frontend/index.js

   1 const sleep = (ms) => new Promise(resolve => setTimeout(resolve, ms));
   2
   3 /**
   4  * Safari iOS pls
   5  */
   6 const formSubmitPolyfill = (form, callback) => {
   7     if (form.requestSubmit) {
   8         form.requestSubmit();
   9     } else {
  10         callback();
  11     }
  12 }
  13
  14 const createGenreListWithClickEvent = (genreList, genres, callback) => {
  15     genreList.append(...genres.map((genre) => {
  16         const name = genre["name"];
  17         const option = document.createElement("option");
  18         option.setAttribute("data-name", name);
  19         option.addEventListener("click", callback);
  20         option.appendChild(document.createTextNode(name));
  21         return option;
  22     }));
  23 }
  24
  25 const relativeToCtx = (x1, x2, y1, y2, ctx) => {
  26     const newX = x1 + x2;
  27     const newY = y1 + y2;
  28     ctx.lineTo(newX, newY);
  29     return [newX, newY];
  30 }
  31
  32 /**
  33  * Return (x,y) of canvas
  34  */
  35 const getDimensions = (canvas) => [canvas.width, canvas.height];
  36
  37 /**
  38  * Return (x,y) midpoint of canvas
  39  */
  40 const getCenter = (canvas) => getDimensions(canvas).map((dim) => dim / 2);
  41
  42 const getRectangleDimensionsUnbound = (canvas, xScale, yScale) => {
  43     [width, height] = getDimensions(canvas);
  44     return [width * xScale, height * yScale];
  45 }
  46
  47 const getRectangleDimensions = (canvas) => getRectangleDimensionsUnbound(canvas, .5, .1);
  48
  49 /**
  50  * Draw champion box and clear background.
  51  */
  52 const drawWinner = (canvas) => {
  53     const ctx = canvas.getContext("2d");
  54     const [width, height] = getDimensions(canvas);
  55     const [mid_x, mid_y] = getCenter(canvas);
  56     const [rect_width, rect_height] = getRectangleDimensions(canvas);
  57     ctx.strokeRect(mid_x - rect_width / 2, mid_y - rect_height / 2, rect_width, rect_height);
  58     ctx.clearRect(mid_x - rect_width / 2, mid_y - rect_height / 2, rect_width, rect_height);
  59 }
  60
  61 /**
  62  * Draws a path in context from the current location to a point xDist * left, yDist * up away from it.
  63  * @param ctx RenderingContext
  64  * @param x, y float current location
  65  * @param x, y float distance away
  66  * @param up, left (-1|1) directions
  67  * @return [newNodeX, newNodeY]
  68  */
  69 const drawBranchFrom = (ctx, x, y, xDist, yDist, left, up) => {
  70     const newX = x + (xDist * left)
  71     const newY = y + (yDist * up)
  72     ctx.lineTo(x, newY);
  73     ctx.lineTo(newX, newY);
  74     ctx.stroke();
  75     return [newX, newY];
  76 }
  77
  78 const drawArtistOnCtx = (ctx, artistName, x, y) => {
  79     ctx.font = "20px sans serif";
  80     ctx.strokeText(artistName, x, y);
  81 }
  82
  83 /**
  84  * Draws paths to the terminal nodes of a round
  85  * @param x, y the point representation of the start of the branch
  86  * @param baseCallback a callback that needs the terminal x,y context
  87  */
  88 const drawMatchup = (canvas, x, y, iter, maxIter, left, artists, baseCallback) => {
  89     if (iter === maxIter) {
  90         return baseCallback(x, y);
  91     }
  92     const ctx =  canvas.getContext("2d");
  93     ctx.direction = left === -1 ? "ltr" : "rtl";
  94     const [width, height] = getDimensions(canvas);
  95
  96     const drawBranchUp = (xDist, yDist) => drawBranchFrom(ctx, x, y, xDist, yDist, left, -1);
  97     const drawBranchDown = (xDist, yDist) => drawBranchFrom(ctx, x, y, xDist, yDist, left, 1);
  98     const drawArtist = (artistName, x, y) => drawArtistOnCtx(ctx, artistName, x, y);
  99     const drawArtist1 = (x, y) => {
 100         const artist1 = artists.shift();
 101         if (!artist1) {
 102             return;
 103         }
 104         drawArtist(artist1["name"], x, y);
 105     }
 106
 107     const drawArtist2 = (x, y) => {
 108         const artist2 = artists.pop();
 109         if (!artist2) {
 110             return;
 111         }
 112         drawArtist(artist2["name"], x, y);
 113     }
 114
 115     ctx.beginPath();
 116     ctx.moveTo(x, y);
 117     const branchDistances = [width / (5 * (iter + 1)), height / (9 * (iter + 1))];
 118     drawMatchup(
 119         canvas,
 120         ...drawBranchUp(...branchDistances),
 121         iter + 1,
 122         maxIter,
 123         left,
 124         artists,
 125         drawArtist1,
 126     );
 127
 128     ctx.moveTo(x, y);
 129     drawMatchup(
 130         canvas,
 131         ...drawBranchDown(...branchDistances),
 132         iter + 1,
 133         maxIter,
 134         left,
 135         artists,
 136         drawArtist2,
 137     );
 138 }
 139
 140 const drawBracket = (canvas, artists, genre) => {
 141     const context = canvas.getContext("2d");
 142     context.clearRect(0, 0, canvas.width, canvas.height);
 143     drawWinner(canvas);
 144     const [mid_x, mid_y] = getCenter(canvas);
 145     context.font = '28px sans serif'
 146     context.textAlign = "center";
 147     context.strokeText(genre.toUpperCase(), mid_x, 40);
 148     context.textAlign = "start";
 149     const [rect_width, rect_height] = getRectangleDimensions(canvas);
 150     const groups = 4;
 151     const rounds = Math.max(
 152         Math.floor(Math.log2(artists.length / groups)),
 153         1
 154     );
 155     for (let group = 1; group <= groups; group++) {
 156         if (artists.length === 0) {
 157             break;
 158         }
 159             drawMatchup(
 160                 canvas,
 161                 mid_x + (Math.pow(-1, group) * (rect_width / 6)),
 162                 mid_y + (Math.pow(-1, Math.floor(group / 2)) * (rect_height * 2.5)),
 163                 0,
 164                 rounds,
 165                 Math.pow(-1, group),
 166                 artists,
 167                 (x, y) => console.log("hello")
 168             );
 169     }
 170 }
 171
 172 window.onload = () => {
 173     const lStorage = window.localStorage;
 174     const genreList = document.getElementById("genre-list");
 175     const genreInput = document.getElementById("genre-input");
 176     const genreForm = document.getElementById("genre-form");
 177     const canvas = document.getElementById("bracket");
 178
 179     const formSubmitAction = () => {
 180         fetch(encodeURI(`http://api.brackets.jacobcasper.com/artist/genre?genre_name=${genreInput.value}`))
 181         .then((response) => response.json())
 182         .then((data) => drawBracket(canvas, data.slice(0, 33), genreInput.value));
 183     }
 184
 185     const genreFormSubmitPolyfill = () => formSubmitPolyfill(genreList, formSubmitAction)
 186
 187     const createGenreList = (genreList, genres) => {
 188         return createGenreListWithClickEvent(genreList, genres, (e) => {
 189             genreInput.value = e.target.innerText;
 190             genreFormSubmitPolyfill()
 191         })
 192     }
 193     let genres = JSON.parse(lStorage.getItem("genres"))
 194     if (genres === null) {
 195         fetch("http://api.brackets.jacobcasper.com/genre")
 196             .then((response) => response.text())
 197             .then((text) => {
 198                 window.localStorage.setItem("genres", text);
 199                 genres = JSON.parse(text);
 200                 createGenreList(genreList, genres);
 201             });
 202     } else {
 203         createGenreList(genreList, genres);
 204     }
 205
 206     genreForm.addEventListener("submit", (e) => {
 207         e.preventDefault();
 208         formSubmitAction()
 209     });
 210
 211     genreInput.addEventListener("change", (e) => {
 212         genreFormSubmitPolyfill()
 213     });
 214
 215
 216     canvas.width = window.innerWidth;
 217     canvas.height = window.innerHeight;
 218     drawBracket(canvas, [], "");
 219
 220     const bgImg = new Image();
 221     bgImg.onload = () => {
 222         const ctx = canvas.getContext("2d");
 223         ctx.drawImage(
 224             bgImg,
 225             0,
 226             0,
 227             (canvas.width / bgImg.width) * bgImg.width,
 228             (canvas.height / bgImg.height) * bgImg.height
 229         );
 230     }
 231
 232     const upload = document.getElementById("image-upload");
 233     upload.addEventListener("change", (e) => {
 234         bgImg.src = URL.createObjectURL(e.target.files[0]);
 235     });
 236 }