"use client";

import { useEffect, useRef, useState, Suspense } from "react";
import { cn } from "@/lib/utils";
import NextLink from "next/link";
import { useSearchParams } from "next/navigation";
import { GraduationCap } from "lucide-react";
import { useAuth } from "@/lib/auth/useAuth";
import { normalizeStudyIntent } from "@/lib/study-intents";
import { MainWorkspace } from "./MainWorkspace";
import { MobileDrawerContent } from "./MobileDrawerContent";
import {
  LeftWorkspaceRail,
  MobileBottomNav,
  MobilePanelDrawer,
  SourceRail,
} from "./WorkspacePanels";
import { RightPanelTabs } from "./RightPanelTabs";
import type { MobilePanel, StudyChatShellProps } from "./types";
import { useStudyConversation } from "./useStudyConversation";
import { useStudySources } from "./useStudySources";
import { useStudyUploads } from "./useStudyUploads";
import { useWorkspaceResources } from "./useWorkspaceResources";
import { firstName } from "./utils";
import { SourceClassificationModal } from "./SourceClassificationModal";
import { MATERIAL_UPLOAD_ACCEPT, PDF_UPLOAD_ACCEPT } from "@/lib/uploads/document-upload-contract";

function StudyChatShellInner({
  initialIntent = "teach_topic",
  title,
  subtitle,
  hideLeftRail = false,
}: StudyChatShellProps) {
  const searchParams = useSearchParams();
  const { user } = useAuth();
  const queryIntent = normalizeStudyIntent(searchParams.get("intent") ?? initialIntent);
  const queryPrompt = searchParams.get("prompt");
  const querySourceId = searchParams.get("sourceId");
  const runOnOpen = searchParams.get("run") === "1";

  const [workspaceSearch, setWorkspaceSearch] = useState("");
  const [plusOpen, setPlusOpen] = useState(false);
  const [mobilePanel, setMobilePanel] = useState<MobilePanel>(null);
  const materialInputRef = useRef<HTMLInputElement | null>(null);
  const paperInputRef = useRef<HTMLInputElement | null>(null);

  const {
    documents,
    documentsLoading,
    selectedSourceIds,
    selectedDocuments,
    sourceSearch,
    setSourceSearch,
    setSelectedSourceIds,
    refreshSources,
    toggleSource,
    clearSelectedSources,
    upsertAndSelectDocument,
  } = useStudySources(querySourceId);
  const { dashboard, videoJobs } = useWorkspaceResources();

  const {
    activeIntent,
    chatNotice,
    chatSessions,
    input,
    isHistoryLoading,
    isLoading,
    messages,
    newChat,
    openSession,
    runAction,
    startVideoRender,
    setInput,
    setMessages,
    submit,
    threadEndRef,
  } = useStudyConversation({
    closeMobilePanel: () => setMobilePanel(null),
    closePlusMenu: () => setPlusOpen(false),
    documents,
    queryIntent,
    queryPrompt,
    querySourceId,
    runOnOpen,
    selectedDocuments,
    selectedSourceIds,
    setSelectedSourceIds,
    user,
  });
  const {
    sourceDraftMode,
    setSourceDraftMode,
    draftTitle,
    setDraftTitle,
    draftText,
    setDraftText,
    isSavingDraft,
    isUploading,
    uploadNotice,
    canRetryUpload,
    retryUpload,
    handleMaterialFile,
    handlePaperFile,
    saveDraftSource,
    classificationModal,
    openClassificationModal,
    closeClassificationModal,
    handleClassificationComplete,
  } = useStudyUploads({
    documents,
    selectedDocuments,
    setMessages,
    refreshSources,
    upsertAndSelectDocument,
  });

  const studentName = firstName(user?.name);
  const promptPlaceholder = "Ask anything...";
  const heroTitle = title ?? "How can I help you today?";
  const heroSubtitle = subtitle ?? "Ask anything, upload a readable PDF, or use the video plugin.";

  useEffect(() => {
    function onKeyDown(event: KeyboardEvent) {
      if (event.key === "Escape") {
        setPlusOpen(false);
        setMobilePanel(null);
      }
    }
    window.addEventListener("keydown", onKeyDown);
    return () => window.removeEventListener("keydown", onKeyDown);
  }, []);

  const composerProps = {
    value: input,
    onChange: setInput,
    onSubmit: () => void submit(),
    placeholder: promptPlaceholder,
    disabled: isLoading,
    selectedDocuments,
    onRemoveSource: toggleSource,
    onMaterialFile: (file: File) => void handleMaterialFile(file),
    onOpenMaterialPicker: () => materialInputRef.current?.click(),
    onOpenPaperPicker: () => paperInputRef.current?.click(),
    sourceDraftMode,
    onSourceDraftModeChange: setSourceDraftMode,
    draftTitle,
    onDraftTitleChange: setDraftTitle,
    draftText,
    onDraftTextChange: setDraftText,
    onSaveDraftSource: () => void saveDraftSource(),
    isSavingDraft,
    isUploading,
    uploadNotice: uploadNotice || chatNotice,
    onRetryUpload: canRetryUpload ? retryUpload : undefined,
    plusOpen,
    onPlusOpenChange: setPlusOpen,
  };

  const sourceRail = (
    <SourceRail
      documents={documents}
      selectedSourceIds={selectedSourceIds}
      isLoading={documentsLoading}
      search={sourceSearch}
      onSearchChange={setSourceSearch}
      onToggleSource={toggleSource}
      onUpload={() => materialInputRef.current?.click()}
      onEditClassification={openClassificationModal}
    />
  );

  const rightPanel = (
    <RightPanelTabs
      documents={documents}
      selectedDocuments={selectedDocuments}
      messages={messages}
      dashboard={dashboard}
      videoJobs={videoJobs}
      onAction={runAction}
      onUpload={() => materialInputRef.current?.click()}
      onMaterialFile={(file) => void handleMaterialFile(file)}
    />
  );

  return (
    <section className="kb-workspace relative h-full min-h-0 overflow-hidden bg-[#030303] text-white">
      <NextLink
        href="/tuition"
        className="absolute right-4 top-4 z-30 hidden min-h-9 items-center gap-2 rounded-xl border border-white/[0.1] bg-[#080808]/90 px-3 text-xs font-bold text-white/72 shadow-lg backdrop-blur transition hover:border-white/[0.18] hover:text-white focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-white/24 lg:inline-flex"
      >
        <GraduationCap className="size-3.5" aria-hidden="true" />
        Today&apos;s Tuition
      </NextLink>

      <input
        id="study-material-file-input"
        name="study-material-file"
        ref={materialInputRef}
        type="file"
        accept={MATERIAL_UPLOAD_ACCEPT}
        className="hidden"
        onChange={(event) => {
          const file = event.target.files?.[0];
          event.target.value = "";
          if (file) void handleMaterialFile(file);
        }}
      />
      <input
        id="study-paper-file-input"
        name="study-paper-file"
        ref={paperInputRef}
        type="file"
        accept={PDF_UPLOAD_ACCEPT}
        className="hidden"
        onChange={(event) => {
          const file = event.target.files?.[0];
          event.target.value = "";
          if (file) void handlePaperFile(file);
        }}
      />

      <div className={cn(
        "relative z-10 grid h-full min-h-0",
        hideLeftRail
          ? "grid-cols-1 xl:grid-cols-[minmax(0,1fr)_260px]"
          : "grid-cols-1 lg:grid-cols-[220px_minmax(0,1fr)] xl:grid-cols-[220px_minmax(0,1fr)_260px]",
      )}>
        {hideLeftRail ? null : <LeftWorkspaceRail
          documents={documents}
          sessions={chatSessions}
          selectedSourceIds={selectedSourceIds}
          search={workspaceSearch}
          onSearchChange={setWorkspaceSearch}
          onNewChat={newChat}
          onOpenSession={(sessionId) => void openSession(sessionId)}
          onToggleSource={toggleSource}
          onUpload={() => materialInputRef.current?.click()}
          isHistoryLoading={isHistoryLoading}
        />}

        <MainWorkspace
          activeIntent={activeIntent}
          composerProps={composerProps}
          documents={documents}
          heroSubtitle={heroSubtitle}
          heroTitle={heroTitle}
          isLoading={isLoading}
          messages={messages}
          onAction={runAction}
          onClearSources={clearSelectedSources}
          onNewChat={newChat}
          onOpenProfile={() => setMobilePanel("profile")}
          onOpenSources={() => setMobilePanel("sources")}
          onStartRender={startVideoRender}
          onToggleSource={toggleSource}
          onUpload={() => materialInputRef.current?.click()}
          selectedDocuments={selectedDocuments}
          studentName={studentName}
          threadEndRef={threadEndRef}
        />

        {rightPanel}
      </div>

      <MobilePanelDrawer panel={mobilePanel} onClose={() => setMobilePanel(null)}>
        <MobileDrawerContent
          activeIntent={activeIntent}
          dashboard={dashboard}
          isLoading={isLoading}
          messages={messages}
          onAction={runAction}
          panel={mobilePanel}
          sourceRail={sourceRail}
          userName={user?.name ?? "Student"}
          videoJobs={videoJobs}
        />
      </MobilePanelDrawer>

      <MobileBottomNav
        activePanel={mobilePanel}
        onOpenPanel={(panel) => setMobilePanel(panel)}
        onClosePanels={() => setMobilePanel(null)}
      />

      <SourceClassificationModal
        isOpen={classificationModal.isOpen}
        onClose={closeClassificationModal}
        documentId={classificationModal.documentId ?? ""}
        documentTitle={classificationModal.documentTitle}
        currentMaterialType={classificationModal.currentMaterialType}
        autoDetectedType={classificationModal.autoDetectedType}
        onClassificationComplete={handleClassificationComplete}
      />
    </section>
  );
}

export function StudyChatShell({
  mode = "home",
  initialIntent = "teach_topic",
  title,
  subtitle,
  hideLeftRail = false,
}: StudyChatShellProps) {
  return (
    <Suspense fallback={
      <div className="flex min-h-screen items-center justify-center">
        <div className="text-white/50">Loading Study Chat...</div>
      </div>
    }>
      <StudyChatShellInner 
        mode={mode}
        initialIntent={initialIntent}
        title={title}
        subtitle={subtitle}
        hideLeftRail={hideLeftRail}
      />
    </Suspense>
  );
}