'use strict';

var _ = require('lodash');
var BufferWriter = require('../encoding/bufferwriter');
var buffer = require('buffer');
var bufferUtil = require('../util/buffer');
var jsUtil = require('../util/js');
var Script = require('../script');

function Input(params) {
  if (!(this instanceof Input)) {
    return new Input(params);
  }
  if (params) {
    return this._fromObject(params);
  }
}

Object.defineProperty(Input.prototype, 'script', {
  configurable: false,
  writeable: false,
  get: function() {
    if (!this._script) {
      this._script = new Script(this._scriptBuffer);
    }
    return this._script;
  }
});

Input.prototype._fromObject = function(params) {
  if (_.isString(params.prevTxId) && jsUtil.isHexa(params.prevTxId)) {
    params.prevTxId = new buffer.Buffer(params.prevTxId, 'hex');
  }
  this.prevTxId = params.prevTxId;
  this.outputIndex = params.outputIndex;
  this.sequenceNumber = params.sequenceNumber;
  if (params.script || params.scriptBuffer) {
    this.setScript(params.script || params.scriptBuffer);
  }
  return this;
};

Input.prototype.toJSON = function() {
  return {
    prevTxId: this.prevTxId,
    outputIndex: this.outputIndex,
    sequenceNumber: this.sequenceNumber,
    script: this._scriptBuffer.toString('hex')
  };
};

Input.fromJSON = function(json) {
  return new Input({
    prevTxId: json.prevTxId || json.txidbuf,
    outputIndex: json.outputIndex || json.txoutnum,
    sequenceNumber: json.sequenceNumber || json.seqnum,
    scriptBuffer: new Script(json.script, 'hex')
  });
};

Input.fromBufferReader = function(br) {
  var input = new Input();
  input.prevTxId = br.readReverse(32);
  input.outputIndex = br.readUInt32LE();
  var scriptSize = br.readVarintNum();
  if (scriptSize) {
    input._scriptBuffer = br.read(scriptSize);
  } else {
    input._scriptBuffer = new buffer.Buffer([]);
  }
  input.sequenceNumber = br.readUInt32LE();
  return input;
};

Input.prototype.toBufferWriter = function(writer) {
  if (!writer) {
    writer = new BufferWriter();
  }
  writer.writeReverse(this.prevTxId);
  writer.writeUInt32LE(this.outputIndex);
  var script = this._scriptBuffer;
  writer.writeVarintNum(script.length);
  writer.write(script);
  writer.writeUInt32LE(this.sequenceNumber);
  return writer;
};

Input.prototype.setScript = function(script) {
  if (script instanceof Script) {
    this._script = script;
    this._scriptBuffer = script.toBuffer();
  } else if (bufferUtil.isBuffer(script)) {
    this._script = null;
    this._scriptBuffer = new buffer.Buffer(script);
  } else {
    console.log(script);
    throw new TypeError('Invalid Argument');
  }
  return this;
};

module.exports = Input;