/*
 * 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.databind.PropertyNamingStrategies;
import com.fasterxml.jackson.databind.annotation.JsonNaming;
import com.juick.model.Chat;
import com.juick.model.Message;
import com.juick.model.User;
import com.juick.service.ChatService;
import com.juick.service.TagService;
import com.juick.service.UserService;
import com.juick.www.WebApp;
import com.juick.www.api.webfinger.model.Account;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
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.time.Instant;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.UUID;
import java.util.stream.Collectors;
import java.util.stream.Stream;

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

    @JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
    public record ApplicationRequest(String clientName,
            String redirectUris,
            String scopes) {
    }

    @JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
    public record ApplicationResponse(String id,
            String name,
            String redirectUri,
            String clientId,
            String clientSecret) {
    }

    @JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
    public record CredentialAccount(String id, String username, String acct,
            String displayName,
            Integer followersCount,
            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", "/api/v2/instance" })
    public Instance getInstance() {
        return new Instance(domain);
    }

    @GetMapping("/api/v1/accounts/verify_credentials")
    public CredentialAccount account(@ModelAttribute User visitor) {
        return toAccount(visitor);
    }

    @GetMapping({ "/api/v1/announcements", "/api/v1/lists", "/api/v1/custom_emojis" })
    public ResponseEntity<List<Void>> arrayStubs() {
        return new ResponseEntity<>(List.of(), HttpStatus.OK);
    }

    public record Preferences() {
    };

    @GetMapping("/api/v1/preferences")
    public Preferences preferences() {
        return new Preferences();
    }

    @JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
    public record Filter(String id, String phrase, List<String> context,
            Instant expiresAt, Boolean irreversible,
            Boolean wholeWord) {

    }

    @GetMapping("/api/v1/filters")
    public List<Filter> filters() {
        return List.of();
    }

    @JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
    public record Relationship(String id, Boolean following, Boolean showingReblogs,
            Boolean notyfing, Boolean followingBy, Boolean blocked, Boolean blockedBy,
            Boolean muting, Boolean mutingNotifications, Boolean requested, Boolean domainBlocking,
            Boolean endorsed, String note) {

    }

    private Relationship findRelationships(String visitorId, String userId) {
        User user = userService.getUserByUID(Integer.valueOf(userId)).orElseThrow();
        var readers = userService.getUserReaders(Integer.valueOf(visitorId));
        var friends = userService.getUserFriends(Integer.valueOf(visitorId));
        var bl = userService.getUserBLUsers(Integer.valueOf(visitorId));
        var isFriend = friends.contains(user);
        var isReader = readers.contains(user);
        var isMuting = bl.contains(user);
        return new Relationship(userId,
                isFriend, isFriend, isFriend, isReader, false, false,
                isMuting, isMuting, false,
                false, false, "");
    }

    @GetMapping("/api/v1/accounts/relationships")
    public List<Relationship> relationships(@ModelAttribute User visitor, @RequestParam(value="id[]") String[] ids) {
        return Stream.of(ids).map(
            id -> findRelationships(String.valueOf(visitor.getUid()), id)
        ).collect(Collectors.toList());
    }
    @JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
    public record Status(String id, Instant createdAt, String inReplyToId, String inReplyToAccountId,
                         Boolean sensitive, String spoilerText, String visibility, String content) {}
    @JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
    public record Conversation(
            String id,
            Boolean unread,
            List<CredentialAccount> accounts,
            Status lastStatus
    ) {}
    public CredentialAccount toAccount(User user) {
        return new CredentialAccount(
                String.valueOf(user.getUid()),
                user.getName(),
                user.getName(),
                user.getFullName(),
                userService.getUserReaders(user.getUid()).size(),
                userService.getUserFriends(user.getUid()).size(),
                webApp.getAvatarUrl(user));
    }

    public Status mapLastMessage(Chat chat) {
        return new Status(
                String.valueOf(chat.getLastMessageTimestamp().toEpochMilli()),
                        chat.getLastMessageTimestamp(),
                null,
                null,
                false,
                "",
                "direct",
                chat.getLastMessageText()
        );
    }

    public Conversation toConversation(User user, Chat chat) {
        return new Conversation(
                String.valueOf(chat.getUid()),
                chat.getUnread() != null && chat.getUnread().size() > 0,
                List.of(toAccount(user), toAccount(chat)),
                mapLastMessage(chat));
    }

    @GetMapping("/api/v1/conversations")
    public List<Conversation> conversations(@ModelAttribute User visitor) {
        return chatService.getLastChats(visitor).stream().map(
                chat -> toConversation(visitor, chat)
        ).collect(Collectors.toList());
    }
}