"use strict";

var currentBoard = null;
var selected = {};
var won = []

function newGroup() {
    var categoryPoint = Math.random();
    for (var category of corpus) {
        if (categoryPoint < category.portion) {
            continue;
        }
        var group = category.groups[category.groups.length * Math.random() << 0]
        var clues = randomSelect(group.clues, 4)
        break;
    }

    return {
        hint: group.hint,
        clues: clues,
        fullClues: group.clues,
    };
}

function first(xs) {
    return xs[0]
}

function newNonintersectingGroup(oldGroups) {
    var group = newGroup();
    for (var oldGroup of oldGroups) {
        var intersection = oldGroup.fullClues.map(first).filter(value => group.fullClues.map(first).includes(value));
        if (intersection.length > 0) {
            return newNonintersectingGroup(oldGroups);
        }
    }
    return group;
}

function newBoard() {
    var groups = [];
    for (var i = 0; i < 4; i++) {
        var group = newNonintersectingGroup(groups);
        groups.push(group);
    }
    var newGroups = [];
    for (var i = 0; i < 4; i++) {
        newGroups.push({hint: groups[i].hint, clues: groups[i].clues});
    }
    return newGroups;
}

function chooseBox(box) {
    var clue = parseInt(box.getAttribute('x-clue'));
    if (box.classList.contains('selected')) {
        box.classList.remove('selected');
        delete selected[clue];
    } else {
        box.classList.add('selected');
        selected[clue] = parseInt(box.getAttribute('x-group'));
    }

    if (Object.keys(selected).length == 4) {
        var [ok, grp] = checkGuess(selected)
        if (ok) {
            consume(grp);
        } else {
            clear();
        }
    }
}

function clear() {
    selected = {}
    var els = [...document.getElementsByClassName('selected')];
    for (var i = 0; i < 4; i++) {
        els[i].classList.remove('selected');
    }
}

function consume(grp) {
    won.push(grp)
    selected = {}
    var els = document.querySelectorAll(`[x-group="${grp}"]`);
    for (var el of els) {
        el.remove();
    }
    var group = currentBoard[grp];

	var cluesString = group.clues.map(x => x[0]).join(', ')
	var defnsString = group.clues.map(clue => {
        var full = getFull(clue);
		var defn = full[1];
		return `<strong>${full[2]}</strong>: <span class="definition">${defn}</span>`
	}).join('<br>')

    var s = `<details class="answerclue"><summary>${cluesString}</summary>${defnsString}</details>`;

    document.getElementById('answers').innerHTML +=
        `<div class="answer">
            <div class="answerline">${group.hint} <a class="flag" href="#" x-flag="${group.hint}">[flag]</a></div>
            <div class="clues">${s}</div>
        </div>`;
}

document.getElementById('answers').addEventListener('click', function(evt) {
    if (evt.target.classList.contains('flag')) {
        evt.preventDefault();
        let options = {
            method: 'GET',
            headers: {}
        };

        fetch('/flag?q=' + encodeURIComponent(evt.target.getAttribute('x-flag')), options)
        .then(body => {
            var el = document.createElement('span')
            el.innerText = `flagged`
            el.classList.add('flagged')
            evt.target.replaceWith(el)
        });
    }
});

function checkGuess(selected) {
    var ans = null;
    for (var clue of Object.keys(selected)) {
        var group = selected[clue];
        if (ans === null) {
            ans = group;
        } else if (ans != group) {
            return [false, 0];
        }
    }
    return [true, group];
}

function getFull(clue) {
    var [i, j, k] = clue[1];
    return fullCorpus[i].groups[j].clues[k];
}

function serializeBoard(board) {
    var copy = []
    for (var group of board) {
        copy.push({
            clues: group.clues,
            hint: group.hint,
        })
    }
    return encodeURIComponent(btoa(JSON.stringify(copy)))
}

function deserializeBoard(s) {
    var copy = JSON.parse(atob(decodeURIComponent(s)))
    var board = []
    for (var group of copy) {
        board.push({
            clues: group.clues,
            hint: group.hint,
        })
    }
    return board;
}

function generateUrl(board) {
    return `${location.origin}/infinite-connections?q=${serializeBoard(board)}`
}

function startBoard(board) {
    selected = {};

    document.getElementById('answers').innerHTML = '';
    var el = document.getElementById('board');

    currentBoard = board;
    won = [];

    var clues = [];
    for (var [i, group] of board.entries()) {
        for (var [j, clue] of group.clues.entries()) {
            clues.push([i, i*4+j, clue]);
        }
    }

    shuffle(clues);
    el.innerHTML = ``;
    for (var [i, j, clue] of clues) {
        el.innerHTML += `<div class="box" x-group=${i} x-clue=${j}>${clue[0]}</div>`;
    }
}

function giveUp() {
    for (var i = 0; i < 4; i++) {
        if (!won.includes(i)) {
            consume(i);
        }
    }
}

document.getElementById('board').addEventListener('click', function(evt) {
    if (evt.target.classList.contains('box')) {
        evt.preventDefault();
        chooseBox(evt.target);
    }
});

document.getElementById('new-board').addEventListener('click', function(evt) {
    startBoard(newBoard());
});

document.getElementById('copy-link').addEventListener('click', function(evt) {
    navigator.clipboard.writeText(generateUrl(currentBoard))
});

document.getElementById('clear').addEventListener('click', function(evt) {
    clear();
});

document.getElementById('reset').addEventListener('click', function(evt) {
    startBoard(currentBoard);
});

document.getElementById('give-up').addEventListener('click', function(evt) {
    giveUp();
});

// Source: https://stackoverflow.com/a/19270021
function randomSelect(arr, n) {
    var result = new Array(n),
        len = arr.length,
        taken = new Array(len);
    if (n > len)
        throw new RangeError("randomSelect: more elements taken than available");
    while (n--) {
        var x = Math.floor(Math.random() * len);
        result[n] = arr[x in taken ? taken[x] : x];
        taken[x] = --len in taken ? taken[len] : len;
    }
    return result;
}

// Source: https://stackoverflow.com/a/2450976
function shuffle(array) {
  let currentIndex = array.length,  randomIndex;

  // While there remain elements to shuffle.
  while (currentIndex > 0) {

    // Pick a remaining element.
    randomIndex = Math.floor(Math.random() * currentIndex);
    currentIndex--;

    // And swap it with the current element.
    [array[currentIndex], array[randomIndex]] = [
      array[randomIndex], array[currentIndex]];
  }

  return array;
}

var urlParams = new URLSearchParams(window.location.search);
var q = urlParams.get('q')
if (q) {
    startBoard(deserializeBoard(q));
} else {
    startBoard(newBoard());
}