import { useState } from 'react';
import { Clipboard, Code, History, MessageSquare, Terminal, X } from 'lucide-react';
import type { WorkspacePane, WorkspaceTabKind } from '@/api/types';
import { StatusDot } from '@/components/StatusDot';
import { PaneHeaderActions } from '@/components/PaneHeaderActions';
import {
  ContextMenu,
  ContextMenuContent,
  ContextMenuItem,
  ContextMenuSeparator,
  ContextMenuTrigger,
} from '@/components/ui/context-menu';
import { useLongPress } from '@/hooks/useLongPress';
import { sessionEvents } from '@/hooks/sessionEvents';
import { cn } from '@/lib/utils';

// Mixed tabs: a pane can hold tabs of different kinds. Each tab is described by
// its id, kind, and label (terminal tabs have no chats row, so their label is
// supplied by the caller).
export interface TabDescriptor {
  id: string;
  kind: WorkspaceTabKind;
  name: string | null;
}

interface Props {
  pane: WorkspacePane;
  tabs: TabDescriptor[];
  // v2.6.x (Batch 3a): stable session-scoped tab number per id.
  tabNumbers: Record<string, number>;
  onSwitchTab: (tabIdx: number) => void;
  onRemoveTab: (id: string) => void;
  onCloseOthers: (id: string) => void;
  onCloseToRight: (id: string) => void;
  onCloseAll: () => void;
  // Mixed tabs: the "+" adds a tab of the chosen kind to THIS pane.
  onNewTab: (kind: WorkspaceTabKind) => void;
  onSplitPane: (kind: 'chat' | 'terminal' | 'coder') => void;
  onReopenPane?: () => void;
  onShowHistory: () => void;
  onRename: (chatId: string, name: string) => Promise<void>;
  onRemovePane?: () => void;
  // iOS-safe terminal paste, shown only when the active tab is a terminal.
  onTerminalPaste?: () => void;
}

function iconForKind(kind: WorkspaceTabKind) {
  if (kind === 'coder') return Code;
  if (kind === 'terminal') return Terminal;
  return MessageSquare;
}

function defaultName(kind: WorkspaceTabKind): string {
  if (kind === 'coder') return 'BooCoder';
  if (kind === 'terminal') return 'Terminal';
  return 'New chat';
}

export function ChatTabBar({
  pane,
  tabs,
  tabNumbers,
  onSwitchTab,
  onRemoveTab,
  onCloseOthers,
  onCloseToRight,
  onCloseAll,
  onNewTab,
  onSplitPane,
  onReopenPane,
  onShowHistory,
  onRename,
  onRemovePane,
  onTerminalPaste,
}: Props) {
  const [renamingId, setRenamingId] = useState<string | null>(null);
  const [renameValue, setRenameValue] = useState('');

  // Long-press: dispatch a synthetic contextmenu event on the tab so the
  // existing Radix ContextMenuTrigger opens at the touch coordinates.
  const longPress = useLongPress(({ clientX, clientY, target }) => {
    if (!target || !(target instanceof Element)) return;
    const tab = target.closest('[data-tab-id]') as HTMLElement | null;
    if (!tab) return;
    tab.dispatchEvent(
      new MouseEvent('contextmenu', { bubbles: true, cancelable: true, clientX, clientY }),
    );
  });

  function startRename(id: string, currentName: string | null) {
    setRenamingId(id);
    setRenameValue(currentName ?? '');
  }

  async function finishRename() {
    if (renamingId && renameValue.trim()) {
      await onRename(renamingId, renameValue.trim());
    }
    setRenamingId(null);
  }

  return (
    <div className="flex items-center border-b border-border bg-muted/20 h-8 shrink-0 overflow-x-auto max-md:hidden">
      {tabs.map((tab, tabIdx) => {
        const isActive = tabIdx === pane.activeChatIdx;
        const isLast = tabIdx === tabs.length - 1;
        const onlyTab = tabs.length === 1;
        const TabIcon = iconForKind(tab.kind);
        const label = tab.name ?? defaultName(tab.kind);
        const canRename = tab.kind !== 'terminal';
        const tabNumber = tabNumbers[tab.id];
        return (
          <ContextMenu key={tab.id}>
            <ContextMenuTrigger asChild>
              <div
                data-tab-id={tab.id}
                onClick={() => onSwitchTab(tabIdx)}
                onTouchStart={longPress.onTouchStart}
                onTouchMove={longPress.onTouchMove}
                onTouchEnd={longPress.onTouchEnd}
                onTouchCancel={longPress.onTouchCancel}
                style={{ WebkitTouchCallout: 'none' }}
                className={cn(
                  'group flex items-center gap-1.5 px-3 py-1.5 text-xs border-r border-border cursor-default select-none shrink-0',
                  isActive
                    ? 'bg-background text-foreground'
                    : 'bg-muted/30 text-muted-foreground hover:bg-muted/60'
                )}
              >
                <TabIcon size={12} className="shrink-0" />
                {tab.kind !== 'terminal' && <StatusDot chatId={tab.id} />}
                {renamingId === tab.id ? (
                  <input
                    autoFocus
                    value={renameValue}
                    onChange={(e) => setRenameValue(e.target.value)}
                    onBlur={() => void finishRename()}
                    onKeyDown={(e) => {
                      if (e.key === 'Enter') void finishRename();
                      if (e.key === 'Escape') setRenamingId(null);
                    }}
                    onClick={(e) => e.stopPropagation()}
                    className="bg-transparent border-b border-border text-xs outline-none w-28"
                  />
                ) : (
                  <span
                    className="truncate max-w-[140px]"
                    title={tabNumber !== undefined ? `${tabNumber} · ${label}` : label}
                  >
                    {tabNumber !== undefined ? `${tabNumber} · ${label}` : label}
                  </span>
                )}
                <button
                  type="button"
                  onClick={(e) => {
                    e.stopPropagation();
                    onRemoveTab(tab.id);
                  }}
                  className="inline-flex items-center justify-center p-0.5 hover:bg-muted rounded opacity-0 group-hover:opacity-60 hover:!opacity-100 shrink-0 max-md:min-h-[44px] max-md:min-w-[44px] max-md:opacity-100"
                  aria-label="Close tab"
                >
                  <X size={10} />
                </button>
              </div>
            </ContextMenuTrigger>
            <ContextMenuContent>
              <ContextMenuItem onSelect={() => onNewTab(tab.kind)}>
                New {defaultName(tab.kind)}
              </ContextMenuItem>
              {tab.kind !== 'terminal' && (
                <ContextMenuItem
                  onSelect={() =>
                    sessionEvents.emit({ type: 'open_chat_in_new_pane', chat_id: tab.id })
                  }
                >
                  Open in new pane
                </ContextMenuItem>
              )}
              {canRename && (
                <>
                  <ContextMenuSeparator />
                  <ContextMenuItem onSelect={() => startRename(tab.id, tab.name)}>
                    Rename
                  </ContextMenuItem>
                </>
              )}
              <ContextMenuSeparator />
              <ContextMenuItem onSelect={() => onRemoveTab(tab.id)}>
                Close
              </ContextMenuItem>
              <ContextMenuItem disabled={onlyTab} onSelect={() => onCloseOthers(tab.id)}>
                Close others
              </ContextMenuItem>
              <ContextMenuItem disabled={isLast} onSelect={() => onCloseToRight(tab.id)}>
                Close to right
              </ContextMenuItem>
              <ContextMenuItem onSelect={() => onCloseAll()}>
                Close all
              </ContextMenuItem>
            </ContextMenuContent>
          </ContextMenu>
        );
      })}

      {tabs.length === 0 && (
        <div className="flex items-center gap-1.5 px-3 py-1.5 text-xs text-muted-foreground">
          <History size={12} className="shrink-0" />
          <span>Session</span>
        </div>
      )}

      <div className="ml-auto flex items-center px-1 shrink-0">
        {onTerminalPaste && (
          <button
            type="button"
            onClick={(e) => {
              e.stopPropagation();
              onTerminalPaste();
            }}
            className="inline-flex items-center justify-center p-1 rounded text-muted-foreground hover:bg-muted hover:text-foreground"
            aria-label="Paste from clipboard"
            title="Paste from clipboard"
          >
            <Clipboard size={12} />
          </button>
        )}
        <PaneHeaderActions
          onNewTab={onNewTab}
          onSplitPane={onSplitPane}
          onReopenPane={onReopenPane}
          onShowHistory={onShowHistory}
          onRemovePane={onRemovePane}
          historyActive={pane.kind === 'empty'}
        />
      </div>
    </div>
  );
}