"use client";

import type { ReactNode } from "react";
import { Menu, ArrowLeft, Plus, Search, X } from "@/components/icons";
import { Button } from "@/components/ui/button";
import { IconButton } from "@/components/ui/icon-button";
import { useUIStore } from "@/stores/ui-store";
import { useShallow } from "zustand/react/shallow";
import { useSettingsStore } from "@/stores/settings-store";
import { useIsDesktop } from "@/hooks/use-media-query";
import { cn } from "@/lib/utils";
import { useTranslations } from "next-intl";
import { AccountSwitcher } from "@/components/layout/account-switcher";
import { PhoneHeaderMenu } from "@/components/layout/phone-header-actions";

interface MobileHeaderProps {
  title: string;
  showBack?: boolean;
  onBack?: () => void;
  onCompose?: () => void;
  onSearch?: () => void;
  className?: string;
  /** Id of the sidebar this header's menu button toggles. */
  sidebarId?: string;
  /**
   * When set, the mailbox title is replaced by a tappable search field and
   * this fires instead. The folder name stays visible in the drawer, so the
   * bar spends its width on the thing you act on rather than a label.
   */
  onOpenSearch?: () => void;
  /** Placeholder shown inside the search field. */
  searchPlaceholder?: string;
  /** Clears the active query without opening the search panel. */
  onClearSearch?: () => void;
  /** Whether a query is currently applied, which reveals the clear button. */
  searchActive?: boolean;
  /** Mountain View: opens the merged across-accounts inbox from the avatar's popover. */
  onSelectAllInboxes?: () => void;
  allInboxesSelected?: boolean;
  /** The app's entries at the top of the ⋮ menu; `close` shuts the menu. */
  menuItems?: (close: () => void) => ReactNode;
}

export function MobileHeader({
  title,
  showBack = false,
  onBack,
  onCompose,
  onSearch,
  className,
  sidebarId,
  onOpenSearch,
  searchPlaceholder,
  onClearSearch,
  searchActive = false,
  onSelectAllInboxes,
  allInboxesSelected = false,
  menuItems,
}: MobileHeaderProps) {
  const t = useTranslations('sidebar');
  const { toggleSidebar, goBack, sidebarOpen } = useUIStore(useShallow((state) => ({ toggleSidebar: state.toggleSidebar, goBack: state.goBack, sidebarOpen: state.sidebarOpen })));
  const mountainView = useSettingsStore((state) => state.interfaceLayout === 'mountain-view');
  // Pane-aware: in Pro split mode the viewport is desktop-wide while the
  // pane is narrow. The Tailwind `lg:hidden` variant alone would never fire
  // there, so we additionally hide via JS when the surrounding pane is
  // desktop-sized. Outside of Pro this still returns the viewport value.
  const isPaneDesktop = useIsDesktop();
  if (isPaneDesktop) return null;

  const handleLeftAction = () => {
    if (showBack && onBack) {
      onBack();
    } else if (showBack) {
      goBack();
    } else {
      toggleSidebar();
    }
  };

  return (
    <header
      data-mobile-mail-header=""
      className={cn(
        "flex items-center justify-between h-14 shrink-0",
        mountainView
          ? "mx-2 mt-2 mb-1 rounded-full border-0 bg-muted px-2 shadow-sm"
          : "border-b border-border bg-background px-4",
        className
      )}
    >
      {/* Left action: Menu or Back button */}
      <div className="flex items-center gap-2 min-w-0 flex-shrink-0">
        <Button
          variant="ghost"
          size="icon"
          onClick={handleLeftAction}
          className={cn(
            "h-11 w-11",
            !showBack && sidebarOpen && "bg-accent"
          )}
          data-sidebar-toggle={!showBack ? "" : undefined}
          aria-label={showBack ? t('mobile.go_back') : t('mobile.toggle_menu')}
          aria-expanded={!showBack ? sidebarOpen : undefined}
          aria-controls={!showBack ? sidebarId : undefined}
        >
          {showBack ? (
            <ArrowLeft className="h-5 w-5" />
          ) : sidebarOpen ? (
            <X className="h-5 w-5" />
          ) : (
            <Menu className="h-5 w-5" />
          )}
        </Button>

        {/* Title, unless the bar is in search-first mode */}
        {/* Not a heading: the app's h1 already names the folder ("Inbox – Mail"). */}
        {!onOpenSearch && <div className="font-semibold text-lg truncate">{title}</div>}
      </div>

      {onOpenSearch && (
        /* Not a single button: the clear control is a button of its own, and
           nesting one inside another is invalid markup. */
        <div
          data-mobile-mail-search=""
          data-tour="search-input"
          className={cn(
            "flex-1 min-w-0 h-10 flex items-center rounded-full pe-1",
            mountainView ? "mx-0 bg-transparent ps-2" : "mx-1 bg-muted ps-3"
          )}
        >
          <button
            type="button"
            onClick={onOpenSearch}
            className="flex-1 min-w-0 h-full flex items-center gap-2 text-start text-muted-foreground"
            aria-label={searchPlaceholder || title}
          >
            <Search className="h-4 w-4 flex-shrink-0" />
            <span className="truncate text-sm">{searchPlaceholder || title}</span>
          </button>
          {searchActive && onClearSearch && (
            <IconButton
              onClick={onClearSearch}
              className="flex-shrink-0 rounded-full text-muted-foreground hover:bg-background/60"
              label={t('clear_search')}
            >
              <X />
            </IconButton>
          )}
        </div>
      )}

      {/* Right actions */}
      <div className="flex items-center gap-1 flex-shrink-0">
        {onSearch && (
          <Button
            variant="ghost"
            size="icon"
            onClick={onSearch}
            className="h-11 w-11"
            aria-label={t('mobile.search')}
          >
            <Search className="h-5 w-5" />
          </Button>
        )}
        {onCompose && (
          <Button
            variant="ghost"
            size="icon"
            onClick={onCompose}
            className="h-11 w-11 text-primary"
            aria-label={t('mobile.compose')}
          >
            <Plus className="h-5 w-5" />
          </Button>
        )}

        <PhoneHeaderMenu menuItems={menuItems} />

        {/* Which account you are reading is otherwise only visible after
            opening the drawer. Last in this group so it sits on the far
            edge — opposite the menu button, and mirrored under RTL because
            the header is laid out with flex rather than fixed sides. */}
        <AccountSwitcher
          variant="header"
          onSelectAllInboxes={onSelectAllInboxes}
          allInboxesSelected={allInboxesSelected}
        />
      </div>
    </header>
  );
}