// Adapted from agentui (https://github.com/ashish200729/agentui), components/agents/message.tsx + message-context.tsx
// Copyright (c) 2026 Saurabh Chauhan. MIT License, see ./LICENSE-agentui.md
// 改造:motion.article 的弹簧入场换成 tw-animate 的 animate-in(duration-base / ease-pop,motion-reduce 关闭);
// 头像底色、字号(text-label / text-meta)、圆角换语义 token;新增 from="system" 行(居中提示,用于压缩/中止等系统消息);
// MessageTyping 三点动画用 animate-pulse + 具名时长的 animation-delay。
import { type ComponentPropsWithRef, createContext, useContext } from "react";
import { cn } from "~/lib/utils.ts";

export type MessageFrom = "user" | "assistant" | "system";
export type MessageSide = "start" | "end";

export const MessageSideContext = createContext<MessageSide | undefined>(undefined);
const MessageContext = createContext<{ from: MessageFrom }>({ from: "assistant" });

export interface MessageProps extends ComponentPropsWithRef<"article"> {
  from: MessageFrom;
  /** 挂载时播一次入场(新到达的消息用;回放历史时不播) */
  animateIn?: boolean;
}

const FROM_LABEL: Record<MessageFrom, string> = { user: "用户消息", assistant: "智能体消息", system: "系统消息" };

export function Message({ from, animateIn = false, className, children, ...props }: MessageProps) {
  return (
    <MessageSideContext.Provider value={from === "user" ? "end" : "start"}>
      <MessageContext.Provider value={{ from }}>
        <article
          data-slot="message"
          data-from={from}
          aria-label={props["aria-label"] ?? FROM_LABEL[from]}
          {...props}
          className={cn(
            "group/message flex w-full min-w-0 items-start gap-2.5",
            from === "user" ? "flex-row-reverse" : "flex-row",
            animateIn &&
              "animate-in fade-in-0 slide-in-from-bottom-1 duration-base ease-pop motion-reduce:animate-none",
            className,
          )}
        >
          {children}
        </article>
      </MessageContext.Provider>
    </MessageSideContext.Provider>
  );
}

export function MessageGroup({
  spacing = "default",
  className,
  ...props
}: ComponentPropsWithRef<"div"> & { spacing?: "compact" | "default" }) {
  return (
    <div
      data-slot="message-group"
      className={cn("flex w-full flex-col", spacing === "compact" ? "gap-1.5" : "gap-4", className)}
      {...props}
    />
  );
}

export function MessageAvatar({
  placeholder = false,
  className,
  ...props
}: ComponentPropsWithRef<"div"> & { placeholder?: boolean }) {
  return (
    <div
      data-slot="message-avatar"
      aria-hidden
      className={cn(
        "mt-0.5 grid size-7 shrink-0 place-items-center overflow-hidden rounded-full bg-foreground/[0.06] text-meta font-medium text-muted-foreground [&_svg]:size-3.5",
        placeholder && "invisible",
        className,
      )}
      {...props}
    />
  );
}

export function MessageContent({ className, ...props }: ComponentPropsWithRef<"div">) {
  const { from } = useContext(MessageContext);
  return (
    <div
      data-slot="message-content"
      className={cn("flex min-w-0 flex-1 flex-col gap-1.5", from === "user" ? "items-end" : "items-start", className)}
      {...props}
    />
  );
}

export function MessageHeader({ className, ...props }: ComponentPropsWithRef<"div">) {
  const { from } = useContext(MessageContext);
  return (
    <div
      data-slot="message-header"
      className={cn(
        "flex items-center gap-1.5 px-1 text-label leading-none text-muted-foreground",
        from === "user" ? "justify-end" : "justify-start",
        className,
      )}
      {...props}
    />
  );
}

export function MessageFooter({ className, ...props }: ComponentPropsWithRef<"div">) {
  const { from } = useContext(MessageContext);
  return (
    <div
      data-slot="message-footer"
      className={cn(
        "flex min-h-5 items-center gap-1 px-1 text-label text-muted-foreground",
        from === "user" ? "justify-end" : "justify-start",
        className,
      )}
      {...props}
    />
  );
}

/** 居中的系统提示条(上下文压缩、续跑等) */
export function MessageMarker({ className, ...props }: ComponentPropsWithRef<"div">) {
  return (
    <div
      data-slot="message-marker"
      role="note"
      className={cn(
        "mx-auto flex w-fit max-w-[88%] items-center gap-1.5 rounded-full border border-border/60 bg-foreground/[0.04] px-2.5 py-1 text-center text-meta text-muted-foreground",
        className,
      )}
      {...props}
    />
  );
}

const DOT_DELAY = ["", "[animation-delay:var(--duration-micro)]", "[animation-delay:var(--duration-layout)]"];

export function MessageTyping({
  label = "正在回复",
  className,
  ...props
}: ComponentPropsWithRef<"span"> & { label?: string }) {
  return (
    <span data-slot="message-typing" className={cn("inline-flex h-5 items-center gap-1", className)} {...props}>
      <span className="sr-only">{label}</span>
      {DOT_DELAY.map((d, i) => (
        <span
          key={i}
          aria-hidden
          className={cn("size-1 rounded-full bg-current opacity-60 animate-pulse motion-reduce:animate-none", d)}
        />
      ))}
    </span>
  );
}