithMembers = get(selectedGuildWithMembersState);
		if (isDevoid(guildWithMembers)) return null;
		if (isFailed(guildWithMembers)) return { guild: guildWithMembers.guild, value: undefined, hasValueError: true, valueError: 'members fetch error' };
		if (isPended(guildWithMembers)) return { guild: guildWithMembers.guild, value: undefined, hasValueError: false, valueError: undefined };
		const selfMember = guildWithMembers.value.find(member => member.id === guildWithMembers.guild.memberId) ?? null;
		if (selfMember === null) {
			LOG.warn('unable to find self member in members');
			return { guild: guildWithMembers.guild, value: undefined, hasValueError: true, valueError: 'unable to find self in members' };
		}
		return { guild: guildWithMembers.guild, value: selfMember, hasValueError: false, valueError: undefined };
	},
	dangerouslyAllowMutability: true
});

export const selectedGuildWithChannelsState = atom<GuildWithErrorableValue<Channel[]> | null>({
	key: 'selectedGuildChannelsState',
	default: null,
	dangerouslyAllowMutability: true
});

export const selectedGuildWithActiveChannelIdState = atom<GuildWithValue<string | null> | null>({
	key: 'selectedGuildWithActiveChannelIdState',
	default: null,
	dangerouslyAllowMutability: true
});


export const selectedGuildWithActiveChannelMessagesState = atom<GuildWithValue<ChannelWithErrorableValue<Message[]>> | null>({
	key: 'selectedGuildWithActiveChannelMessagesState',
	default: null,
	dangerouslyAllowMutability: true
});

// TODO: selectedGuildWithActiveChannelState