import fs from "fs";
import path from "path";

export function findProjectRoot(): string {
  // Start from current directory and walk up until we find package.json
  let currentDir = process.cwd();
  while (currentDir !== path.parse(currentDir).root) {
    const packageJsonPath = path.join(currentDir, "package.json");
    if (fs.existsSync(packageJsonPath)) {
      return currentDir;
    }
    currentDir = path.dirname(currentDir);
  }
  // Fallback to current directory if package.json not found
  return process.cwd();
}

// Helper function to find and parse go.mod file
export function findAndParseGoMod(
  startDir: string
): { root: string; modulePath: string } | null {
  let currentDir = startDir;
  while (currentDir !== path.parse(currentDir).root) {
    const goModPath = path.join(currentDir, "go.mod");
    if (fs.existsSync(goModPath)) {
      try {
        const goModContent = fs.readFileSync(goModPath, "utf-8");
        const moduleMatch = goModContent.match(/^module\s+(\S+)/m);
        if (moduleMatch && moduleMatch[1]) {
          return {
            root: currentDir,
            modulePath: moduleMatch[1],
          };
        }
      } catch (error) {
        console.warn(`Error reading go.mod at ${goModPath}:`, error);
      }
    }
    currentDir = path.dirname(currentDir);
  }
  return null;
}

// Helper function to calculate import path from file path
export function calculateImportPath(filePath: string): string | null {
  const goModInfo = findAndParseGoMod(path.dirname(filePath));
  if (!goModInfo) {
    return null;
  }

  const relativePath = path.relative(goModInfo.root, path.dirname(filePath));
  if (relativePath && relativePath !== ".") {
    return path.join(goModInfo.modulePath, relativePath).replace(/\\/g, "/");
  }
  return goModInfo.modulePath;
}

// Helper function to normalize import path
export function normalizeImportPath(importPath: string): string {
  // Remove leading ./
  if (importPath.startsWith("./")) {
    return importPath.substring(2);
  }
  return importPath;
}