/* Imports */
import Head from "next/head";
import React, { useState } from "react";
import { DrawGraph, removeOldSvg } from "./labeledGraph";
import { SubmitButton } from "./submitButton";
import { DisplayElement } from "./displayElement";
import { DisplayAsMarkdown } from "./displayAsMarkdown";
import { CreateTable, buildRows } from "./findPaths";
import { DataSetChanger } from "./datasetChanger";
import { ComparisonsChanger } from "./comparisonsChanger";
import { pushToMongo } from "./pushToMongo.js";
import {
  increasingList,
  maxMergeSortSteps,
  expectedNumMergeSortSteps,
  conservativeNumMergeSortSteps,
} from "./utils.js";

/* DEFINTIONS */
const DEFAULT_COMPARE = () => "x to y"; // 1/Math.random() - 1 // Useful for testing, cause I can make the default number change.
const estimatedMergeSortSteps = conservativeNumMergeSortSteps; // pander to human biases so that users complain less.

/* Misc. helpers */
let buildLinks = (quantitativeComparisons) =>
  quantitativeComparisons.map(
    ([element1, element2, distance, reasoning, squiggleString]) => ({
      source: element1,
      target: element2,
      distance: distance,
      reasoning: reasoning,
      squiggleString: squiggleString,
    })
  );

Array.prototype.containsArray = function (val) {
  var hash = {};
  for (var i = 0; i < this.length; i++) {
    hash[this[i]] = i;
  }
  return hash.hasOwnProperty(val);
};

let checkIfListIsOrdered = (arr, binaryComparisons) => {
  let l = arr.length;
  let isOrdered = true;
  for (let i = 0; i < l - 1; i++) {
    isOrdered =
      isOrdered && binaryComparisons.containsArray([arr[i], arr[i + 1]]);
  }
  return isOrdered;
};

let nicelyFormatLinks = (quantitativeComparisons, listOfElements) =>
  quantitativeComparisons.map(
    ([element1, element2, distance, reasoning, squiggleString]) => ({
      source: listOfElements[element1].name,
      target: listOfElements[element2].name,
      distance: distance,
      reasoning: reasoning,
      squiggleString: squiggleString,
    })
  );

// Main react component
export default function ComparisonView({ listOfElementsForView }) {
  /* State */
  // initial state values
  let initialListOfElements = listOfElementsForView.map((element, i) => ({
    ...element,
    id: i,
  }));
  let initialPosList = increasingList(listOfElementsForView.length); // [0,1,2,3,4]
  let initialComparePair = [
    initialPosList[initialPosList.length - 2],
    initialPosList[initialPosList.length - 1],
  ];
  let initialInputValue = "x to y";
  let initialReasoning = "";
  let initialBinaryComparisons = [];
  let initialQuantitativeComparisons = [];
  let initialIsListOdered = false;
  let initialOrderedList = [];
  let initialShowAdvancedOptions = false;
  let initialShowComparisons = false;
  let initialShowLoadComparisons = false;
  let initialShowChangeDataSet = false;
  let initialNumSteps = 0;
  let initialMaxSteps = maxMergeSortSteps(listOfElementsForView.length);
  let initialExpectedSteps = estimatedMergeSortSteps(
    listOfElementsForView.length
  );
  let initialTableRows = [];
  let initialDontPushSubmitButtonAnyMore = false;

  // state variables and functions
  const [listOfElements, setListOfElements] = useState(initialListOfElements);
  const [posList, setPosList] = useState(initialPosList);
  const [toComparePair, setToComparePair] = useState(initialComparePair);
  const [inputValue, setInputValue] = useState(initialInputValue);
  const [reasoning, setReasoning] = useState(initialReasoning);
  const [binaryComparisons, setBinaryComparisons] = useState(
    initialBinaryComparisons
  );
  const [quantitativeComparisons, setQuantitativeComparisons] = useState(
    initialQuantitativeComparisons
  ); // More expressive, but more laborious to search through. For the ordering step, I only manipulate the binaryComparisons.

  const [isListOrdered, setIsListOrdered] = useState(initialIsListOdered);
  const [orderedList, setOrderedList] = useState(initialOrderedList);
  const [dontPushSubmitButtonAnyMore, setDontPushSubmitButtonAnyMore] =
    useState(initialDontPushSubmitButtonAnyMore);

  let [showAdvancedOptions, changeShowAdvanceOptions] = useState(
    initialShowAdvancedOptions
  );
  let [showComparisons, changeShowComparisons] = useState(
    initialShowComparisons
  );
  let [showLoadComparisons, changeShowLoadComparisons] = useState(
    initialShowLoadComparisons
  );
  let [showChangeDataSet, changeshowChangeDataSet] = useState(
    initialShowChangeDataSet
  );
  let [numSteps, changeNumSteps] = useState(initialNumSteps);
  let [maxSteps, changeMaxSteps] = useState(initialMaxSteps);
  let [expectedSteps, changeExpectedSteps] = useState(initialExpectedSteps);
  let [tableRows, setTableRows] = useState(initialTableRows);

  /* Convenience utils: restart + changeDataSet */
  let restart = (
    posList,
    initialBinaryComparisons2,
    initialQuantitativeComparisons2
  ) => {
    //({posList, initialBinaryComparisons2, initialQuantitativeComparisons2}) => {
    setToComparePair([
      posList[posList.length - 2],
      posList[posList.length - 1],
    ]);
    setInputValue(initialInputValue);
    setBinaryComparisons(initialBinaryComparisons2 || initialBinaryComparisons);
    setQuantitativeComparisons(
      initialQuantitativeComparisons2 || initialQuantitativeComparisons
    );
    setIsListOrdered(initialIsListOdered);
    setOrderedList(initialOrderedList);
    changeNumSteps(initialNumSteps);
    removeOldSvg();
    setTableRows(initialTableRows);
    setDontPushSubmitButtonAnyMore(initialDontPushSubmitButtonAnyMore);
  };

  let changeDataSet = (listOfElementsNew) => {
    listOfElementsNew = listOfElementsNew.map((element, i) => ({
      ...element,
      id: i,
    }));
    let newPosList = increasingList(listOfElementsNew.length);
    let newListLength = listOfElementsNew.length;

    setListOfElements(listOfElementsNew);
    setPosList(increasingList(listOfElementsNew.length));
    setToComparePair([
      newPosList[newPosList.length - 2],
      newPosList[newPosList.length - 1],
    ]);

    changeExpectedSteps(estimatedMergeSortSteps(newListLength));
    changeMaxSteps(maxMergeSortSteps(newListLength));

    restart(newPosList);
    // restart({posList: newPosList})
  };

  let changeComparisons = async (links) => {
    let quantitativeComparisons2 = [];
    let binaryComparisons2 = [];
    links.shift();
    for (let link of links) {
      let { source, target, distance, reasoning, squiggleString } = link;
      let searchByName = (name, candidate) => candidate.name == name;
      let testForSource = (candidate) => searchByName(source, candidate);
      let testForTarget = (candidate) => searchByName(target, candidate);
      let element1 = listOfElements.findIndex(testForSource);
      let element2 = listOfElements.findIndex(testForTarget);
      if (element1 == -1 || element2 == -1) {
        console.log("link", link);
        console.log(source);
        console.log(target);
        throw new Error("Comparisons include unknown elements, please retry");
      }
      quantitativeComparisons2.push([
        element1,
        element2,
        distance,
        reasoning,
        squiggleString || distance,
      ]);
      binaryComparisons2.push([element1, element2]);
    }
    // return ({quantitativeComparisons: quantitativeComparisons2, binaryComparisons: binaryComparisons2})
    //restart({posList, initialBinaryComparisons2=initialBinaryComparisons, initialQuantitativeComparisons2=initialQuantitativeComparisons})
    // restart(posList, binaryComparisons2, quantitativeComparisons2)
    setQuantitativeComparisons(quantitativeComparisons2);
    setBinaryComparisons(binaryComparisons2);
  };

  // Manipulations
  let compareTwoElements = (newBinaryComparisons, element1, element2) => {
    let element1Greater = newBinaryComparisons.containsArray([
      element1,
      element2,
    ]);
    let element2Greater = newBinaryComparisons.containsArray([
      element2,
      element1,
    ]);
    if (element1Greater || element2Greater) {
      return element1Greater && !element2Greater;
    } else {
      setToComparePair([element1, element2]);
      //console.log(`No comparison found between ${element1} and ${element2}`)
      //console.log(`Comparisons:`)
      //console.log(JSON.stringify(newBinaryComparisons, null, 4));
      return "No comparison found";
    }
  };

  function merge(newBinaryComparisons, left, right) {
    let sortedArr = []; // the sorted elements will go here

    while (left.length && right.length) {
      // insert the biggest element to the sortedArr
      let comparison = compareTwoElements(
        newBinaryComparisons,
        left[0],
        right[0]
      );
      if (comparison == "No comparison found") {
        return "No comparison found; unable to proceed";
      } else if (comparison) {
        // left[0] > right[0]
        sortedArr.push(left.shift());
      } else {
        sortedArr.push(right.shift());
      }
    }

    // use spread operator and create a new array, combining the three arrays
    return [...sortedArr, ...left, ...right]; // if they don't have the same size, the remaining ones will be greater than the ones before
  }

  function mergeSort({ array, comparisons }) {
    if (array == "No comparison found; unable to proceed") {
      return "No comparison found; unable to proceed";
    }
    const half = array.length / 2;

    // the base case is array length <=1
    if (array.length <= 1) {
      return array;
    }

    const left = array.slice(0, half); // the first half of the array
    const right = array.slice(half, array.length); // Note that splice is destructive.
    let orderedFirstHalf = mergeSort({ array: left, comparisons });
    let orderedSecondHalf = mergeSort({ array: right, comparisons });
    if (
      orderedFirstHalf != "No comparison found; unable to proceed" &&
      orderedSecondHalf != "No comparison found; unable to proceed"
    ) {
      let result = merge(comparisons, orderedFirstHalf, orderedSecondHalf);
      return result;
    } else {
      return "No comparison found; unable to proceed";
    }
  }

  let nextStepSimple = (posList, binaryComparisons, element1, element2) => {
    //console.log("Binary comparisons: ")
    //console.log(JSON.stringify(binaryComparisons, null, 4));

    let newComparison = [element1, element2]; // [element1, element2]
    let newBinaryComparisons = [...binaryComparisons, newComparison];
    //console.log("New binaryComparisons: ")
    //console.log(JSON.stringify(newBinaryComparisons, null, 4));
    setBinaryComparisons(newBinaryComparisons);

    let result = mergeSort({
      array: posList,
      comparisons: newBinaryComparisons,
    });
    //console.log(result)
    if (
      result != "No comparison found; unable to proceed" &&
      checkIfListIsOrdered(result, newBinaryComparisons)
    ) {
      // console.log(`isListOrdered: ${isListOrdered}`)
      console.log("poslist@nextStepSimple");
      console.log(posList);
      console.log("result@nextStepSimple");
      console.log(result);

      return [true, result];
    } else {
      return [false, result];
    }
  };

  let nextStepInput = async ({
    posList,
    binaryComparisons,
    inputValue,
    reasoning,
    element1,
    element2,
    squiggleString,
  }) => {
    if (!dontPushSubmitButtonAnyMore) {
      if (inputValue < 1 && inputValue > 0) {
        let inverse = 1 / inputValue;
        if (squiggleString == inputValue) {
          inputValue = inverse;
          squiggleString = inverse;
        } else {
          inputValue = inverse;
          squiggleString = `(${squiggleString})^(-1)`;
        }
        [element1, element2] = [element2, element1];
      }
      console.log(`posList@nextStepInput:`);
      console.log(posList);
      let [successStatus, result] = nextStepSimple(
        posList,
        binaryComparisons,
        element1,
        element2
      );

      let newQuantitativeComparison = [
        element1,
        element2,
        inputValue,
        reasoning,
        squiggleString || inputValue,
      ];
      let newQuantitativeComparisons = [
        ...quantitativeComparisons,
        newQuantitativeComparison,
      ];
      setQuantitativeComparisons(newQuantitativeComparisons);

      setInputValue(DEFAULT_COMPARE());
      setReasoning("");
      changeNumSteps(numSteps + 1);
      if (successStatus) {
        setDontPushSubmitButtonAnyMore(true);

        let jsObject = nicelyFormatLinks(
          quantitativeComparisons,
          listOfElements
        );
        await pushToMongo(jsObject);
        console.log(jsObject);

        alert(
          "Comparisons completed. Background work might take a while, or straight-out fail"
        );
        setIsListOrdered(true);
        setOrderedList(result);

        await buildRows({
          isListOrdered: true,
          orderedList: result,
          listOfElements,
          links: buildLinks(newQuantitativeComparisons),
          rows: tableRows,
          setTableRows,
        });
        /*
        setTimeout(async () => {
          // Make sure to do this after the 

        }, 100);
        */
      }
    }
  };

  // Html
  return (
    <div className="flex flex-col items-center justify-center min-h-screen py-2">
      {/* Webpage name & favicon */}
      <div className="mt-20">
        <Head>
          <title>Utility Function Extractor</title>
          <link rel="icon" href="/favicon.ico" />
        </Head>
      </div>
      <main className="flex flex-col items-center w-full flex-1 px-20 text-center">
        {/* Heading */}
        <h1 className="text-6xl font-bold">Utility Function Extractor</h1>
        {/* Approximate progress indicator */}

        <p>{`${numSteps} out of ~${expectedSteps} (max ${maxSteps}) comparisons`}</p>

        {/* Comparison section */}
        <div className={isListOrdered ? "hidden" : ""}>
          <div className="flex flex-wrap items-center max-w-4xl sm:w-full mt-10">
            {/* Element 1 */}
            <div className="flex m-auto border-gray-300 border-4 h-72 w-72 p-5">
              <div className="block m-auto text-center">
                <DisplayElement
                  element={listOfElements[toComparePair[0]]}
                ></DisplayElement>
              </div>
            </div>

            {/* Comparison actuator (text, previously number) */}
            <div className="flex m-auto w-72">
              <div className="block m-auto text-center">
                <br />
                <label>
                  {`... is `}
                  <br />
                  <input
                    type="text"
                    className="text-center text-blueGray-600 bg-white rounded text-lg border-0 shadow outline-none focus:outline-none focus:ring w-8/12 h-10 m-2"
                    value={inputValue}
                    onChange={(event) => {
                      //console.log(event)
                      //console.log(event.target.value)
                      setInputValue(event.target.value);
                    }}
                  />
                  <br />
                  {`times as valuable as ...`}
                </label>
                <br />

                <SubmitButton
                  posList={posList}
                  binaryComparisons={binaryComparisons}
                  inputValue={inputValue}
                  reasoning={reasoning}
                  toComparePair={toComparePair}
                  nextStepInput={nextStepInput}
                  dontPushSubmitButtonAnyMore={dontPushSubmitButtonAnyMore}
                />
              </div>
            </div>

            {/* Element 2 */}
            <div className="flex m-auto border-gray-300 border-4 h-72 w-72 p-5">
              <div className="block m-auto text-center">
                <DisplayElement
                  element={listOfElements[toComparePair[1]]}
                ></DisplayElement>
              </div>
            </div>
          </div>
          <br />

          <label className="">
            {"Notes and reasoning:"}
            <textarea
              className="mt-2 px-3 py-4 placeholder-blueGray-300 text-blueGray-600 relative bg-white bg-white rounded text-base border-0 shadow outline-none focus:outline-none focus:ring w-full"
              placeholder={
                numSteps == 0
                  ? "Please write your name here if you want QURI to be able to identify your answers later"
                  : ""
              }
              value={reasoning}
              onChange={(event) => setReasoning(event.target.value)}
            />
          </label>
          <br />
        </div>

        {/* Results section */}
        <div className={isListOrdered ? "" : "hidden"}>
          {/* Graph */}
          <div className="flex items-center text-center">
            <DrawGraph
              isListOrdered={isListOrdered}
              orderedList={orderedList}
              listOfElements={listOfElements}
              links={buildLinks(quantitativeComparisons)}
            ></DrawGraph>
          </div>

          {/* Comparison table */}
          <div className="flex items-center text-center ">
            <CreateTable
              isListOrdered={isListOrdered}
              orderedList={orderedList}
              listOfElements={listOfElements}
              links={buildLinks(quantitativeComparisons)}
              tableRows={tableRows}
              setTableRows={setTableRows}
            ></CreateTable>
          </div>
        </div>

        {/* Convenience functions */}
        <div className="w-2/12 flex justify-center mt-10">
          <button
            className="text-gray-500 text-sm"
            onClick={() => changeShowAdvanceOptions(!showAdvancedOptions)}
          >
            Advanced options ▼
          </button>
        </div>

        <div
          className={
            showAdvancedOptions
              ? "flex flex-wrap -mx-4 overflow-hidden"
              : "hidden"
          }
        >
          {/* Button: Restart */}
          <div className="my-4 px-4 w-1/4 overflow-hidden">
            <button
              className="bg-transparent hover:bg-blue-500 text-blue-700 font-semibold hover:text-white py-2 px-4 border border-blue-500 hover:border-transparent rounded mt-5"
              onClick={() => restart(posList)}
            >
              {/* onClick={() => restart({posList})}> */}
              Restart
            </button>
          </div>
          {/* Button: Show comparisons */}
          <div className="my-4 px-4 w-1/4 overflow-hidden">
            <button
              className="bg-transparent hover:bg-blue-500 text-blue-700 font-semibold hover:text-white py-2 px-4 border border-blue-500 hover:border-transparent rounded mt-5"
              onClick={() => changeShowComparisons(!showComparisons)}
            >
              Show comparisons
            </button>
          </div>
          {/* Button: Load comparisons */}
          <div className="my-4 px-4 w-1/4 overflow-hidden">
            <button
              className="bg-transparent hover:bg-blue-500 text-blue-700 font-semibold hover:text-white py-2 px-4 border border-blue-500 hover:border-transparent rounded mt-5"
              onClick={() => changeShowLoadComparisons(!showLoadComparisons)}
            >
              Load comparisons
            </button>
          </div>
          {/* Button: Change dataset */}
          <div className="my-4 px-4 w-1/4 overflow-hidden">
            <button
              className="bg-transparent hover:bg-blue-500 text-blue-700 font-semibold hover:text-white py-2 px-4 border border-blue-500 hover:border-transparent rounded mt-5"
              onClick={() => changeshowChangeDataSet(!showChangeDataSet)}
            >
              Use your own data
            </button>
          </div>
        </div>
        {/* Change dataset section */}
        <div className={showChangeDataSet ? "inline mt-5" : "hidden"}>
          <DataSetChanger handleSubmit={changeDataSet} />
        </div>

        {/* Show comparisons section */}
        <div className={showComparisons ? "inline mt-5" : "hidden"}>
          <div className="text-left">
            <DisplayAsMarkdown
              markdowntext={`
${
  "" /*
## Comparisons
### Binary comparisons
${JSON.stringify(binaryComparisons, null, 4)}
*/
}
### Numerical comparisons
${JSON.stringify(
  nicelyFormatLinks(quantitativeComparisons, listOfElements),
  null,
  4
)}
              `}
              className={""}
            ></DisplayAsMarkdown>
          </div>
        </div>
        {/* Load comparisons section */}
        <div className={showLoadComparisons ? "inline mt-5" : "hidden"}>
          <ComparisonsChanger handleSubmit={changeComparisons} />
          {/*<ComparisonsChanger handleSubmit={changeComparisons} />*/}
        </div>
      </main>
    </div>
  );
}