/**
 * Registry credential vault RPC handlers.
 */
import * as vault from '../core/registry-vault.js'
import * as validation from '../utils/validation.js'
import { docker } from '../services/docker.js'
import logger from '../utils/logger.js'
import { getSessionAuthconfig, setSessionAuthconfig, clearSessionAuthconfig } from './system.js'

/**
 * Resolve Docker authconfig for pull/push from vault id, inline auth, or session.
 * @param {import('../rpc/session.js').PeerSession} session
 * @param {{ credentialId?: string, auth?: object, autoVault?: boolean, image?: string }} args
 * @returns {{ username: string, password: string, serveraddress: string }|null}
 */
export function resolveRegistryAuth(session, args = {}) {
  if (args.credentialId) {
    const cred = vault.getCredential(String(args.credentialId))
    if (!cred) throw Object.assign(new Error('Vault credential not found'), { code: 'VAULT_NOT_FOUND' })
    return {
      username: cred.username,
      password: cred.password,
      serveraddress: cred.serveraddress,
    }
  }
  if (args.auth && args.auth.username && args.auth.password) {
    return {
      username: String(args.auth.username),
      password: String(args.auth.password),
      serveraddress:
        args.auth.serveraddress || 'https://index.docker.io/v1/',
    }
  }
  const sessionAuth = getSessionAuthconfig(session)
  if (sessionAuth) {
    return {
      username: sessionAuth.username,
      password: sessionAuth.password,
      serveraddress: sessionAuth.serveraddress,
    }
  }
  // Optional: match vault entry from image registry host
  if (args.autoVault !== false && args.image) {
    const host = registryHostFromImage(args.image)
    if (host) {
      const found = vault.findCredentialForServer(host)
      if (found) {
        return {
          username: found.username,
          password: found.password,
          serveraddress: found.serveraddress,
        }
      }
    }
  }
  return null
}

/**
 * @param {string} image
 * @returns {string|null}
 */
export function registryHostFromImage(image) {
  if (!image || typeof image !== 'string') return null
  const ref = image.split('@')[0]
  const withoutTag = ref.includes('/')
    ? ref.replace(/:[^/]+$/, '')
    : ref
  // docker.io short names: nginx, library/nginx, user/app
  const parts = withoutTag.split('/')
  if (parts.length === 1) return 'docker.io'
  if (parts.length === 2 && !parts[0].includes('.') && !parts[0].includes(':') && parts[0] !== 'localhost') {
    return 'docker.io'
  }
  return parts[0].split(':')[0] || null
}

async function checkDockerAuth(authconfig) {
  return new Promise((resolve, reject) => {
    docker.checkAuth(authconfig, (err, res) => (err ? reject(err) : resolve(res)))
  })
}

export function registerVaultHandlers(session) {
  session.respond('listVaultCredentials', async () => {
    return {
      success: true,
      type: 'vaultCredentials',
      data: vault.listCredentials(),
    }
  })

  session.respond('vaultStoreCredential', async (args) => {
    const username = validation.sanitizeString(args.username, 128)
    const password = args.password
    const serveraddress = validation.sanitizeString(
      args.serveraddress || 'https://index.docker.io/v1/',
      512
    )
    const label = validation.sanitizeString(args.label || '', 128)
    if (!username || !password) throw new Error('username and password required')

    // Optional verify against engine
    if (args.verify !== false) {
      try {
        await checkDockerAuth({ username, password, serveraddress })
      } catch (err) {
        if (args.requireAuth) throw new Error(`Auth failed: ${err.message}`)
        logger.warn('vault store: checkAuth soft-fail', { error: err.message })
      }
    }

    const stored = vault.storeCredential({
      id: args.id,
      username,
      password,
      serveraddress,
      label: label || username,
    })
    return { success: true, message: 'Credential stored encrypted at rest', data: stored }
  })

  session.respond('vaultDeleteCredential', async (args) => {
    if (!args.id) throw new Error('credential id required')
    return vault.deleteCredential(args.id)
  })

  session.respond('vaultUseCredential', async (args) => {
    if (!args.id) throw new Error('credential id required')
    const listed = vault.listCredentials().find((c) => c.id === args.id)
    const cred = vault.getCredential(args.id)
    if (!cred) throw new Error('Credential not found')
    const auth = {
      username: cred.username,
      password: cred.password,
      serveraddress: cred.serveraddress,
      credentialId: args.id,
      label: listed?.label || cred.username,
    }
    setSessionAuthconfig(session, auth)
    return {
      success: true,
      message: `Using vault credential for ${cred.username}`,
      data: {
        id: args.id,
        username: cred.username,
        serveraddress: cred.serveraddress,
        label: listed?.label || null,
      },
    }
  })

  session.respond('vaultTestCredential', async (args) => {
    let authconfig = null
    if (args.id) {
      const cred = vault.getCredential(String(args.id))
      if (!cred) throw new Error('Credential not found')
      authconfig = {
        username: cred.username,
        password: cred.password,
        serveraddress: cred.serveraddress,
      }
    } else {
      const username = validation.sanitizeString(args.username, 128)
      const password = args.password
      const serveraddress = validation.sanitizeString(
        args.serveraddress || 'https://index.docker.io/v1/',
        512
      )
      if (!username || !password) throw new Error('id or username+password required')
      authconfig = { username, password, serveraddress }
    }
    try {
      const res = await checkDockerAuth(authconfig)
      return {
        success: true,
        ok: true,
        message: `Authenticated as ${authconfig.username}`,
        data: {
          username: authconfig.username,
          serveraddress: authconfig.serveraddress,
          identityToken: Boolean(res?.IdentityToken),
          status: res?.Status || null,
        },
      }
    } catch (err) {
      throw Object.assign(new Error(`Auth failed: ${err.message}`), {
        code: 'REGISTRY_AUTH_FAILED',
      })
    }
  })

  session.respond('vaultClearSession', async () => {
    clearSessionAuthconfig(session)
    return { success: true, message: 'Registry session credentials cleared' }
  })
}