// containerService.js
const docker = require('./dockerClient');
const calculateCPUPercent = require('../utils/calculateCPU');
const chalk = require('chalk').default;

async function listContainers() {
  const containers = await docker.listContainers({ all: true });
  return Promise.all(containers.map(async (containerInfo) => {
    const container = docker.getContainer(containerInfo.Id);
    const inspect = await container.inspect();
    return {
      id: containerInfo.Id,
      name: containerInfo.Names[0].replace('/', ''),
      image: containerInfo.Image,
      status: containerInfo.State,
      state: containerInfo.Status,
      ports: containerInfo.Ports,
      created: containerInfo.Created,
      labels: containerInfo.Labels || {},
      inspect: {
        config: inspect.Config,
        hostConfig: inspect.HostConfig,
        networkSettings: inspect.NetworkSettings
      }
    };
  }));
}

async function getContainerStats(id) {
  const container = docker.getContainer(id);
  const stats = await container.stats({ stream: false });
  const cpuPercent = calculateCPUPercent(stats);
  const memoryUsage = stats.memory_stats.usage || 0;
  const memoryLimit = stats.memory_stats.limit || 0;
  const memoryPercent = memoryLimit > 0 ? (memoryUsage / memoryLimit) * 100 : 0;
  const networks = stats.networks || {};
  const networkIO = Object.keys(networks).reduce((acc, key) => ({
    rx_bytes: acc.rx_bytes + (networks[key].rx_bytes || 0),
    tx_bytes: acc.tx_bytes + (networks[key].tx_bytes || 0)
  }), { rx_bytes: 0, tx_bytes: 0 });
  return {
    cpu_percent: cpuPercent,
    memory: { usage: memoryUsage, limit: memoryLimit, percent: memoryPercent },
    network: networkIO,
    block_io: stats.blkio_stats
  };
}

async function startContainer(id) {
  const container = docker.getContainer(id);
  await container.start();
  console.log(chalk.yellow('Container started:'), chalk.cyan(id));
}

async function stopContainer(id) {
  const container = docker.getContainer(id);
  await container.stop();
  console.log(chalk.yellow('Container stopped:'), chalk.cyan(id));
}

async function restartContainer(id) {
  const container = docker.getContainer(id);
  await container.restart();
  console.log(chalk.yellow('Container restarted:'), chalk.cyan(id));
}

async function createContainer(options) {
  const container = await docker.createContainer(options);
  await container.start();
  console.log(chalk.green('Container created and started:'), chalk.cyan(container.id));
  return container.id;
}

async function removeContainer(id) {
  const container = docker.getContainer(id);
  try { await container.stop(); } catch (e) {}
  await container.remove();
  console.log(chalk.red('Container deleted:'), chalk.cyan(id));
}

async function getContainerLogs(id) {
  const container = docker.getContainer(id);
  const logs = await container.logs({
    stdout: true,
    stderr: true,
    tail: 100,
    timestamps: true
  });
  return logs.toString();
}

async function execCommand(id, command) {
  const container = docker.getContainer(id);
  
  // Check if container is running
  const info = await container.inspect();
  if (!info.State.Running) {
    throw new Error('Container is not running');
  }

  // Create exec instance
  const exec = await container.exec({
    Cmd: ['/bin/sh', '-c', command],
    AttachStdout: true,
    AttachStderr: true,
  });

  // Start exec and capture output
  return new Promise((resolve, reject) => {
    exec.start({ hijack: true, stdin: false }, (err, stream) => {
      if (err) {
        return reject(err);
      }

      let output = '';
      let errorOutput = '';

      // Docker multiplexes stdout and stderr into a single stream
      // Each frame has an 8-byte header
      stream.on('data', (chunk) => {
        // Parse Docker stream format
        let offset = 0;
        while (offset < chunk.length) {
          if (chunk.length - offset < 8) break;
          
          const header = chunk.slice(offset, offset + 8);
          const streamType = header[0]; // 1=stdout, 2=stderr
          const size = header.readUInt32BE(4);
          
          offset += 8;
          
          if (chunk.length - offset < size) break;
          
          const payload = chunk.slice(offset, offset + size).toString('utf8');
          
          if (streamType === 1) {
            output += payload;
          } else if (streamType === 2) {
            errorOutput += payload;
          }
          
          offset += size;
        }
      });

      stream.on('end', async () => {
        try {
          const execInfo = await exec.inspect();
          console.log(chalk.blue('Command executed:'), chalk.cyan(command), chalk.yellow('Exit code:'), execInfo.ExitCode);
          
          resolve({
            output: (output + errorOutput).trim(),
            exitCode: execInfo.ExitCode,
            error: execInfo.ExitCode !== 0 ? errorOutput.trim() : null
          });
        } catch (inspectError) {
          reject(inspectError);
        }
      });

      stream.on('error', (streamError) => {
        reject(streamError);
      });

      // Set timeout (30 seconds)
      setTimeout(() => {
        stream.destroy();
        reject(new Error('Command execution timeout'));
      }, 30000);
    });
  });
}

async function renameContainer(id, newName) {
  const container = docker.getContainer(id);
  await container.rename({ name: newName });
  console.log(chalk.yellow('Container renamed:'), chalk.cyan(id), chalk.green('→'), chalk.cyan(newName));
}

module.exports = {
  listContainers,
  getContainerStats,
  startContainer,
  stopContainer,
  restartContainer,
  createContainer,
  removeContainer,
  getContainerLogs,
  execCommand,
  renameContainer
};