const { logger, webSearchKeys } = require('@hanzochat/data-schemas');
const { Tools, CacheKeys, Constants, FileSources } = require('@hanzochat/data-provider');
const {
  MCPOAuthHandler,
  MCPTokenStorage,
  normalizeHttpError,
  extractWebSearchEnvVars,
  resolveTenantBearer,
} = require('@hanzochat/api');
const {
  deleteAllSharedLinks,
  updateUserPlugins,
  deleteUserById,
  deleteMessages,
  deletePresets,
  deleteUserKey,
  deleteConvos,
  deleteFiles,
  deleteAllAgentApiKeys,
  updateUser,
  findToken,
  getFiles,
} = require('~/models');
const {
  ConversationTag,
  Transaction,
  MemoryEntry,
  Assistant,
  AclEntry,
  Balance,
  Action,
  Group,
  Token,
  User,
} = require('~/db/models');
const { updateUserPluginAuth, deleteUserPluginAuth } = require('~/server/services/PluginService');
const { getMCPManager, getFlowStateManager, getMCPServersRegistry } = require('~/config');
const { invalidateCachedTools } = require('~/server/services/Config/getCachedTools');
const { needsRefresh, getNewS3URL } = require('~/server/services/Files/S3/crud');
const { processDeleteRequest } = require('~/server/services/Files/process');
const { getAppConfig } = require('~/server/services/Config');
const { buildGuestUser } = require('~/server/services/guestConfig');
const { publicUser } = require('~/server/services/publicUser');
const { pictureFromUserinfo } = require('~/server/services/iamUser');
const { deleteToolCalls } = require('~/models/ToolCall');
const { deleteUserPrompts } = require('~/models/Prompt');
const { deleteUserAgents } = require('~/models/Agent');
const { getLogStores } = require('~/cache');

/**
 * Adopt the visitor's hanzo.id photo, for a session that already existed.
 *
 * The avatar is adopted when the account is first seen (services/iamUser), which
 * is the right place for it and the only place that needs to run for anyone
 * arriving from here on. It leaves out exactly one group: everybody who already
 * had an account when that shipped, who would have had to sign out and back in
 * to see their own face. Telling a signed-in person to re-authenticate to
 * collect a photo the platform already holds is a workaround, not a fix.
 *
 * So this reads the SAME userinfo endpoint, through the SAME
 * `pictureFromUserinfo` — never a second copy of the discovery-and-fetch dance,
 * because two of those drift and the wrong one is invisible until a photo
 * silently stops arriving.
 *
 * Three things keep it cheap and quiet:
 *
 * - It runs ONLY when the record has no avatar. A photo already here — uploaded
 *   by hand, or adopted on a previous pass — is the visitor's own and is never
 *   overwritten from upstream.
 * - It runs only from HERE, the one endpoint that renders a person's identity,
 *   rather than from the per-request identification every API call goes through.
 *   That is the difference between a couple of round-trips a session and two in
 *   front of every call an account without a photo ever makes.
 * - It cannot fail the read. A guest carries no bearer and
 *   `pictureFromUserinfo` resolves to '' on every error, so the worst case is
 *   the response this function was never called for.
 *
 * It runs AFTER the S3 branch above, and that order is load-bearing: that branch
 * is gated on an avatar EXISTING and treats it as an S3 key to re-sign. Adopting
 * first would hand it a hanzo.id data URI to refresh as one.
 */
async function adoptIamPhoto(req, userData) {
  if (userData.avatar) {
    return;
  }
  try {
    const bearer = resolveTenantBearer(req);
    if (!bearer) {
      return;
    }
    const picture = await pictureFromUserinfo(bearer);
    if (!picture) {
      return;
    }
    userData.avatar = picture;
    await updateUser(userData.id, { avatar: picture });
  } catch (error) {
    logger.debug('[getUserController] could not adopt the hanzo.id photo', error);
  }
}

const getUserController = async (req, res) => {
  if (req.user?.guest === true) {
    return res.status(200).send(buildGuestUser(req.user));
  }
  const appConfig = await getAppConfig({ role: req.user?.role });
  /** @type {IUser} */
  const raw = req.user.toObject != null ? req.user.toObject() : { ...req.user };
  /**
   * ONE projection, at the boundary. This was three `delete`s against a
   * deny-list the jwt strategy also spells (`-password -__v -totpSecret
   * -backupCodes`), which between them named four fields and shipped the other
   * twenty-six — `refreshToken` among them. See services/publicUser.
   */
  const userData = publicUser(raw);
  if (appConfig.fileStrategy === FileSources.s3 && userData.avatar) {
    const avatarNeedsRefresh = needsRefresh(userData.avatar, 3600);
    if (!avatarNeedsRefresh) {
      return res.status(200).send(userData);
    }
    const originalAvatar = userData.avatar;
    try {
      userData.avatar = await getNewS3URL(userData.avatar);
      await updateUser(userData.id, { avatar: userData.avatar });
    } catch (error) {
      userData.avatar = originalAvatar;
      logger.error('Error getting new S3 URL for avatar:', error);
    }
  }
  await adoptIamPhoto(req, userData);
  res.status(200).send(userData);
};

const getTermsStatusController = async (req, res) => {
  try {
    const user = await User.findById(req.user.id);
    if (!user) {
      return res.status(404).json({ message: 'User not found' });
    }
    res.status(200).json({ termsAccepted: !!user.termsAccepted });
  } catch (error) {
    logger.error('Error fetching terms acceptance status:', error);
    res.status(500).json({ message: 'Error fetching terms acceptance status' });
  }
};

const acceptTermsController = async (req, res) => {
  try {
    const user = await User.findByIdAndUpdate(req.user.id, { termsAccepted: true }, { new: true });
    if (!user) {
      return res.status(404).json({ message: 'User not found' });
    }
    res.status(200).json({ message: 'Terms accepted successfully' });
  } catch (error) {
    logger.error('Error accepting terms:', error);
    res.status(500).json({ message: 'Error accepting terms' });
  }
};

/**
 * Records that this account has seen the welcome card, so it is shown once and
 * not once per device. There is no matching GET: `toured` rides the projected
 * user document out of `GET /v1/chat/user`, which the client already holds.
 */
const tourController = async (req, res) => {
  try {
    const user = await User.findByIdAndUpdate(req.user.id, { toured: true }, { new: true });
    if (!user) {
      return res.status(404).json({ message: 'User not found' });
    }
    res.status(200).json({ toured: true });
  } catch (error) {
    logger.error('Error recording tour:', error);
    res.status(500).json({ message: 'Error recording tour' });
  }
};

const deleteUserFiles = async (req) => {
  try {
    const userFiles = await getFiles({ user: req.user.id });
    await processDeleteRequest({
      req,
      files: userFiles,
    });
  } catch (error) {
    logger.error('[deleteUserFiles]', error);
  }
};

const updateUserPluginsController = async (req, res) => {
  const appConfig = await getAppConfig({ role: req.user?.role });
  const { user } = req;
  const { pluginKey, action, auth, isEntityTool } = req.body;
  try {
    if (!isEntityTool) {
      await updateUserPlugins(user._id, user.plugins, pluginKey, action);
    }

    if (auth == null) {
      return res.status(200).send();
    }

    let keys = Object.keys(auth);
    const values = Object.values(auth); // Used in 'install' block

    const isMCPTool = pluginKey.startsWith('mcp_') || pluginKey.includes(Constants.mcp_delimiter);

    // Early exit condition:
    // If keys are empty (meaning auth: {} was likely sent for uninstall, or auth was empty for install)
    // AND it's not web_search (which has special key handling to populate `keys` for uninstall)
    // AND it's NOT (an uninstall action FOR an MCP tool - we need to proceed for this case to clear all its auth)
    // THEN return.
    if (
      keys.length === 0 &&
      pluginKey !== Tools.web_search &&
      !(action === 'uninstall' && isMCPTool)
    ) {
      return res.status(200).send();
    }

    /** @type {number} */
    let status = 200;
    /** @type {string} */
    let message;
    /** @type {IPluginAuth | Error} */
    let authService;

    if (pluginKey === Tools.web_search) {
      /** @type  {TCustomConfig['webSearch']} */
      const webSearchConfig = appConfig?.webSearch;
      keys = extractWebSearchEnvVars({
        keys: action === 'install' ? keys : webSearchKeys,
        config: webSearchConfig,
      });
    }

    if (action === 'install') {
      for (let i = 0; i < keys.length; i++) {
        authService = await updateUserPluginAuth(user.id, keys[i], pluginKey, values[i]);
        if (authService instanceof Error) {
          logger.error('[authService]', authService);
          ({ status, message } = normalizeHttpError(authService));
        }
      }
    } else if (action === 'uninstall') {
      // const isMCPTool was defined earlier
      if (isMCPTool && keys.length === 0) {
        // This handles the case where auth: {} is sent for an MCP tool uninstall.
        // It means "delete all credentials associated with this MCP pluginKey".
        authService = await deleteUserPluginAuth(user.id, null, true, pluginKey);
        if (authService instanceof Error) {
          logger.error(
            `[authService] Error deleting all auth for MCP tool ${pluginKey}:`,
            authService,
          );
          ({ status, message } = normalizeHttpError(authService));
        }
        try {
          // if the MCP server uses OAuth, perform a full cleanup and token revocation
          await maybeUninstallOAuthMCP(user.id, pluginKey, appConfig);
        } catch (error) {
          logger.error(
            `[updateUserPluginsController] Error uninstalling OAuth MCP for ${pluginKey}:`,
            error,
          );
        }
      } else {
        // This handles:
        // 1. Web_search uninstall (keys will be populated with all webSearchKeys if auth was {}).
        // 2. Other tools uninstall (if keys were provided).
        // 3. MCP tool uninstall if specific keys were provided in `auth` (not current frontend behavior).
        // If keys is empty for non-MCP tools (and not web_search), this loop won't run, and nothing is deleted.
        for (let i = 0; i < keys.length; i++) {
          authService = await deleteUserPluginAuth(user.id, keys[i]); // Deletes by authField name
          if (authService instanceof Error) {
            logger.error('[authService] Error deleting specific auth key:', authService);
            ({ status, message } = normalizeHttpError(authService));
          }
        }
      }
    }

    if (status === 200) {
      // If auth was updated successfully, disconnect MCP sessions as they might use these credentials
      if (pluginKey.startsWith(Constants.mcp_prefix)) {
        try {
          const mcpManager = getMCPManager();
          if (mcpManager) {
            // Extract server name from pluginKey (format: "mcp_<serverName>")
            const serverName = pluginKey.replace(Constants.mcp_prefix, '');
            logger.info(
              `[updateUserPluginsController] Attempting disconnect of MCP server "${serverName}" for user ${user.id} after plugin auth update.`,
            );
            await mcpManager.disconnectUserConnection(user.id, serverName);
            await invalidateCachedTools({ userId: user.id, serverName });
          }
        } catch (disconnectError) {
          logger.error(
            `[updateUserPluginsController] Error disconnecting MCP connection for user ${user.id} after plugin auth update:`,
            disconnectError,
          );
          // Do not fail the request for this, but log it.
        }
      }
      return res.status(status).send();
    }

    const normalized = normalizeHttpError({ status, message });
    return res.status(normalized.status).send({ message: normalized.message });
  } catch (err) {
    logger.error('[updateUserPluginsController]', err);
    return res.status(500).json({ message: 'Something went wrong.' });
  }
};

const deleteUserController = async (req, res) => {
  const { user } = req;

  try {
    await deleteMessages({ user: user.id }); // delete user messages
    await Transaction.deleteMany({ user: user.id }); // delete user transactions
    await deleteUserKey({ userId: user.id, all: true }); // delete user keys
    await Balance.deleteMany({ user: user._id }); // delete user balances
    await deletePresets(user.id); // delete user presets
    try {
      await deleteConvos(user.id); // delete user convos
    } catch (error) {
      logger.error('[deleteUserController] Error deleting user convos, likely no convos', error);
    }
    await deleteUserPluginAuth(user.id, null, true); // delete user plugin auth
    await deleteUserById(user.id); // delete user
    await deleteAllSharedLinks(user.id); // delete user shared links
    await deleteUserFiles(req); // delete user files
    await deleteFiles(null, user.id); // delete database files in case of orphaned files from previous steps
    await deleteToolCalls(user.id); // delete user tool calls
    await deleteUserAgents(user.id); // delete user agents
    /**
     * `deleteAllAgentApiKeys`, not `AgentApiKey.deleteMany({ user })` — the
     * schema's owner field is `userId` and there is no `user` field at all, so
     * that filter matched nothing while every other line in this chain quietly
     * did its job around it. Deleting an account left its API key rows, hashed
     * key material included, in the store forever.
     *
     * Bounded, because the key middleware loads the owning user and 401s when
     * it is gone: an orphaned key cannot authenticate. It is retention, not a
     * live credential — and the account had asked to be erased.
     *
     * Going through the model layer is the actual repair. A filter written at
     * the call site is a second place that has to know the field name; there is
     * nowhere to be wrong when the query lives with the schema.
     */
    await deleteAllAgentApiKeys(user._id); // delete user agent API keys
    await Assistant.deleteMany({ user: user.id }); // delete user assistants
    await ConversationTag.deleteMany({ user: user.id }); // delete user conversation tags
    await MemoryEntry.deleteMany({ userId: user.id }); // delete user memory entries
    await deleteUserPrompts(req, user.id); // delete user prompts
    await Action.deleteMany({ user: user.id }); // delete user actions
    await Token.deleteMany({ userId: user.id }); // delete user OAuth tokens
    await Group.updateMany(
      // remove user from all groups
      { memberIds: user.id },
      { $pull: { memberIds: user.id } },
    );
    await AclEntry.deleteMany({ principalId: user._id }); // delete user ACL entries
    logger.info(`User deleted account. Email: ${user.email} ID: ${user.id}`);
    res.status(200).send({ message: 'User deleted' });
  } catch (err) {
    logger.error('[deleteUserController]', err);
    return res.status(500).json({ message: 'Something went wrong.' });
  }
};

/**
 * Forget everything this deployment stores about one user's OAuth session with
 * one MCP server: the tokens and the flow state. Never throws — it is the last
 * step of an uninstall the user already asked for, and a failure to tidy up is
 * not a reason to fail it.
 */
const clearStoredMCPOAuthState = async (userId, serverName) => {
  try {
    await MCPTokenStorage.deleteUserTokens({
      userId,
      serverName,
      deleteToken: async (filter) => {
        await Token.deleteOne(filter);
      },
    });
  } catch (error) {
    logger.warn(
      `[clearStoredMCPOAuthState] Failed to delete MCP OAuth tokens for ${serverName}:`,
      error,
    );
  }

  try {
    const flowManager = getFlowStateManager(getLogStores(CacheKeys.FLOWS));
    const flowId = MCPOAuthHandler.generateFlowId(userId, serverName);
    await flowManager.deleteFlow(flowId, 'mcp_get_tokens');
    await flowManager.deleteFlow(flowId, 'mcp_oauth');
  } catch (error) {
    logger.warn(
      `[clearStoredMCPOAuthState] Failed to clear MCP OAuth flow state for ${serverName}:`,
      error,
    );
  }
};

/**
 * Uninstalling an MCP plugin: revoke its OAuth tokens at the provider, then
 * forget them here.
 *
 * Revocation is best-effort and clearing is not. Every path that could not
 * revoke — the server no longer declares OAuth, the client metadata is gone,
 * the tokens will not decrypt — used to RETURN, leaving the stored tokens
 * behind for a plugin the user had just removed. Reconfiguring a server without
 * OAuth was enough to strand them permanently. So the local state goes in all
 * cases, and a failure upstream only costs the revocation.
 */
const maybeUninstallOAuthMCP = async (userId, pluginKey, appConfig) => {
  if (!pluginKey.startsWith(Constants.mcp_prefix)) {
    // this is not an MCP server, so nothing to do here
    return;
  }

  const serverName = pluginKey.replace(Constants.mcp_prefix, '');
  const serverConfig =
    (await getMCPServersRegistry().getServerConfig(serverName, userId)) ??
    appConfig?.mcpServers?.[serverName];
  const oauthServers = await getMCPServersRegistry().getOAuthServers(userId);
  if (!oauthServers.has(serverName)) {
    return clearStoredMCPOAuthState(userId, serverName);
  }

  // 1. get client info used for revocation (client id, secret)
  let clientTokenData = null;
  try {
    clientTokenData = await MCPTokenStorage.getClientInfoAndMetadata({
      userId,
      serverName,
      findToken,
    });
  } catch (error) {
    logger.warn(
      `[maybeUninstallOAuthMCP] Unable to load OAuth client metadata for ${serverName}; clearing local MCP OAuth state only.`,
      error,
    );
  }
  if (clientTokenData == null) {
    return clearStoredMCPOAuthState(userId, serverName);
  }
  const { clientInfo, clientMetadata } = clientTokenData;

  // 2. get decrypted tokens before deletion
  let tokens = null;
  try {
    tokens = await MCPTokenStorage.getTokens({
      userId,
      serverName,
      findToken,
    });
  } catch (error) {
    logger.warn(
      `[maybeUninstallOAuthMCP] Unable to load OAuth tokens for ${serverName}; clearing local token state.`,
      error,
    );
  }

  // 3. revoke OAuth tokens at the provider
  const revocationEndpoint =
    serverConfig.oauth?.revocation_endpoint ?? clientMetadata.revocation_endpoint;
  const revocationEndpointAuthMethodsSupported =
    serverConfig.oauth?.revocation_endpoint_auth_methods_supported ??
    clientMetadata.revocation_endpoint_auth_methods_supported;
  const oauthHeaders = serverConfig.oauth_headers ?? {};

  if (tokens?.access_token) {
    try {
      await MCPOAuthHandler.revokeOAuthToken(
        serverName,
        tokens.access_token,
        'access',
        {
          serverUrl: serverConfig.url,
          clientId: clientInfo.client_id,
          clientSecret: clientInfo.client_secret ?? '',
          revocationEndpoint,
          revocationEndpointAuthMethodsSupported,
        },
        oauthHeaders,
      );
    } catch (error) {
      logger.error(`Error revoking OAuth access token for ${serverName}:`, error);
    }
  }

  if (tokens?.refresh_token) {
    try {
      await MCPOAuthHandler.revokeOAuthToken(
        serverName,
        tokens.refresh_token,
        'refresh',
        {
          serverUrl: serverConfig.url,
          clientId: clientInfo.client_id,
          clientSecret: clientInfo.client_secret ?? '',
          revocationEndpoint,
          revocationEndpointAuthMethodsSupported,
        },
        oauthHeaders,
      );
    } catch (error) {
      logger.error(`Error revoking OAuth refresh token for ${serverName}:`, error);
    }
  }

  // 4. forget the tokens and the flow state, whether or not revocation ran
  await clearStoredMCPOAuthState(userId, serverName);
};

module.exports = {
  getUserController,
  getTermsStatusController,
  acceptTermsController,
  tourController,
  deleteUserController,
  /** Not a route — uninstalling an MCP plugin revokes its OAuth tokens at the
   * provider, and `maybeUninstallOAuthMCP.spec.js` tests that directly. */
  maybeUninstallOAuthMCP,
  updateUserPluginsController,
};