feat(endpoint): Added getTokenData() method to bch-api

src/routes/v5/psf-slp-indexer.js

@@ -35,6 +35,7 @@ class PsfSlpIndexer {
     this.router.post('/address', this.getAddress)
     this.router.post('/txid', this.getTxid)
     this.router.post('/token', this.getTokenStats)
+    this.router.post('/token/data', this.getTokenData)
 
     _this = this
   }
@@ -224,6 +225,176 @@ class PsfSlpIndexer {
     }
   }
 
+  async getTokenData (req, res, next) {
+    try {
+      // Verify env var is set for interacting with the indexer.
+      _this.checkEnvVar()
+      const tokenData = {}
+
+      const tokenId = req.body.tokenId
+      if (!tokenId || tokenId === '') {
+        res.status(400)
+        return res.json({
+          success: false,
+          error: 'tokenId can not be empty'
+        })
+      }
+
+      // get token stats
+      const withTxHistory = false
+      const response = await _this.axios.post(
+        `${_this.psfSlpIndexerApi}slp/token/`,
+        { tokenId, withTxHistory }
+      )
+      // console.log('response', response.data)
+
+      const tokenStats = response.data.tokenData
+
+      tokenData.genesisData = tokenStats
+      // try to get immutable data
+      try {
+        const immutableData = await _this.getCIDData(tokenStats.documentUri)
+        tokenData.immutableData = immutableData
+      } catch (error) {
+        tokenData.immutableData = ''
+      }
+
+      // try to get mutable data
+      try {
+        const mutableData = await _this.getMutableData(tokenStats.documentHash)
+        tokenData.mutableData = mutableData
+      } catch (error) {
+        tokenData.mutableData = ''
+      }
+      res.status(200)
+      return res.json(tokenData)
+    } catch (err) {
+      return _this.errorHandler(err, res)
+    }
+  }
+
+  // Retrieves the mutable data associated with a token document hash.
+  async getMutableData (documentHash) {
+    try {
+      if (!documentHash || typeof documentHash !== 'string') {
+        throw new Error(
+          'documentHash string required when calling mutableData().'
+        )
+      }
+
+      // Gets the OP_RETURN data and decodes it
+      const mutableData = await _this.decodeOpReturn(documentHash)
+      const jsonData = JSON.parse(mutableData)
+
+      const mspAddress = jsonData.mspAddress
+
+      // Gets the mspAddress transactions
+      const transactions = await _this.bchjs.Electrumx.transactions(mspAddress)
+
+      const mspTxs = transactions.transactions
+      // console.log(`mspTxs: ${JSON.stringify(mspTxs, null, 2)}`)
+
+      let data = false
+      // Maps each transaction of the mspAddress
+      // if finds an OP_RETURN decode is and closes the loop
+      // Start with the newest TXID entry and scan the history to find the first
+      // entry with an IPFS CID.
+      for (let i = mspTxs.length - 1; i > -1; i--) {
+        const tx = mspTxs[i]
+        const txid = tx.tx_hash
+        console.log(`Retrieving and decoding txid ${txid}`)
+
+        data = await _this.decodeOpReturn(txid)
+        // console.log('data: ', data)
+
+        //  Try parse the OP_RETURN data to a JSON object.
+        if (data) {
+          try {
+            // console.log('Mutable Data  : ', data)
+
+            // Convert the OP_RETURN data to a JSON object.
+            const obj = JSON.parse(data)
+            console.log(`obj: ${JSON.stringify(obj, null, 2)}`)
+
+            // Keep searching if this TX does not have a cid value.
+            if (!obj.cid) continue
+
+            // TODO: Ensure data was generated by the MSP address and not an
+            // update from a different address.
+
+            break
+          } catch (error) {
+            continue
+          }
+        }
+      }
+      if (!data) {
+        console.log('Mutable Data  Not found ')
+      }
+
+      // Get the CID:
+      const obj = JSON.parse(data)
+      const cid = obj.cid
+      if (!cid) {
+        throw new Error('CID could not be found in OP_RETURN data')
+      }
+
+      const result = await _this.getCIDData(cid)
+      // console.log(`response.data: ${JSON.stringify(response.data, null, 2)}`)
+
+      return result
+    } catch (err) {
+      console.log('Error in getMutableData().')
+      throw err
+    }
+  }
+
+  // Decodes the OP_RETURN of a transaction if this exists
+  async decodeOpReturn (txid) {
+    try {
+      if (!txid || typeof txid !== 'string') {
+        throw new Error('txid must be a string.')
+      }
+      // get transaction data
+      const txData = await _this.bchjs.Electrumx.txData(txid)
+      let data = false
+      // Maps the vout of the transaction in search of an OP_RETURN
+      for (let i = 0; i < txData.details.vout.length; i++) {
+        const vout = txData.details.vout[i]
+
+        const script = _this.bchjs.Script.toASM(
+          Buffer.from(vout.scriptPubKey.hex, 'hex')
+        ).split(' ')
+
+        if (script[0] === 'OP_RETURN') {
+          data = Buffer.from(script[1], 'hex').toString('ascii')
+          break
+        }
+      }
+      return data
+    } catch (error) {
+      console.log('Error in decodeOpReturn().')
+      throw error
+    }
+  }
+
+  async getCIDData (cid) {
+    try {
+      if (!cid || typeof cid !== 'string') {
+        throw new Error('cid must be a string.')
+      }
+      const dataUrl = `https://${cid}.ipfs.dweb.link/data.json`
+
+      const response = await _this.axios.get(dataUrl)
+      // console.log(`response.data: ${JSON.stringify(response.data, null, 2)}`)
+
+      return response.data
+    } catch (error) {
+      console.log('Error in getCIDData().')
+      throw error
+    }
+  }
+
   // Check the the environment variable is set correctly.
   checkEnvVar () {
     _this.psfSlpIndexerApi = process.env.SLP_INDEXER_API