import * as acorn from "npm:acorn";
import { assertEquals } from "https://deno.land/std@0.224.0/testing/asserts.ts";

/**
 * Proof of Concept: Local Code Intelligence (Gen 2)
 *
 * Replaces the naive regex extraction in Gen 1 with actual AST parsing using
 * acorn, proving that we can extract a true Semantic
 * Code graph structure from code files.
 */

export interface ExportSymbol {
  name: string;
  type: "function" | "class" | "const";
  signature: string;
}

export function extractExports(sourceCode: string): ExportSymbol[] {
  // Strip TypeScript annotations using a regex just to let acorn parse it as JS
  // In a real scenario we'd use a TS-capable parser like @typescript-eslint/typescript-estree or swc,
  // but this proves the concept of AST walking vs regex scraping.
  const jsCode = sourceCode
    .replace(/:\s*Promise<[^>]+>/g, '')
    .replace(/:\s*[a-zA-Z0-9_]+/g, '')
    .replace(/<[^>]+>/g, '');

  const ast = acorn.parse(jsCode, { ecmaVersion: 2022, sourceType: "module" }) as any;
  const exports: ExportSymbol[] = [];

  for (const node of ast.body) {
    if (node.type === "ExportNamedDeclaration") {
      if (node.declaration) {
        if (node.declaration.type === "FunctionDeclaration") {
          const name = node.declaration.id.name;
          // Simple mock signature from JS AST
          const params = node.declaration.params.map((p: any) => p.name).join(", ");
          exports.push({
            name,
            type: "function",
            signature: `(${params}) => any`,
          });
        } else if (node.declaration.type === "VariableDeclaration") {
          for (const decl of node.declaration.declarations) {
            exports.push({
              name: decl.id.name,
              type: "const",
              signature: "const",
            });
          }
        }
      }
    }
  }

  return exports;
}

if (import.meta.main) {
  console.log("Running Local Code Intelligence PoC (Gen 2) tests...");

  const mockSourceCode = `
import { stuff } from "somewhere";

/**
 * Calculates a complex value.
 */
export async function calculateValue(input: number, mode: string): Promise<number> {
  return input * 2;
}

// An internal helper
function internalHelper() {
  return true;
}

export const MAX_RETRIES = 5;

export function doSomethingElse(): void {
  console.log(MAX_RETRIES);
}
`;

  try {
    const extracted = extractExports(mockSourceCode);

    assertEquals(extracted.length, 3);

    const calcFunc = extracted.find((e) => e.name === "calculateValue");
    assertEquals(calcFunc?.type, "function");
    assertEquals(
      calcFunc?.signature,
      "(input, mode) => any",
    );

    const maxRetries = extracted.find((e) => e.name === "MAX_RETRIES");
    assertEquals(maxRetries?.type, "const");

    const doSomething = extracted.find((e) => e.name === "doSomethingElse");
    assertEquals(doSomething?.type, "function");
    assertEquals(doSomething?.signature, "() => any");

    console.log(
      "✅ Local Code Intelligence PoC (Gen 2) successful: Extracted structured context from raw source using AST Parser.",
    );

    console.log("\n--- Agent Context Payload ---");
    console.log(JSON.stringify(extracted, null, 2));
    console.log("-----------------------------\n");
  } catch (err) {
    console.error("❌ Local Code Intelligence PoC (Gen 2) failed:", err);
  }
}