const fs = require("fs-extra");
const path = require("path");
const Odmdb = require("./Odmdb.js");

const DATA_PATH = process.env.DATAPATH;
const TRIBE_NAME = process.env.TOWN;
const log = process.env.ACTIVELOG?.split(',').includes('Towns');

/**
 * Manages towns, which represent server instances in the network.
 */
class Towns {

  /**
   * Changes the owner (mayor) of a town.
   * @param {string} newOwnerAlias - The alias of the new owner.
   * @param {string} requestedByAlias - The alias of the user requesting the change (must be the current owner).
   * @returns {Promise<object>} A response object.
   */
  static async changeowner(newOwnerAlias, requestedByAlias) {
    try {
      const townsDb = new Odmdb('towns', TRIBE_NAME);
      const pagansDb = new Odmdb('pagans', TRIBE_NAME);
      const confPath = path.join(DATA_PATH, TRIBE_NAME, 'conf.json');

      // 1. Verify the new owner exists as a pagan
      const newOwnerResult = await pagansDb.read(newOwnerAlias, { xprofils: ['admin'] });
      if (newOwnerResult.status !== 200) {
        return { status: 404, ref: "Towns", msg: "new_owner_alias_not_found", data: { alias: newOwnerAlias } };
      }

      // 2. Verify the requester is the current mayor
      const townConf = await fs.readJson(confPath);
      if (townConf.mayorId !== requestedByAlias) {
        return { status: 403, ref: "Towns", msg: "permission_denied_not_current_mayor" };
      }

      // 3. Update the town's data file
      const townId = townConf.townId;
      const townUpdateData = { townId, mayorId: newOwnerAlias };
      const role = { xprofils: ['admin', 'mayor'], xalias: requestedByAlias };
      const updateResult = await townsDb.update( townUpdateData, role);

      if (updateResult.status !== 200) {
        return updateResult; // Forward the error from Odmdb
      }

      // 4. Update the local server configuration file
      townConf.mayorId = newOwnerAlias;
      await fs.outputJson(confPath, townConf, { spaces: 2 });

      if (log) console.log(`[Towns] Town owner changed successfully to '${newOwnerAlias}' by '${requestedByAlias}'.`);
      return { status: 200, ref: "Towns", msg: "owner_change_successful", data: { alias: newOwnerAlias, townId } };

    } catch (error) {
      console.error(`[Towns] Error changing owner to '${newOwnerAlias}':`, error);
      return { status: 500, ref: "Towns", msg: "internal_server_error", error: error.message };
    }
  }

  /**
   * @deprecated The create method contains server setup logic (like nginx config)
   * and should not be part of a data model. This logic should be moved to a
   * dedicated setup or installation script.
   */
  static create() {
    console.error("[Towns] The 'create' method is deprecated and should not be used. Please use a dedicated setup script.");
    return { status: 501, ref: "Towns", msg: "create_method_is_deprecated" };
  }

  static async addCrontabEntry(cronExpression, command, identifier) {
    try {
      const { exec } = require('child_process');
      const { promisify } = require('util');
      const execAsync = promisify(exec);
      
      const tmpCronFile = path.join(DATA_PATH, TRIBE_NAME, 'tmp', `cron_${Date.now()}.txt`);
      await fs.ensureDir(path.dirname(tmpCronFile));
      
      const { stdout: currentCron } = await execAsync('crontab -l 2>/dev/null || true');
      
      const cronLines = currentCron.split('\n').filter(line => {
        if (!line.trim()) return false;
        if (identifier && line.includes(identifier)) return false;
        return true;
      });
      
      const cronEntry = `${cronExpression} ${command} # ${identifier}`;
      cronLines.push(cronEntry);
      
      await fs.writeFile(tmpCronFile, cronLines.join('\n') + '\n');
      
      await execAsync(`crontab "${tmpCronFile}"`);
      await fs.remove(tmpCronFile);
      
      if (log) console.log(`[Towns] Crontab entry added: ${cronEntry}`);
      return { status: 200, ref: "Towns", msg: "crontab_entry_added", data: { cronEntry } };
      
    } catch (error) {
      console.error('[Towns] Error adding crontab entry:', error);
      return { status: 500, ref: "Towns", msg: "crontab_entry_failed", error: error.message };
    }
  }

  static async removeCrontabEntry(identifier) {
    try {
      const { exec } = require('child_process');
      const { promisify } = require('util');
      const execAsync = promisify(exec);
      
      const tmpCronFile = path.join(DATA_PATH, TRIBE_NAME, 'tmp', `cron_${Date.now()}.txt`);
      await fs.ensureDir(path.dirname(tmpCronFile));
      
      const { stdout: currentCron } = await execAsync('crontab -l 2>/dev/null || true');
      
      const cronLines = currentCron.split('\n').filter(line => {
        if (!line.trim()) return false;
        if (identifier && line.includes(identifier)) return false;
        return true;
      });
      
      await fs.writeFile(tmpCronFile, cronLines.join('\n') + '\n');
      
      await execAsync(`crontab "${tmpCronFile}"`);
      await fs.remove(tmpCronFile);
      
      if (log) console.log(`[Towns] Crontab entries removed for: ${identifier}`);
      return { status: 200, ref: "Towns", msg: "crontab_entry_removed", data: { identifier } };
      
    } catch (error) {
      console.error('[Towns] Error removing crontab entry:', error);
      return { status: 500, ref: "Towns", msg: "crontab_remove_failed", error: error.message };
    }
  }
}

module.exports = Towns;