"use client";

/**
 * ProfileHeader — Instagram-style centered header used at the top of
 * /u/me and /u/[handle]. Avatar, display name, @handle, a single stat
 * line, and an action row.
 *
 * The action row hosts:
 *   • "Edit profile" link — only on the owner's own profile (via the
 *     `editHref` prop set by /u/me layout).
 *   • Reading-settings gear — also owner-only. We use `editHref` as the
 *     "is this my profile?" signal (the /u/me layout passes it; the
 *     /u/[handle] layout does not), so the two buttons stay in lockstep
 *     and visitors on someone else's profile see a clean row with no
 *     personal-settings affordances. The gear links to /settings (the
 *     dedicated settings page) rather than opening a popover —
 *     centred-row popovers tend to spill off the left edge on narrow
 *     viewports.
 *
 * Clicking the avatar (when there's an uploaded image) opens a portal
 * modal showing the full-size image inside a circular crop. Tap the
 * backdrop or press Escape to close.
 *
 * Auth users on someone else's profile reach reading settings via the
 * sidebar rail on desktop. Anonymous visitors use SiteHeader's mobile
 * gear.
 */

import { useEffect, useState } from "react";
import { createPortal } from "react-dom";
import Image from "next/image";
import Link from "next/link";
import { Settings, X } from "lucide-react";
import { cn } from "@/lib/utils";

export function ProfileHeader({
  avatarURL,
  name,
  handle,
  postCount,
  joinedAt,
  editHref,
}: {
  avatarURL: string | null;
  name: string;
  handle: string;
  postCount?: number;
  joinedAt?: string;
  /** When provided, shows an "Edit profile" CTA below the handle AND
   *  the reading-settings gear. Acts as the canonical "this is my own
   *  profile" signal across the action row. */
  editHref?: string;
}) {
  // Both action-row affordances are owner-only and ride on the same
  // `editHref` signal — when it's absent we render no action row at
  // all, which keeps visitor profile views clean.
  const showReadingSettings = !!editHref;
  const showActions = !!editHref;

  const [zoomOpen, setZoomOpen] = useState(false);

  return (
    <>
      <header className="flex flex-col items-center text-center gap-4 pt-4 pb-6 sm:pt-6 sm:pb-8">
        <Avatar
          src={avatarURL}
          name={name}
          onZoom={avatarURL ? () => setZoomOpen(true) : undefined}
        />
        <div className="space-y-1">
          <h1 className="font-[family-name:var(--font-title)] font-semibold text-xl sm:text-2xl text-foreground leading-tight">
            {name}
          </h1>
          <p className="text-sm text-muted-foreground">@{handle}</p>
          {typeof postCount === "number" || joinedAt ? (
            <p className="text-xs text-muted-foreground">
              {typeof postCount === "number" ? (
                <>
                  <span className="tabular-nums">{postCount}</span> post
                  {postCount === 1 ? "" : "s"}
                </>
              ) : null}
              {typeof postCount === "number" && joinedAt ? " · " : null}
              {joinedAt ? <>Joined {new Date(joinedAt).toLocaleDateString()}</> : null}
            </p>
          ) : null}
        </div>
        {showActions ? (
          <div className="flex items-center gap-2">
            {editHref ? (
              <Link
                href={editHref}
                className="inline-flex items-center justify-center h-9 px-5 rounded-lg border border-border text-sm font-medium text-foreground hover:bg-muted transition-colors"
              >
                Edit profile
              </Link>
            ) : null}
            {showReadingSettings ? (
              <Link
                href="/settings"
                aria-label="Settings"
                title="Settings"
                className={cn(
                  "size-9 inline-flex items-center justify-center rounded-lg",
                  "border border-border text-foreground hover:bg-muted",
                  "transition-colors outline-none",
                  "focus-visible:ring-2 focus-visible:ring-ring",
                )}
              >
                <Settings className="size-4" />
              </Link>
            ) : null}
          </div>
        ) : null}
      </header>
      {avatarURL ? (
        <AvatarZoomModal
          src={avatarURL}
          name={name}
          open={zoomOpen}
          onClose={() => setZoomOpen(false)}
        />
      ) : null}
    </>
  );
}

function Avatar({
  src,
  name,
  onZoom,
}: {
  src: string | null;
  name: string;
  /** Provided when the avatar should be interactive — the parent shows
   *  the zoom modal on click. Omit (or pass undefined) to render the
   *  initials placeholder as a plain non-clickable element. */
  onZoom?: () => void;
}) {
  if (src) {
    return (
      <button
        type="button"
        onClick={onZoom}
        aria-label={`View ${name}'s profile picture`}
        className="rounded-full focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2"
      >
        <Image
          src={src}
          alt={name}
          width={112}
          height={112}
          className="size-24 sm:size-28 rounded-full object-cover ring-1 ring-foreground/10 hover:ring-foreground/30 transition"
          unoptimized
        />
      </button>
    );
  }
  const initials =
    name
      .split(/\s+/)
      .map((p) => p[0])
      .slice(0, 2)
      .join("")
      .toUpperCase() || "?";
  return (
    <div className="size-24 sm:size-28 rounded-full bg-primary/15 text-primary flex items-center justify-center text-3xl font-semibold ring-1 ring-foreground/10">
      {initials}
    </div>
  );
}

/**
 * AvatarZoomModal — portaled full-screen overlay with the avatar shown
 * inside a large circular crop. Click the backdrop or press Escape to
 * close. Body scroll is locked while open so the page underneath
 * doesn't jitter when the modal mounts.
 */
function AvatarZoomModal({
  src,
  name,
  open,
  onClose,
}: {
  src: string;
  name: string;
  open: boolean;
  onClose: () => void;
}) {
  useEffect(() => {
    if (!open) return;
    function onKey(e: KeyboardEvent) {
      if (e.key === "Escape") onClose();
    }
    document.addEventListener("keydown", onKey);
    return () => document.removeEventListener("keydown", onKey);
  }, [open, onClose]);

  useEffect(() => {
    if (!open) return;
    const prev = document.body.style.overflow;
    document.body.style.overflow = "hidden";
    return () => {
      document.body.style.overflow = prev;
    };
  }, [open]);

  if (!open || typeof document === "undefined") return null;

  return createPortal(
    <div
      role="dialog"
      aria-modal="true"
      aria-label={`${name}'s profile picture`}
      onClick={onClose}
      className="fixed inset-0 z-100 bg-black/80 backdrop-blur-sm flex items-center justify-center p-6 animate-in fade-in-0"
    >
      {/* Stop-propagation so clicks on the image itself don't dismiss
          the modal — only the surrounding backdrop closes. */}
      <div
        onClick={(e) => e.stopPropagation()}
        className="relative rounded-full overflow-hidden ring-1 ring-white/20 shadow-2xl"
        style={{
          // Square box capped at 80% of the smaller viewport dimension —
          // keeps the circle large but always fully visible with a
          // comfortable margin on tiny screens.
          width: "min(80vw, 80vh, 28rem)",
          height: "min(80vw, 80vh, 28rem)",
        }}
      >
        <Image
          src={src}
          alt={name}
          fill
          sizes="(max-width: 640px) 80vw, 28rem"
          className="object-cover"
          unoptimized
        />
      </div>
      <button
        type="button"
        onClick={onClose}
        aria-label="Close"
        className="fixed top-4 right-4 size-10 inline-flex items-center justify-center rounded-full bg-white/10 hover:bg-white/20 text-white transition-colors"
      >
        <X className="size-5" />
      </button>
    </div>,
    document.body,
  );
}