package de.anxietyprime.swajodel;

import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.server.ResponseStatusException;

import java.sql.*;

import java.util.Optional;
import java.util.Vector;

@RestController
public class Routes {

    @GetMapping("/posts/{longitude}/{latitude}")
    public Vector<JodelPost> getPostsByLocation(@PathVariable("longitude") float longitude, @PathVariable("latitude") float latitude) {
        // list of all posts (not comments) in range
        Vector<JodelPost> posts = new Vector<>();

        // DB connection and statement
        Connection c = null;
        PreparedStatement stmt = null;

        // try to get data from db
        try {
            // check for the driver
            Class.forName("org.postgresql.Driver");
            // get the connection with credentials from env variables
            c = DriverManager
                    .getConnection("jdbc:postgresql://"+
                                    System.getenv("POSTGRES_IP")+"/"+System.getenv("POSTGRES_DB"),
                                    System.getenv("POSTGRES_USER"), System.getenv("POSTGRES_PASSWORD"));
            // disable auto commits
            c.setAutoCommit(false);

            // create a new statement
            stmt = c.prepareStatement("WITH RECURSIVE targets AS (\n" +
                    "  SELECT\n" +
                    "    posts.id,\n" +
                    "    posts.id AS parent,\n" +
                    "    posts.author,\n" +
                    "    posts.title,\n" +
                    "    posts.content,\n" +
                    "    posts.postdate,\n" +
                    "    posts.postlocation[0] AS longitude,\n" +
                    "    posts.postlocation[1] AS latitude,\n" +
                    "    (SELECT count(*) FROM reaction WHERE reaction.post = posts.id AND positive = TRUE) AS positive,\n" +
                    "    (SELECT count(*) FROM reaction WHERE reaction.post = posts.id AND positive = FALSE) AS negative\n" +
                    "  FROM\n" +
                    "    posts\n" +
                    "  WHERE\n" +
                    "    deleted IS NULL\n" +
                    "    AND sqrt(power(postlocation[0] - (?), 2) + power(postlocation[1] - (?), 2)) <= 10\n" +
                    "    AND posts.id NOT IN (SELECT child FROM comments)\n" +
                    "  UNION\n" +
                    "  SELECT\n" +
                    "    com.child,\n" +
                    "    com.parent,\n" +
                    "    com.author,\n" +
                    "    com.title,\n" +
                    "    com.content,\n" +
                    "    com.postdate,\n" +
                    "    com.postlocation[0],\n" +
                    "    com.postlocation[1],\n" +
                    "    (SELECT count(*) FROM reaction WHERE reaction.post = com.child AND positive = TRUE) AS positive,\n" +
                    "    (SELECT count(*) FROM reaction WHERE reaction.post = com.child AND positive = FALSE) AS negative\n" +
                    "  FROM\n" +
                    "      (SELECT * FROM comments inner join posts ON comments.child = posts.id) com\n" +
                    "          inner join targets ON targets.id = com.parent\n" +
                    ")\n" +
                    "SELECT * FROM targets;");

            stmt.setObject(1, longitude);
            stmt.setObject(2, latitude);

            // query recursively for posts inside a 10km radius
            ResultSet rs = stmt.executeQuery();

            // for all the posts found
            while ( rs.next() ) {
                // create a post from the author id
                JodelPost post = new JodelPost(rs);

                // get the posts parent
                long parent = rs.getLong("parent");

                // check if the parent is the own id
                // if it is, it is a post
                if (parent == post.id) {
                    // add the post to the posts
                    posts.add(post);
                }
                // else it is a comment
                else {
                    // iterate over all posts
                    for (JodelPost p : posts) {
                        // try to add the post to a parent
                        p.addComment(post, parent);
                    }
                }
            }

            // close all connections to db
            rs.close();
            stmt.close();
            c.close();
        }

        // else log the error
        catch ( Exception e ) {
            System.err.println( e.getClass().getName()+": "+ e.getMessage() );
            throw new ResponseStatusException(HttpStatus.SERVICE_UNAVAILABLE, "Database is offline");
        }

        // calculate anonymous IDs for the posts
        posts.forEach(post -> {
            post.anonymize(Optional.empty());
        });
        // return the posts
        return posts;
    }

    @GetMapping("/post/{id}")
    public JodelPost getPostByID(@PathVariable("id") long id) {
        // list of all posts (not comments) in range
        Optional<JodelPost> root_post = Optional.empty();

        // DB connection and statement
        Connection c = null;
        PreparedStatement stmt = null;

        // try to get data from db
        try {
            // check for the driver
            Class.forName("org.postgresql.Driver");
            // get the connection with credentials from env variables
            c = DriverManager
                    .getConnection("jdbc:postgresql://"+
                                    System.getenv("POSTGRES_IP")+"/"+System.getenv("POSTGRES_DB"),
                            System.getenv("POSTGRES_USER"), System.getenv("POSTGRES_PASSWORD"));
            // disable auto commits
            c.setAutoCommit(false);

            // create a new statement
            stmt = c.prepareStatement("WITH RECURSIVE targets AS (\n" +
                    "  SELECT\n" +
                    "    posts.id,\n" +
                    "    posts.id AS parent,\n" +
                    "    posts.author,\n" +
                    "    posts.title,\n" +
                    "    posts.content,\n" +
                    "    posts.postdate,\n" +
                    "    posts.postlocation[0] AS longitude,\n" +
                    "    posts.postlocation[1] AS latitude,\n" +
                    "    (SELECT count(*) FROM reaction WHERE reaction.post = posts.id AND positive = TRUE) AS positive,\n" +
                    "    (SELECT count(*) FROM reaction WHERE reaction.post = posts.id AND positive = FALSE) AS negative\n" +
                    "  FROM\n" +
                    "    posts\n" +
                    "  WHERE\n" +
                    "    deleted IS NULL\n" +
                    "    AND posts.id = (?)\n" +
                    "    AND posts.id NOT IN (SELECT child FROM comments)\n" +
                    "  UNION\n" +
                    "  SELECT\n" +
                    "    com.child,\n" +
                    "    com.parent,\n" +
                    "    com.author,\n" +
                    "    com.title,\n" +
                    "    com.content,\n" +
                    "    com.postdate,\n" +
                    "    com.postlocation[0],\n" +
                    "    com.postlocation[1],\n" +
                    "    (SELECT count(*) FROM reaction WHERE reaction.post = com.child AND positive = TRUE) AS positive,\n" +
                    "    (SELECT count(*) FROM reaction WHERE reaction.post = com.child AND positive = FALSE) AS negative\n" +
                    "  FROM\n" +
                    "      (SELECT * FROM comments inner join posts ON comments.child = posts.id) com\n" +
                    "          inner join targets ON targets.id = com.parent\n" +
                    ")\n" +
                    "SELECT * FROM targets;");

            stmt.setObject(1, id);

            // query recursively for posts inside a 10km radius
            ResultSet rs = stmt.executeQuery();

            // for all the posts found
            while ( rs.next() ) {
                // create a post from the author id
                JodelPost post = new JodelPost(rs);

                // get the posts parent
                long parent = rs.getLong("parent");

                // check if the parent is the own id
                // if it is, it is a post
                if (parent == post.id) {
                    // add the post to the posts
                    root_post = Optional.of(post);
                }
                // else it is a comment
                else {
                    // try to add the post to parent
                    root_post.ifPresent(root -> root.addComment(post, parent));
                }
            }

            // close all connections to db
            rs.close();
            stmt.close();
            c.close();
        }

        // else log the error
        catch ( Exception e ) {
            System.err.println( e.getClass().getName()+": "+ e.getMessage() );
            throw new ResponseStatusException(HttpStatus.SERVICE_UNAVAILABLE, "Database is offline");
        }

        // calculate anonymous IDs for the post
         root_post.ifPresent(root -> root.anonymize(Optional.empty()));

        // return the posts
        if (root_post.isEmpty()) throw new ResponseStatusException(HttpStatus.NOT_FOUND, "No post found");
        return root_post.get();
    }
}