/*******************************************************************************
 * ============LICENSE_START====================================================
 * * org.onap.aaf
 * * ===========================================================================
 * * Copyright © 2017 AT&T Intellectual Property. All rights reserved.
 * * ===========================================================================
 * * Licensed under the Apache License, Version 2.0 (the "License");
 * * you may not use this file except in compliance with the License.
 * * You may obtain a copy of the License at
 * *
 *  *      http://www.apache.org/licenses/LICENSE-2.0
 * *
 *  * Unless required by applicable law or agreed to in writing, software
 * * distributed under the License is distributed on an "AS IS" BASIS,
 * * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * * See the License for the specific language governing permissions and
 * * limitations under the License.
 * * ============LICENSE_END====================================================
 * *
 * *
 ******************************************************************************/
package org.onap.aaf.org;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.regex.Pattern;

import org.onap.aaf.auth.env.AuthzTrans;
import org.onap.aaf.auth.org.EmailWarnings;
import org.onap.aaf.auth.org.Executor;
import org.onap.aaf.auth.org.Organization;
import org.onap.aaf.auth.org.OrganizationException;
import org.onap.aaf.cadi.util.FQI;
import org.onap.aaf.misc.env.Env;

public class DefaultOrg implements Organization {
	private static final String AAF_DATA_DIR = "aaf_data_dir";
	private static final String PROPERTY_IS_REQUIRED = " property is Required";
	// Package on Purpose
	final String domain;
	final String atDomain;
	final String realm;

	private final String NAME,mailHost,mailFrom;
	private final Set<String> supportedRealms;


	public DefaultOrg(Env env, String realm) throws OrganizationException {

		this.realm = realm;
		supportedRealms=new HashSet<>();
		supportedRealms.add(realm);
		domain=FQI.reverseDomain(realm);
		atDomain = '@'+domain;
		String s;
		NAME=env.getProperty(realm + ".name","Default Organization");
		mailHost = env.getProperty(s=(realm + ".mailHost"), null);
		if(mailHost==null) {
			throw new OrganizationException(s + PROPERTY_IS_REQUIRED);
		}
		mailFrom = env.getProperty(s=(realm + ".mailFrom"), null);
		if(mailFrom==null) {
			throw new OrganizationException(s + PROPERTY_IS_REQUIRED);
		}
		
		// Note: This code is to avoid including javax.mail into ONAP, because there are security/licence 
		// exceptions
		try {
			Class.forName("javax.mail.Session"); // ensure package is loaded
			@SuppressWarnings("unchecked")
			Class<Mailer> minst = (Class<Mailer>)Class.forName("org.onap.aaf.org.JavaxMailer");
			mailer = minst.newInstance();
		} catch (ClassNotFoundException | InstantiationException | IllegalAccessException e1) {
			env.warn().log("JavaxMailer not loaded. Mailing disabled");
		}

		System.getProperties().setProperty("mail.smtp.host",mailHost);
		System.getProperties().setProperty("mail.user", mailFrom);

		try {
			String defFile;
			String temp=env.getProperty(defFile = (getClass().getName()+".file"));
			File fIdentities=null;
			if(temp==null) {
				temp = env.getProperty(AAF_DATA_DIR);
				if(temp!=null) {
					env.warn().log(defFile, " is not defined. Using default: ",temp+"/identities.dat");
					File dir = new File(temp);
					fIdentities=new File(dir,"identities.dat");

					if(!fIdentities.exists()) {
						env.warn().log("No",fIdentities.getCanonicalPath(),"exists.  Creating.");
						if(!dir.exists()) {
							dir.mkdirs();
						}
						fIdentities.createNewFile();
					}
				}
			} else {
				fIdentities = new File(temp);
				if(!fIdentities.exists()) {
					String dataDir = env.getProperty(AAF_DATA_DIR);
					if(dataDir!=null) {
						fIdentities = new File(dataDir,temp);
					}
				}
			}

			if(fIdentities!=null && fIdentities.exists()) {
				identities = new Identities(fIdentities);
			} else {
				if(fIdentities==null) {
					throw new OrganizationException("No Identities");
				} else {
					throw new OrganizationException(fIdentities.getCanonicalPath() + " does not exist.");
				}
			}
		} catch (IOException e) {
			throw new OrganizationException(e);
		}
	}

	// Implement your own Delegation System
	static final List<String> NULL_DELEGATES = new ArrayList<>();

	public Identities identities;
	private boolean dryRun;
	private Mailer mailer;
	public enum Types {Employee, Contractor, Application, NotActive};
	private final static Set<String> typeSet;

	static {
		typeSet = new HashSet<>();
		for(Types t : Types.values()) {
			typeSet.add(t.name());
		}
	}

	private static final EmailWarnings emailWarnings = new DefaultOrgWarnings();

	@Override
	public String getName() {
		return NAME;
	}

	@Override
	public String getRealm() {
		return realm;
	}

	@Override
	public String getDomain() {
		return domain;
	}

	@Override
	public DefaultOrgIdentity getIdentity(AuthzTrans trans, String id) throws OrganizationException {
		int at = id.indexOf('@');
		return new DefaultOrgIdentity(trans,at<0?id:id.substring(0, at),this);
	}

	// Note: Return a null if found; return a String Message explaining why not found.
	@Override
	public String isValidID(final AuthzTrans trans, final String id) {
		try {
			DefaultOrgIdentity u = getIdentity(trans,id);
			return (u==null||!u.isFound())?id + "is not an Identity in " + getName():null;
		} catch (OrganizationException e) {
			return getName() + " could not lookup " + id + ": " + e.getLocalizedMessage();
		}
	}
	// Possible ID Pattern
	//	private static final Pattern ID_PATTERN=Pattern.compile("([\\w.-]+@[\\w.-]+).{4-13}");
	// Another one: ID_PATTERN = "(a-z[a-z0-9]{5-8}@.*).{4-13}";

	@Override
	public boolean isValidCred(final AuthzTrans trans, final String id) {
		// have domain?
		int at = id.indexOf('@');
		String sid;
		if(at > 0) {
			// Use this to prevent passwords to any but THIS domain.
//			if(!id.regionMatches(at+1, domain, 0, id.length()-at-1)) {
//				return false;
//			}
			sid = id.substring(0,at);
		} else {
			sid = id;
		}
		// We'll validate that it exists, rather than check patterns.

		return isValidID(trans, sid)==null;
		// Check Pattern (if checking existing is too long)
		//		if(id.endsWith(SUFFIX) && ID_PATTERN.matcher(id).matches()) {
		//			return true;
		//		}
		//		return false;
	}

	private static final String SPEC_CHARS = "!@#$%^*-+?/,:;.";
	private static final Pattern PASS_PATTERN=Pattern.compile("(((?=.*[a-z,A-Z])(((?=.*\\d))|(?=.*[" + SPEC_CHARS +"]))).{6,20})");
	/**
	 *  (				# Start of group
	 *  (?=.*[a-z,A-Z])	#   must contain one character
	 *  
	 *  (?=.*\d)		#   must contain one digit from 0-9 
	 *        OR
	 *  (?=.*[@#$%])	#   must contain one special symbols in the list SPEC_CHARS
	 *  
	 *        	.		#     match anything with previous condition checking
	 *          {6,20}	#        length at least 6 characters and maximum of 20
	 *  )				# End of group
	 *
	 * Another example, more stringent pattern
	 private static final Pattern PASS_PATTERN=Pattern.compile("((?=.*\\d)(?=.*[a-z])(?=.*[A-Z])(?=.*[" + SPEC_CHARS +"]).{6,20})");
	 *  Attribution: from mkyong.com
	 *  (				# Start of group
	 *  (?=.*\d)		#   must contain one digit from 0-9
	 *  (?=.*[a-z])		#   must contain one lowercase characters
	 *  (?=.*[A-Z])		#   must contain one uppercase characters
	 *  (?=.*[@#$%])	#   must contain one special symbols in the list SPEC_CHARS
	 *        	.		#     match anything with previous condition checking
	 *          {6,20}	#        length at least 6 characters and maximum of 20
	 *  )				# End of group
	 */
	@Override
	public String isValidPassword(final AuthzTrans trans, final String user, final String password, final String... prev) {
		for(String p : prev) {
			if(password.contains(p)) { // A more sophisticated algorithm might be better.
				return "Password too similar to previous passwords";
			}
		}
		// If you have an Organization user/Password scheme, replace the following
		if(PASS_PATTERN.matcher(password).matches()) {
			return "";
		}
		return "Password does not match " + NAME + " Password Standards";
	}

	private static final String[] rules = new String[] {
			"Passwords must contain letters",
			"Passwords must contain one of the following:",
			"  Number",
			"  One special symbols in the list \""+ SPEC_CHARS + '"',
			"Passwords must be between 6 and 20 chars in length",
	};

	@Override
	public String[] getPasswordRules() {
		return rules;
	}

	@Override
	public Set<String> getIdentityTypes() {
		return typeSet;
	}

	@Override
	public Response notify(AuthzTrans trans, Notify type, String url, String[] identities, String[] ccs, String summary, Boolean urgent) {
		String system = trans.getProperty("CASS_ENV", "");

		ArrayList<String> toList = new ArrayList<>();
		Identity identity;
		if (identities != null) {
			for (String user : identities) {
				try {
					identity = getIdentity(trans, user);
					if (identity == null) {
						trans.error().log(
								"Failure to obtain User " + user + " for "
										+ getName());
					} else {
						toList.add(identity.email());
					}
				} catch (Exception e) {
					trans.error().log(
							e,
							"Failure to obtain User " + user + " for "
									+ getName());
				}
			}
		}

		if (toList.isEmpty()) {
			trans.error().log("No Users listed to email");
			return Response.ERR_NotificationFailure;
		}

		ArrayList<String> ccList = new ArrayList<>();

		// If we're sending an urgent email, CC the user's supervisor
		//
		if (urgent) {
			trans.info().log("urgent msg for: " + identities[0]);
			try {
				List<Identity> supervisors = getApprovers(trans, identities[0]);
				for (Identity us : supervisors) {
					trans.info().log("supervisor: " + us.email());
					ccList.add(us.email());
				}
			} catch (Exception e) {
				trans.error().log(e,
						"Failed to find supervisor for  " + identities[0]);
			}
		}

		if (ccs != null) {
			for (String user : ccs) {
				try {
					identity = getIdentity(trans, user);
					ccList.add(identity.email());
				} catch (Exception e) {
					trans.error().log(
							e,
							"Failure to obtain User " + user + " for "
									+ getName());
				}
			}
		}

		if (summary == null) {
			summary = "";
		}

		switch (type) {
		case Approval:
			try {
				sendEmail(trans, toList, ccList,
						"AAF Approval Notification "
								+ (system.length() == 0 ? "" : "(ENV: "
										+ system + ")"),
						"AAF is the "
						+ NAME
						+ "System for Fine-Grained Authorizations.  You are being asked to Approve"
								+ (system.length() == 0 ? "" : " in the "
										+ system + " environment")
								+ " before AAF Actions can be taken.\n\n"
								+ "Please follow this link: \n\n\t" + url
								+ "\n\n" + summary, urgent);
			} catch (Exception e) {

				trans.error().log(e, "Failure to send Email");
				return Response.ERR_NotificationFailure;
			}
			break;
		case PasswordExpiration:
			try {
				sendEmail(trans,
						toList,
						ccList,
						"AAF Password Expiration Warning "
								+ (system.length() == 0 ? "" : "(ENV: "
										+ system + ")"),
						"AAF is the "
						+ NAME
						+ " System for Authorizations.\n\nOne or more passwords will expire soon or have expired"
								+ (system.length() == 0 ? "" : " in the "
										+ system + " environment")
								+ ".\n\nPasswords expired for more than 30 days without action are subject to deletion.\n\n"
								+ "Please follow each link to add a New Password with Expiration Date. Either are valid until expiration. "
								+ "Use this time to change the passwords on your system. If issues, reply to this email.\n\n"
								+ summary, urgent);
			} catch (Exception e) {
				trans.error().log(e, "Failure to send Email");
				return Response.ERR_NotificationFailure;
			}
			break;

		case RoleExpiration:
			try {
				sendEmail(
						trans,
						toList,
						ccList,
						"AAF Role Expiration Warning "
								+ (system.length() == 0 ? "" : "(ENV: "
										+ system + ")"),
						"AAF is the "
						+ NAME
						+ " System for Authorizations. One or more roles will expire soon"
								+ (system.length() == 0 ? "" : " in the "
										+ system + " environment")
								+ ".\n\nRoles expired for more than 30 days are subject to deletion."
								+ "Please follow this link the GUI Command line, and either 'extend' or 'del' the user in the role.\n"
								+ "If issues, reply to this email.\n\n\t" + url
								+ "\n\n" + summary, urgent);
			} catch (Exception e) {
				trans.error().log(e, "Failure to send Email");
				return Response.ERR_NotificationFailure;
			}
			break;
		default:
			return Response.ERR_NotImplemented;
		}
		return Response.OK;
	}


	/**
	 * Default Policy is to set to 6 Months for Notification Types.
	 * add others/change as required
	 */
	@Override
	public Date whenToValidate(Notify type, Date lastValidated) {
		switch(type) {
			case Approval:
			case PasswordExpiration:
				return null;
			default:
				GregorianCalendar gc = new GregorianCalendar();
				gc.setTime(lastValidated);
				gc.add(GregorianCalendar.MONTH, 6);  // 6 month policy
				return gc.getTime();
		}
	}

	@Override
	public GregorianCalendar expiration(GregorianCalendar gc, Expiration exp, String... extra) {
		GregorianCalendar now = new GregorianCalendar();
		GregorianCalendar rv = gc==null?now:(GregorianCalendar)gc.clone();
		switch (exp) {
			case ExtendPassword:
				// Extending Password give 5 extra days, max 8 days from now
				rv.add(GregorianCalendar.DATE, 5);
				now.add(GregorianCalendar.DATE, 8);
				if(rv.after(now)) {
					rv = now;
				}
				break;
			case Future:
				// Future requests last 15 days.
				now.add(GregorianCalendar.DATE, 15);
				rv = now;
				break;
			case Password:
				// Passwords expire in 90 days
				now.add(GregorianCalendar.DATE, 90);
				rv = now;
				break;
			case TempPassword:
				// Temporary Passwords last for 12 hours.
				now.add(GregorianCalendar.DATE, 90);
				rv = now;
				break;
			case UserDelegate:
				// Delegations expire max in 2 months, renewable to 3
				rv.add(GregorianCalendar.MONTH, 2);
				now.add(GregorianCalendar.MONTH, 3);
				if(rv.after(now)) {
					rv = now;
				}
				break;
			case UserInRole:
				// Roles expire in 6 months
				now.add(GregorianCalendar.MONTH, 6);
				rv = now;
				break;
			default:
				// Unless other wise set, 6 months is default
				now.add(GregorianCalendar.MONTH, 6);
				rv = now;
				break;
		}
		return rv;
	}

	@Override
	public EmailWarnings emailWarningPolicy() {
		return emailWarnings;
	}

	/**
	 * Assume the Supervisor is the Approver.
	 */
	@Override
	public List<Identity> getApprovers(AuthzTrans trans, String user) throws OrganizationException {
		Identity orgIdentity = getIdentity(trans, user);
		List<Identity> orgIdentitys = new ArrayList<>();
		if(orgIdentity!=null) {
			Identity supervisor = orgIdentity.responsibleTo();
			if(supervisor!=null) {
				orgIdentitys.add(supervisor);
			}
		}
		return orgIdentitys;
	}

	@Override
	public String getApproverType() {
		return "supervisor";
	}

	@Override
	public int startOfDay() {
		// TODO Auto-generated method stub
		return 0;
	}

	@Override
	public boolean canHaveMultipleCreds(String id) {
		// External entities are likely mono-password... if you change it, it is a global change.
		// This is great for people, but horrible for Applications.
		//
		// AAF's Password can have multiple Passwords, each with their own Expiration Date.
		// For Default Org, we'll assume true for all, but when you add your external
		// Identity stores, you need to return "false" if they cannot support multiple Passwords like AAF
		return true;
	}

	@Override
	public String validate(AuthzTrans trans, Policy policy, Executor executor, String... vars) throws OrganizationException {
		switch(policy) {
			case OWNS_MECHID:
			case CREATE_MECHID:
				if(vars.length>0) {
					DefaultOrgIdentity thisID = getIdentity(trans,vars[0]);
					if("a".equals(thisID.identity.status)) { // MechID
						DefaultOrgIdentity requestor = getIdentity(trans, trans.user());
						if(requestor!=null) {
							Identity mechid = getIdentity(trans, vars[0]);
							if(mechid!=null) {
								Identity sponsor = mechid.responsibleTo();
								if(sponsor!=null && requestor.fullID().equals(sponsor.fullID())) {
									return null;
								} else {
									return trans.user() + " is not the Sponsor of MechID " + vars[0];
								}
							}
						}
					}
				}
				return null;

			case CREATE_MECHID_BY_PERM_ONLY:
				return getName() + " only allows sponsors to create MechIDs";

			default:
				return policy.name() + " is unsupported at " + getName();
		}
	}

	@Override
	public boolean isTestEnv() {
		return false;
	}

	@Override
	public void setTestMode(boolean dryRun) {
		this.dryRun = dryRun;
	}

	private String extractRealm(final String r) {
		int at;
		if((at=r.indexOf('@'))>=0) {
			return FQI.reverseDomain(r.substring(at+1));
		}
		return r;
	}
	@Override
	public boolean supportsRealm(final String r) {
		if(r.endsWith(realm)) {
			return true;
		} else {
			String erealm = extractRealm(r);
			for(String sr : supportedRealms) {
				if(erealm.startsWith(sr)) {
					return true;
				}
			}
		}
		return false;
	}

	@Override
	public synchronized void addSupportedRealm(final String r) {
		supportedRealms.add(extractRealm(r));
	}

	@Override
	public int sendEmail(AuthzTrans trans, List<String> toList, List<String> ccList, String subject, String body,
			Boolean urgent) throws OrganizationException {
		if (mailer!=null) {
			List<String> to = new ArrayList<>();
			for(String em : toList) {
				if(em.indexOf('@')<0) {
					to.add(new DefaultOrgIdentity(trans, em, this).email());
				} else {
					to.add(em);
				}
			}

			List<String> cc = new ArrayList<>();
			if(ccList!=null) {
				if(!ccList.isEmpty()) {

					for(String em : ccList) {
						if(em.indexOf('@')<0) {
							cc.add(new DefaultOrgIdentity(trans, em, this).email());
						} else {
							cc.add(em);
						}
					}
				}

				// for now, I want all emails so we can see what goes out. Remove later
				if (!ccList.contains(mailFrom)) {
					ccList.add(mailFrom);
				}
			}

			return mailer.sendEmail(trans,dryRun,mailFrom,to,cc,subject,body,urgent);
		} else {
			return 0;
		}
	}
}