"use client";

import {
  BookOpen,
  ClipboardList,
  Download,
  FileQuestion,
  Layers3,
  LoaderCircle,
  Moon,
  RefreshCw,
  ShieldCheck,
  Sparkles,
  Upload,
  Video,
} from "lucide-react";
import ReactMarkdown from "react-markdown";
import remarkGfm from "remark-gfm";
import {
  inferStudyIntentFromPrompt,
  type StudyIntent,
} from "@/lib/study-intents";
import type { StudyCard } from "./types";
import { RichStudyCard } from "./StudyCardPrimitives";
import { StagedThinkingLine } from "./StagedThinking";
import {
  ExamAnswerCard,
  ExplanationCard,
  FlashcardDeckCard,
  NotesCard,
  QuizCard,
  RevisionPlanCard,
  StudyPathCard,
  VideoPlanCard,
} from "./StudyResultCards";
import { AnswerCorrectionCard } from "./AnswerCorrectionCard";
import { DeepChapterCard, VisualLessonCard } from "./DeepChapterCards";
import { InlineVideoRender } from "./InlineVideoRender";
import { PyqAnalysisCard } from "./PyqAnalysisCard";
import { StructuredStudyResponseCard } from "./StructuredStudyResponseCard";

import { PlainAssistantMessage } from "./PlainAssistantMessage";

export { PlainAssistantMessage };

// ── Casual / welcome card ──────────────────────────────────────────────────────
function WelcomeCard({ card, onAction }: { card: Extract<StudyCard, { kind: "welcome" }>; onAction: (intent: StudyIntent, prompt: string) => void }) {
  const suggestions: Array<{ label: string; intent: StudyIntent; prompt: string; icon: typeof BookOpen }> = [
    { label: "Teach a topic", intent: "teach_topic", prompt: "Teach me ", icon: BookOpen },
    { label: "One-night plan", intent: "create_revision_plan", prompt: "I need to learn ", icon: Moon },
    { label: "Make notes", intent: "generate_notes", prompt: "Make notes on ", icon: ClipboardList },
    { label: "Quiz me", intent: "generate_quiz", prompt: "Make a quiz on ", icon: FileQuestion },
    { label: "Study video", intent: "create_video_plan", prompt: "Create a study video plan for ", icon: Video },
  ];
  return (
    <div className="animate-msg-assistant max-w-[min(48rem,100%)] rounded-[1.25rem] border border-white/[0.085] bg-white/[0.035] px-4 py-4 shadow-[0_14px_50px_rgba(0,0,0,0.2)]">
      <div className="flex items-center gap-2 mb-3">
        <span className="grid size-7 shrink-0 place-items-center rounded-xl bg-white text-black">
          <Sparkles className="size-3.5" />
        </span>
        <span className="text-[11px] font-bold uppercase tracking-[0.14em] text-white/40">Study Chat</span>
      </div>
      <div className="text-sm leading-7 text-white/76 prose-sm">
        <ReactMarkdown
          remarkPlugins={[remarkGfm]}
          components={{
            p: ({ children }) => <p className="mb-2 last:mb-0">{children}</p>,
            strong: ({ children }) => <strong className="font-semibold text-white">{children}</strong>,
          }}
        >
          {card.message}
        </ReactMarkdown>
      </div>
      <div className="mt-4 flex flex-wrap gap-2">
        {suggestions.map((s) => {
          const Icon = s.icon;
          return (
            <button
              key={s.label}
              type="button"
              onClick={() => onAction(s.intent, s.prompt)}
              className="inline-flex items-center gap-1.5 rounded-full border border-white/[0.1] bg-white/[0.04] px-3 py-1.5 text-xs font-semibold text-white/66 transition hover:border-white/[0.2] hover:text-white focus:outline-none focus-visible:ring-2 focus-visible:ring-white/22"
            >
              <Icon className="size-3.5" />
              {s.label}
            </button>
          );
        })}
      </div>
    </div>
  );
}

// ── Needs-source CTA card ──────────────────────────────────────────────────────
function NeedsSourceCard({
  card,
  onUpload,
}: {
  card: Extract<StudyCard, { kind: "needs_source" }>;
  onUpload?: () => void;
}) {
  return (
    <div className="animate-msg-assistant max-w-[min(42rem,100%)] rounded-[1.25rem] border border-white/[0.085] bg-white/[0.025] px-4 py-4 shadow-[0_14px_50px_rgba(0,0,0,0.2)]">
      <p className="text-sm leading-7 text-white/76">{card.message}</p>
      {onUpload ? (
        <button
          type="button"
          onClick={onUpload}
          className="mt-4 inline-flex items-center gap-2 rounded-xl border border-white/[0.12] bg-white/[0.05] px-4 py-2 text-sm font-semibold text-white/72 transition hover:bg-white/[0.09] hover:text-white focus:outline-none focus-visible:ring-2 focus-visible:ring-white/22"
        >
          <Upload className="size-4" />
          Upload source
        </button>
      ) : null}
    </div>
  );
}

// ── Clarify options card ───────────────────────────────────────────────────────
const CLARIFY_OPTIONS: Array<{ label: string; intent: StudyIntent; prompt: string; icon: typeof BookOpen }> = [
  { label: "Explain topic", intent: "teach_topic", prompt: "Explain ", icon: BookOpen },
  { label: "One-night plan", intent: "create_revision_plan", prompt: "I need to learn ", icon: Moon },
  { label: "Make notes", intent: "generate_notes", prompt: "Make notes on ", icon: ClipboardList },
  { label: "Quiz me", intent: "generate_quiz", prompt: "Quiz me on ", icon: FileQuestion },
  { label: "Flashcards", intent: "generate_flashcards", prompt: "Make flashcards for ", icon: Layers3 },
  { label: "Study plan", intent: "continue_learning", prompt: "Build my study plan", icon: Moon },
];

function ClarifyCard({
  onAction,
}: {
  card: Extract<StudyCard, { kind: "clarify" }>;
  onAction: (intent: StudyIntent, prompt: string) => void;
}) {
  return (
    <div className="animate-msg-assistant max-w-[min(42rem,100%)] rounded-[1.25rem] border border-white/[0.085] bg-white/[0.025] px-4 py-4 shadow-[0_14px_50px_rgba(0,0,0,0.2)]">
      <p className="text-sm leading-7 text-white/76">
        Specify the topic, exam, time left, or goal. I can work from a typed question, pasted text, or an uploaded source.
      </p>
      <div className="mt-4 flex flex-wrap gap-2">
        {CLARIFY_OPTIONS.map((opt) => {
          const Icon = opt.icon;
          return (
            <button
              key={opt.label}
              type="button"
              onClick={() => onAction(opt.intent, opt.prompt)}
              className="inline-flex items-center gap-1.5 rounded-full border border-white/[0.1] bg-white/[0.04] px-3 py-1.5 text-xs font-semibold text-white/66 transition hover:border-white/[0.2] hover:text-white focus:outline-none focus-visible:ring-2 focus-visible:ring-white/22"
            >
              <Icon className="size-3.5" />
              {opt.label}
            </button>
          );
        })}
      </div>
    </div>
  );
}

// ── Real PYQ papers card ───────────────────────────────────────────────────────
function PyqPapersCard({ card }: { card: Extract<StudyCard, { kind: "pyq_papers" }> }) {
  const data = card.data;
  const papers = (data.papers ?? []).filter((p) => p?.url);
  const years = (data.years_covered ?? []).join(", ");
  return (
    <div className="animate-msg-assistant w-full rounded-[1.25rem] border border-white/[0.085] bg-white/[0.025] p-4 shadow-[0_14px_50px_rgba(0,0,0,0.2)] sm:p-5">
      <div className="mb-3 flex items-center gap-2">
        <span className="grid size-7 shrink-0 place-items-center rounded-xl bg-white text-black">
          <FileQuestion className="size-3.5" />
        </span>
        <div>
          <p className="text-[11px] font-bold uppercase tracking-[0.14em] text-white/40">Real previous papers</p>
          <p className="text-sm font-semibold text-white">{data.board} {data.level !== "SSLC" ? data.level : ""} — actual board papers</p>
        </div>
      </div>
      <p className="mb-3 flex items-center gap-1.5 text-xs leading-5 text-emerald-300/80">
        <ShieldCheck className="size-3.5 shrink-0" />
        Verified Kerala board papers with answer keys — not AI-generated.{years ? ` Years: ${years}.` : ""}
      </p>
      <div className="space-y-2">
        {papers.map((p) => (
          <a
            key={p.url}
            href={p.url}
            target="_blank"
            rel="noreferrer noopener"
            className="group flex items-center gap-3 rounded-2xl border border-white/[0.08] bg-white/[0.025] p-3 transition hover:border-white/[0.2] hover:bg-white/[0.05] focus:outline-none focus-visible:ring-2 focus-visible:ring-white/22"
          >
            <span className="grid size-9 shrink-0 place-items-center rounded-xl border border-white/[0.08] bg-white/[0.04] text-white/60 group-hover:text-white">
              <Download className="size-4" />
            </span>
            <span className="min-w-0 flex-1">
              <span className="block text-sm font-semibold text-white/86">{p.title}</span>
              <span className="block truncate text-xs text-white/38">
                {p.source === "official" ? "Official Kerala portal" : p.source === "archive" ? "Public paper archive" : p.source}
                {p.medium ? ` · ${p.medium}` : ""}
              </span>
            </span>
          </a>
        ))}
      </div>
      <p className="mt-3 text-xs leading-5 text-white/38">{data.trust_note}</p>
    </div>
  );
}

export function StudyCardRenderer({
  card,
  onAction,
  onUpload,
  onStartRender,
}: {
  card: StudyCard;
  onAction: (intent: StudyIntent, prompt: string) => void;
  onUpload?: () => void;
  onStartRender?: (topic: string, sourceId: string | null, minutes: number) => void;
}) {
  if (card.kind === "streaming") {
    return (
      <div className="animate-msg-assistant w-full">
        <PlainAssistantMessage text={card.text} streaming />
        {card.evidenceLabel ? (
          <p className="mt-2 text-[11px] text-white/38">Basis: {card.evidenceLabel}</p>
        ) : null}
      </div>
    );
  }

  if (card.kind === "loading") {
    return (
      <RichStudyCard icon={LoaderCircle} title="DocDoe is preparing your answer" eyebrow="Reading and structuring">
        <div className="flex items-start gap-3 text-sm text-white/60">
          <span className="inline-flex items-center gap-1 pt-0.5" aria-label="DocDoe is preparing your answer">
            <span className="typing-dot" />
            <span className="typing-dot" />
            <span className="typing-dot" />
          </span>
          <StagedThinkingLine intent={card.intent} />
        </div>
      </RichStudyCard>
    );
  }

  if (card.kind === "error") {
    const variant = card.variant ?? "generic";
    const copy: Record<string, { title: string; eyebrow: string; hint: string | null }> = {
      quota: {
        title: "You've hit today's limit",
        eyebrow: "Plan limit",
        hint: "Your limit refreshes later. Upgrade your plan for more.",
      },
      daily_limit: {
        title: "Today's AI allowance is used",
        eyebrow: "Daily limit",
        hint: "Your saved classes and notes are still available.",
      },
      rate_limit: {
        title: "Going a bit fast",
        eyebrow: "Slow down",
        hint: "Wait a few seconds, then send again.",
      },
      auth: {
        title: "Session expired",
        eyebrow: "Sign in needed",
        hint: "Sign in again to pick up where you left off.",
      },
      offline: {
        title: "Request did not complete",
        eyebrow: "Study tools busy",
        hint: "This usually clears in a moment. Try again.",
      },
      generic: {
        title: "Request did not complete",
        eyebrow: "Something went wrong",
        hint: "Try again, or rephrase your request.",
      },
    };
    const { title, eyebrow, hint } = copy[variant] ?? copy.generic;
    return (
      <RichStudyCard icon={RefreshCw} title={title} eyebrow={eyebrow}>
        <p className="text-sm leading-6 text-white/68">{card.message}</p>
        {hint ? <p className="mt-2 text-xs leading-5 text-white/42">{hint}</p> : null}
        {variant === "auth" ? (
          <a
            href="/login"
            className="mt-4 inline-flex items-center gap-2 rounded-xl bg-white px-4 py-2 text-sm font-semibold text-black transition hover:bg-white/88"
          >
            Sign in
          </a>
        ) : variant === "daily_limit" ? (
          <a
            href="/classes"
            className="mt-4 inline-flex items-center gap-2 rounded-xl bg-white px-4 py-2 text-sm font-semibold text-black transition hover:bg-white/88"
          >
            Continue saved classes
          </a>
        ) : variant === "quota" ? (
          <a
            href="/pricing"
            className="mt-4 inline-flex items-center gap-2 rounded-xl border border-white/14 bg-white/[0.04] px-4 py-2 text-sm font-semibold text-white/80 transition hover:bg-white/[0.08] hover:text-white"
          >
            See plans
          </a>
        ) : (
          <button
            type="button"
            onClick={() => onAction(inferStudyIntentFromPrompt(card.prompt), card.prompt)}
            className="mt-4 inline-flex items-center gap-2 rounded-xl bg-white px-4 py-2 text-sm font-semibold text-black transition hover:bg-white/88"
          >
            Try again
            <RefreshCw className="size-4" />
          </button>
        )}
      </RichStudyCard>
    );
  }

  // ── New response-mode card kinds ──────────────────────────────────────────
  if (card.kind === "welcome") return <WelcomeCard card={card} onAction={onAction} />;
  if (card.kind === "needs_source") return <NeedsSourceCard card={card} onUpload={onUpload} />;
  if (card.kind === "clarify") return <ClarifyCard card={card} onAction={onAction} />;
  if (card.kind === "pyq_papers") return <PyqPapersCard card={card} />;

  if (card.kind === "notes") return <NotesCard card={card} onAction={onAction} />;
  if (card.kind === "quiz") return <QuizCard card={card} onAction={onAction} />;
  if (card.kind === "flashcards") return <FlashcardDeckCard card={card} onAction={onAction} />;
  if (card.kind === "exam_answer") return <ExamAnswerCard card={card} onAction={onAction} />;
  if (card.kind === "revision_plan") return <RevisionPlanCard card={card} onAction={onAction} />;
  if (card.kind === "study_path") return <StudyPathCard card={card} onAction={onAction} />;
  if (card.kind === "video_plan") return <VideoPlanCard card={card} onAction={onAction} onStartRender={onStartRender} />;
  if (card.kind === "video_render") return <InlineVideoRender topic={card.topic} sourceId={card.sourceId} minutes={card.minutes} format={card.format} />;
  if (card.kind === "answer_correction") return <AnswerCorrectionCard data={card.data} topic={card.topic} meta={card.meta} />;
  if (card.kind === "deep_chapter") return <DeepChapterCard data={card.data} topic={card.topic} />;
  if (card.kind === "structured_study_response") return <StructuredStudyResponseCard data={card.data} onAction={onAction} />;
  if (card.kind === "visual_lesson") return <VisualLessonCard data={card.data} topic={card.topic} />;
  if (card.kind === "pyq_analysis") return <PyqAnalysisCard data={card.data} topic={card.topic} meta={card.meta} onAction={onAction} />;

  return <ExplanationCard card={card} onAction={onAction} />;
}