feat(agent): Implement simplified chat agent tools and state management

src/lib/tools/agents/fileSearchTool.ts

@@ -0,0 +1,148 @@
+import { tool } from '@langchain/core/tools';
+import { z } from 'zod';
+import { RunnableConfig } from '@langchain/core/runnables';
+import { Document } from 'langchain/document';
+import { Embeddings } from '@langchain/core/embeddings';
+import {
+  processFilesToDocuments,
+  getRankedDocs,
+} from '@/lib/utils/fileProcessing';
+
+// Schema for file search tool input
+const FileSearchToolSchema = z.object({
+  query: z
+    .string()
+    .describe('The search query to find relevant content in files'),
+  fileIds: z.array(z.string()).describe('Array of file IDs to search through'),
+  maxResults: z
+    .number()
+    .optional()
+    .default(12)
+    .describe('Maximum number of results to return'),
+  similarityThreshold: z
+    .number()
+    .optional()
+    .default(0.3)
+    .describe('Minimum similarity threshold for results'),
+});
+
+/**
+ * FileSearchTool - Reimplementation of FileSearchAgent as a tool
+ *
+ * This tool handles:
+ * 1. Processing uploaded files into searchable documents
+ * 2. Performing similarity search across file content
+ * 3. Ranking and filtering results by relevance
+ * 4. Returning relevant file sections as documents
+ */
+export const fileSearchTool = tool(
+  async (
+    input: z.infer<typeof FileSearchToolSchema>,
+    config?: RunnableConfig,
+  ): Promise<{
+    documents: Document[];
+    processedFiles: number;
+    relevantSections: number;
+    relevantDocuments?: any[];
+  }> => {
+    try {
+      const {
+        query,
+        fileIds,
+        maxResults = 12,
+        similarityThreshold = 0.3,
+      } = input;
+
+      console.log(
+        `FileSearchTool: Processing ${fileIds.length} files for query: "${query}"`,
+      );
+
+      // Check if we have files to process
+      if (!fileIds || fileIds.length === 0) {
+        console.log('FileSearchTool: No files provided for search');
+        return {
+          documents: [],
+          processedFiles: 0,
+          relevantSections: 0,
+        };
+      }
+
+      // Get embeddings from config
+      if (!config?.configurable?.embeddings) {
+        throw new Error('Embeddings not available in config');
+      }
+
+      const embeddings: Embeddings = config.configurable.embeddings;
+
+      // Step 1: Process files to documents
+      console.log('FileSearchTool: Processing files to documents...');
+      const fileDocuments = await processFilesToDocuments(fileIds);
+
+      if (fileDocuments.length === 0) {
+        console.log('FileSearchTool: No processable content found in files');
+        return {
+          documents: [],
+          processedFiles: fileIds.length,
+          relevantSections: 0,
+        };
+      }
+
+      console.log(
+        `FileSearchTool: Processed ${fileDocuments.length} file sections`,
+      );
+
+      // Step 2: Generate query embedding for similarity search
+      console.log('FileSearchTool: Generating query embedding...');
+      const queryEmbedding = await embeddings.embedQuery(query);
+
+      // Step 3: Perform similarity search and ranking
+      console.log('FileSearchTool: Performing similarity search...');
+      const rankedDocuments = getRankedDocs(
+        queryEmbedding,
+        fileDocuments,
+        maxResults,
+        similarityThreshold,
+      );
+
+      console.log(
+        `FileSearchTool: Found ${rankedDocuments.length} relevant file sections`,
+      );
+
+      // Add search metadata to documents
+      const documentsWithMetadata = rankedDocuments.map((doc) => {
+        return new Document({
+          pageContent: doc.pageContent,
+          metadata: {
+            ...doc.metadata,
+            source: 'file_search',
+            searchQuery: query,
+            similarityScore: doc.metadata?.similarity || 0,
+          },
+        });
+      });
+
+      return {
+        documents: documentsWithMetadata,
+        processedFiles: fileIds.length,
+        relevantSections: rankedDocuments.length,
+      };
+    } catch (error) {
+      console.error('FileSearchTool: Error during file search:', error);
+      const errorMessage =
+        error instanceof Error ? error.message : 'Unknown error';
+
+      // Return empty results on error, but don't throw to allow graceful handling
+      return {
+        documents: [],
+        processedFiles: input.fileIds?.length || 0,
+        relevantSections: 0,
+      };
+    }
+  },
+  {
+    name: 'file_search',
+    description:
+      'Searches through uploaded files to find relevant content sections based on a query using semantic similarity',
+    schema: FileSearchToolSchema,
+  },
+);