import { promises as fs } from "fs";
import path from "path";
import { existsSync } from "fs";
import bcrypt from "bcryptjs";

const PASSWORD_FILE = path.join(process.cwd(), "prisma", "password.json");

interface PasswordData {
  hash: string;
  createdAt: string;
  updatedAt: string;
}

async function ensurePasswordFile(): Promise<void> {
  if (!existsSync(PASSWORD_FILE)) {
    // Create default password "admin" if file doesn't exist
    const defaultHash = await bcrypt.hash("admin", 10);
    const defaultData: PasswordData = {
      hash: defaultHash,
      createdAt: new Date().toISOString(),
      updatedAt: new Date().toISOString(),
    };
    await fs.writeFile(PASSWORD_FILE, JSON.stringify(defaultData, null, 2), "utf-8");
  }
}

async function loadPasswordData(): Promise<PasswordData> {
  await ensurePasswordFile();
  const content = await fs.readFile(PASSWORD_FILE, "utf-8");
  return JSON.parse(content);
}

async function savePasswordData(data: PasswordData): Promise<void> {
  await fs.writeFile(PASSWORD_FILE, JSON.stringify(data, null, 2), "utf-8");
}

export const authService = {
  async verifyPassword(password: string): Promise<boolean> {
    try {
      const data = await loadPasswordData();
      return await bcrypt.compare(password, data.hash);
    } catch (error) {
      console.error("Error verifying password:", error);
      return false;
    }
  },

  async changePassword(oldPassword: string, newPassword: string): Promise<{ success: boolean; error?: string }> {
    try {
      // Verify old password
      const isValid = await this.verifyPassword(oldPassword);
      if (!isValid) {
        return { success: false, error: "Mot de passe actuel incorrect" };
      }

      // Hash new password
      const newHash = await bcrypt.hash(newPassword, 10);
      const data = await loadPasswordData();
      
      // Update password
      data.hash = newHash;
      data.updatedAt = new Date().toISOString();
      
      await savePasswordData(data);
      
      return { success: true };
    } catch (error) {
      console.error("Error changing password:", error);
      return { success: false, error: "Erreur lors du changement de mot de passe" };
    }
  },

  async hasPassword(): Promise<boolean> {
    try {
      await ensurePasswordFile();
      return existsSync(PASSWORD_FILE);
    } catch {
      return false;
    }
  },
};