import {
  createContext,
  type ReactNode,
  useCallback,
  useContext,
  useEffect,
  useMemo,
  useState,
} from "react";
import { useLocation, useNavigate } from "react-router";

import * as rawApi from "../services/api";
import type { WorkspaceBoundApi } from "../services/api";

export type AuthUser = {
  user_id: string;
  username: string;
  display_name: string;
  email: string | null;
  status: string;
  role_code: string | null;
  is_system_admin: boolean;
  permissions: string[];
};

export type AuthWorkspace = {
  workspace_id: string;
  workspace_code: string;
  workspace_name: string;
  role_code: string;
  role_name: string;
};

type AuthSession = {
  user: AuthUser;
  workspaces: AuthWorkspace[];
  default_workspace_id: string | null;
};

type ApiEnvelope<T> = {
  data: T;
};

type AuthContextValue = {
  user: AuthUser | null;
  workspaces: AuthWorkspace[];
  currentWorkspace: AuthWorkspace | null;
  loading: boolean;
  login: (username: string, password: string) => Promise<void>;
  logout: () => Promise<void>;
  setCurrentWorkspace: (workspaceId: string) => void;
  refreshWorkspaces: () => Promise<void>;
};

const AuthContext = createContext<AuthContextValue | null>(null);
const workspaceStorageKey = "model-platform-current-workspace";

async function authRequest<T>(path: string, init: RequestInit = {}): Promise<T> {
  const response = await fetch(path, {
    ...init,
    credentials: "same-origin",
    headers: {
      ...(init.body ? { "Content-Type": "application/json" } : {}),
      ...init.headers,
    },
  });
  const payload = await response.json().catch(() => ({})) as
    | ApiEnvelope<T>
    | { detail?: string };
  if (!response.ok) {
    throw new Error(
      "detail" in payload && typeof payload.detail === "string"
        ? payload.detail
        : `请求失败（HTTP ${response.status}）`,
    );
  }
  return (payload as ApiEnvelope<T>).data;
}

function selectWorkspace(
  session: AuthSession,
  preferredId?: string | null,
): AuthWorkspace | null {
  return session.workspaces.find((item) => item.workspace_id === preferredId)
    ?? session.workspaces.find(
      (item) => item.workspace_id === session.default_workspace_id,
    )
    ?? session.workspaces[0]
    ?? null;
}

export function AuthProvider({ children }: { children: ReactNode }) {
  const location = useLocation();
  const navigate = useNavigate();
  const [user, setUser] = useState<AuthUser | null>(null);
  const [workspaces, setWorkspaces] = useState<AuthWorkspace[]>([]);
  const [currentWorkspace, setWorkspace] = useState<AuthWorkspace | null>(null);
  const [loading, setLoading] = useState(true);

  const applySession = useCallback((session: AuthSession) => {
    const storedId = typeof window === "undefined"
      ? null
      : window.localStorage.getItem(workspaceStorageKey);
    const workspace = selectWorkspace(session, storedId);
    setUser(session.user);
    setWorkspaces(session.workspaces);
    setWorkspace(workspace);
    if (workspace && typeof window !== "undefined") {
      window.localStorage.setItem(workspaceStorageKey, workspace.workspace_id);
    }
  }, []);

  useEffect(() => {
    let cancelled = false;
    void authRequest<AuthSession>("/api/v1/auth/me")
      .then((session) => {
        if (!cancelled) applySession(session);
      })
      .catch(() => {
        if (!cancelled) {
          setUser(null);
          setWorkspaces([]);
          setWorkspace(null);
        }
      })
      .finally(() => {
        if (!cancelled) setLoading(false);
      });
    return () => {
      cancelled = true;
    };
  }, [applySession]);

  useEffect(() => {
    if (loading) return;
    if (!user && location.pathname !== "/login") {
      navigate("/login", { replace: true });
    } else if (user && location.pathname === "/login") {
      navigate("/workbench", { replace: true });
    }
  }, [loading, location.pathname, navigate, user]);

  const login = useCallback(async (username: string, password: string) => {
    const session = await authRequest<AuthSession>("/api/v1/auth/login", {
      method: "POST",
      body: JSON.stringify({ username, password }),
    });
    applySession(session);
    navigate("/workbench", { replace: true });
  }, [applySession, navigate]);

  const logout = useCallback(async () => {
    try {
      await authRequest<{ logged_out: boolean }>("/api/v1/auth/logout", {
        method: "POST",
      });
    } finally {
      setUser(null);
      setWorkspaces([]);
      setWorkspace(null);
      navigate("/login", { replace: true });
    }
  }, [navigate]);

  const setCurrentWorkspace = useCallback((workspaceId: string) => {
    const workspace = workspaces.find((item) => item.workspace_id === workspaceId);
    if (!workspace) return;
    setWorkspace(workspace);
    window.localStorage.setItem(workspaceStorageKey, workspace.workspace_id);
  }, [workspaces]);

  const refreshWorkspaces = useCallback(async () => {
    try {
      const session = await authRequest<AuthSession>("/api/v1/auth/me");
      const storedId = typeof window === "undefined"
        ? null
        : window.localStorage.getItem(workspaceStorageKey);
      const newWorkspace = selectWorkspace(session, storedId);
      setWorkspaces(session.workspaces);
      setWorkspace(newWorkspace);
      if (newWorkspace && typeof window !== "undefined") {
        window.localStorage.setItem(workspaceStorageKey, newWorkspace.workspace_id);
      }
    } catch (error) {
      console.error("刷新 workspace 列表失败:", error);
    }
  }, []);

  const value = useMemo<AuthContextValue>(() => ({
    user,
    workspaces,
    currentWorkspace,
    loading,
    login,
    logout,
    setCurrentWorkspace,
    refreshWorkspaces,
  }), [currentWorkspace, loading, login, logout, setCurrentWorkspace, user, workspaces, refreshWorkspaces]);

  if (loading) {
    return (
      <div className="flex min-h-screen items-center justify-center gap-3 text-[#61758a]" role="status">
        <span className="h-5 w-5 animate-spin rounded-full border-2 border-[#bfd5e9] border-t-[#1677ff]" />
        正在验证登录状态…
      </div>
    );
  }

  return <AuthContext.Provider value={value}>{children}</AuthContext.Provider>;
}

export function useAuth(): AuthContextValue {
  const context = useContext(AuthContext);
  if (!context) {
    throw new Error("useAuth 必须在 AuthProvider 内使用");
  }
  return context;
}

export function useApi(): WorkspaceBoundApi {
  const { currentWorkspace } = useAuth();
  const workspaceId = currentWorkspace?.workspace_id ?? "";

  return useMemo<WorkspaceBoundApi>(() => ({
   listScripts: (parentPath, ownerUserId) =>
      rawApi.listScripts(workspaceId, parentPath, ownerUserId),
   countScripts: () => rawApi.countScripts(workspaceId),
   listResources: (parentPath, opts) =>
      rawApi.listResources(workspaceId, parentPath, opts),
   createScript: (input) => rawApi.createScript(workspaceId, input),
    uploadScript: (file, parentPath, visibility) =>
      rawApi.uploadScript(workspaceId, file, parentPath, visibility),
    createResourceUpload: (body) =>
      rawApi.createResourceUpload(workspaceId, body),
    uploadResourceBytes: (uploadId, fileBytes, contentType) =>
      rawApi.uploadResourceBytes(workspaceId, uploadId, fileBytes, contentType),
    bindResourceUpload: (uploadId, body) =>
      rawApi.bindResourceUpload(workspaceId, uploadId, body),
    deleteResource: (resourceId) =>
      rawApi.deleteResource(workspaceId, resourceId),
    updateScript: (scriptId, input) =>
      rawApi.updateScript(workspaceId, scriptId, input),
    deleteScript: (scriptId) => rawApi.deleteScript(workspaceId, scriptId),
    setScriptLock: (scriptId, isLocked) =>
      rawApi.setScriptLock(workspaceId, scriptId, isLocked),
    listWorkspaceDirectories: (parentPath, ownerUserId) =>
      rawApi.listWorkspaceDirectories(workspaceId, parentPath ?? "", ownerUserId),
    createWorkspaceDirectory: (directoryName, parentPath) =>
      rawApi.createWorkspaceDirectory(workspaceId, directoryName, parentPath),
    deleteWorkspaceDirectory: (path) =>
      rawApi.deleteWorkspaceDirectory(workspaceId, path),
    acquireFileLock: (script) => rawApi.acquireFileLock(workspaceId, script),
    heartbeatFileLock: (session) => rawApi.heartbeatFileLock(workspaceId, session),
    releaseFileLock: (session) => rawApi.releaseFileLock(workspaceId, session),
    releaseFileLockOnUnload: (session) =>
      rawApi.releaseFileLockOnUnload(workspaceId, session),
    createJupyterAccessTicket: (session) =>
      rawApi.createJupyterAccessTicket(workspaceId, session),
    getLatestScriptVersion: (scriptId) =>
      rawApi.getLatestScriptVersion(workspaceId, scriptId),
    publishScriptVersion: (input) => rawApi.publishScriptVersion(workspaceId, input),
    listSchedules: () => rawApi.listSchedules(workspaceId),
    getSchedule: (scheduleId) => rawApi.getSchedule(workspaceId, scheduleId),
    createSchedule: (input) => rawApi.createSchedule(workspaceId, input),
    updateSchedule: (scheduleId, input) =>
      rawApi.updateSchedule(workspaceId, scheduleId, input),
    deleteSchedule: (scheduleId, workflowVersion) =>
      rawApi.deleteSchedule(workspaceId, scheduleId, workflowVersion),
    listScheduleArtifacts: () => rawApi.listScheduleArtifacts(workspaceId),
    hideScheduleArtifact: (versionsId) =>
      rawApi.hideScheduleArtifact(workspaceId, versionsId),
    listEmployees: () => rawApi.listEmployees(workspaceId),
    listPlatformEmployees: () => rawApi.listPlatformEmployees(),
    createEmployee: (input) => rawApi.createEmployee(workspaceId, input),
    createPlatformEmployee: (input) => rawApi.createPlatformEmployee(input),
    updateEmployee: (userId, input) =>
      rawApi.updateEmployee(workspaceId, userId, input),
    updatePlatformEmployee: (userId, input) =>
      rawApi.updatePlatformEmployee(userId, input),
    deleteEmployee: (userId) => rawApi.deleteEmployee(workspaceId, userId),
    deletePlatformEmployee: (userId) => rawApi.deletePlatformEmployee(userId),
    createScheduleNode: (scheduleId, input) =>
      rawApi.createScheduleNode(workspaceId, scheduleId, input),
    updateScheduleNode: (scheduleId, nodeId, input) =>
      rawApi.updateScheduleNode(workspaceId, scheduleId, nodeId, input),
    deleteScheduleNode: (scheduleId, nodeId, workflowVersion, options) =>
      rawApi.deleteScheduleNode(
        workspaceId,
        scheduleId,
        nodeId,
        workflowVersion,
        options,
      ),
    createScheduleEdge: (scheduleId, input) =>
      rawApi.createScheduleEdge(workspaceId, scheduleId, input),
    deleteScheduleEdge: (scheduleId, edgeId, workflowVersion) =>
      rawApi.deleteScheduleEdge(workspaceId, scheduleId, edgeId, workflowVersion),
    validateSchedule: (scheduleId) => rawApi.validateSchedule(workspaceId, scheduleId),
    previewCron: (input) => rawApi.previewCron(workspaceId, input),
    runScheduleNow: (scheduleId) => rawApi.runScheduleNow(workspaceId, scheduleId),
    listScheduleRuns: (input) => rawApi.listScheduleRuns(workspaceId, input),
    getScheduleRun: (runId) => rawApi.getScheduleRun(workspaceId, runId),
    getScheduleNodeRunArtifacts: (runId, nodeRunId) =>
      rawApi.getScheduleNodeRunArtifacts(workspaceId, runId, nodeRunId),
    // Workspace (Project) Management - 系统管理接口（跨 workspace，不需要传入 workspaceId）
    listWorkspaces: () => rawApi.listWorkspaces(),
    createWorkspace: (input) => rawApi.createWorkspace(input),
    updateWorkspace: (workspaceId, input) => rawApi.updateWorkspace(workspaceId, input),
    deleteWorkspace: (workspaceId) => rawApi.deleteWorkspace(workspaceId),
    listWorkspaceMembers: (workspaceId) => rawApi.listWorkspaceMembers(workspaceId),
    addWorkspaceMember: (workspaceId, input) => rawApi.addWorkspaceMember(workspaceId, input),
    updateWorkspaceMember: (workspaceId, userId, input) => rawApi.updateWorkspaceMember(workspaceId, userId, input),
    deleteWorkspaceMember: (workspaceId, userId) => rawApi.deleteWorkspaceMember(workspaceId, userId),
  }), [workspaceId]);
}

export function usePermission(code: string): boolean {
  const { user } = useAuth();
  return user?.permissions.includes(code) ?? false;
}