import path from 'node:path';
import { mkdir, readFile, writeFile } from 'node:fs/promises';
import {
  createProjectConversationState,
  normalizeProjectConversationState,
  type ProjectConversationState,
} from '../../shared/project-conversations';

export const PROJECT_CONVERSATIONS_PATH = '.niancode/conversations.json';

function statePath(projectPath: string): string {
  return path.join(projectPath, PROJECT_CONVERSATIONS_PATH);
}

export async function readProjectConversationState(projectPath: string): Promise<ProjectConversationState> {
  try {
    const raw = JSON.parse(await readFile(statePath(projectPath), 'utf8')) as unknown;
    return normalizeProjectConversationState(raw);
  } catch (error) {
    if ((error as NodeJS.ErrnoException).code === 'ENOENT') return createProjectConversationState();
    throw error;
  }
}

export async function writeProjectConversationState(
  projectPath: string,
  value: unknown,
): Promise<ProjectConversationState> {
  const state = normalizeProjectConversationState(value);
  await mkdir(path.dirname(statePath(projectPath)), { recursive: true });
  await writeFile(statePath(projectPath), `${JSON.stringify(state, null, 2)}\n`, 'utf8');
  return state;
}