class BlockService {
    constructor(storageService) {
        this.storage = storageService;
        this.blockedUsers = new Set();
        this.onBlockChange = null;
    }

    init() {
        const blocked = this.storage.getBlockedUsers();
        this.blockedUsers = new Set(blocked.map(u => u.toLowerCase()));
    }

    isBlocked(username) {
        if (!username) return false;
        return this.blockedUsers.has(username.toLowerCase());
    }

    block(username) {
        if (!username) return false;
        const normalized = username.toLowerCase();
        if (this.blockedUsers.has(normalized)) return false;
        this.blockedUsers.add(normalized);
        this.save();
        this.notifyChange();
        return true;
    }

    unblock(username) {
        if (!username) return false;
        const normalized = username.toLowerCase();
        if (!this.blockedUsers.has(normalized)) return false;
        this.blockedUsers.delete(normalized);
        this.save();
        this.notifyChange();
        return true;
    }

    toggle(username) {
        if (this.isBlocked(username)) {
            return this.unblock(username);
        }
        return this.block(username);
    }

    getBlockedUsers() {
        return Array.from(this.blockedUsers).sort();
    }

    getBlockedCount() {
        return this.blockedUsers.size;
    }

    clear() {
        this.blockedUsers.clear();
        this.save();
        this.notifyChange();
    }

    save() {
        this.storage.setBlockedUsers(Array.from(this.blockedUsers));
    }

    notifyChange() {
        if (this.onBlockChange) {
            this.onBlockChange(this.getBlockedUsers());
        }
        window.dispatchEvent(new CustomEvent('rantii:block-change', {
            detail: { blockedUsers: this.getBlockedUsers() }
        }));
    }

    setBlockChangeCallback(callback) {
        this.onBlockChange = callback;
    }

    filterRants(rants) {
        if (!rants || !Array.isArray(rants)) return [];
        return rants.filter(rant => !this.isBlocked(rant.user_username));
    }

    filterComments(comments) {
        if (!comments || !Array.isArray(comments)) return [];
        return comments.filter(comment => !this.isBlocked(comment.user_username));
    }

    filterNotifications(notifications) {
        if (!notifications || !Array.isArray(notifications)) return [];
        return notifications.filter(notif => {
            const username = notif.username?.name || notif.user_username?.name || notif.name;
            return !this.isBlocked(username);
        });
    }
}

export { BlockService };