/**
 * Google Cloud Logging resources for MCP
 */
import { McpServer, ResourceTemplate } from '@modelcontextprotocol/sdk/server/mcp.js';
import { getProjectId } from '../../utils/auth.js';
import { GcpMcpError } from '../../utils/error.js';
import { formatLogEntry, getLoggingClient, LogEntry } from './types.js';

/**
 * Registers Google Cloud Logging resources with the MCP server
 * 
 * @param server The MCP server instance
 */
export function registerLoggingResources(server: McpServer): void {
  // Register a resource for listing recent logs
  server.resource(
    'recent-logs',
    new ResourceTemplate('gcp-logs://{projectId}/recent', { list: undefined }),
    async (uri, { projectId }, _extra) => {
      try {
        const actualProjectId = projectId || await getProjectId();
        const logging = getLoggingClient();
        
        const defaultFilter = process.env.LOG_FILTER || '';
        const [entries] = await logging.getEntries({
          pageSize: 50,
          filter: defaultFilter
        });

        if (!entries || entries.length === 0) {
          return {
            contents: [{
              uri: uri.href,
              text: 'No log entries found.'
            }]
          };
        }

        // Format logs with error handling for each entry
        const formattedLogs = entries
          .map((entry) => {
            try {
              return formatLogEntry(entry as unknown as LogEntry);
            } catch (err: unknown) {
              const errorMessage = err instanceof Error ? err.message : 'Unknown error';
              return `## Error Formatting Log Entry\n\nAn error occurred while formatting a log entry: ${errorMessage}`;
            }
          })
          .join('\n\n');

        return {
          contents: [{
            uri: uri.href,
            text: `# Recent Logs for Project: ${actualProjectId}\n\n${formattedLogs}`
          }]
        };
      } catch (error: unknown) {
        // Get project ID safely
        let projectIdForError: string;
        try {
          projectIdForError = Array.isArray(projectId) ? projectId[0] : (projectId as string || process.env.GOOGLE_CLOUD_PROJECT || 'unknown');
        } catch {
          projectIdForError = 'unknown';
        }
        
        const errorMessage = error instanceof Error ? error.message : 'Unknown error';
        
        // Return a user-friendly error message instead of throwing
        return {
          contents: [{
            uri: uri.href,
            text: `# Error Fetching Recent Logs\n\nAn error occurred while fetching recent logs for project ${projectIdForError}: ${errorMessage}\n\nPlease check your Google Cloud credentials and project configuration.`
          }]
        };
      }
    }
  );

  // Register a resource for querying logs with a filter
  server.resource(
    'filtered-logs',
    new ResourceTemplate('gcp-logs://{projectId}/filter/{filter}', { list: undefined }),
    async (uri, { projectId, filter }, _extra) => {
      try {
        const actualProjectId = projectId || await getProjectId();
        const logging = getLoggingClient();
        
        if (!filter) {
          throw new GcpMcpError('Log filter is required', 'INVALID_ARGUMENT', 400);
        }

        const decodedFilter = Array.isArray(filter) ? decodeURIComponent(filter[0]) : decodeURIComponent(filter);
        
        const [entries] = await logging.getEntries({
          pageSize: 50,
          filter: decodedFilter
        });

        if (!entries || entries.length === 0) {
          return {
            contents: [{
              uri: uri.href,
              text: `No log entries found matching filter: ${decodedFilter}`
            }]
          };
        }

        // Format logs with error handling for each entry
        const formattedLogs = entries
          .map((entry) => {
            try {
              return formatLogEntry(entry as unknown as LogEntry);
            } catch (err: unknown) {
              const errorMessage = err instanceof Error ? err.message : 'Unknown error';
              return `## Error Formatting Log Entry\n\nAn error occurred while formatting a log entry: ${errorMessage}`;
            }
          })
          .join('\n\n');

        return {
          contents: [{
            uri: uri.href,
            text: `# Filtered Logs for Project: ${actualProjectId}\n\nFilter: ${decodedFilter}\n\n${formattedLogs}`
          }]
        };
      } catch (error: unknown) {
        // Get project ID and filter safely
        let projectIdForError: string;
        let filterForError: string;
        try {
          projectIdForError = Array.isArray(projectId) ? projectId[0] : (projectId as string || process.env.GOOGLE_CLOUD_PROJECT || 'unknown');
          filterForError = Array.isArray(filter) ? filter[0] : String(filter || 'unknown');
        } catch {
          projectIdForError = 'unknown';
          filterForError = 'unknown';
        }
        
        const errorMessage = error instanceof Error ? error.message : 'Unknown error';
        
        // Return a user-friendly error message instead of throwing
        return {
          contents: [{
            uri: uri.href,
            text: `# Error Fetching Filtered Logs\n\nAn error occurred while fetching logs with filter "${filterForError}" for project ${projectIdForError}: ${errorMessage}\n\nPlease check your filter syntax and Google Cloud credentials.`
          }]
        };
      }
    }
  );
}