/*
 * Copyright (C) 2008-2023, Juick
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.juick.www.api;

import com.fasterxml.jackson.annotation.JsonProperty;
import com.juick.model.User;
import com.juick.service.UserService;
import com.juick.www.WebApp;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.http.MediaType;
import org.springframework.security.oauth2.core.AuthorizationGrantType;
import org.springframework.security.oauth2.core.ClientAuthenticationMethod;
import org.springframework.security.oauth2.server.authorization.client.RegisteredClient;
import org.springframework.security.oauth2.server.authorization.client.RegisteredClientRepository;
import org.springframework.security.oauth2.server.authorization.settings.ClientSettings;
import org.springframework.web.bind.annotation.*;

import javax.inject.Inject;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.UUID;

@RestController
public class Mastodon {
    @Value("${web_domain:localhost}")
    private String domain;
    @Inject
    WebApp webApp;
    @Inject
    UserService userService;
    @Inject
    RegisteredClientRepository registeredClientRepository;

    public record ApplicationRequest(@JsonProperty("client_name") String clientName,
                                     @JsonProperty("redirect_uris") String redirectUris,
                                     @JsonProperty("scopes") String scopes) {
    }

    public record ApplicationResponse(String id,
                                      @JsonProperty("client_name") String name,
                                      @JsonProperty("redirect_uri") String redirectUri,
                                      @JsonProperty("client_id") String clientId,
                                      @JsonProperty("client_secret") String clientSecret) {
    }

    public record CredentialAccount(String id, String username, String acct,
                                    @JsonProperty("display_name") String displayName,
                                    @JsonProperty("followers_count") Integer followersCount,
                                    @JsonProperty("following_count") Integer followingCount,
                                    String avatar) {

    }
    private Collection<String> parseScopes(String s) {
        return s != null ? Arrays.asList(s.split(" ")) : Collections.emptyList();
    }

    @PostMapping(value = "/api/v1/apps", consumes = { MediaType.APPLICATION_JSON_VALUE })
    public ApplicationResponse apps(@RequestBody ApplicationRequest application) {
        return apps(application.clientName(), application.redirectUris(), application.scopes());
    }

    @PostMapping(value = "/api/v1/apps", consumes = { MediaType.APPLICATION_FORM_URLENCODED_VALUE, MediaType.MULTIPART_FORM_DATA_VALUE })
    public ApplicationResponse apps(@RequestParam("client_name") String clientName,
                                    @RequestParam("redirect_uris") String redirectUris,
                                    @RequestParam("scopes") String scopes) {
        var secret = UUID.randomUUID().toString();
        RegisteredClient registeredClient = RegisteredClient.withId(UUID.randomUUID().toString())
                .clientId(UUID.randomUUID().toString())
                .clientSecret("{noop}" + secret)
                .clientName(clientName)
                .clientAuthenticationMethods(coll -> coll.addAll(List.of(
                    ClientAuthenticationMethod.CLIENT_SECRET_POST,
                    ClientAuthenticationMethod.CLIENT_SECRET_BASIC
                )))
                .authorizationGrantType(AuthorizationGrantType.AUTHORIZATION_CODE)
                .redirectUri(redirectUris)
                .scopes((coll) -> coll.addAll(parseScopes(scopes)))
                .clientSettings(ClientSettings.builder().requireAuthorizationConsent(true).build()).build();
        registeredClientRepository.save(registeredClient);
        return new ApplicationResponse(
                registeredClient.getId(),
                registeredClient.getClientName(),
                String.join(",", registeredClient.getRedirectUris()),
                registeredClient.getClientId(),
                secret
        );
    }
    public record Instance(String domain) {}
    @GetMapping("/api/v1/instance")
    public Instance getInstance() {
        return new Instance(domain);
    }
    @GetMapping("/api/v1/accounts/verify_credentials")
    public CredentialAccount account(@ModelAttribute User visitor) {
        return new CredentialAccount(
                String.valueOf(visitor.getUid()),
                visitor.getName(),
                visitor.getName(),
                visitor.getFullName(),
                userService.getUserReaders(visitor.getUid()).size(),
                userService.getUserFriends(visitor.getUid()).size(),
                webApp.getAvatarUrl(visitor)
        );
    }
}