/*
 * Copyright 2016 Red Hat, Inc. and/or its affiliates
 * and other contributors as indicated by the @author tags.
 *
 * 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.
 */

package org.keycloak.client.registration.cli.commands;

import com.fasterxml.jackson.core.JsonParseException;
import org.jboss.aesh.cl.Arguments;
import org.jboss.aesh.cl.CommandDefinition;
import org.jboss.aesh.cl.Option;
import org.jboss.aesh.console.command.CommandException;
import org.jboss.aesh.console.command.CommandResult;
import org.jboss.aesh.console.command.invocation.CommandInvocation;
import org.keycloak.client.registration.cli.aesh.EndpointTypeConverter;
import org.keycloak.client.registration.cli.common.AttributeOperation;
import org.keycloak.client.registration.cli.config.ConfigData;
import org.keycloak.client.registration.cli.common.CmdStdinContext;
import org.keycloak.client.registration.cli.common.EndpointType;
import org.keycloak.client.registration.cli.util.ParseUtil;
import org.keycloak.client.registration.cli.util.ReflectionUtil;
import org.keycloak.representations.idm.ClientRepresentation;
import org.keycloak.representations.oidc.OIDCClientRepresentation;
import org.keycloak.util.JsonSerialization;

import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

import static org.keycloak.client.registration.cli.common.AttributeOperation.Type.DELETE;
import static org.keycloak.client.registration.cli.common.AttributeOperation.Type.SET;
import static org.keycloak.client.registration.cli.util.AuthUtil.ensureToken;
import static org.keycloak.client.registration.cli.util.ConfigUtil.DEFAULT_CONFIG_FILE_STRING;
import static org.keycloak.client.registration.cli.util.ConfigUtil.credentialsAvailable;
import static org.keycloak.client.registration.cli.util.ConfigUtil.getRegistrationToken;
import static org.keycloak.client.registration.cli.util.ConfigUtil.loadConfig;
import static org.keycloak.client.registration.cli.util.ConfigUtil.saveMergeConfig;
import static org.keycloak.client.registration.cli.util.ConfigUtil.setRegistrationToken;
import static org.keycloak.client.registration.cli.common.EndpointType.DEFAULT;
import static org.keycloak.client.registration.cli.common.EndpointType.OIDC;
import static org.keycloak.client.registration.cli.util.HttpUtil.doGet;
import static org.keycloak.client.registration.cli.util.HttpUtil.doPut;
import static org.keycloak.client.registration.cli.util.HttpUtil.urlencode;
import static org.keycloak.client.registration.cli.util.IoUtil.printOut;
import static org.keycloak.client.registration.cli.util.IoUtil.warnfErr;
import static org.keycloak.client.registration.cli.util.IoUtil.readFully;
import static org.keycloak.client.registration.cli.util.HttpUtil.APPLICATION_JSON;
import static org.keycloak.client.registration.cli.util.OsUtil.CMD;
import static org.keycloak.client.registration.cli.util.OsUtil.PROMPT;
import static org.keycloak.client.registration.cli.util.ParseUtil.mergeAttributes;
import static org.keycloak.client.registration.cli.util.ParseUtil.parseFileOrStdin;
import static org.keycloak.client.registration.cli.util.ParseUtil.parseKeyVal;

/**
 * @author <a href="mailto:mstrukel@redhat.com">Marko Strukelj</a>
 */
@CommandDefinition(name = "update", description = "CLIENT_ID [ARGUMENTS]")
public class UpdateCmd extends AbstractAuthOptionsCmd {

    @Option(shortName = 'e', name = "endpoint", description = "Endpoint type to use - one of: 'default', 'oidc'", hasValue = true, converter = EndpointTypeConverter.class)
    private EndpointType regType = null;

    //@GroupOption(shortName = 's', name = "set", description = "Set specific attribute to a specified value", hasValue = true)
    //private List<String> attributes = new ArrayList<>();

    @Option(shortName = 'f', name = "file", description = "Use the file or standard input if '-' is specified", hasValue = true)
    private String file = null;

    @Option(shortName = 'm', name = "merge", description = "Merge new values with existing configuration on the server", hasValue = false)
    private boolean mergeMode = true;

    @Option(shortName = 'u', name = "unsafe", description = "Allow updating without registration access token - no optimistic locking", hasValue = false)
    private boolean allowUnsafe = true;

    @Option(shortName = 'o', name = "output", description = "After update output the new client configuration", hasValue = false)
    private boolean outputClient = false;

    @Option(shortName = 'c', name = "compressed", description = "Don't pretty print the output", hasValue = false)
    private boolean compressed = false;

    @Arguments
    private List<String> args;


    @Override
    public CommandResult execute(CommandInvocation commandInvocation) throws CommandException, InterruptedException {

        List<AttributeOperation> attrs = new LinkedList<>();

        try {
            processGlobalOptions();

            String clientId = null;

            if (args != null) {
                Iterator<String> it = args.iterator();
                if (!it.hasNext()) {
                    throw new RuntimeException("CLIENT_ID not specified");
                }

                clientId = it.next();

                if (clientId.startsWith("-")) {
                    warnfErr(ParseUtil.CLIENTID_OPTION_WARN, clientId);
                }

                while (it.hasNext()) {
                    String option = it.next();
                    switch (option) {
                        case "-s":
                        case "--set": {
                            if (!it.hasNext()) {
                                throw new RuntimeException("Option " + option + " requires a value");
                            }
                            String[] keyVal = parseKeyVal(it.next());
                            attrs.add(new AttributeOperation(SET, keyVal[0], keyVal[1]));
                            break;
                        }
                        case "-d":
                        case "--delete": {
                            attrs.add(new AttributeOperation(DELETE, it.next()));
                            break;
                        }
                        default: {
                            throw new RuntimeException("Unsupported option: " + option);
                        }
                    }
                }
            }

            if (file == null && attrs.size() == 0) {
                throw new RuntimeException("No file nor attribute values specified");
            }

            // We have several options for update:
            //
            // A) if a file is specified, then we can overwrite server state with that file
            //   (that's the normal flow - get and save locally, edit, post to server)
            //
            //   update my_client -f new_client.json
            //
            // B) if a file is specified, and overrides are specified, then we override the file values with those from command line
            //   (that allows us to have a local file as a template, it's also batch job friendly)
            //
            //   update my_client -s public=true -s enableDirectGrants=false -f new_client.json
            //
            // C) if no file is specified, then we can fetch the client definition from server, apply changes to it, and post it back
            //   (again a batch job friendly mode)
            //
            //   update my_client -s public=true -s enableDirectGrants=false
            //
            //   This is merge mode by default - if --merge is additionally specified, it is ignored
            //
            // D) if a file is specified, then we can merge the file with current state on the server
            //   (that is similar to previous mode except that the overrides are also taken from a file)
            //
            //   update my_client --merge -f new_client.json
            //   update my_client --merge -s public=true -s enableDirectGrants=false -f new_client.json
            //
            // We could also support environment variables in input file, and apply them before parsing it.
            //
            // One problem - what if it is SAML XML? No problem as we don't support update for SAML - only create.
            //
            if (file == null && attrs.size() > 0) {
                mergeMode = true;
            }

            CmdStdinContext ctx = new CmdStdinContext();
            if (file != null) {
                ctx = parseFileOrStdin(file, regType);
                regType = ctx.getEndpointType();
            }

            if (regType == null) {
                regType = DEFAULT;
                ctx.setEndpointType(regType);
            } else if (regType != DEFAULT && regType != OIDC) {
                throw new RuntimeException("Update not supported for endpoint type: " + regType.getEndpoint());
            }

            // initialize config only after reading from stdin,
            // to allow proper operation when piping 'get' - which consumes the old
            // registration access token, and saves the new one to the config
            ConfigData config = loadConfig();
            config = copyWithServerInfo(config);

            final String server = config.getServerUrl();
            final String realm = config.getRealm();

            if (token == null) {
                // if registration access token is not set via --token, see if it's in the body of any input file
                // but first see if it's overridden by --set, or maybe deliberately muted via -d registrationAccessToken
                boolean processed = false;
                for (AttributeOperation op: attrs) {
                    if ("registrationAccessToken".equals(op.getKey().toString())) {
                        processed = true;
                        if (op.getType() == AttributeOperation.Type.SET) {
                            token = op.getValue();
                        }
                        // otherwise it's delete - meaning it should stay null
                        break;
                    }
                }
                if (!processed) {
                    token = ctx.getRegistrationAccessToken();
                }
            }

            if (token == null) {
                // if registration access token is not set, try use the one from configuration
                token = getRegistrationToken(config.sessionRealmConfigData(), clientId);
            }

            setupTruststore(config, commandInvocation);

            String auth = token;
            if (auth == null) {
                config = ensureAuthInfo(config, commandInvocation);
                config = copyWithServerInfo(config);
                if (credentialsAvailable(config)) {
                    auth = ensureToken(config);
                }
            }

            auth = auth != null ? "Bearer " + auth : null;


            if (mergeMode) {
                InputStream response = doGet(server + "/realms/" + realm + "/clients-registrations/" + regType.getEndpoint() + "/" + urlencode(clientId),
                        APPLICATION_JSON, auth);

                String json = readFully(response);

                CmdStdinContext ctxremote = new CmdStdinContext();
                ctxremote.setContent(json);
                ctxremote.setEndpointType(regType);
                try {

                    if (regType == DEFAULT) {
                        ctxremote.setClient(JsonSerialization.readValue(json, ClientRepresentation.class));
                        token = ctxremote.getClient().getRegistrationAccessToken();
                    } else if (regType == OIDC) {
                        ctxremote.setOidcClient(JsonSerialization.readValue(json, OIDCClientRepresentation.class));
                        token = ctxremote.getOidcClient().getRegistrationAccessToken();
                    }
                } catch (JsonParseException e) {
                    throw new RuntimeException("Not a valid JSON document. " + e.getMessage(), e);
                } catch (IOException e) {
                    throw new RuntimeException("Not a valid JSON document", e);
                }

                // we have to use registration access token retrieved from previous operation
                // that ensures optimistic locking semantics
                if (token != null) {
                    // we use auth with doPost later
                    auth = "Bearer " + token;

                    String newToken = token;
                    String clientToUpdate = clientId;
                    saveMergeConfig(cfg -> {
                        setRegistrationToken(cfg.ensureRealmConfigData(server, realm), clientToUpdate, newToken);
                    });
                } else if (!allowUnsafe) {
                    throw new RuntimeException("No Registration Access Token found for client: " + clientId + ". Provide one or use --unsafe.");
                }

                // merge local representation over remote one
                if (ctx.getClient() != null) {
                    ReflectionUtil.merge(ctx.getClient(), ctxremote.getClient());
                } else if (ctx.getOidcClient() != null) {
                    ReflectionUtil.merge(ctx.getOidcClient(), ctxremote.getOidcClient());
                }
                ctx = ctxremote;
            }

            if (attrs.size() > 0) {
                ctx = mergeAttributes(ctx, attrs);
            }

            // now update
            InputStream response = doPut(server + "/realms/" + realm + "/clients-registrations/" + regType.getEndpoint() + "/" + urlencode(clientId),
                    APPLICATION_JSON, APPLICATION_JSON, ctx.getContent(), auth);
            try {
                if (regType == DEFAULT) {
                    ClientRepresentation clirep = JsonSerialization.readValue(response, ClientRepresentation.class);
                    outputResult(clirep);
                    token = clirep.getRegistrationAccessToken();
                } else if (regType == OIDC) {
                    OIDCClientRepresentation clirep = JsonSerialization.readValue(response, OIDCClientRepresentation.class);
                    outputResult(clirep);
                    token = clirep.getRegistrationAccessToken();
                }

                String newToken = token;
                String clientToUpdate = clientId;
                saveMergeConfig(cfg -> {
                    setRegistrationToken(cfg.ensureRealmConfigData(server, realm), clientToUpdate, newToken);
                });

            } catch (IOException e) {
                throw new RuntimeException("Failed to process HTTP response", e);
            }

            return CommandResult.SUCCESS;

        } finally {
            commandInvocation.stop();
        }
    }

    private void outputResult(Object result) throws IOException {
        if (outputClient) {
            if (compressed) {
                printOut(JsonSerialization.writeValueAsString(result));
            } else {
                printOut(JsonSerialization.writeValueAsPrettyString(result));
            }
        }
    }

    public static String usage() {
        StringWriter sb = new StringWriter();
        PrintWriter out = new PrintWriter(sb);
        out.println("Usage: " + CMD + " update CLIENT [ARGUMENTS]");
        out.println();
        out.println("Command to update an existing client configuration. If registration access token is specified it is used.");
        out.println("Otherwise, if 'registrationAccessToken' attribute is set, that is used. Otherwise, if registration access");
        out.println("token is available in configuration file, we use that. Finally, if it's not available anywhere, the current ");
        out.println("active session is used.");
        out.println();
        out.println("Arguments:");
        out.println();
        out.println("  Global options:");
        out.println("    -x                    Print full stack trace when exiting with error");
        out.println("    -c, --config          Path to the config file (" + DEFAULT_CONFIG_FILE_STRING + " by default)");
        out.println("    --truststore PATH     Path to a truststore containing trusted certificates");
        out.println("    --trustpass PASSWORD  Truststore password (prompted for if not specified and --truststore is used)");
        out.println("    --token TOKEN         Registration access token to use");
        out.println("    CREDENTIALS OPTIONS   Same set of options as accepted by '" + CMD + " config credentials' in order to establish");
        out.println("                          an authenticated sessions. This allows on-the-fly transient authentication that does");
        out.println("                          not touch a config file.");
        out.println();
        out.println("  Command specific options:");
        out.println("    CLIENT                ClientId of the client to update");
        out.println("    -s, --set KEY=VALUE   Set specific attribute to a specified value");
        out.println("              KEY+=VALUE  Add item to an array");
        out.println("    -d, --delete NAME     Delete the specific attribute, or array item");
        out.println("    -e, --endpoint TYPE   Endpoint type to use - one of: 'default', 'oidc'");
        out.println("    -f, --file FILENAME   Use the file or standard input if '-' is specified");
        out.println("    -m, --merge           Merge new values with existing configuration on the server");
        out.println("                          Merge is automatically enabled unless --file is specified");
        out.println("    -u, --unsafe          Allow updating without registration access token - no optimistic locking");
        out.println("    -o, --output          After update output the new client configuration");
        out.println("    -c, --compressed      Don't pretty print the output");
        out.println();
        out.println();
        out.println("Nested attributes are supported by using '.' to separate components of a KEY. Optionaly, the KEY components ");
        out.println("can be quoted with double quotes - e.g. my_client.attributes.\"external.user.id\". If VALUE starts with [ and ");
        out.println("ends with ] the attribute will be set as a JSON array. If VALUE starts with { and ends with } the attribute ");
        out.println("will be set as a JSON object. If KEY ends with an array index - e.g. clients[3]=VALUE - then the specified item");
        out.println("of the array is updated. If KEY+=VALUE syntax is used, then KEY is assumed to be an array, and another item is");
        out.println("added to it.");
        out.println();
        out.println("Attributes can also be deleted. If KEY ends with an array index, then the targeted item of an array is removed");
        out.println("and the following items are shifted.");
        out.println();
        out.println("Merged mode fetches current configuration from the server, applies attribute changes to it, and sends it");
        out.println("back to the server, overwriting existing configuration there. To ensure there are no unexpected changes");
        out.println("Registration Access Token is used for authorization when doing changes. Alternatively, one can specify to use");
        out.println("unsafe mode in which case login session's authorization is used - user requires manage-clients permission.");
        out.println();
        out.println();
        out.println("Examples:");
        out.println();
        out.println("Update a client by fetching current configuration from server, and applying specified changes.");
        out.println("  " + PROMPT + " " + CMD + " update my_client -s enabled=true -s 'redirectUris=[\"http://localhost:8080/myapp/*\"]'");
        out.println();
        out.println("Update a client by overwriting existing configuration on the server with a new one:");
        out.println("  " + PROMPT + " " + CMD + " update my_client -f new_my_client.json");
        out.println();
        out.println("Update a client by overwriting existing configuration using local file as a template:");
        out.println("  " + PROMPT + " " + CMD + " update my_client -f new_my_client.json -s enabled=true");
        out.println();
        out.println("Update client by fetching current configuration from server and merging with specified changes:");
        out.println("  " + PROMPT + " " + CMD + " update my_client -f new_my_client.json -s enabled=true --merge");
        out.println();
        out.println("Update a client using 'oidc' endpoint:");
        out.println("  " + PROMPT + " " + CMD + " update my_client -e oidc -s 'redirect_uris=[\"http://localhost:8080/myapp/*\"]'");
        out.println();
        out.println();
        out.println("Use '" + CMD + " help' for general information and a list of commands");
        return sb.toString();
    }
}
