Prerequisite

You should have following things installed:

• Jsipfs
• Ganache
• MongoDB
• NodeJS

How to run

Follow the steps to run Backend of Application:

• open terminal and run jsipfs daemon command
• start ganache ethereum workspace
• run contractDeployement using node contractDeployement.js command
• open terminal in project directory and run npm i command, to make sure all dependencies are installed
• now run mongodbUri=<Connection URI of MongoDB> npm start command with your mongodb connection uri, to start backend
• now you should move to frontend directory and start it, You will find instructions to run frontend in README file of frontend repository!

Description of APIs

UserInfo goal: get information of user such as profile, name and bio input: send ethereum address in body with key as "ethAddress". working: find record where the ethAddress is same(body.ethAddress). send retrieved record as response.

Content goal: fetch content from database on the basis of some condition input: send condition(mongodb query) in body with key as "condition" working: find records that meet the condition. send retrieved records in array format as response.

• login goal: register/authenticate user and send information of user input: send ethereum address in body with key as "user" and cookies.token working: find record where ethAddress is same (body.user). if record is null (means user is not registered) so insert record in database and remember it for further steps retrieve token from database associated with ethAddress of user if token (from Database) is equal to cookies.token then send account info as response else send message "logout account from database" and if token(from database) is null (means user is doing first time login) then generate token store it in database with ethAddress and send token in cookie and send account info as response.

Note: token is hash of ethAddress of user and timestamp, for hashing sha256 algorithm is used.

• updateProfile goal: update the profile picture of user. input: send image file in body with key as "image" working: if file not sent in request, send message "account update failed" as response otherwise store image on server and update user record(set img field to filename of image) send message "account profile update successful!" as response

• updateDetails goal: update the details of user such as name and bio. input: send details json object in body with key as "details" and ethAdress with key as "ethAddress" working; update detail of user with same ethAddress (body.ethAddress) send message "account update successful" as response.

• uploadMainContent goal: upload main content of user of IPfS, ensure uniqueness of content input: send file in body with key as "file" working: store file in temporary directory upload file on IPFS and find CID (content id) and remove content from temporary directory create hash of cid find that is hash already available in database? if hash is available send message "content already uploaded" as response otherwise store hash in database and send encrypted cid as response

Note: we are storing hash CID in databse to avoid plagirised content and we are doing hash so if some one find database record it will get nothing. We are encrypting cid with a public key so that if some one remeber CID he cannot actually get the content without our platform.

• uploadClipContent goal: upload clip/preview of main content on ipfs input: send file in body with key as "file" working: store file in temporary directory upload file on IPFS and find CID (content id) and remove content from temporary directory send CID as response.

• uploadContent goal: upload detail of content on database such as thumbnail, title, description, contract address input: send image of thumbnail with key as file and other details. working: extract title, description, clip CID, and address from request. add record with above details and additionally add current data into database send message "content uploaded successful" as response.

• uploadReview goal: upload review of content on databse. input: send review, contract address of content ethAddress of user. working: extract review, address and ethAddress from request store all things on database send message "review uploaded" as response.

• content/:address goal: fetch content detail from database associated to contract address. input: send contract address of content in parameter of url as "address" working: fetch address from url find record with same address in database send record as response

• review/:address goal: get all reviews related to contract address of content input: send contract address of content as parameter in url as "address" working: fetch address from url find record with same address in database send record as response

profileImgs/:filename goal: fetch profile image from server storage input: send filename of profile image as parameter in url as "filename" working: extract filename parameter read image from server storage send image as response

thumbnail/:filename goal: fetch thumbnail image from server storage input: send filename of thumbnail image as parameter in url as "filename" working: extract filename parameter read image from server storage send image as response

ipfs/:cid goal: fetch clip/preview from IPFS input: send cid as parameter in url as "cid" working: extract cid from parameter read content from IPFS in buffer. store it in temprary directory send file as reponse and remove file from temporary directory.

• view/:txHash goal: ensure transaction for viewership of content, avoid double spending of view and send content from ipfs to user. input: send transaction hash as parameter in url as "txHash" working: extract txHash from parameter find record with same txhash if record is already available send message "view already claimed" otherwise move further read transaction from blockchain and read cid of content from event of transaction decrypt cid with private key, read content from IPFS in buffer store content file on temprary directory send file as response and remove file from temporary directory store transaction hash on database

• licenseOrOwner/:contractAddr/:userAddr/:cid goal: ensure that user is licensor or owner then send content from IPFS to user. input: send contract address, user address, and CID as parameter in url as contractAddr, userAddr and cid working: extract all input parameters call isLicensor and isOwner function of contract with userAddr as function parameter if both are false send message "not owner or licensor" otherwise move forward decrypt cid with private key, read content from IPFS in buffer store content file on temprary directory send file as response and remove file from temporary directory store transaction hash on database

digitalAssetContract goal: send digital asset contract ABI(application binary interface) and address input: none working: read ABI and address of digital asset contract from constants JSON send ABI and address as response

assetContract goal: send asset contract ABI input: none working: read ABI of asset contract from constants JSON send ABI as response.

Note: ABI and address are added so that user can interact with contract directly to do transactions