/**
 * Users store effects (load, kick, ban, host election, profile persistence).
 */
/* eslint-disable @typescript-eslint/member-ordering */
import { Injectable, inject } from '@angular/core';
import {
  Actions,
  createEffect,
  ofType
} from '@ngrx/effects';
import { Store } from '@ngrx/store';
import {
  of,
  from,
  EMPTY
} from 'rxjs';
import {
  map,
  mergeMap,
  catchError,
  withLatestFrom,
  tap,
  switchMap
} from 'rxjs/operators';
import { v4 as uuidv4 } from 'uuid';
import { UsersActions } from './users.actions';
import {
  selectCurrentUser,
  selectCurrentUserId,
  selectHostId
} from './users.selectors';
import { selectCurrentRoom } from '../rooms/rooms.selectors';
import { DatabaseService } from '../../core/services/database.service';
import { WebRTCService } from '../../core/services/webrtc.service';
import { BanEntry, User } from '../../core/models/index';

@Injectable()
export class UsersEffects {
  private actions$ = inject(Actions);
  private store = inject(Store);
  private db = inject(DatabaseService);
  private webrtc = inject(WebRTCService);

  // Load current user from storage
  /** Loads the persisted current user from the local database on startup. */
  loadCurrentUser$ = createEffect(() =>
    this.actions$.pipe(
      ofType(UsersActions.loadCurrentUser),
      switchMap(() =>
        from(this.db.getCurrentUser()).pipe(
          switchMap((user) => {
            if (!user) {
              return of(UsersActions.loadCurrentUserFailure({ error: 'No current user' }));
            }

            const sanitizedUser = this.clearStartupVoiceConnection(user);

            if (sanitizedUser === user) {
              return of(UsersActions.loadCurrentUserSuccess({ user }));
            }

            return from(this.db.updateUser(user.id, { voiceState: sanitizedUser.voiceState })).pipe(
              map(() => UsersActions.loadCurrentUserSuccess({ user: sanitizedUser })),
              // If persistence fails, still load a sanitized in-memory user to keep UI correct.
              catchError(() => of(UsersActions.loadCurrentUserSuccess({ user: sanitizedUser })))
            );
          }),
          catchError((error) =>
            of(UsersActions.loadCurrentUserFailure({ error: error.message }))
          )
        )
      )
    )
  );

  private clearStartupVoiceConnection(user: User): User {
    const voiceState = user.voiceState;

    if (!voiceState)
      return user;

    const hasStaleConnectionState =
      voiceState.isConnected ||
      voiceState.isSpeaking ||
      voiceState.roomId !== undefined ||
      voiceState.serverId !== undefined;

    if (!hasStaleConnectionState)
      return user;

    return {
      ...user,
      voiceState: {
        ...voiceState,
        isConnected: false,
        isSpeaking: false,
        roomId: undefined,
        serverId: undefined
      }
    };
  }

  /** Loads all users associated with a specific room from the local database. */
  loadRoomUsers$ = createEffect(() =>
    this.actions$.pipe(
      ofType(UsersActions.loadRoomUsers),
      switchMap(({ roomId }) =>
        from(this.db.getUsersByRoom(roomId)).pipe(
          map((users) => UsersActions.loadRoomUsersSuccess({ users })),
          catchError((error) =>
            of(UsersActions.loadRoomUsersFailure({ error: error.message }))
          )
        )
      )
    )
  );

  /** Kicks a user from the room (requires moderator+ role). Broadcasts a kick signal. */
  kickUser$ = createEffect(() =>
    this.actions$.pipe(
      ofType(UsersActions.kickUser),
      withLatestFrom(
        this.store.select(selectCurrentUser),
        this.store.select(selectCurrentRoom)
      ),
      mergeMap(([
        { userId },
        currentUser,
        currentRoom
      ]) => {
        if (!currentUser || !currentRoom)
          return EMPTY;

        const canKick =
          currentUser.role === 'host' ||
          currentUser.role === 'admin' ||
          currentUser.role === 'moderator';

        if (!canKick)
          return EMPTY;

        this.webrtc.broadcastMessage({
          type: 'kick',
          targetUserId: userId,
          roomId: currentRoom.id,
          kickedBy: currentUser.id
        });

        return of(UsersActions.kickUserSuccess({ userId }));
      })
    )
  );

  /** Bans a user, persists the ban locally, and broadcasts a ban signal to peers. */
  banUser$ = createEffect(() =>
    this.actions$.pipe(
      ofType(UsersActions.banUser),
      withLatestFrom(
        this.store.select(selectCurrentUser),
        this.store.select(selectCurrentRoom)
      ),
      mergeMap(([
        { userId, reason, expiresAt },
        currentUser,
        currentRoom
      ]) => {
        if (!currentUser || !currentRoom)
          return EMPTY;

        const canBan = currentUser.role === 'host' || currentUser.role === 'admin';

        if (!canBan)
          return EMPTY;

        const ban: BanEntry = {
          oderId: uuidv4(),
          userId,
          roomId: currentRoom.id,
          bannedBy: currentUser.id,
          reason,
          expiresAt,
          timestamp: Date.now()
        };

        this.db.saveBan(ban);
        this.webrtc.broadcastMessage({
          type: 'ban',
          targetUserId: userId,
          roomId: currentRoom.id,
          bannedBy: currentUser.id,
          reason
        });

        return of(UsersActions.banUserSuccess({ userId,
          ban }));
      })
    )
  );

  /** Removes a ban entry from the local database. */
  unbanUser$ = createEffect(() =>
    this.actions$.pipe(
      ofType(UsersActions.unbanUser),
      switchMap(({ oderId }) =>
        from(this.db.removeBan(oderId)).pipe(
          map(() => UsersActions.unbanUserSuccess({ oderId })),
          catchError(() => EMPTY)
        )
      )
    )
  );

  /** Loads all active bans for the current room from the local database. */
  loadBans$ = createEffect(() =>
    this.actions$.pipe(
      ofType(UsersActions.loadBans),
      withLatestFrom(this.store.select(selectCurrentRoom)),
      switchMap(([, currentRoom]) => {
        if (!currentRoom) {
          return of(UsersActions.loadBansSuccess({ bans: [] }));
        }

        return from(this.db.getBansForRoom(currentRoom.id)).pipe(
          map((bans) => UsersActions.loadBansSuccess({ bans })),
          catchError(() => of(UsersActions.loadBansSuccess({ bans: [] })))
        );
      })
    )
  );

  /** Elects the current user as host if the previous host leaves. */
  handleHostLeave$ = createEffect(() =>
    this.actions$.pipe(
      ofType(UsersActions.userLeft),
      withLatestFrom(
        this.store.select(selectHostId),
        this.store.select(selectCurrentUserId)
      ),
      mergeMap(([
        { userId },
        hostId,
        currentUserId
      ]) =>
        userId === hostId && currentUserId
          ? of(UsersActions.updateHost({ userId: currentUserId }))
          : EMPTY
      )
    )
  );

  /** Persists user profile changes to the local database whenever the current user is updated. */
  persistUser$ = createEffect(
    () =>
      this.actions$.pipe(
        ofType(
          UsersActions.setCurrentUser,
          UsersActions.loadCurrentUserSuccess,
          UsersActions.updateCurrentUser
        ),
        withLatestFrom(this.store.select(selectCurrentUser)),
        tap(([, user]) => {
          if (user) {
            this.db.saveUser(user);
            // Ensure current user ID is persisted when explicitly set
            this.db.setCurrentUserId(user.id);
          }
        })
      ),
    { dispatch: false }
  );
}