/**
 * Volume RPC handlers.
 */
import fs from 'fs'
import path from 'path'
import { docker, extractVolumesList } from '../services/docker.js'
import * as validation from '../utils/validation.js'
import { Pushes } from '../../shared/protocol.js'
import { peers } from '../core/peer-registry.js'
import logger from '../utils/logger.js'

export function registerVolumeHandlers(session) {
  session.respond('listVolumes', async () => {
    try {
      const volumesResult = await docker.listVolumes()
      const volumesList = extractVolumesList(volumesResult)
      return {
        type: 'volumes',
        data: volumesList,
        success: true,
        volumes: volumesList,
      }
    } catch (error) {
      return {
        type: 'volumes',
        success: false,
        error: `Failed to list volumes: ${error.message}`,
        data: [],
        volumes: [],
      }
    }
  })

  session.respond('createVolume', async (args) => {
    const volumeConfig = {
      Name: validation.sanitizeString(args.name, 128),
    }
    if (args.driver) volumeConfig.Driver = args.driver
    if (args.options && typeof args.options === 'object') {
      volumeConfig.DriverOpts = args.options
    }
    const volume = await docker.createVolume(volumeConfig)
    await broadcastVolumes()
    return {
      success: true,
      message: `Volume "${args.name}" created successfully`,
      data: volume.name,
    }
  })

  session.respond('removeVolume', async (args) => {
    await docker.getVolume(args.name).remove()
    await broadcastVolumes()
    return { success: true, message: `Volume ${args.name} removed` }
  })

  session.respond('inspectVolume', async (args) => {
    const volumeData = await docker.getVolume(args.name).inspect()
    return { type: 'volumeConfig', data: volumeData }
  })

  /**
   * List files in a local volume mountpoint (server-side Docker host).
   * Requires the volume mountpoint to be readable; path is confined under Mountpoint.
   */
  session.respond('browseVolume', async (args = {}) => {
    const name = validation.sanitizeString(args.name || args.volume || '', 128)
    if (!name) throw Object.assign(new Error('Volume name required'), { code: 'INVALID_ARGS' })
    let rel = String(args.path || '/').trim() || '/'
    if (!rel.startsWith('/')) rel = `/${rel}`
    if (rel.includes('..')) {
      throw Object.assign(new Error('Invalid path'), { code: 'INVALID_ARGS' })
    }

    const volumeData = await docker.getVolume(name).inspect()
    const mountpoint = volumeData.Mountpoint
    if (!mountpoint) {
      throw Object.assign(
        new Error('Volume has no local mountpoint (remote/cloud volumes cannot be browsed here)'),
        { code: 'INVALID_ARGS' }
      )
    }

    const target = path.normalize(path.join(mountpoint, rel === '/' ? '' : rel.slice(1)))
    const root = path.normalize(mountpoint)
    if (target !== root && !target.startsWith(root + path.sep)) {
      throw Object.assign(new Error('Path escapes volume mountpoint'), { code: 'PERMISSION_DENIED' })
    }

    let stats
    try {
      stats = fs.statSync(target)
    } catch (err) {
      if (err.code === 'ENOENT') {
        throw Object.assign(new Error('Path not found in volume'), { code: 'INVALID_ARGS' })
      }
      throw err
    }
    if (!stats.isDirectory()) {
      throw Object.assign(new Error('Not a directory'), { code: 'INVALID_ARGS' })
    }

    const entries = []
    for (const ent of fs.readdirSync(target, { withFileTypes: true })) {
      let size = null
      let mtime = null
      try {
        const st = fs.statSync(path.join(target, ent.name))
        size = st.size
        mtime = st.mtime?.toISOString?.() || null
      } catch {
        // ignore
      }
      entries.push({
        name: ent.name,
        type: ent.isDirectory() ? 'dir' : ent.isSymbolicLink() ? 'link' : 'file',
        size,
        mtime,
      })
    }
    entries.sort((a, b) => {
      if (a.type === 'dir' && b.type !== 'dir') return -1
      if (a.type !== 'dir' && b.type === 'dir') return 1
      return a.name.localeCompare(b.name)
    })

    return {
      success: true,
      type: 'volumeBrowse',
      name,
      path: rel,
      mountpoint,
      entries,
    }
  })

  session.respond('pruneVolumes', async (args) => {
    const opts = {}
    if (args.filters) opts.filters = args.filters
    const result = await docker.pruneVolumes(opts)
    await broadcastVolumes()
    return {
      success: true,
      type: 'pruneVolumes',
      message: 'Unused volumes pruned',
      data: result,
    }
  })
}

export async function broadcastVolumes() {
  try {
    const volumesResult = await docker.listVolumes()
    const volumesList = extractVolumesList(volumesResult)
    peers.broadcast(Pushes.volumes, {
      type: 'volumes',
      data: volumesList,
      success: true,
      volumes: volumesList,
    })
  } catch (err) {
    logger.error('Failed to broadcast volumes', { error: err.message })
  }
}