"use client";

import type { ReactNode, MouseEvent } from "react";
import { Fragment } from "react";
import { Tabs, TabsList, TabsTrigger } from "@kandev/ui/tabs";

export type SessionTab = {
  id: string;
  label: string;
  icon?: ReactNode;
  /** Optional badge rendered before the label — e.g. "#3" for an ordinary terminal. */
  badge?: ReactNode;
  closable?: boolean;
  alwaysShowClose?: boolean;
  onClose?: (event: MouseEvent) => void;
  onContextMenu?: (event: MouseEvent) => void;
  onDoubleClick?: (event: MouseEvent) => void;
  className?: string;
  testId?: string;
  closeTestId?: string;
  /** When true (default) keeps the existing 120px max-width; ordinary terminals with custom names benefit from `false`. */
  truncate?: boolean;
};

type SessionTabsProps = {
  children?: ReactNode; // TabsContent elements (optional for cases where tabs are just visible)
  tabs: SessionTab[];
  activeTab: string;
  onTabChange: (tabId: string) => void;
  showAddButton?: boolean;
  onAddTab?: () => void;
  addButtonLabel?: string;
  separatorAfterIndex?: number;
  className?: string;
  /** Overrides the default `TabsList` className — use to drop the pill background, etc. */
  listClassName?: string;
  // Collapse support
  collapsible?: boolean;
  isCollapsed?: boolean;
  onToggleCollapse?: () => void;
  // Right content (e.g., approve button)
  rightContent?: ReactNode;
};

const SVG_PROPS = {
  xmlns: "http://www.w3.org/2000/svg",
  viewBox: "0 0 24 24",
  fill: "none",
  stroke: "currentColor",
  strokeWidth: "2",
  strokeLinecap: "round" as const,
  strokeLinejoin: "round" as const,
};

function CloseIcon() {
  return (
    <svg className="h-3 w-3" {...SVG_PROPS}>
      <line x1="18" y1="6" x2="6" y2="18" />
      <line x1="6" y1="6" x2="18" y2="18" />
    </svg>
  );
}

function CollapseIcon({ isCollapsed }: { isCollapsed: boolean }) {
  return (
    <svg className="h-4 w-4" {...SVG_PROPS}>
      {isCollapsed ? <polyline points="18 15 12 9 6 15" /> : <polyline points="6 9 12 15 18 9" />}
    </svg>
  );
}

function SessionTabItem({
  tab,
  index,
  separatorAfterIndex,
}: {
  tab: SessionTab;
  index: number;
  separatorAfterIndex?: number;
}) {
  return (
    <Fragment key={tab.id}>
      {separatorAfterIndex !== undefined && index === separatorAfterIndex + 1 && (
        <div className="h-4 w-px bg-border mx-1" />
      )}
      <TabsTrigger
        value={tab.id}
        data-testid={tab.testId}
        onContextMenu={tab.onContextMenu}
        onDoubleClick={tab.onDoubleClick}
        className={
          (tab.className ?? "") +
          " group relative py-1 cursor-pointer rounded-sm " +
          (tab.truncate === false ? "max-w-[200px]" : "max-w-[120px]")
        }
      >
        {tab.icon}
        {tab.badge && (
          <span
            data-testid={`${tab.testId ?? tab.id}-seq-badge`}
            className="mr-1 inline-flex items-center justify-center rounded-sm bg-muted text-muted-foreground text-[10px] font-mono leading-none px-1 py-0.5"
          >
            {tab.badge}
          </span>
        )}
        <span className={`truncate ${tab.icon ? "ml-1.5" : ""}`} style={{ textOverflow: "clip" }}>
          {tab.label}
        </span>
        {tab.closable && tab.onClose && (
          <span
            role="button"
            tabIndex={-1}
            data-testid={tab.closeTestId}
            className={`absolute right-1 rounded bg-background hover:bg-muted hover:text-foreground text-muted-foreground transition-opacity ${tab.alwaysShowClose ? "opacity-100" : "opacity-0 group-hover:opacity-100"}`}
            onClick={tab.onClose}
          >
            <CloseIcon />
          </span>
        )}
      </TabsTrigger>
    </Fragment>
  );
}

function SessionTabsHeader({
  tabsList,
  collapsible,
  isCollapsed,
  onToggleCollapse,
  rightContent,
  hasChildren,
}: {
  tabsList: ReactNode;
  collapsible: boolean;
  isCollapsed: boolean;
  onToggleCollapse?: () => void;
  rightContent?: ReactNode;
  hasChildren: boolean;
}) {
  if (collapsible && onToggleCollapse) {
    return (
      <div className={`flex items-center justify-between gap-2 ${hasChildren ? "" : "p-2"}`}>
        {tabsList}
        <div className="flex items-center gap-2 shrink-0">
          {rightContent}
          <button
            type="button"
            className="text-muted-foreground hover:text-foreground cursor-pointer"
            onClick={onToggleCollapse}
          >
            <CollapseIcon isCollapsed={isCollapsed} />
          </button>
        </div>
      </div>
    );
  }
  if (rightContent) {
    return (
      <div className="flex items-center justify-between gap-2">
        {tabsList}
        <div className="shrink-0">{rightContent}</div>
      </div>
    );
  }
  return <>{tabsList}</>;
}

export function SessionTabs({
  children,
  tabs,
  activeTab,
  onTabChange,
  showAddButton = false,
  onAddTab,
  addButtonLabel = "+",
  separatorAfterIndex,
  className,
  listClassName,
  collapsible = false,
  isCollapsed = false,
  onToggleCollapse,
  rightContent,
}: SessionTabsProps) {
  const defaultListClassName =
    "p-0 !h-7 rounded-sm overflow-x-auto overflow-y-hidden min-w-0 shrink [&::-webkit-scrollbar]:hidden [-ms-overflow-style:none] [scrollbar-width:none]";
  const tabsList = (
    <TabsList className={listClassName ?? defaultListClassName}>
      {tabs.map((tab, index) => (
        <SessionTabItem
          key={tab.id}
          tab={tab}
          index={index}
          separatorAfterIndex={separatorAfterIndex}
        />
      ))}
      {showAddButton && onAddTab && (
        <button
          type="button"
          onClick={onAddTab}
          className="inline-flex items-center justify-center whitespace-nowrap rounded-sm px-2 py-1 h-6 text-sm ring-offset-background focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 cursor-pointer hover:bg-muted"
        >
          {addButtonLabel}
        </button>
      )}
    </TabsList>
  );
  return (
    <Tabs value={activeTab} onValueChange={onTabChange} className={className}>
      <SessionTabsHeader
        tabsList={tabsList}
        collapsible={collapsible}
        isCollapsed={isCollapsed}
        onToggleCollapse={onToggleCollapse}
        rightContent={rightContent}
        hasChildren={Boolean(children)}
      />
      {children}
    </Tabs>
  );
}