/*
 * Copyright (C) 2008-2017, 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.server.api;

import com.juick.Message;
import com.juick.Tag;
import com.juick.User;
import com.juick.server.Utils;
import com.juick.server.component.MessageReadEvent;
import com.juick.server.helpers.CommandResult;
import com.juick.server.util.HttpBadRequestException;
import com.juick.server.util.UserUtils;
import com.juick.service.MessagesService;
import com.juick.service.TagService;
import com.juick.service.UserService;
import org.apache.commons.io.IOUtils;
import org.springframework.context.ApplicationEventPublisher;
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.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Objects;

/**
 * @author ugnich
 */
@RestController
@RequestMapping(produces = MediaType.APPLICATION_JSON_UTF8_VALUE)
public class Messages {

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

    private static final ResponseEntity<List<com.juick.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;

    // TODO: serialize image urls

    @GetMapping("/home")
    public ResponseEntity<List<com.juick.Message>> getHome(
            @RequestParam(defaultValue = "0") int before_mid) {
        User visitor = UserUtils.getCurrentUser();
        if (!visitor.isAnonymous()) {
            int vuid = visitor.getUid();
            List<Integer> mids = messagesService.getMyFeed(vuid, before_mid, true);
            return ResponseEntity.ok(messagesService.getMessages(mids));
        }
        return FORBIDDEN;
    }

    @GetMapping("/messages")
    public ResponseEntity<List<com.juick.Message>> getMessages(
            @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) {

        User visitor = UserUtils.getCurrentUser();

        List<Integer> mids;
        if (!StringUtils.isEmpty(uname)) {
            User user = userService.getUserByName(uname);
            if (user != null) {
                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(user.getUid(), Utils.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(Utils.encodeSphinx(search), page);
            } else {
                mids = messagesService.getAll(visitor.getUid(), before);
            }
        }
        return ResponseEntity.ok(messagesService.getMessages(mids));
    }
    @DeleteMapping("/messages")
    public CommandResult deleteMessage(@RequestParam int mid, @RequestParam(required = false, defaultValue = "0") int rid) {
        User visitor = UserUtils.getCurrentUser();
        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("/messages/discussions")
    public List<Message> getDiscussions(
        @RequestParam(required = false, defaultValue = "0") Long to) {
        return messagesService.getMessages(messagesService.getDiscussions(UserUtils.getCurrentUser().getUid(), to));
    }
    @GetMapping("/thread")
    public ResponseEntity<List<com.juick.Message>> getThread(
            @RequestParam(defaultValue = "0") int mid) {
        User visitor = UserUtils.getCurrentUser();
        com.juick.Message msg = messagesService.getMessage(mid);
        if (msg != null) {
            if (!messagesService.canViewThread(mid, visitor.getUid())) {
                return FORBIDDEN;
            } else {
                msg.setRecommendations(new HashSet<>(messagesService.getMessageRecommendations(msg.getMid())));
                List<com.juick.Message> replies = messagesService.getReplies(visitor, mid);
                if (!visitor.isAnonymous()) {
                    applicationEventPublisher.publishEvent(new MessageReadEvent(this, visitor, msg));
                }
                replies.add(0, msg);
                return ResponseEntity.ok(replies);
            }
        }
        return NOT_FOUND;
    }
    @GetMapping(value = "/thread/mark_read/{mid}-{rid}.gif", produces = MediaType.IMAGE_GIF_VALUE)
    public byte[] markThreadRead(@PathVariable int mid, @PathVariable int rid) throws IOException {
        User visitor = UserUtils.getCurrentUser();
        if (!visitor.isAnonymous()) {
            messagesService.setLastReadComment(visitor, mid, rid);
            Message msg = messagesService.getMessage(mid);
            applicationEventPublisher.publishEvent(new MessageReadEvent(this, visitor, msg));
            return IOUtils.toByteArray(
                    Objects.requireNonNull(getClass().getClassLoader().getResource("Transparent.gif")));
        }
        throw new HttpBadRequestException();
    }
}