import * as fs from "fs";
import * as path from "path";

export interface MarkdownFile {
  path: string;
  content: string;
}

const FILENAMES = ["LLMTUNE.md", "CLAUDE.md", ".llmtune", ".claude"];

export function loadProjectInstructions(
  workspaceRoot: string,
  cwd: string
): MarkdownFile[] {
  const files: MarkdownFile[] = [];
  const seen = new Set<string>();

  const dirsToCheck = [cwd];
  let current = cwd;
  while (current !== workspaceRoot && current !== path.dirname(current)) {
    current = path.dirname(current);
    dirsToCheck.push(current);
  }
  dirsToCheck.push(workspaceRoot);

  for (const dir of dirsToCheck) {
    for (const filename of FILENAMES) {
      const filePath = path.join(dir, filename);
      const resolved = path.resolve(filePath);
      if (seen.has(resolved)) continue;

      try {
        const stat = fs.statSync(filePath);
        if (stat.isFile()) {
          const content = fs.readFileSync(filePath, "utf-8");
          if (content.trim()) {
            seen.add(resolved);
            files.push({ path: resolved, content: content.trim() });
          }
        }
      } catch {
        // file doesn't exist, skip
      }
    }
  }

  return files;
}