import { computed, inject } from '@angular/core';
import {
    addEntity,
    removeEntities,
    setAllEntities,
    updateEntity,
    withEntities,
} from '@ngrx/signals/entities';
import {
    signalStore,
    withComputed,
    withHooks,
    withMethods,
    withState,
} from '@ngrx/signals';
import { rxMethod } from '@ngrx/signals/rxjs-interop';
import {
    setError,
    setLoaded,
    setLoading,
    updateState,
    withCallState,
    withDevtools,
    withLocalStorage,
    withStorageSync,
} from '@angular-architects/ngrx-toolkit';
import { EMPTY, pipe } from 'rxjs';
import { catchError, switchMap, tap } from 'rxjs/operators';
import { Task, TaskFilter, TaskPriority } from './task.model';
import { TasksApiService } from './tasks-api.service';

interface TasksState {
    filter: TaskFilter;
    draftPriority: TaskPriority;
    searchTerm: string;
    lastSyncedAt: string | null;
}

const initialState: TasksState = {
    filter: 'all',
    draftPriority: 'medium',
    searchTerm: '',
    lastSyncedAt: null,
};

function matchesFilter(task: Task, filter: TaskFilter): boolean {
    switch (filter) {
        case 'active':
            return !task.completed;
        case 'completed':
            return task.completed;
        default:
            return true;
    }
}

export const TasksStore = signalStore(
    { providedIn: 'root' },
    withState(initialState),
    withEntities<Task>(),
    withCallState(),
    withDevtools('tasks-store'),
    withStorageSync(
        {
            key: 'ngrx-playground.tasks',
            select: (state) => ({
                ids: state.ids,
                entityMap: state.entityMap,
                filter: state.filter,
                draftPriority: state.draftPriority,
                searchTerm: state.searchTerm,
                lastSyncedAt: state.lastSyncedAt,
            }),
        },
        withLocalStorage(),
    ),
    withComputed((store) => ({
        filteredTasks: computed(() => {
            const normalizedSearch = store.searchTerm().trim().toLowerCase();

            return store.entities().filter((task) => {
                const matchesText = normalizedSearch.length === 0 || task.title.toLowerCase().includes(normalizedSearch);

                return matchesFilter(task, store.filter()) && matchesText;
            });
        }),
        totalCount: computed(() => store.entities().length),
        activeCount: computed(() => store.entities().filter((task) => !task.completed).length),
        completedCount: computed(() => store.entities().filter((task) => task.completed).length),
        hasCompletedTasks: computed(() => store.entities().some((task) => task.completed)),
        emptyStateMessage: computed(() => {
            if (store.loading()) {
                return 'Loading tasks...';
            }

            if (store.error()) {
                return 'The task list could not be refreshed.';
            }

            if (store.entities().length === 0) {
                return 'No tasks saved yet. Create the first one.';
            }

            return 'No tasks match the current filters.';
        }),
        lastSyncedLabel: computed(() => {
            const value = store.lastSyncedAt();
            return value ? new Date(value).toLocaleTimeString('en-US') : 'Never';
        }),
    })),
    methodsStore(),
    withHooks({
        onInit(store) {
            if (store.entities().length === 0) {
                store.loadTasks();
            }
        },
    }),
);

function methodsStore() {
    return withMethods((store, api = inject(TasksApiService)) => ({
        loadTasks: rxMethod<void>(
            pipe(
                tap(() => updateState(store, 'tasks load started', setLoading())),
                switchMap(() =>
                    api.getTasks().pipe(
                        tap((tasks) =>
                            updateState(
                                store,
                                'tasks load succeeded',
                                setAllEntities(tasks),
                                { lastSyncedAt: new Date().toISOString() },
                                setLoaded(),
                            ),
                        ),
                        catchError((error: unknown) => {
                            updateState(store, 'tasks load failed', setError(error));
                            return EMPTY;
                        }),
                    ),
                ),
            ),
        ),

        createTask: rxMethod<{ title: string; priority: TaskPriority }>(
            pipe(
                tap(() => updateState(store, 'task create started', setLoading())),
                switchMap(({ title, priority }) =>
                    api.createTask(title, priority).pipe(
                        tap((task) =>
                            updateState(store, 'task create succeeded', addEntity(task), { lastSyncedAt: task.updatedAt }, setLoaded()),
                        ),
                        catchError((error: unknown) => {
                            updateState(store, 'task create failed', setError(error));
                            return EMPTY;
                        }),
                    ),
                ),
            ),
        ),

        toggleTask: rxMethod<string>(
            pipe(
                tap(() => updateState(store, 'task toggle started', setLoading())),
                switchMap((taskId) =>
                    api.toggleTask(taskId).pipe(
                        tap((task) =>
                            updateState(
                                store,
                                'task toggle succeeded',
                                updateEntity({ id: task.id, changes: task }),
                                { lastSyncedAt: task.updatedAt },
                                setLoaded(),
                            ),
                        ),
                        catchError((error: unknown) => {
                            updateState(store, 'task toggle failed', setError(error));
                            return EMPTY;
                        }),
                    ),
                ),
            ),
        ),

        archiveCompleted: rxMethod<void>(
            pipe(
                tap(() => updateState(store, 'completed tasks archive started', setLoading())),
                switchMap(() =>
                    api.archiveCompleted().pipe(
                        tap((archivedIds) =>
                            updateState(
                                store,
                                'completed tasks archive succeeded',
                                removeEntities(archivedIds),
                                { lastSyncedAt: new Date().toISOString() },
                                setLoaded(),
                            ),
                        ),
                        catchError((error: unknown) => {
                            updateState(store, 'completed tasks archive failed', setError(error));
                            return EMPTY;
                        }),
                    ),
                ),
            ),
        ),

        setFilter(filter: TaskFilter): void {
            updateState(store, 'task filter changed', { filter });
        },

        setDraftPriority(priority: TaskPriority): void {
            updateState(store, 'task priority draft changed', { draftPriority: priority });
        },

        setSearchTerm(searchTerm: string): void {
            updateState(store, 'task search changed', { searchTerm });
        },
    }));
}