"use client";

import type { ComponentProps, RefObject } from "react";
import { LoaderCircle, Plus } from "lucide-react";
import type { ApiDocument } from "@/lib/api/types";
import { studyIntentConfig, type StudyIntent } from "@/lib/study-intents";
import { cn } from "@/lib/utils";
import { QuickActions } from "./QuickActions";
import { StagedThinkingLine } from "./StagedThinking";
import { SelectedSourcesStrip } from "./SourceControls";
import { PlainAssistantMessage, StudyCardRenderer } from "./StudyCards";
import { StudyComposer } from "./StudyComposer";
import type { ChatMessage, StudyActionHandler } from "./types";

type ConversationWorkspaceProps = {
  activeIntent: StudyIntent;
  composerProps: ComponentProps<typeof StudyComposer>;
  documents: ApiDocument[];
  isLoading: boolean;
  messages: ChatMessage[];
  onAction: StudyActionHandler;
  onClearSources: () => void;
  onNewChat: () => void;
  onStartRender?: (topic: string, sourceId: string | null, minutes: number) => void;
  onToggleSource: (sourceId: string) => void;
  onUpload?: () => void;
  selectedDocuments: ApiDocument[];
  threadEndRef: RefObject<HTMLDivElement | null>;
};

export function ConversationWorkspace({
  activeIntent,
  composerProps,
  documents,
  isLoading,
  messages,
  onAction,
  onClearSources,
  onNewChat,
  onStartRender,
  onToggleSource,
  onUpload,
  selectedDocuments,
  threadEndRef,
}: ConversationWorkspaceProps) {
  const intentLabel = studyIntentConfig[activeIntent].shortLabel ?? studyIntentConfig[activeIntent].label;
  const lastMessage = messages[messages.length - 1];
  const showTypingIndicator =
    isLoading && (!lastMessage || lastMessage.role !== "assistant" || !lastMessage.card || lastMessage.card.kind !== "loading");

  return (
    <>
      <div className="kb-thread-scroll min-h-0 flex-1 overflow-y-auto px-4 pb-6 pt-4 sm:px-6 lg:px-8">
        <div className="mx-auto w-full max-w-4xl xl:max-w-[min(100%,52rem)]">
          <div className="mb-5 flex flex-wrap items-center justify-between gap-3">
            <div className="min-w-0">
              <p className="text-[11px] font-bold uppercase tracking-[0.14em] text-white/32">Study Chat</p>
              <div className="mt-1 flex flex-wrap items-center gap-2">
                <h1 className="text-lg font-semibold text-white sm:text-xl">Study session</h1>
                <span className="inline-flex items-center rounded-full border border-white/[0.1] bg-white/[0.04] px-2.5 py-1 text-[11px] font-semibold text-white/52">
                  {intentLabel}
                </span>
              </div>
            </div>
            <button
              type="button"
              onClick={onNewChat}
              className="inline-flex min-h-10 items-center gap-2 rounded-xl border border-white/[0.1] bg-white/[0.035] px-3 text-sm font-semibold text-white/62 transition hover:border-white/[0.18] hover:bg-white/[0.05] hover:text-white focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-white/22"
            >
              <Plus className="size-4" />
              New chat
            </button>
          </div>

          <SelectedSourcesStrip
            selectedDocuments={selectedDocuments}
            documents={documents}
            onToggleSource={onToggleSource}
            onClear={onClearSources}
          />

          <ConversationThread
            messages={messages}
            onAction={onAction}
            onUpload={onUpload}
            onStartRender={onStartRender}
            showTypingIndicator={showTypingIndicator}
            activeIntent={activeIntent}
            threadEndRef={threadEndRef}
          />
        </div>
      </div>

      <div className="kb-composer-dock relative shrink-0 border-t border-white/[0.075] bg-[#030303]/92 p-3 pb-[calc(5rem+env(safe-area-inset-bottom))] backdrop-blur-xl lg:p-4 lg:pb-4">
        <div className="pointer-events-none absolute inset-x-0 -top-8 h-8 bg-gradient-to-t from-[#030303] to-transparent" aria-hidden="true" />
        <div className="mx-auto w-full max-w-4xl xl:max-w-[min(100%,52rem)]">
          <StudyComposer {...composerProps} compact />
          <div className="mt-3 hidden lg:block">
            <QuickActions activeIntent={activeIntent} disabled={isLoading} onAction={onAction} layout="grid" />
          </div>
        </div>
      </div>
    </>
  );
}

function ConversationThread({
  messages,
  onAction,
  onUpload,
  onStartRender,
  showTypingIndicator,
  activeIntent,
  threadEndRef,
}: {
  messages: ChatMessage[];
  onAction: StudyActionHandler;
  onUpload?: () => void;
  onStartRender?: (topic: string, sourceId: string | null, minutes: number) => void;
  showTypingIndicator: boolean;
  activeIntent: StudyIntent;
  threadEndRef: RefObject<HTMLDivElement | null>;
}) {
  return (
    <div className="mt-5 space-y-6">
      {messages.map((message) => (
        <div key={message.id} className={cn("flex", message.role === "user" ? "justify-end" : "justify-start")}>
          {message.role === "user" ? (
            <div className="animate-msg-user max-w-[min(42rem,88vw)] rounded-[1.15rem] border border-white/[0.09] bg-white px-4 py-3 text-sm leading-6 text-black shadow-[0_14px_40px_rgba(0,0,0,0.24)]">
              {message.text}
            </div>
          ) : message.card ? (
            <div className="w-full">
              <StudyCardRenderer card={message.card} onAction={onAction} onUpload={onUpload} onStartRender={onStartRender} />
            </div>
          ) : (
            <PlainAssistantMessage text={message.text} />
          )}
        </div>
      ))}

      {showTypingIndicator ? <TypingIndicator intent={activeIntent} /> : null}
      <div ref={threadEndRef} />
    </div>
  );
}

function TypingIndicator({ intent }: { intent: StudyIntent }) {
  return (
    <div className="flex justify-start">
      <div
        className="animate-msg-assistant inline-flex items-center gap-3 rounded-[1.15rem] border border-white/[0.08] bg-white/[0.03] px-4 py-3 text-sm text-white/52"
        aria-live="polite"
        aria-label="DocDoe is preparing your answer"
      >
        <LoaderCircle className="size-4 shrink-0 animate-spin text-white/42" />
        <span className="inline-flex items-center gap-1">
          <span className="typing-dot" />
          <span className="typing-dot" />
          <span className="typing-dot" />
        </span>
        <StagedThinkingLine intent={intent} />
      </div>
    </div>
  );
}