// PayToLaugh front end.
//
// NOTE ON THE TOKEN BELOW: it is public by construction. A static page cannot
// keep a secret, so the endpoint behind it is built to be safe in public
// hands. It reads and writes small records only and cannot spend money.
// Script and video generation are deliberately NOT reachable from here.
//
// NOTE ON "LOGIN": an email address identifies you, it does not authenticate
// you. Anyone who knows an address can see that account. Temporary, by
// agreement, until real auth lands.

var API = "https://api.corben.world/functions/da0474ea-4e56-405c-9f0d-35c3e4037a69/invoke"
        + "?token=97cd624cd2bd6a74eb692a940e71851f";

var PHOTO_KINDS = ["head shot", "profile", "full body", "sitting",
                   "playing", "sleeping", "action", "other"];
// A plate is built from a head-on shot; these are the ones worth having.
var REFERENCE_KINDS = ["head shot", "profile", "full body"];

async function api(action, payload) {
  var body = Object.assign({ action: action }, payload || {});
  var res;
  try {
    res = await fetch(API, {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify(body)
    });
  } catch (e) {
    return { ok: false, error: "Could not reach the server. Check your connection and try again." };
  }
  var outer;
  try { outer = await res.json(); }
  catch (e) { return { ok: false, error: "The server sent something unreadable." }; }
  return outer && outer.result ? outer.result : outer;
}

var Session = {
  key: "ptl_email",
  nameKey: "ptl_name",
  get: function () { try { return localStorage.getItem(this.key); } catch (e) { return null; } },
  name: function () { try { return localStorage.getItem(this.nameKey) || ""; } catch (e) { return ""; } },
  set: function (email, name) {
    try {
      localStorage.setItem(this.key, email);
      if (name) localStorage.setItem(this.nameKey, name);
    } catch (e) {}
  },
  clear: function () {
    try { localStorage.removeItem(this.key); localStorage.removeItem(this.nameKey); } catch (e) {}
  }
};

function esc(s) {
  return String(s == null ? "" : s).replace(/[&<>\"']/g, function (c) {
    return { "&": "&amp;", "<": "&lt;", ">": "&gt;", '\"': "&quot;", "'": "&#39;" }[c];
  });
}

function navBar(current) {
  var email = Session.get();
  var links = [["/", "Home", "home"], ["/pets.html", "My pets", "pets"],
               ["/create.html", "New video", "create"], ["/videos.html", "My videos", "videos"]];
  var html = '<nav><div class="inner">'
    + '<a class="brand" href="/">Pay<span>To</span>Laugh</a>'
    + links.map(function (l) {
        return '<a class="link' + (l[2] === current ? ' on' : '') + '" href="' + l[0] + '">' + l[1] + '</a>';
      }).join("")
    + '<div class="who">'
    + (email
        ? esc(email) + ' <button type="button" id="ptl-signout">Sign out</button>'
        : '<a class="link" href="/register.html">Sign in</a>')
    + '</div></div></nav>';
  document.body.insertAdjacentHTML("afterbegin", html);
  var b = document.getElementById("ptl-signout");
  if (b) b.onclick = function () { Session.clear(); location.href = "/register.html"; };
}

function requireSession() {
  var e = Session.get();
  if (!e) { location.href = "/register.html?next=" + encodeURIComponent(location.pathname); return null; }
  return e;
}

function showMsg(id, text, kind) {
  var el = document.getElementById(id);
  if (!el) return;
  el.className = "msg " + (kind || "err");
  el.textContent = text;
}
function hideMsg(id) {
  var el = document.getElementById(id);
  if (el) el.className = "msg";
}

// Mirrors the server's arithmetic exactly: $0.40 per 8s clip plus $0.17 for
// script and plate, at a 5x markup. If one changes, change both.
function priceFor(segments) {
  var cost = segments * 0.40 + 0.17;
  return { cost: cost, price: Math.round(cost * 5 * 100) / 100, seconds: segments * 8 };
}

// Shrink in the browser before upload. Phone photos run to 5-10MB, which is
// slow to send and far more detail than a reference plate needs; 1600px is
// ample. Returns base64 without the data: prefix.
function resizeImage(file, maxPx, quality) {
  maxPx = maxPx || 1600;
  quality = quality || 0.85;
  return new Promise(function (resolve, reject) {
    var reader = new FileReader();
    reader.onerror = function () { reject(new Error("Could not read that file.")); };
    reader.onload = function () {
      var img = new Image();
      img.onerror = function () { reject(new Error("That file is not an image we can read.")); };
      img.onload = function () {
        var w = img.naturalWidth, h = img.naturalHeight;
        if (!w || !h) { reject(new Error("That image looks empty.")); return; }
        var scale = Math.min(1, maxPx / Math.max(w, h));
        var cw = Math.round(w * scale), ch = Math.round(h * scale);
        var c = document.createElement("canvas");
        c.width = cw; c.height = ch;
        var g = c.getContext("2d");
        g.fillStyle = "#ffffff";
        g.fillRect(0, 0, cw, ch);          // flatten transparency for JPEG
        g.drawImage(img, 0, 0, cw, ch);
        var url;
        try { url = c.toDataURL("image/jpeg", quality); }
        catch (e) { reject(new Error("That image could not be processed.")); return; }
        resolve({ b64: url.split(",")[1], width: cw, height: ch });
      };
      img.src = reader.result;
    };
    reader.readAsDataURL(file);
  });
}