const ldapjs = require("ldapjs");
import ConfigManager, { LDAPAttribute, LDAPCategory } from "./ConfigLoader";
import { LDAPSchemaAttribute, LDAPSchemaObjectClass } from './LDAPSchema';
import LDAPEntry from "./LDAPEntry";
import LDAPTree from "./LDAPTree";

interface ILDAPManager {
	Release(): Promise<void>;
	/**
	 * Try to login as user to check password
	 * @param dn
	 * @param password
	 */
	TryBind(dn: string, password: string): Promise<boolean>;
	CheckLoginExists(user: string): Promise<string>;
	ListEntries(category: LDAPCategory): Promise<LDAPEntry[]>;
	/** @return all dn */
	GetTree(): Promise<LDAPTree>;
	GetEntry(dn: string): Promise<Map<string, string[]>>;
	Remove(dn: string): Promise<void>;
	GetSchema(): Promise<Map<string, LDAPSchemaObjectClass>>;
}

class LDAPManager implements ILDAPManager {
	protected cli: any;

	public constructor(cli: any) {
		this.cli = cli;
	}

	public static Create(): Promise<LDAPManager> {
		return new Promise((ok, ko) => {
			let config = ConfigManager.GetInstance();

			let cli = ldapjs.createClient({
				url: config.GetLDAPUrls()
			});
			cli.on('error', (err: any) => {
				console.error("LDAP general error: ", err);
				ko(err);
			});
			cli.bind(config.GetBindDn(), config.GetBindPassword(), (err: any) => {
				if (err) {
					console.error("LDAP bind error: ", err);
					ko(err);
				} else {
					ok(new LDAPManager(cli));
				}
			});
		});
	}

	public TryBind(userDn: string, password: string): Promise<boolean> {
		return new Promise((ok, ko) => {
			let cli = ldapjs.createClient({
				url: ConfigManager.GetInstance().GetLDAPUrls()
			});
			cli.on('error', (err: any) => {
				console.error("LDAP general error: ", err);
				ko(err);
			});
			cli.bind(userDn, password, (err: any) => {
				if (err) {
					ok(false);
				} else {
					ok(true);
				}
			});
		});
	}

	private Search(base: string, scope: string, filter: string|undefined =undefined, attributes: string[]|undefined =undefined): Promise<Map<string, Map<string, string[]>>> {
		return new Promise((ok, ko) => {
			this.cli.search(base, { scope: scope, filter: filter, attributes: attributes || ['*', 'memberof'], paged: false }, (err: any, res: any) => {
				if (err) {
					console.error("Search error: ", { base: base, scope: scope, filter: filter, attributes: attributes });
					ko(err);
					return;
				}
				let result = new Map<string, any>();
				let error = false;

				res.on('searchEntry', (i: any) => {
					if (error) return;
					let LDAPEntry = new Map<string, string[]>();
					for (let attr in i.object) {
						let value = i.object[attr];
						if (Array.isArray(value)) {
							let arr = new Array();
							for (let j of value)
								arr.push(j);
							value = arr;
						} else {
							let arr = new Array();
							arr.push(value);
							value = arr;
						}
						LDAPEntry.set(attr, value);
					}
					result.set(i.dn, LDAPEntry);
				});
				res.on('error', (err: any) => {
					error = true;
					console.error("Search error: ", { base: base, scope: scope, filter: filter, attributes: attributes });
					ko(err);
				});
				res.on('end', () => {
					if (error) return;
					ok(result);
				});
			});
		});
	}

	public GetEntry(dn: string): Promise<Map<string, string[]>> {
		return new Promise((ok, ko) => {
			this.Search(dn, "sub").then(result => {
				for (let [_, val] of result) {
					ok(val);
					return;
				}
			}).catch(err => {
				ko(err);
			});
		});
	}

	public CheckLoginExists(user: string): Promise<string> {
		return new Promise((ok, ko) => {
			let config = ConfigManager.GetInstance();
			return this.Search(config.GetLoginBase(), config.GetLoginScope(), config.GetLoginFilter(user), []).then(result => {
				if (!result || result.size !== 1)
					ko();
				for (let [addr, _] of result) {
					ok(addr);
				}
			});
		});
	}

	public GetTree(): Promise<LDAPTree> {
		return new Promise(ok => {
			const rootDn: string = ConfigManager.GetInstance().GetLDAPRoot();
			this.Search(rootDn, "sub", undefined, ["dn", "ObjectClass"]).then(searchDns => {
				let result = LDAPTree.CreateRoot();
				searchDns.forEach((val, dn) => {
					let classes = val.get("objectClass");
					classes && result.push(dn, classes);
				});
				ok(result.Compress());
			});
		});
	}

	public ListEntries(category: LDAPCategory): Promise<LDAPEntry[]> {
		return new Promise((ok, _) => {
			this.Search(category.GetBaseDn(), category.GetScope(), category.GetFilter() || undefined, category.GetAttributes().map(i => i.mapped)).then(result => {
				let userArray = new Array();
				for (let [addr, val] of result)
					userArray.push(new LDAPEntry(category.GetAttributes(), addr, val));
				ok(userArray);
			});
		});
	}

	public Release():Promise<void> {
		return new Promise(ok => {
			this.cli.unbind((err: any) => {
				if (err)
					console.error("LDAP unbind error: ", err);
				ok();
			});
		});
	}

	public Remove(dn: string): Promise<void> {
		return new Promise((ok, ko) => {
			this.cli.del(dn, (err: any) => {
				if (err)
					ko(err["message"]);
				else
					ok();
			});
		});
	}

	public GetSchema(): Promise<Map<string, LDAPSchemaObjectClass>> {
		return new Promise((ok, ko) => {
			const rootDn = ConfigManager.GetInstance().GetLDAPRoot();
			let subschema: string;
			this.Search(rootDn, "base", undefined, ["subschemaSubentry"]).then(result => {
				const baseItem = result?.get(rootDn)?.get("subschemaSubentry");
				const _subschema = baseItem && baseItem.length ? baseItem[0] : null;
				if (!_subschema) {
					console.error("Cannot find schema for base " + rootDn);
					ko("Schema not found");
					return;
				}
				subschema = _subschema;
				return this.Search(subschema, "base", undefined, ["attributeTypes", "objectClasses"]);
			}).then(result => {
				const attributesArr = result?.get(subschema)?.get("attributeTypes");
				const classesArr = result?.get(subschema)?.get("objectClasses");
				if (!attributesArr || !classesArr) {
					console.error("Cannot find schema definition for " + rootDn);
					ko("Schema definition not found");
					return;
				}
				let attributes: Map<string, LDAPSchemaAttribute> = new Map();
				let schemas: Map<string, LDAPSchemaObjectClass> = new Map();

				for (let i of attributesArr) {
					let attr = new LDAPSchemaAttribute(i);
					attributes.set(attr.GetName(), attr);
				}
				for (let i of classesArr) {
					let schema = new LDAPSchemaObjectClass(i, attributes);
					schemas.set(schema.GetName(), schema);
				}
				for (let [_, schema] of schemas)
					schema.Consolidate(schemas, attributes);
				ok(schemas);
			}).catch(err => {
				console.error("Failed to retreive schema: ", err);
				ko(err);
			});
		});
	}
}

export default class LDAPFactory {
	private _instance: ILDAPManager|null = null;

	public GetInstance(): Promise<ILDAPManager> {
		if (!this._instance) {
			return new Promise((ok, ko) => {
				LDAPManager.Create().then(inst => {
					this._instance = inst;
					ok(this._instance);
				});
			});
		}
		return Promise.resolve(this._instance);
	}

	public Release(): Promise<null> {
		if (this._instance)
			return this._instance.Release().then(() => this._instance = null);
		return Promise.resolve(null);
	}
}

export { ILDAPManager };