import { getContext, setContext } from 'svelte'
import { api, auth } from './pocketbase.svelte'
import { getTeamContext } from './teams.svelte'
import { isRecent } from '$lib/time'
import type { TrailCommentsResponse, UsersResponse } from '$lib/types'

const KEY = Symbol('trailComment')

/** Kommentar samt Verfasser, sofern dessen Datensatz sichtbar ist. */
export type TrailComment = Omit<TrailCommentsResponse, 'expand'> & {
	expand?: { created_by?: UsersResponse }
}

/**
 * Kommentare lagen bisher direkt in der Trail-Seite — als es sie nur dort
 * gab, war das die einfachere Lösung. Die Trail-Liste zeigt jetzt ebenfalls
 * ihre Anzahl, und zwei Ladewege auf dieselben Daten wären einer zu viel.
 */
export class TrailCommentStore {
	records = $state<TrailComment[]>([])
	loading = $state(false)
	error = $state<string | null>(null)

	private unsubscribe: (() => void) | null = null
	private teams = getTeamContext()

	get scoped(): TrailComment[] {
		const teamId = this.teams.activeId
		if (!teamId) return []
		return this.records.filter((r) => r.team === teamId)
	}

	/** Kommentare eines Trails, jüngste zuerst */
	byTrail(trailId: string): TrailComment[] {
		return this.scoped
			.filter((r) => r.trail === trailId)
			.sort((a, b) => (a.created < b.created ? 1 : -1))
	}

	/** Gab es zuletzt Bewegung? Für die Hervorhebung in der Liste. */
	hasRecent(trailId: string, days?: number): boolean {
		return this.byTrail(trailId).some((r) => isRecent(r.created, days))
	}

	async load() {
		this.loading = true
		this.error = null
		try {
			this.records = (await api.collection('trail_comments').getFullList({
				sort: '-created',
				expand: 'created_by',
				requestKey: null,
			})) as TrailComment[]
		} catch (e: any) {
			this.error = e.message ?? 'Fehler beim Laden der Kommentare'
			console.error(e)
		} finally {
			this.loading = false
		}
	}

	subscribe() {
		if (this.unsubscribe) return
		api.collection('trail_comments').subscribe('*', (e) => {
			const record = e.record as TrailComment
			const idx = this.records.findIndex((r) => r.id === record.id)
			if (e.action === 'create' && idx === -1) this.records = [record, ...this.records]
			else if (e.action === 'update' && idx !== -1) this.records[idx] = record
			else if (e.action === 'delete' && idx !== -1) this.records = this.records.filter((r) => r.id !== record.id)
		}, { expand: 'created_by' }).then((unsub) => {
			this.unsubscribe = unsub
		}).catch((e) => console.warn('trail_comments subscribe failed:', e))
	}

	async create(trailId: string, teamId: string, text: string) {
		return await api.collection('trail_comments').create({
			trail: trailId,
			team: teamId,
			text: text.trim(),
			created_by: auth.user?.id,
		})
	}

	async remove(id: string) {
		await api.collection('trail_comments').delete(id)
	}

	destroy() {
		if (this.unsubscribe) {
			this.unsubscribe()
			this.unsubscribe = null
		}
	}
}

export function setTrailCommentContext() {
	const store = new TrailCommentStore()
	setContext(KEY, store)
	return store
}

export function getTrailCommentContext(): TrailCommentStore {
	return getContext<TrailCommentStore>(KEY)
}