// ========= Copyright 2026 @ Strukto.AI All Rights Reserved. =========
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ========= Copyright 2026 @ Strukto.AI All Rights Reserved. =========

import {
  IOResult,
  ResourceName,
  command,
  featherLs,
  featherLsFallback,
  materialize,
  specOf,
  type ByteSource,
  type CommandFnResult,
  type CommandOpts,
  type PathSpec,
} from '../../../../index.ts'
import { stream as s3Stream } from '../../../../core/s3/stream.ts'
import { stat as s3Stat } from '../../../../core/s3/stat.ts'
import type { S3Accessor } from '../../../../accessor/s3.ts'

const ENC = new TextEncoder()

async function lsFeatherCommand(
  accessor: S3Accessor,
  paths: PathSpec[],
  _texts: string[],
  _opts: CommandOpts,
): Promise<CommandFnResult> {
  const [first] = paths
  if (first === undefined) {
    return [null, new IOResult({ exitCode: 1, stderr: ENC.encode('ls: missing operand\n') })]
  }
  const stat = await s3Stat(accessor, first)
  const meta = { size: stat.size ?? 0, modified: stat.modified, name: stat.name }
  try {
    const raw = await materialize(s3Stream(accessor, first))
    const out: ByteSource = featherLs(raw, meta)
    return [out, new IOResult({ cache: [first.stripPrefix] })]
  } catch {
    return [featherLsFallback(meta), new IOResult()]
  }
}

export const S3_LS_FEATHER = [
  ...command({
    name: 'ls',
    resource: ResourceName.S3,
    spec: specOf('ls'),
    filetype: '.arrow',
    fn: lsFeatherCommand,
  }),
  ...command({
    name: 'ls',
    resource: ResourceName.S3,
    spec: specOf('ls'),
    filetype: '.ipc',
    fn: lsFeatherCommand,
  }),
  ...command({
    name: 'ls',
    resource: ResourceName.S3,
    spec: specOf('ls'),
    filetype: '.feather',
    fn: lsFeatherCommand,
  }),
]
