import { useState, useEffect, useRef } from "react";
import { Document, AuthUser, SyncLog, TeamMember } from "../types";
import { INITIAL_DOCUMENTS, INITIAL_TEAM_MEMBERS } from "../data";
import { DEFAULT_VALUES } from "../config";

export function useWorkspaceState() {
  // Core Document State
  const [documents, setDocuments] = useState<Document[]>(() => {
    const cached = localStorage.getItem("workspace_documents");
    return cached ? JSON.parse(cached) : INITIAL_DOCUMENTS;
  });
  const [activeDocId, setActiveDocId] = useState<string>("");

  const activeDoc =
    documents.find((d) => d.id === activeDocId) || documents[0] || INITIAL_DOCUMENTS[0];

  const [editorText, setEditorText] = useState(activeDoc.content);

  // Sync state & Offline detection
  const [isOnline, setIsOnline] = useState(navigator.onLine);
  const [syncStatus, setSyncStatus] = useState<"synced" | "syncing" | "offline" | "error">("synced");
  const [syncLogs, setSyncLogs] = useState<SyncLog[]>([]);

  // Auth — no hardcoded credentials
  const [user, setUser] = useState<AuthUser>(() => {
    const cached = localStorage.getItem("workspace_user");
    return cached
      ? JSON.parse(cached)
      : {
          email: null,
          displayName: null,
          isLoggedIn: false,
          tier: DEFAULT_VALUES.TIER,
          privateKeySeed: "",
        };
  });

  // Team
  const [teamMembers, setTeamMembers] = useState<TeamMember[]>(INITIAL_TEAM_MEMBERS);
  const [teamChangesEnabled, setTeamChangesEnabled] = useState(true);
  const [activeCollaborators, setActiveCollaborators] = useState(1);

  // Toast
  const [toast, setToast] = useState<{
    show: boolean;
    message: string;
    timestamp: string;
  }>({ show: false, message: "", timestamp: "" });

  // Form states
  const [showDocModal, setShowDocModal] = useState(false);
  const [newDocTitle, setNewDocTitle] = useState("");
  const [documentSearchTerm, setDocumentSearchTerm] = useState("");
  const [uploadFile, setUploadFile] = useState<File | null>(null);
  const [uploadLoading, setUploadLoading] = useState(false);
  const [uploadError, setUploadError] = useState<string | null>(null);

  // Admin
  const [adminPassword, setAdminPassword] = useState("");
  const [isAdminLoggedIn, setIsAdminLoggedIn] = useState(false);
  const [adminVerifyLoading] = useState(false);

  // Analytics
  const [tokensConsumed, setTokensConsumed] = useState(0);

  // Other UI state
  const [showVersionHistory, setShowVersionHistory] = useState(false);
  const [isReadingMode, setIsReadingMode] = useState(false);
  const [showExportPreview, setShowExportPreview] = useState(false);
  const [exportPreviewFormat, setExportPreviewFormat] = useState<"markdown" | "pdf" | "html">("pdf");
  const [showPreferenceModal, setShowPreferenceModal] = useState(false);
  const [showShareModal, setShowShareModal] = useState(false);
  const [isSidebarOpen, setIsSidebarOpen] = useState(true);
  const [copiedDoc, setCopiedDoc] = useState(false);
  const [showStatsPopover, setShowStatsPopover] = useState(false);
  const [leftPanelMode, setLeftPanelMode] = useState<"edit" | "preview" | "folding">("edit");
  const [foldedBlockIds, setFoldedBlockIds] = useState<Record<string, boolean>>({});

  // Refs
  const saveTimeoutRef = useRef<NodeJS.Timeout | null>(null);
  const isFirstLocalStorageSave = useRef(true);

  // Load editor text when active doc changes
  useEffect(() => {
    setEditorText(activeDoc.content);
  }, [activeDoc.id]); // eslint-disable-line react-hooks/exhaustive-deps

  // Parse shared links on mount
  useEffect(() => {
    const urlStr = window.location.href;
    const match = urlStr.match(/\/share\/doc\/([^/?#]+)/);
    if (match) {
      const docId = match[1];
      // Fetch the real document from the server
      import("../lib/apiClient").then(({ getDocument }) => {
        getDocument(docId)
          .then((serverDoc) => {
            const docExists = documents.some((d) => d.id === docId);
            if (!docExists) {
              const loadedDoc: Document = {
                id: serverDoc.id,
                title: serverDoc.title,
                content: serverDoc.content,
                version: serverDoc.version,
                lastSaved: serverDoc.lastSaved,
                isSynced: true
              };
              setDocuments((prev) => [loadedDoc, ...prev]);
            }
            setActiveDocId(docId);
            setIsReadingMode(true);
            addLog(`Shared document loaded successfully.`, "success");
          })
          .catch(() => {
            addLog(`Shared document not found on server.`, "error");
          });
      });
    }
  }, []); // eslint-disable-line react-hooks/exhaustive-deps

  // Load or generate device UUID, and perform guest authentication on mount
  useEffect(() => {
    async function initAuth() {
      // Check for OAuth callback
      const urlParams = new URLSearchParams(window.location.search);
      const oauthCode = urlParams.get("code");
      if (oauthCode) {
        // Handle OAuth callback
        const provider = sessionStorage.getItem("oauth_provider") || "google";
        const redirectUri = sessionStorage.getItem("oauth_redirect_uri") || `${window.location.origin}/auth/callback`;
        sessionStorage.removeItem("oauth_provider");
        sessionStorage.removeItem("oauth_redirect_uri");
        try {
          const { oauthCallback } = await import("../lib/apiClient");
          const res = await oauthCallback(provider, oauthCode, redirectUri);
          localStorage.setItem("workspace_auth_token", res.token);
          setUser({
            email: res.user.email,
            displayName: res.user.display_name,
            isLoggedIn: true,
            isGuest: false,
            tier: res.user.tier,
            privateKeySeed: "",
            hasPasskey: res.user.has_passkey,
            oauthProvider: res.user.oauth_provider,
          });
          addLog(`Signed in via ${provider}: ${res.user.display_name}`, "success");
          // Clean URL
          window.history.replaceState({}, "", window.location.pathname);
        } catch (err: any) {
          addLog(`OAuth callback failed: ${err.message}`, "error");
        }
        return;
      }

      // Check for existing token
      const existingToken = localStorage.getItem("workspace_auth_token");
      if (existingToken) {
        const cached = localStorage.getItem("workspace_user");
        const parsed = cached ? JSON.parse(cached) : null;
        if (parsed && parsed.isLoggedIn) {
          addLog(`Restored session for ${parsed.displayName || parsed.email}`, "success");
          return;
        }
      }

      // Fallback to guest auth
      let deviceUuid = localStorage.getItem("workspace_device_uuid");
      if (!deviceUuid) {
        deviceUuid = (typeof crypto.randomUUID === "function")
          ? crypto.randomUUID()
          : `device-${Math.random().toString(36).substring(2, 15)}`;
        localStorage.setItem("workspace_device_uuid", deviceUuid);
      }

      try {
        const { authGuest } = await import("../lib/apiClient");
        const res = await authGuest(deviceUuid);
        localStorage.setItem("workspace_auth_token", res.token);
        setUser({
          email: res.user.email,
          displayName: res.user.display_name,
          isLoggedIn: true,
          isGuest: res.user.is_guest,
          tier: res.user.tier,
          privateKeySeed: "",
        });
        addLog(`Guest session: ${res.user.display_name}`, "success");

        // Load documents from server
        try {
          const { getDocuments } = await import("../lib/apiClient");
          const docRes = await getDocuments();
          if (docRes.documents && docRes.documents.length > 0) {
            const serverDocs: Document[] = docRes.documents.map((d: any) => ({
              id: d.id,
              title: d.title,
              content: d.content,
              version: d.version,
              lastSaved: d.lastSaved,
              isSynced: true
            }));
            setDocuments(serverDocs);
          }
        } catch {
          // Keep local docs
        }
      } catch (err: any) {
        addLog(`Auth failed: ${err.message}`, "error");
      }
    }

    initAuth();
  }, []); // eslint-disable-line react-hooks/exhaustive-deps

  // Online/Offline listeners
  useEffect(() => {
    const handleOnline = () => {
      setIsOnline(true);
      setSyncStatus("synced");
      addLog("Network connection restored. Re-authenticating sync tunnel.", "success");
    };
    const handleOffline = () => {
      setIsOnline(false);
      setSyncStatus("offline");
      addLog("Offline mode active. All edits are being buffered securely in local IndexDB.", "info");
    };
    window.addEventListener("online", handleOnline);
    window.addEventListener("offline", handleOffline);
    return () => {
      window.removeEventListener("online", handleOnline);
      window.removeEventListener("offline", handleOffline);
    };
  }, []);

  // Auto-save to localStorage
  const [autoSaveEnabled, setAutoSaveEnabled] = useState<boolean>(() => {
    return localStorage.getItem("workspace_pref_autoSave") !== "false";
  });

  useEffect(() => {
    if (!autoSaveEnabled) return;
    if (isFirstLocalStorageSave.current) {
      isFirstLocalStorageSave.current = false;
      return;
    }
    const timer = setTimeout(() => {
      localStorage.setItem("workspace_documents", JSON.stringify(documents));
      const now = new Date();
      const formattedTime = now.toLocaleTimeString([], {
        hour: "2-digit",
        minute: "2-digit",
        second: "2-digit",
      });
      setToast({
        show: true,
        message: "All document progress autosaved locally",
        timestamp: formattedTime,
      });
    }, 1500);
    return () => clearTimeout(timer);
  }, [documents, autoSaveEnabled]);

  // Toast dismiss
  useEffect(() => {
    if (toast.show) {
      const timer = setTimeout(() => {
        setToast((prev) => ({ ...prev, show: false }));
      }, 3000);
      return () => clearTimeout(timer);
    }
  }, [toast.show]);

  // Beforeunload save
  useEffect(() => {
    const handleBeforeUnload = () => {
      if (autoSaveEnabled) {
        localStorage.setItem("workspace_documents", JSON.stringify(documents));
      }
    };
    window.addEventListener("beforeunload", handleBeforeUnload);
    return () => window.removeEventListener("beforeunload", handleBeforeUnload);
  }, [documents, autoSaveEnabled]);

  // Save credentials
  useEffect(() => {
    localStorage.setItem("workspace_user", JSON.stringify(user));
  }, [user]);

  // Helpers
  const addLog = (text: string, type: "success" | "info" | "sync" | "error") => {
    setSyncLogs((prev) => [
      {
        id: `log-${Date.now()}-${Math.random().toString(36).substring(2, 9)}`,
        text,
        timestamp: new Date().toISOString(),
        type,
      },
      ...prev.slice(0, 24),
    ]);
  };

  const handleManualSave = () => {
    localStorage.setItem("workspace_documents", JSON.stringify(documents));
    const now = new Date();
    const formattedTime = now.toLocaleTimeString([], {
      hour: "2-digit",
      minute: "2-digit",
      second: "2-digit",
    });
    setToast({
      show: true,
      message: "Document progress manually saved locally",
      timestamp: formattedTime,
    });
    addLog("Document progress manually saved locally.", "success");
  };

  return {
    documents,
    setDocuments,
    activeDocId,
    setActiveDocId,
    activeDoc,
    editorText,
    setEditorText,
    isOnline,
    syncStatus,
    setSyncStatus,
    syncLogs,
    user,
    setUser,
    teamMembers,
    setTeamMembers,
    teamChangesEnabled,
    setTeamChangesEnabled,
    activeCollaborators,
    setActiveCollaborators,
    toast,
    setToast,
    showDocModal,
    setShowDocModal,
    newDocTitle,
    setNewDocTitle,
    documentSearchTerm,
    setDocumentSearchTerm,
    uploadFile,
    setUploadFile,
    uploadLoading,
    setUploadLoading,
    uploadError,
    setUploadError,
    adminPassword,
    setAdminPassword,
    isAdminLoggedIn,
    setIsAdminLoggedIn,
    adminVerifyLoading,
    tokensConsumed,
    setTokensConsumed,
    showVersionHistory,
    setShowVersionHistory,
    isReadingMode,
    setIsReadingMode,
    showExportPreview,
    setShowExportPreview,
    exportPreviewFormat,
    setExportPreviewFormat,
    showPreferenceModal,
    setShowPreferenceModal,
    showShareModal,
    setShowShareModal,
    isSidebarOpen,
    setIsSidebarOpen,
    copiedDoc,
    setCopiedDoc,
    showStatsPopover,
    setShowStatsPopover,
    leftPanelMode,
    setLeftPanelMode,
    foldedBlockIds,
    setFoldedBlockIds,
    autoSaveEnabled,
    setAutoSaveEnabled,
    saveTimeoutRef,
    isFirstLocalStorageSave,
    addLog,
    handleManualSave,
  };
}