'use strict';

let lbry;
let mongo;
let discordBot;
let moment = require('moment');
let request = require('request');
let sleep = require('sleep');
let config = require('config');
let channels = config.get('claimbot').channels;
const Discord = require('discord.js');

module.exports = {
  init: init
};

function init(discordBot_) {
  if (lbry) {
    throw new Error('init was already called once');
  }

  discordBot = discordBot_;

  const MongoClient = require('mongodb').MongoClient;
  MongoClient.connect(config.get('mongodb').url, function(err, db) {
    if (err) {
      throw err;
    }
    mongo = db;

    const bitcoin = require('bitcoin');
    lbry = new bitcoin.Client(config.get('lbrycrd'));

    console.log('Activating claimbot ');
    discordBot.channels.get(channels[0]).send('activating claimbot');

    setInterval(function() {
      announceNewClaims();
    }, 60 * 1000);
    announceNewClaims();
  });
}

function announceNewClaims() {
  if (!mongo) {
    discordPost('Failed to connect to mongo', {});
    return;
  }

  if (!lbry) {
    discordPost('Failed to connect to lbrycrd', {});
    return;
  }

  Promise.all([getLastBlock(), lbryCall('getinfo')])
    .then(function([lastProcessedBlock, currentBlockInfo]) {
      const currentHeight = currentBlockInfo['blocks'];
      console.log(currentHeight);
      if (lastProcessedBlock === null) {
        console.log('First run. Setting last processed block to ' + currentHeight + ' and exiting.');
        return setLastBlock(currentHeight);
      }

      const testBlock = false;

      if (testBlock || lastProcessedBlock < currentHeight) {
        const firstBlockToProcess = testBlock || lastProcessedBlock + 1,
          lastBlockToProcess = testBlock || currentHeight;

        console.log('Doing blocks ' + firstBlockToProcess + ' to ' + lastBlockToProcess);
        return announceClaimsLoop(firstBlockToProcess, lastBlockToProcess, currentHeight);
      }
    })
    .catch(function(err) {
      discordPost(err.stack, {});
    });
}

function announceClaimsLoop(block, lastBlock, currentHeight) {
  let claimsFound = 0;
  return lbryCall('getblockhash', block)
    .then(function(blockHash) {
      return lbryCall('getblock', blockHash);
    })
    .then(function(blockData) {
      return Promise.all(blockData['tx'].map(getClaimsForTxid));
    })
    .then(function(arrayOfClaimArrays) {
      const claims = Array.prototype.concat(...arrayOfClaimArrays).filter(function(c) {
        return !!c;
      });
      console.log('Found ' + claims.length + ' claims in ' + block);
      claimsFound = claims.length;
      return Promise.all(
        claims.map(function(claim) {
          //the API has a rate limit. to avoid hitting it we must have a small delay between each message
          //if claims were found in this block, then we wait, otherwise we don't
          if (claimsFound > 0 && claim.hasOwnProperty('claimId')) sleep.msleep(300);
          return announceClaim(claim, block, currentHeight);
        })
      );
    })
    .then(function() {
      return setLastBlock(block);
    })
    .then(function() {
      const nextBlock = block + 1;
      if (nextBlock <= lastBlock) {
        return announceClaimsLoop(nextBlock, lastBlock, currentHeight);
      }
    });
}

function announceClaim(claim, claimBlockHeight, currentHeight) {
  console.log('' + claimBlockHeight + ': New claim for ' + claim['name']);
  console.log(claim);

  //ignore supports for now
  //the issue with supports is that they should be treated completely differently
  //they are not new claims...
  if (claim.hasOwnProperty('supported claimId')) return;

  let options = {
    method: 'GET',
    url: 'http://127.0.0.1:5000/claim_decode/' + claim['name']
  };

  request(options, function(error, response, body) {
    if (error) throw new Error(error);
    try {
      console.log(JSON.stringify(JSON.parse(body), null, 2));
      let claimData = null;
      let channelName = null;
      try {
        body = JSON.parse(body);
        if (body.hasOwnProperty('stream') && body.stream.hasOwnProperty('metadata')) {
          claimData = body.stream.metadata;
          channelName = body.hasOwnProperty('channel_name') ? body['channel_name'] : null;
        }
      } catch (e) {
        console.error(e);
        return;
      }

      return Promise.all([lbryCall('getvalueforname', claim['name']), lbryCall('getclaimsforname', claim['name'])]).then(function([currentWinningClaim, claimsForName]) {
        //console.log(JSON.stringify(claimData));
        let value = null;
        if (claimData !== null) value = claimData;
        else {
          try {
            value = JSON.parse(claim['value']);
          } catch (e) {}
        }

        const text = [];

        if (value) {
          /*
          if (channelName) {
            text.push("Channel: lbry://" + channelName);
          }
          else
          */
          console.log(value);
          if (value['author']) {
            text.push('author: ' + value['author']);
          }
          if (value['description']) {
            text.push(value['description']);
          }
          // if (value['content_type'])
          // {
          //   text.push("*Content Type:* " + value['content_type']);
          // }
          if (value['nsfw']) {
            text.push('*Warning: Adult Content*');
          }

          //"fee":{"currency":"LBC","amount":186,"version":"_0_0_1","address":"bTGoFCakvQXvBrJg1b7FJzombFUu6iRJsk"}
          if (value['fee']) {
            const fees = [];
            text.push('Price: ' + value['fee'].amount + ' *' + value['fee'].currency + '*');
          }

          if (!claim['is controlling']) {
            // the following is based on https://lbry.io/faq/claimtrie-implementation
            const lastTakeoverHeight = claimsForName['nLastTakeoverHeight'],
              maxDelay = 4032, // 7 days of blocks at 2.5min per block
              activationDelay = Math.min(maxDelay, Math.floor((claimBlockHeight - lastTakeoverHeight) / 32)),
              takeoverHeight = claimBlockHeight + activationDelay,
              secondsPerBlock = 161, // in theory this should be 150, but in practice its closer to 161
              takeoverTime = Date.now() + (takeoverHeight - currentHeight) * secondsPerBlock * 1000;

            text.push('Takes effect on approx. **' + moment(takeoverTime, 'x').format('MMMM Do [at] HH:mm [UTC]') + '** (block ' + takeoverHeight + ')');
          }

          const richEmbeded = {
            author: {
              name: value['author'] || 'Anonymous',
              url: `http://open.lbry.io/${claim['name']}#${claim['claimId']}`,
              icon_url: 'http://barkpost-assets.s3.amazonaws.com/wp-content/uploads/2013/11/3dDoge.gif'
            },
            title: 'lbry://' + (channelName ? channelName + '/' : '') + claim['name'],
            color: 1399626,
            description: escapeSlackHtml(text.join('\n')),
            footer: {
              text: 'Block ' + claimBlockHeight + ' • Claim ID ' + claim['claimId']
            },
            image: { url: !value['nsfw'] ? value['thumbnail'] || '' : '' },
            url: `http://open.lbry.io/${claim['name']}#${claim['claimId']}`
          };

          discordPost(text, richEmbeded);
        }
      });
    } catch (e) {
      console.error(e);
    }
  });
}

function escapeSlackHtml(txt) {
  return txt
    .replace('&', '&amp;')
    .replace('<', '&lt;')
    .replace('>', '&gt;');
}

function getClaimsForTxid(txid) {
  return lbryCall('getclaimsfortx', txid).catch(function(err) {
    // an error here most likely means the transaction is spent,
    // which also means there are no claims worth looking at
    return [];
  });
}

function getLastBlock() {
  return new Promise(function(resolve, reject) {
    mongo.collection('claimbot').findOne({}, function(err, obj) {
      if (err) {
        reject(err);
      } else if (!obj) {
        mongo.collection('claimbot').createIndex({ last_block: 1 }, { unique: true });
        resolve(null);
      } else {
        resolve(obj.last_block);
      }
    });
  });
}

function setLastBlock(block) {
  return new Promise(function(resolve, reject) {
    mongo.collection('claimbot').findOneAndUpdate({ last_block: { $exists: true } }, { last_block: block }, { upsert: true, returnOriginal: false }, function(err, obj) {
      if (!err && obj && obj.value.last_block != block) {
        reject('Last value should be ' + block + ', but it is ' + obj.value.last_block);
      } else {
        resolve();
      }
    });
  });
}

function discordPost(text, params) {
  let richEmbeded = new Discord.RichEmbed(params);

  channels.forEach(channel => {
    discordBot.channels
      .get(channel)
      .send('', richEmbeded)
      .catch(console.error);
  });
}

function lbryCall(...args) {
  return new Promise(function(resolve, reject) {
    lbry.cmd(...args, function(err, ...response) {
      if (err) {
        reject(new Error('JSONRPC call failed. Args: [' + args.join(', ') + ']'));
      } else {
        resolve(...response);
      }
    });
  });
}