import {
  dirname,
  fromFileUrl,
  join,
} from "https://deno.land/std@0.224.0/path/mod.ts";
import { assertEquals } from "https://deno.land/std@0.224.0/testing/asserts.ts";
import { execTool, requireTool } from "./sys_exec.ts";

/**
 * Proof of Concept: Local Code Intelligence (Gen 2)
 *
 * Replaces the naive regex extraction in Gen 1 with actual AST parsing using
 * the tree-sitter CLI binary natively via system execution, 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 async function extractExports(
  sourceCode: string,
): Promise<ExportSymbol[]> {
  const currentDir = dirname(fromFileUrl(import.meta.url));
  const TEMP_FILE = join(currentDir, "dummy_intelligence_target.js");
  const exports: ExportSymbol[] = [];

  try {
    // Strip TypeScript annotations using a regex just to let the basic js tree-sitter parse it
    const jsCode = sourceCode
      .replace(/:\s*Promise<[^>]+>/g, "")
      .replace(/:\s*[a-zA-Z0-9_]+/g, "")
      .replace(/<[^>]+>/g, "");

    await Deno.writeTextFile(TEMP_FILE, jsCode);

    // Call native tree-sitter parser
    const { code, stdout, stderr } = await execTool("tree-sitter", [
      "parse",
      TEMP_FILE,
      "-x",
    ]);

    if (code !== 0) {
      throw new Error(`Tree-sitter CLI execution failed: ${stderr || stdout}`);
    }

    // In a full implementation, we'd use a real XML or s-expression parser
    // For this PoC, we will do basic extraction from the XML output format
    // of tree-sitter to demonstrate the tree traversal concept.

    // Look for exported functions
    const funcMatches = stdout.matchAll(
      /<export_statement.*?<function_declaration.*?<identifier field="name".*?>(.*?)<\/identifier>.*?<formal_parameters field="parameters".*?>(.*?)<\/formal_parameters>.*?<\/function_declaration>.*?<\/export_statement>/gs,
    );
    for (const match of funcMatches) {
      const name = match[1];
      const paramsXml = match[2];
      const params = [
        ...paramsXml.matchAll(/<identifier.*?>(.*?)<\/identifier>/gs),
      ].map((m) => m[1]).join(", ");

      exports.push({
        name,
        type: "function",
        signature: `(${params}) => any`,
      });
    }

    // Look for exported consts
    const constMatches = stdout.matchAll(
      /<export_statement.*?<lexical_declaration.*?<variable_declarator.*?<identifier field="name".*?>(.*?)<\/identifier>.*?<\/variable_declarator>.*?<\/lexical_declaration>.*?<\/export_statement>/gs,
    );
    for (const match of constMatches) {
      exports.push({
        name: match[1],
        type: "const",
        signature: "const",
      });
    }
  } finally {
    try {
      await Deno.remove(TEMP_FILE);
    } catch {
      // ignore
    }
  }

  return exports;
}

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);
}
`;

async function run() {
  const hasTreeSitter = await requireTool(
    "tree-sitter",
    "npm install -g tree-sitter-cli",
  );
  if (!hasTreeSitter) {
    console.warn(
      "⚠️ Local Code Intelligence PoC skipped due to missing host dependency.",
    );
    return;
  }

  try {
    const extracted = await 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 native tree-sitter CLI.",
    );

    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);
    Deno.exit(1);
  }
}

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