/*
 * Copyright (C) 2008-2020, 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.juick.model.Message;
import com.juick.model.Tag;
import com.juick.model.User;
import com.juick.util.WebUtils;
import com.juick.www.WebApp;
import com.juick.model.CommandResult;
import com.juick.util.HttpBadRequestException;
import com.juick.service.MessagesService;
import com.juick.service.TagService;
import com.juick.service.UserService;
import com.juick.service.component.SystemEvent;
import com.juick.service.security.annotation.Visitor;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.tuple.Pair;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.core.io.Resource;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.*;

import javax.inject.Inject;
import java.io.IOException;
import java.util.*;
import java.util.stream.Collectors;

/**
 * @author ugnich
 */
@RestController
@RequestMapping(produces = MediaType.APPLICATION_JSON_VALUE)
public class Messages {

    private static final ResponseEntity<List<Message>> NOT_FOUND = ResponseEntity
            .status(HttpStatus.NOT_FOUND)
            .body(Collections.emptyList());

    private static final ResponseEntity<List<Message>> FORBIDDEN = ResponseEntity
            .status(HttpStatus.FORBIDDEN)
            .body(Collections.emptyList());

    @Inject
    private MessagesService messagesService;
    @Inject
    private UserService userService;
    @Inject
    private TagService tagService;
    @Inject
    private ApplicationEventPublisher applicationEventPublisher;
    @Inject
    private WebApp webApp;
    @Value("classpath:Transparent.gif")
    private Resource invisiblePixel;

    // TODO: serialize image urls

    @GetMapping("/api/home")
    public ResponseEntity<List<Message>> getHome(
            @Visitor User visitor,
            @RequestParam(defaultValue = "0") int before_mid) {
        if (!visitor.isAnonymous()) {
            int vuid = visitor.getUid();
            List<Integer> mids = messagesService.getMyFeed(vuid, before_mid, true);
            List<Message> msgs = messagesService.getMessages(visitor, mids);
            msgs.forEach(m -> m.getUser().setAvatar(webApp.getAvatarUrl(m.getUser())));
            return ResponseEntity.ok(msgs);
        }
        return FORBIDDEN;
    }

    @GetMapping("/api/messages")
    public ResponseEntity<List<Message>> getMessages(
            @Visitor User visitor,
            @RequestParam(required = false) String uname,
            @RequestParam(name = "before_mid", defaultValue = "0") Integer before,
            @RequestParam(required = false, defaultValue = "0") Integer daysback,
            @RequestParam(required = false) String withrecommended,
            @RequestParam(required = false) String popular,
            @RequestParam(required = false) String search,
            @RequestParam(required = false, defaultValue = "0") Integer page,
            @RequestParam(required = false) String media,
            @RequestParam(required = false) String tag) {
        List<Integer> mids;
        if (!StringUtils.isEmpty(uname)) {
            User user = userService.getUserByName(uname);
            if (!user.isAnonymous() && !user.isBanned()) {
                if (!StringUtils.isEmpty(media)) {
                    mids = messagesService.getUserPhotos(user.getUid(), 0, before);
                } else if (!StringUtils.isEmpty(tag)) {
                    Tag tagObject = tagService.getTag(tag, false);
                    if (tagObject != null) {
                        mids = messagesService.getUserTag(user.getUid(), tagObject.TID, 0, before);
                    } else {
                        return NOT_FOUND;
                    }
                } else if (!StringUtils.isEmpty(withrecommended)) {
                    mids = messagesService.getUserBlogWithRecommendations(user.getUid(), 0, before);
                } else if (daysback > 0) {
                    mids = messagesService.getUserBlogAtDay(user.getUid(), 0, daysback);
                } else if (!StringUtils.isEmpty(search)) {
                    mids = messagesService.getUserSearch(visitor, user.getUid(), WebUtils.encodeSphinx(search), 0, page);
                } else {
                    mids = messagesService.getUserBlog(user.getUid(), 0, before);
                }
            } else {
                return NOT_FOUND;
            }
        } else {
            if (!StringUtils.isEmpty(popular)) {
                mids = messagesService.getPopular(visitor.getUid(), before);
            } else if (!StringUtils.isEmpty(media)) {
                mids = messagesService.getPhotos(visitor.getUid(), before);
            } else if (!StringUtils.isEmpty(tag)) {
                Tag tagObject = tagService.getTag(tag, false);
                if (tagObject != null) {
                    mids = messagesService.getTag(tagObject.TID, visitor.getUid(), before, 20);
                } else {
                    return NOT_FOUND;
                }
            } else if (!StringUtils.isEmpty(search)) {
                mids = messagesService.getSearch(visitor, WebUtils.encodeSphinx(search), page);
            } else {
                mids = messagesService.getAll(visitor.getUid(), before);
            }
        }
        List<Message> msgs = messagesService.getMessages(visitor, mids);
        msgs.forEach(m -> m.getUser().setAvatar(webApp.getAvatarUrl(m.getUser())));
        return ResponseEntity.ok(msgs);
    }
    @DeleteMapping("/api/messages")
    public CommandResult deleteMessage(
            @Visitor User visitor,
            @RequestParam int mid, @RequestParam(required = false, defaultValue = "0") int rid) {
        if (rid > 0) {
            if (messagesService.deleteReply(visitor.getUid(), mid, rid)) {
                return CommandResult.fromString("Reply deleted");
            }
        }
        if (messagesService.deleteMessage(visitor.getUid(), mid)) {
            return CommandResult.fromString("Message deleted");
        }
        throw new HttpBadRequestException();
    }

    @GetMapping("/api/messages/discussions")
    public List<Message> getDiscussions(
            @Visitor User visitor,
            @RequestParam(required = false, defaultValue = "0") Long to) {
        List<Message> msgs = messagesService.getMessages(visitor,
                messagesService.getDiscussions(visitor.getUid(), to));
        msgs.forEach(m -> m.getUser().setAvatar(webApp.getAvatarUrl(m.getUser())));
        return msgs;
    }
    @GetMapping("/api/thread")
    public ResponseEntity<List<Message>> getThread(
            @Visitor User visitor,
            @RequestParam(defaultValue = "0") int mid) {
        Optional<Message> message = messagesService.getMessage(mid);
        if (message.isPresent()) {
            Message msg = message.get();
            if (!messagesService.canViewThread(mid, visitor.getUid())) {
                return FORBIDDEN;
            } else {
                msg.getUser().setAvatar(webApp.getAvatarUrl(msg.getUser()));
                msg.setRecommendations(new HashSet<>(messagesService.getMessagesRecommendations(
                        Collections.singletonList(msg.getMid()))
                        .stream().map(Pair::getRight).collect(Collectors.toList())));
                msg.getRecommendations().forEach(r -> r.setAvatar(webApp.getAvatarUrl(r)));
                List<Message> replies = messagesService.getReplies(visitor, mid);
                replies.forEach(m -> m.getUser().setAvatar(webApp.getAvatarUrl(m.getUser())));
                if (!visitor.isAnonymous()) {
                    userService.updateLastSeen(visitor);
                    applicationEventPublisher.publishEvent(
                            new SystemEvent(this, SystemActivity.read(visitor, msg)));
                }
                replies.add(0, msg);
                return ResponseEntity.ok(replies);
            }
        }
        return NOT_FOUND;
    }
    @GetMapping(value = "/api/thread/mark_read/{mid}-{rid}.gif", produces = MediaType.IMAGE_GIF_VALUE)
    public byte[] markThreadRead(
            @Visitor User visitor,
            @PathVariable int mid, @PathVariable int rid) throws IOException {
        if (!visitor.isAnonymous()) {
            messagesService.setLastReadComment(visitor, mid, rid);
            Message msg = messagesService.getMessage(mid).orElseThrow(IllegalStateException::new);
            userService.updateLastSeen(visitor);
            applicationEventPublisher.publishEvent(
                    new SystemEvent(this, SystemActivity.read(visitor, msg)));
            return IOUtils.toByteArray(invisiblePixel.getInputStream());
        }
        throw new HttpBadRequestException();
    }
}