const containerCustomizationsManager = {
    apiBase: window.location.origin,
    _initialized: false,
    _loadPromise: null,

    byKey: new Map(),
    listeners: new Set(),

    getAuthHeaders() {
        const token = localStorage.getItem('accessToken');
        const apiKey = localStorage.getItem('apiKey');

        const headers = {
            'Content-Type': 'application/json'
        };

        if (token) {
            headers['Authorization'] = `Bearer ${token}`;
        } else if (apiKey) {
            headers['X-API-Key'] = apiKey;
        }

        return headers;
    },

    async fetchAPI(endpoint, options = {}) {
        const response = await fetch(`${this.apiBase}${endpoint}`, {
            ...options,
            headers: {
                ...this.getAuthHeaders(),
                ...(options.headers || {})
            }
        });

        if (!response.ok) {
            if (response.status === 401) {
                if (window.dashboard?.logout) {
                    window.dashboard.logout();
                }
                return null;
            }
            throw new Error(`API Error: ${response.status}`);
        }

        if (response.status === 204) return null;
        return response.json();
    },

    _key(hostId, containerId) {
        return `${hostId}::${containerId}`;
    },

    setData(items) {
        this.byKey.clear();
        (items || []).forEach((c) => {
            if (!c?.host_id || !c?.container_id) return;
            this.byKey.set(this._key(c.host_id, c.container_id), c);
        });
        this._emitChange();
    },

    async load() {
        const res = await this.fetchAPI('/api/docker/container-customizations');
        this.setData(res?.customizations || []);
    },

    async ensureInit() {
        if (this._initialized) return;
        if (this._loadPromise) {
            await this._loadPromise;
            return;
        }

        this._loadPromise = (async () => {
            try {
                await this.load();
            } finally {
                this._initialized = true;
            }
        })();

        await this._loadPromise;
    },

    onChange(callback) {
        this.listeners.add(callback);
        return () => this.listeners.delete(callback);
    },

    _emitChange() {
        for (const cb of this.listeners) {
            try {
                cb();
            } catch (e) {
                console.error('containerCustomizationsManager listener error:', e);
            }
        }
    },

    get(hostId, containerId) {
        return this.byKey.get(this._key(hostId, containerId)) || null;
    },

    async upsert(hostId, containerId, { icon_key = null, icon_color = null, bg_color = null }) {
        const payload = { icon_key, icon_color, bg_color };
        const res = await this.fetchAPI(`/api/docker/container-customizations/${encodeURIComponent(hostId)}/${encodeURIComponent(containerId)}`, {
            method: 'PUT',
            body: JSON.stringify(payload)
        });
        if (!res) return null;
        this.byKey.set(this._key(hostId, containerId), res);
        this._emitChange();
        return res;
    },

    async remove(hostId, containerId) {
        await this.fetchAPI(`/api/docker/container-customizations/${encodeURIComponent(hostId)}/${encodeURIComponent(containerId)}`, {
            method: 'DELETE'
        });
        this.byKey.delete(this._key(hostId, containerId));
        this._emitChange();
    }
};

window.containerCustomizationsManager = containerCustomizationsManager;