import type { Block, BlockIndex } from './api.js'
import type { CID } from 'multiformats/cid'

export interface CarEncoder {
  setRoots(roots: CID[]): Promise<void>

  writeBlock(block: Block): Promise<void>

  close(): Promise<void>

  version(): number
}

export interface IteratorChannel_Writer<T> {
  write(chunk: T): Promise<void>
  end(): Promise<void>
}

export interface IteratorChannel<T> {
  writer: IteratorChannel_Writer<T>

  iterator: AsyncIterator<T>
}

export interface CarHeader {
  version: 1
  roots: CID[]
}

export interface CarV2FixedHeader {
  characteristics: [bigint, bigint]
  dataOffset: number
  dataSize: number
  indexOffset: number
}

export interface CarV2Header extends CarV2FixedHeader {
  version: 2
  roots: CID[]
}

export interface CarDecoder {
  header(): Promise<CarHeader | CarV2Header>

  blocks(): AsyncGenerator<Block>

  blocksIndex(): AsyncGenerator<BlockIndex>
}

export interface Seekable {
  seek(length: number): void
}

export interface BytesReader extends Seekable {
  upTo(length: number): Promise<Uint8Array>

  exactly(length: number, seek?: boolean): Promise<Uint8Array>

  pos: number
}

export interface BytesBufferReader extends Seekable {
  upTo(length: number): Uint8Array

  exactly(length: number, seek?: boolean): Uint8Array

  pos: number
}