/**
 * TitleBar Component
 * macOS: light application toolbar with native traffic lights overlaid by the
 * full-size hidden title bar.
 * Windows: drag region with custom minimize/maximize/close controls.
 * Linux: use native window chrome (no custom title bar).
 */
import { useState, useEffect } from 'react';
import { createPortal } from 'react-dom';
import { Copy, FolderOpen, Minus, PanelLeft, PanelLeftClose, Square, X } from 'lucide-react';
import { invokeIpc } from '@/lib/api-client';
import { observeNativeFullscreen } from '@/lib/window-fullscreen';
import { cn } from '@/lib/utils';
import { useCodingWorkspaceStore } from '@/stores/coding-workspace';
import { useSettingsStore } from '@/stores/settings';
import { normalizeClassroomSidebarWidth } from '@/lib/classroom-layout';
import logoWordmarkSource from '@/assets/makelore-wordmark-source.png';
import type { SidebarPeekSource } from './sidebar-peek';
import { ModuleSwitcher } from './ModuleSwitcher';
import { getClassroomTitlebarWidth, TITLEBAR_LOGO_WIDTH, WINDOWS_TITLEBAR_CONTROLS_WIDTH } from './titlebar-metrics';

type SidebarPeekChange = (open: boolean, source: SidebarPeekSource) => void;

type TitleBarProps = {
  integrated?: boolean;
  workspaceLayout?: boolean;
  overlay?: boolean;
  showSidebarControls?: boolean;
  pageTitle?: string;
  sidebarPeekOpen?: boolean;
  onSidebarPeekChange?: SidebarPeekChange;
};

export function TitleBar({ integrated = false, workspaceLayout = false, overlay = false, showSidebarControls = true, pageTitle, sidebarPeekOpen = false, onSidebarPeekChange }: TitleBarProps) {
  const platform = window.electron?.platform;

  if (platform === 'darwin') {
    return <ProductTitleBar integrated={integrated} workspaceLayout={workspaceLayout} overlay={overlay} showSidebarControls={showSidebarControls} pageTitle={pageTitle} nativeTrafficLights sidebarPeekOpen={sidebarPeekOpen} onSidebarPeekChange={onSidebarPeekChange} />;
  }

  // Linux keeps the native frame/title bar for better IME compatibility.
  if (platform !== 'win32') {
    return null;
  }

  return <WindowsTitleBar integrated={integrated} workspaceLayout={workspaceLayout} overlay={overlay} showSidebarControls={showSidebarControls} pageTitle={pageTitle} sidebarPeekOpen={sidebarPeekOpen} onSidebarPeekChange={onSidebarPeekChange} />;
}

function ProductTitleBar({
  integrated,
  workspaceLayout = false,
  overlay = false,
  showSidebarControls = true,
  pageTitle,
  children,
  windowControlsWidth = 0,
  nativeTrafficLights = false,
  sidebarPeekOpen = false,
  onSidebarPeekChange,
}: {
  integrated: boolean;
  workspaceLayout?: boolean;
  overlay?: boolean;
  showSidebarControls?: boolean;
  pageTitle?: string;
  children?: React.ReactNode;
  windowControlsWidth?: number;
  nativeTrafficLights?: boolean;
  sidebarPeekOpen?: boolean;
  onSidebarPeekChange?: SidebarPeekChange;
}) {
  const [nativeFullscreen, setNativeFullscreen] = useState(false);
  useEffect(() => {
    if (nativeTrafficLights) return observeNativeFullscreen(setNativeFullscreen);
  }, [nativeTrafficLights]);
  const sidebarCollapsed = useSettingsStore((state) => state.sidebarCollapsed);
  const sidebarWidth = useSettingsStore((state) => normalizeClassroomSidebarWidth(state.classroomSidebarWidth));
  const classroomTitlebarWidth = getClassroomTitlebarWidth(nativeTrafficLights ? 'darwin' : 'win32', sidebarCollapsed, sidebarWidth);
  const activeProject = useCodingWorkspaceStore((state) => state.activeProject);
  const toolbarButtonClass = 'no-drag motion-press flex h-8 w-8 shrink-0 items-center justify-center rounded-md text-muted-foreground hover:bg-surface-subtle hover:text-foreground';
  const setSidebarCollapsed = useSettingsStore((state) => state.setSidebarCollapsed);
  const toggleSidebar = () => setSidebarCollapsed(!sidebarCollapsed);
  const handleSidebarPeekEnter = (source: SidebarPeekSource) => {
    if (sidebarCollapsed) onSidebarPeekChange?.(true, source);
  };
  const handleSidebarPeekLeave = (source: SidebarPeekSource) => {
    if (sidebarCollapsed) onSidebarPeekChange?.(false, source);
  };
  // The project sidebar preview is rendered below the title bar, so mirror
  // its full width in the title bar for ordinary pages. The chat workspace
  // keeps project conversations in the sidebar and must preserve its title rail.
  const sidebarPreviewTitlebarVisible = sidebarCollapsed && sidebarPeekOpen && !workspaceLayout && !overlay;
  const sidebarTitlebarHidden = sidebarCollapsed && !sidebarPreviewTitlebarVisible;
  const sidebarToggle = (
    <button
      type="button"
      data-testid="titlebar-sidebar-toggle"
      aria-label={sidebarCollapsed ? (sidebarPeekOpen ? '固定侧栏' : '展开侧栏') : '折叠侧栏'}
      aria-expanded={!sidebarCollapsed || sidebarPeekOpen}
      title={sidebarCollapsed ? (sidebarPeekOpen ? '固定侧栏' : '展开侧栏') : '折叠侧栏'}
      className={cn(
        toolbarButtonClass,
        'pointer-events-auto absolute top-1 z-[401]',
        workspaceLayout ? 'right-2' : nativeTrafficLights ? 'left-[88px]' : 'left-2',
      )}
      onClick={toggleSidebar}
      onPointerEnter={() => handleSidebarPeekEnter('toggle')}
      onPointerLeave={() => handleSidebarPeekLeave('toggle')}
      onFocus={!workspaceLayout ? () => handleSidebarPeekEnter('focus') : undefined}
      onBlur={!workspaceLayout ? () => handleSidebarPeekLeave('focus') : undefined}
    >
      {sidebarCollapsed ? <PanelLeft className="h-4 w-4" /> : <PanelLeftClose className="h-4 w-4" />}
    </button>
  );
  const sidebarTogglePortal = (
    <div
      data-testid="titlebar-sidebar-toggle-layer"
      className={cn(
        'no-drag pointer-events-auto fixed left-0 top-0 z-[400] h-10',
        !workspaceLayout && (nativeTrafficLights ? 'w-[132px]' : 'w-[52px]'),
      )}
      style={workspaceLayout ? { width: classroomTitlebarWidth } : undefined}
      onPointerEnter={workspaceLayout ? () => handleSidebarPeekEnter('titlebar') : undefined}
      onPointerLeave={workspaceLayout ? () => handleSidebarPeekLeave('titlebar') : undefined}
      onFocusCapture={workspaceLayout ? () => handleSidebarPeekEnter('focus') : undefined}
      onBlurCapture={workspaceLayout ? (event) => {
        if (!event.currentTarget.contains(event.relatedTarget as Node | null)) handleSidebarPeekLeave('focus');
      } : undefined}
    >
      {workspaceLayout ? <div
        data-testid="classroom-titlebar-navigation"
        className={cn('flex h-full items-center gap-2 pr-12', nativeTrafficLights && !nativeFullscreen ? 'pl-[88px]' : 'pl-3')}
      >
        <ModuleSwitcher sidebarCollapsed={false} toolbar iconOnly />
        {sidebarToggle}
      </div> : sidebarToggle}
    </div>
  );
  const titlebarLogo = (
    <div
      data-testid="titlebar-logo"
      className={cn(
        'pointer-events-none absolute top-1/2 z-10 h-6 -translate-y-1/2 overflow-hidden',
        overlay ? 'bg-transparent' : 'bg-background',
      )}
      style={{
        width: TITLEBAR_LOGO_WIDTH,
        right: `${windowControlsWidth}px`,
      }}
    >
      <img
        src={logoWordmarkSource}
        alt="Makelore logo"
        data-logo-variant="wordmark"
        data-logo-source="original-wordmark"
        className="h-full w-full object-cover object-center mix-blend-multiply"
      />
    </div>
  );

  return (
    <div
      data-testid="product-titlebar"
      className={cn(
        overlay ? 'absolute' : 'relative',
        'z-30 flex h-10 shrink-0 text-foreground',
        overlay && 'pointer-events-none inset-x-0 top-0 z-[300] bg-transparent',
        (!nativeTrafficLights || !integrated) && 'drag-region',
        !workspaceLayout && !overlay && 'glass-surface',
        integrated && !overlay && (workspaceLayout ? 'bg-transparent' : sidebarTitlebarHidden ? 'bg-background' : 'bg-background/70'),
        integrated && !overlay && sidebarTitlebarHidden && !workspaceLayout && 'border-b border-border/80',
      )}
    >
      {integrated && showSidebarControls ? (
        <>
          <div
            data-testid="titlebar-sidebar-surface"
            style={workspaceLayout ? { width: classroomTitlebarWidth, minWidth: classroomTitlebarWidth, flexBasis: classroomTitlebarWidth } : undefined}
            className={cn(
              'flex h-full shrink-0 items-center gap-1 px-2',
              workspaceLayout
                ? ''
                : sidebarTitlebarHidden
                ? nativeTrafficLights
                  ? 'w-[132px]'
                  : 'w-[52px]'
                : 'w-64',
              overlay
                ? 'pointer-events-none border-r-0 bg-transparent'
                : sidebarTitlebarHidden
                  ? 'border-r-0 bg-background'
                  : cn(
                    sidebarPreviewTitlebarVisible ? 'sidebar-peek-surface' : 'sidebar-glass-surface',
                    'border-r border-border/80',
                  ),
              nativeTrafficLights && 'pl-[88px]',
            )}
            onPointerEnter={sidebarPreviewTitlebarVisible ? () => handleSidebarPeekEnter('titlebar') : undefined}
            onPointerLeave={sidebarPreviewTitlebarVisible ? () => handleSidebarPeekLeave('titlebar') : undefined}
          />
          {typeof document !== 'undefined' ? createPortal(sidebarTogglePortal, document.body) : sidebarTogglePortal}
        </>
      ) : null}
      {integrated ? (
        <div
          data-testid="titlebar-main-surface"
          className={cn(
            'relative flex min-w-0 flex-1 bg-background',
            overlay && 'pointer-events-none border-b-0 bg-transparent',
            nativeTrafficLights && 'drag-region',
            !overlay && (workspaceLayout || sidebarTitlebarHidden ? 'border-b-0' : 'border-b border-border/80'),
          )}
          style={{
            marginRight: 'var(--agent-browser-panel-width, 0px)',
          }}
        >
          {pageTitle ? (
            <h1
              data-testid="titlebar-page-title"
              className="flex min-w-0 flex-1 items-center truncate px-3 text-sm font-semibold tracking-[-0.02em]"
            >
              {pageTitle}
            </h1>
          ) : !workspaceLayout && !overlay ? (
            <div
              data-testid="titlebar-project-context"
              className={cn(
                'flex min-w-0 flex-1 items-center gap-2 px-3',
              )}
            >
              <FolderOpen className="h-4 w-4 shrink-0 text-muted-foreground" aria-hidden="true" />
              <span className="truncate text-sm font-semibold">{activeProject?.name ?? 'Makelore 工作台'}</span>
            </div>
          ) : null}
          {!overlay && !workspaceLayout ? titlebarLogo : null}
          <div
            className={cn(
              'no-drag absolute inset-y-0 right-0 z-10 flex items-center justify-end gap-1 px-2',
              overlay && 'pointer-events-auto',
            )}
            style={windowControlsWidth ? { width: `${windowControlsWidth}px` } : undefined}
          >
            {children}
          </div>
        </div>
      ) : (
        <div className="flex min-w-0 flex-1 items-center justify-end gap-1 px-2">{children}</div>
      )}
      {integrated && overlay && (nativeTrafficLights || showSidebarControls) ? titlebarLogo : null}
    </div>
  );
}

function WindowsTitleBar({ integrated, workspaceLayout, overlay, showSidebarControls, pageTitle, sidebarPeekOpen, onSidebarPeekChange }: Omit<TitleBarProps, 'integrated'> & { integrated: boolean }) {
  const [maximized, setMaximized] = useState(false);

  useEffect(() => {
    // Check initial state
    invokeIpc('window:isMaximized').then((val) => {
      setMaximized(val as boolean);
    });
  }, []);

  const handleMinimize = () => {
    invokeIpc('window:minimize');
  };

  const handleMaximize = () => {
    invokeIpc('window:maximize').then(() => {
      invokeIpc('window:isMaximized').then((val) => {
        setMaximized(val as boolean);
      });
    });
  };

  const handleClose = () => {
    invokeIpc('window:close');
  };

  return (
    <ProductTitleBar
      integrated={integrated}
      workspaceLayout={workspaceLayout}
      overlay={overlay}
      showSidebarControls={showSidebarControls}
      pageTitle={pageTitle}
      windowControlsWidth={WINDOWS_TITLEBAR_CONTROLS_WIDTH}
      sidebarPeekOpen={sidebarPeekOpen}
      onSidebarPeekChange={onSidebarPeekChange}
    >
      <div className="no-drag pointer-events-auto flex h-full">
        <button
          onClick={handleMinimize}
          className="motion-press flex h-full w-11 items-center justify-center text-muted-foreground hover:bg-surface-subtle"
          title="Minimize"
        >
          <Minus className="h-4 w-4" />
        </button>
        <button
          onClick={handleMaximize}
          className="motion-press flex h-full w-11 items-center justify-center text-muted-foreground hover:bg-surface-subtle"
          title={maximized ? 'Restore' : 'Maximize'}
        >
          {maximized ? <Copy className="h-3.5 w-3.5" /> : <Square className="h-3.5 w-3.5" />}
        </button>
        <button
          onClick={handleClose}
          className="motion-press flex h-full w-11 items-center justify-center text-muted-foreground hover:bg-accent hover:text-primary-foreground"
          title="Close"
        >
          <X className="h-4 w-4" />
        </button>
      </div>
    </ProductTitleBar>
  );
}