"use client";

import type { ComponentProps } from "react";
import NextLink from "next/link";
import {
  ArrowRight,
  BookOpen,
  CheckCircle2,
  FileQuestion,
  FileText,
  GraduationCap,
  Layers3,
  Moon,
  Network,
  Sparkles,
  Target,
  Upload,
  Video,
} from "lucide-react";
import type { ApiDocument } from "@/lib/api/types";
import type { StudyIntent } from "@/lib/study-intents";

import { QuickActions } from "./QuickActions";
import { SelectedSourcesStrip } from "./SourceControls";
import { StudyComposer } from "./StudyComposer";
import type { StudyActionHandler } from "./types";
import { greetingForNow } from "./utils";

type EmptyStudyWorkspaceProps = {
  activeIntent: StudyIntent;
  composerProps: ComponentProps<typeof StudyComposer>;
  documents: ApiDocument[];
  heroSubtitle: string;
  heroTitle: string;
  isLoading: boolean;
  onAction: StudyActionHandler;
  onClearSources: () => void;
  onToggleSource: (sourceId: string) => void;
  onUpload?: () => void;
  selectedDocuments: ApiDocument[];
  studentName: string;
};

export function EmptyStudyWorkspace({
  activeIntent,
  composerProps,
  documents,
  heroSubtitle,
  heroTitle,
  isLoading,
  onAction,
  onClearSources,
  onToggleSource,
  onUpload,
  selectedDocuments,
  studentName,
}: EmptyStudyWorkspaceProps) {
  const readySourceCount = documents.filter((document) => document.status === "ready").length;
  const selectedSourceLabel =
    selectedDocuments.length > 0
      ? `${selectedDocuments.length} active source${selectedDocuments.length === 1 ? "" : "s"}`
      : documents.length > 0
        ? `${readySourceCount} ready source${readySourceCount === 1 ? "" : "s"}`
        : "No source selected";

  const starterPrompts: Array<{
    label: string;
    detail: string;
    intent: StudyIntent;
    prompt: string;
    icon: typeof BookOpen;
  }> = [
    {
      label: "Explain a concept",
      detail: "Definition, keywords, mark-wise structure",
      intent: "teach_topic",
      prompt: "Explain photosynthesis with exam keywords and a 4-mark answer frame",
      icon: BookOpen,
    },
    {
      label: "Scoring notes",
      detail: "Definitions, traps, revision checklist",
      intent: "generate_notes",
      prompt: "Generate exam-ready notes on chemical bonding with common mistakes",
      icon: FileText,
    },
    {
      label: "Practice quiz",
      detail: "MCQs with explanations and traps",
      intent: "generate_quiz",
      prompt: "Create a 5-question quiz on trigonometry with answer explanations",
      icon: FileQuestion,
    },
    {
      label: "Flashcards",
      detail: "Active recall with memory hooks",
      intent: "generate_flashcards",
      prompt: "Build flashcards for organic chemistry reactions and named examples",
      icon: Layers3,
    },
    {
      label: "Video plan",
      detail: "Scene script with exam focus",
      intent: "create_video_plan",
      prompt: "Create a 10-minute exam-focused study video plan for electromagnetic induction",
      icon: Video,
    },
    {
      label: "Revision plan",
      detail: "Time-blocked cram schedule",
      intent: "create_revision_plan",
      prompt: "I have one night before my physics exam. Build a focused revision plan",
      icon: Moon,
    },
  ];

  const groundingHint = selectedDocuments.length
    ? `Grounding in ${selectedDocuments[0].title}`
    : documents.length
      ? "Select a source for textbook-matched retrieval, or ask any topic."
      : "Upload material for source-grounded answers, or ask a topic directly.";

  const workspaceSignals = [
    { label: selectedSourceLabel, icon: CheckCircle2 },
    { label: "Textbook-aware answers", icon: Network },
    { label: "Exam answer practice", icon: Target },
  ];

  return (
    <div className="kb-empty-scroll min-h-0 flex-1 overflow-y-auto px-4 pb-28 pt-5 sm:px-6 lg:flex lg:items-center lg:px-8 lg:pb-10">
      <div className="mx-auto flex w-full max-w-3xl flex-col py-4 sm:py-8 lg:max-w-none lg:py-6 xl:max-w-[min(100%,56rem)]">
        <div className="kb-empty-enter lg:grid lg:grid-cols-[minmax(0,1fr)_17.5rem] lg:items-end lg:gap-8 xl:grid-cols-[minmax(0,1fr)_19rem] xl:gap-10">
          <div className="text-center lg:text-left">
            <div className="inline-flex items-center gap-2 rounded-full border border-white/[0.09] bg-white/[0.035] px-3 py-1.5 text-xs font-semibold text-white/58">
              <BookOpen className="size-3.5" />
              {greetingForNow()}, {studentName}
            </div>
            <h1 className="mt-4 text-balance text-[1.85rem] font-semibold leading-[1.08] tracking-[-0.02em] text-white sm:text-[2.35rem] lg:text-[2.75rem] xl:text-[3rem]">
              {heroTitle}
            </h1>
            <p className="mx-auto mt-3 max-w-xl text-balance text-sm leading-6 text-white/52 sm:text-[15px] lg:mx-0 lg:max-w-2xl lg:text-base">
              {heroSubtitle}
            </p>
            <div className="mt-5 hidden flex-wrap gap-2 lg:flex">
              {workspaceSignals.map((signal) => {
                const Icon = signal.icon;
                return (
                  <span
                    key={signal.label}
                    className="inline-flex min-h-8 items-center gap-2 rounded-full border border-white/[0.08] bg-white/[0.025] px-3 text-[11px] font-semibold text-white/44"
                  >
                    <Icon className="size-3.5 text-white/48" />
                    {signal.label}
                  </span>
                );
              })}
            </div>
          </div>

          <div className="mt-6 hidden rounded-[1.2rem] border border-white/[0.08] bg-white/[0.028] p-4 lg:mt-0 lg:block">
            <div className="flex items-start gap-3">
              <span className="grid size-10 shrink-0 place-items-center rounded-2xl bg-white text-black">
                <Sparkles className="size-5" />
              </span>
              <div className="min-w-0">
                <p className="text-sm font-semibold text-white">Study tools ready</p>
                <p className="mt-1 text-xs leading-5 text-white/42">{groundingHint}</p>
              </div>
            </div>
            {onUpload ? (
              <button
                type="button"
                onClick={onUpload}
                className="mt-4 inline-flex min-h-10 w-full items-center justify-center gap-2 rounded-xl border border-white/[0.1] bg-white/[0.045] px-3 text-sm font-semibold text-white/70 transition hover:border-white/[0.18] hover:text-white focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-white/22"
              >
                <Upload className="size-4" />
                Add study source
              </button>
            ) : null}
          </div>
        </div>

        <div className="kb-empty-enter kb-empty-enter-d1 mt-5">
          <NextLink
            href="/tuition"
            className="mx-auto flex min-h-12 w-full max-w-xl items-center justify-between gap-3 rounded-2xl border border-white/[0.1] bg-white/[0.04] px-4 text-left transition hover:border-white/[0.18] hover:bg-white/[0.065] focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-white/22 lg:mx-0"
          >
            <span className="flex min-w-0 items-center gap-3">
              <span className="grid size-9 shrink-0 place-items-center rounded-xl bg-white text-black">
                <GraduationCap className="size-4" aria-hidden="true" />
              </span>
              <span className="min-w-0">
                <span className="block text-sm font-bold text-white">Continue Today&apos;s Tuition</span>
                <span className="mt-0.5 block text-xs leading-5 text-white/44">
                  Study Chat is for doubts. Your official class stays in Tuition.
                </span>
              </span>
            </span>
            <ArrowRight className="size-4 shrink-0 text-white/40" aria-hidden="true" />
          </NextLink>
        </div>

        <div className="kb-empty-enter kb-empty-enter-d2 mt-7 sm:mt-8 lg:mt-8">
          <StudyComposer {...composerProps} variant="hero" />
        </div>

        <div className="kb-empty-enter kb-empty-enter-d2 mt-4 lg:hidden">
          <QuickActions activeIntent={activeIntent} disabled={isLoading} onAction={onAction} layout="scroll" />
        </div>

        <div className="kb-empty-enter kb-empty-enter-d2 mt-4 hidden lg:block xl:hidden">
          <QuickActions activeIntent={activeIntent} disabled={isLoading} onAction={onAction} layout="grid" />
        </div>

        <div className="kb-empty-enter kb-empty-enter-d3 mt-4 flex flex-wrap items-center justify-center gap-2 lg:hidden">
          {workspaceSignals.map((signal) => {
            const Icon = signal.icon;
            return (
              <span
                key={signal.label}
                className="inline-flex min-h-8 items-center gap-2 rounded-full border border-white/[0.08] bg-white/[0.025] px-3 text-[11px] font-semibold text-white/44"
              >
                <Icon className="size-3.5 text-white/48" />
                {signal.label}
              </span>
            );
          })}
        </div>

        {onUpload ? (
          <div className="kb-empty-enter kb-empty-enter-d3 mt-4 lg:hidden">
            <button
              type="button"
              onClick={onUpload}
              className="mx-auto flex min-h-10 w-full max-w-sm items-center justify-center gap-2 rounded-xl border border-white/[0.1] bg-white/[0.04] px-4 text-sm font-semibold text-white/68 transition hover:border-white/[0.18] hover:text-white focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-white/22"
            >
              <Upload className="size-4" />
              Add study source
            </button>
          </div>
        ) : null}

        <div className="kb-empty-enter kb-empty-enter-d4 mt-5 hidden min-[390px]:block">
          <SelectedSourcesStrip
            selectedDocuments={selectedDocuments}
            documents={documents}
            onToggleSource={onToggleSource}
            onClear={onClearSources}
          />
        </div>

        <div className="kb-empty-enter kb-empty-enter-d5 mt-8 lg:mt-10">
          <div className="flex items-baseline justify-between gap-3 border-b border-white/10 pb-3">
            <p className="text-[11px] font-bold uppercase tracking-[0.14em] text-white/32">Start here</p>
            <p className="hidden text-sm text-white/46 sm:block">or type your own question above</p>
          </div>

          <ol className="dd-stagger sm:columns-2 sm:gap-10">
            {starterPrompts.map((item, index) => (
              <li key={item.label} className="break-inside-avoid border-b border-white/[0.07]">
                <button
                  type="button"
                  disabled={isLoading}
                  onClick={() => onAction(item.intent, item.prompt)}
                  className="dd-press group grid w-full grid-cols-[28px_1fr_auto] items-baseline gap-3 py-3.5 text-left transition focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-white/22 disabled:cursor-not-allowed disabled:opacity-45"
                >
                  <span className="font-mono text-[11px] text-white/30 transition group-hover:text-white/60">
                    {String(index + 1).padStart(2, "0")}
                  </span>
                  <span className="min-w-0">
                    <span className="block text-sm font-semibold text-white/84 transition group-hover:text-white">
                      {item.label}
                    </span>
                    <span className="mt-0.5 block text-xs leading-5 text-white/40">{item.detail}</span>
                  </span>
                  <ArrowRight className="size-4 shrink-0 self-center text-white/20 transition group-hover:translate-x-0.5 group-hover:text-white/70" />
                </button>
              </li>
            ))}
          </ol>
        </div>
      </div>
    </div>
  );
}