// bracket-lines.js
// Draws smooth SVG bezier connector lines between series cards in a playoff bracket.
// Lines connect from the bottom-center of a source card to the top-center of a
// destination card. Winner paths are solid green, loser paths are dashed red.
//
// Usage: Add data-bracket-lines to a container element. Inside, series cards
// should have data-series="N" attributes. The container needs a data-connections
// attribute with a JSON array of connection objects:
//   [{"from": 1, "to": 3, "type": "winner"}, ...]
//
// Optional toSide field ("left" or "right") makes the line arrive at the
// left or right edge (vertically centered) of the destination card instead
// of the top-center.
//
// An SVG element with data-bracket-svg inside the container is used for drawing.

(function () {
  var WINNER_COLOR = "var(--green)";
  var LOSER_COLOR = "var(--red)";
  var STROKE_WIDTH = 2;
  var DASH_ARRAY = "6 3";

  // Curvature control: how far the control points extend
  // as a fraction of the total distance between cards
  var CURVE_FACTOR = 0.4;

  function drawBracketLines(container) {
    var svg = container.querySelector("[data-bracket-svg]");
    if (!svg) return;

    var connectionsAttr = container.getAttribute("data-connections");
    if (!connectionsAttr) return;

    var connections;
    try {
      connections = JSON.parse(connectionsAttr);
    } catch (e) {
      return;
    }

    // Clear existing paths
    while (svg.firstChild) {
      svg.removeChild(svg.firstChild);
    }

    // Get container position for relative coordinates
    var containerRect = container.getBoundingClientRect();

    // Size SVG to match container
    svg.setAttribute("width", containerRect.width);
    svg.setAttribute("height", containerRect.height);

    connections.forEach(function (conn) {
      var fromCard = container.querySelector(
        '[data-series="' + conn.from + '"]',
      );
      var toCard = container.querySelector('[data-series="' + conn.to + '"]');
      if (!fromCard || !toCard) return;

      var fromRect = fromCard.getBoundingClientRect();
      var toRect = toCard.getBoundingClientRect();

      // Start: bottom-center of source card
      var x1 = fromRect.left + fromRect.width / 2 - containerRect.left;
      var y1 = fromRect.bottom - containerRect.top;

      var x2, y2, d;

      if (conn.toSide === "left") {
        // End: left edge, vertically centered
        x2 = toRect.left - containerRect.left;
        y2 = toRect.top + toRect.height / 2 - containerRect.top;

        // Bezier: go down first, then curve into the left side
        var dy = y2 - y1;
        var dx = x2 - x1;
        d =
          "M " + x1 + " " + y1 +
          " C " + x1 + " " + (y1 + dy * 0.5) +
          ", " + (x2 + dx * 0.2) + " " + y2 +
          ", " + x2 + " " + y2;
      } else if (conn.toSide === "right") {
        // End: right edge, vertically centered
        x2 = toRect.right - containerRect.left;
        y2 = toRect.top + toRect.height / 2 - containerRect.top;

        // Bezier: go down first, then curve into the right side
        var dy = y2 - y1;
        var dx = x2 - x1;
        d =
          "M " + x1 + " " + y1 +
          " C " + x1 + " " + (y1 + dy * 0.5) +
          ", " + (x2 + dx * 0.2) + " " + y2 +
          ", " + x2 + " " + y2;
      } else {
        // Default: end at top-center of destination card
        x2 = toRect.left + toRect.width / 2 - containerRect.left;
        y2 = toRect.top - containerRect.top;

        var dy = y2 - y1;
        d =
          "M " + x1 + " " + y1 +
          " C " + x1 + " " + (y1 + dy * CURVE_FACTOR) +
          ", " + x2 + " " + (y2 - dy * CURVE_FACTOR) +
          ", " + x2 + " " + y2;
      }

      var path = document.createElementNS("http://www.w3.org/2000/svg", "path");
      path.setAttribute("d", d);
      path.setAttribute("fill", "none");
      path.setAttribute("stroke-width", STROKE_WIDTH);

      if (conn.type === "winner") {
        path.setAttribute("stroke", WINNER_COLOR);
      } else {
        path.setAttribute("stroke", LOSER_COLOR);
        path.setAttribute("stroke-dasharray", DASH_ARRAY);
      }

      svg.appendChild(path);
    });
  }

  function drawAllBrackets() {
    var containers = document.querySelectorAll("[data-bracket-lines]");
    containers.forEach(drawBracketLines);
  }

  // Draw on initial load
  if (document.readyState === "loading") {
    document.addEventListener("DOMContentLoaded", drawAllBrackets);
  } else {
    // DOM already loaded (e.g. script loaded via HTMX swap)
    drawAllBrackets();
  }

  // Redraw on window resize (debounced)
  var resizeTimer;
  window.addEventListener("resize", function () {
    clearTimeout(resizeTimer);
    resizeTimer = setTimeout(drawAllBrackets, 100);
  });

  // Redraw after HTMX swaps
  document.addEventListener("htmx:afterSwap", function () {
    // Small delay to let the DOM settle
    setTimeout(drawAllBrackets, 50);
  });

  // Expose for manual triggering if needed
  window.drawBracketLines = drawAllBrackets;
})();