app.js

const express = require('express')
const path = require('path')

const {open} = require('sqlite')
const sqlite3 = require('sqlite3')
const bcrypt = require('bcrypt')
const jwt = require('jsonwebtoken')

const app = express()
app.use(express.json())
const dbpath = path.join(__dirname, 'twitterClone.db')

let db = null

const init = async () => {
  try {
    db = await open({
      filename: dbpath,
      driver: sqlite3.Database,
    })
    app.listen(3000, () => {
      console.log('Server hosted at 3000')
    })
  } catch (e) {
    console.log(`Error is -> ${e}`)
    process.exit(1)
  }
}

init()

const authentication = (req, res, next) => {
  let jwtToken
  const headers = req.headers['authorization']
  if (headers !== undefined) {
    jwtToken = headers.split(' ')[1]
  }

  if (jwtToken === undefined) {
    res.status(401)
    res.send('Invalid JWT Token')
  } else {
    jwt.verify(jwtToken, 'MY_SECRET_TOKEN', async (error, payload) => {
      if (error) {
        res.status(401)
        res.send('Invalid JWT Token')
      } else {
        req.userId = payload.user_id
        console.log('auth end..')
        next()
      }
    })
  }
}

app.post('/register/', async (req, res) => {
  const {username, password, name, gender} = req.body
  if (password.length < 6) {
    res.status(400)
    res.send('Password is too short')
    return
  }
  const checkuserquery = `
  SELECT * FROM user
  WHERE
    username = '${username}' ;`
  const checkuser = await db.get(checkuserquery)

  if (checkuser !== undefined) {
    res.status(400)
    res.send('User already exists')
  } else {
    const epassword = await bcrypt.hash(password, 10)
    const query = `
    INSERT INTO 
    user (username,password,name,gender)
    VALUES ('${username}','${epassword}','${name}','${gender}')`
    await db.run(query)
    res.status(200)
    res.send('User created successfully')
  }
})

app.post('/login/', async (req, res) => {
  const {username, password} = req.body
  const checkuserquery = `
  SELECT * FROM user
  WHERE
    username = '${username}';`
  const dbuser = await db.get(checkuserquery)

  if (dbuser === undefined) {
    res.status(400)
    res.send('Invalid user')
  } else {
    const checkpassword = await bcrypt.compare(password, dbuser.password)

    if (checkpassword) {
      const user_id = dbuser.user_id
      const payload = {
        user_id: user_id,
      }
      const jwtToken = await jwt.sign(payload, 'MY_SECRET_TOKEN')
      console.log(jwtToken)
      res.send({jwtToken})
    } else {
      res.status(400)
      res.send('Invalid password')
    }
  }
})

app.get('/user/tweets/feed/', authentication, async (req, res) => {
  const {userId} = req
  const query = `
  SELECT 
      u.username AS username,
      t.tweet AS tweet,
      t.date_time AS dateTime
    FROM 
      follower f
    JOIN 
      tweet t ON f.following_user_id = t.user_id
    JOIN 
      user u ON u.user_id = t.user_id
    WHERE 
      f.follower_user_id = ${userId}
    ORDER BY 
      t.date_time DESC
    LIMIT 4;`
  const dbuser = await db.all(query)
  res.send(dbuser)
})
const uname = i => ({
  name: i.name,
})

app.get('/user/following/', authentication, async (req, res) => {
  const {userId} = req
  const query = `
  SELECT  
    u2.name
  FROM 
    follower f
  JOIN
    user u1 ON u1.user_id = f.follower_user_id
  JOIN
    user u2 ON u2.user_id = f.following_user_id
  WHERE
    u1.user_id = ${userId};
  `
  const dbres = await db.all(query)
  res.send(dbres.map(i => uname(i)))
})

app.get('/user/followers/', authentication, async (req, res) => {
  const {userId} = req
  const query = `
  SELECT  
    u1.name
  FROM 
    follower f
  JOIN
    user u1 ON u1.user_id = f.follower_user_id
  JOIN
    user u2 ON u2.user_id = f.following_user_id
  WHERE
    u2.user_id = ${userId} ;
  `
  const dbres = await db.all(query)
  res.send(dbres.map(i => uname(i)))
})

//userfollowing verifiying function
const verifyfollowing = async (req, res, next) => {
  const {tweetId} = req.params
  const {userId} = req
  const query = `
  SELECT * 
  FROM
    follower f
  JOIN
    tweet t ON f.following_user_id= t.user_id
  WHERE
    f.follower_user_id = ${userId} AND t.tweet_id = ${tweetId};
  `
  const tweeterId = await db.all(query)
  console.log(tweeterId.length)
  console.log('very...')
  if (tweeterId.length === 0) {
    console.log('very...')
    res.status(401)
    res.send('Invalid Request')
    return
  } else {
    next()
  }
}

// twitter and like

//reply and tweet

app.get(
  '/tweets/:tweetId/',
  authentication,
  verifyfollowing,
  async (req, res) => {
    const {tweetId} = req.params
    const likequery = `
  SELECT COUNT(like_id) AS likes FROM 
    like
  WHERE 
    tweet_id = ${tweetId}`
    const likecount = await db.get(likequery)

    const replyquery = `
  SELECT COUNT(reply_id) AS replies FROM 
    reply
  WHERE 
    tweet_id = ${tweetId}`
    const replycount = await db.get(replyquery)

    const tweetquery = `
  SELECT tweet,date_time FROM 
    tweet
  WHERE
    tweet_id = ${tweetId}`
    const dbrestweet = await db.get(tweetquery)

    res.send({
      tweet: dbrestweet.tweet,
      likes: likecount.likes,
      replies: replycount.replies,
      dateTime: dbrestweet.date_time,
    })
  },
)

//API 7

app.get(
  '/tweets/:tweetId/likes/',
  authentication,
  verifyfollowing,
  async (req, res) => {
    const {tweetId} = req.params
    const query = `
  SELECT  u1.username FROM
    user u1
  JOIN
    like l ON u1.user_id = l.user_id
  WHERE
    tweet_id = ${tweetId};
  `
    const dbres = await db.all(query)
    res.send({
      likes: dbres.map(i => i.username),
    })
  },
)

//API 8

app.get(
  '/tweets/:tweetId/replies/',
  authentication,
  verifyfollowing,
  async (req, res) => {
    const {tweetId} = req.params
    const query = `
  SELECT  u1.name,l.reply FROM
    user u1
  JOIN
    reply l ON u1.user_id = l.user_id
  WHERE
    tweet_id = ${tweetId};
  `
    const dbres = await db.all(query)
    res.send({
      replies: dbres.map(i => ({
        name: i.name,
        reply: i.reply,
      })),
    })
  },
)

//API 9

app.get('/user/tweets/', authentication, async (req, res) => {
  const {userId} = req
  const query = `
  SELECT 
     t.tweet AS tweets, 
     t.date_time AS time, 
     (SELECT COUNT(like_id) FROM like WHERE tweet_id = t.tweet_id) AS likes, 
     (SELECT COUNT(reply_id) FROM reply WHERE tweet_id = t.tweet_id) AS replies
   FROM
     tweet t
   WHERE 
     t.user_id = ${userId};
  `
  const dbres = await db.all(query)
  res.send(
    dbres.map(i => ({
      tweet: i.tweets,
      likes: i.likes,
      replies: i.replies,
      dateTime: i.time,
    })),
  )
})

app.get('/deek/', async (req, res) => {
  const r = `
  SELECT * FROM user;`
  const dbres = await db.all(r)
  res.send(dbres)
})

app.post('/user/tweets/', authentication, async (req, res) => {
  const {tweet} = req.body
  const {userId} = req
  const query = `
  INSERT INTO 
    tweet (tweet,user_id)
  VALUES
    ('${tweet}',${userId})`
  await db.run(query)
  res.send('Created a Tweet')
})

app.delete('/tweets/:tweetId/', authentication, async (req, res) => {
  const {userId} = req
  const {tweetId} = req.params
  const query = `
  SELECT user_id  FROM tweet
  WHERE
    tweet_id = ${tweetId};
  `
  const check = await db.get(query)
  if (check.user_id !== userId) {
    res.status(401)
    res.send('Invalid Request')
  } else {
    const q1 = `
    DELETE FROM tweet
    WHERE
      tweet_id = ${tweetId};
    `
    await db.run(q1)
    res.send('Tweet Removed')
  }
})

module.exports = app