import { MAX_FIRMWARE_FILE_SIZE } from '@/lib/firmware'
import {
  buildFirmwareHashInput,
  type FirmwareHashByteOrder,
} from '@/lib/firmwareHash'
import { concatenateBlocks, parseIntelHex } from '@/lib/intelHex'

export type SignatureFileMode = 'raw-file' | 'intel-hex' | 'intel-hex-block-header'

export interface ParsedSignatureFile {
  data: Uint8Array
  dataBytes: number
  effectiveDataBytes: number
  headerBytes: number
  blockCount?: number
  warnings: string[]
}

export async function parseSignatureFile(
  file: File,
  mode: SignatureFileMode,
  byteOrder: FirmwareHashByteOrder = 'big-endian',
): Promise<ParsedSignatureFile> {
  if (file.size > MAX_FIRMWARE_FILE_SIZE) throw new Error('文件不能超过 64 MiB')
  if (mode === 'raw-file') {
    const data = new Uint8Array(await file.arrayBuffer())
    return { data, dataBytes: data.length, effectiveDataBytes: data.length, headerBytes: 0, warnings: [] }
  }
  if (mode !== 'intel-hex' && mode !== 'intel-hex-block-header') throw new Error('文件数据模式无效')
  const parsed = parseIntelHex(await file.text())
  const headerBytes = mode === 'intel-hex-block-header' ? parsed.blocks.length * 8 : 0
  if (parsed.totalBytes + headerBytes > MAX_FIRMWARE_FILE_SIZE) {
    throw new Error('加入 Block 校验头后的待验签数据不能超过 64 MiB')
  }
  const data = mode === 'intel-hex-block-header'
    ? buildFirmwareHashInput(parsed.blocks, 'block-header', byteOrder)
    : concatenateBlocks(parsed.blocks)
  return {
    data,
    dataBytes: data.length,
    effectiveDataBytes: parsed.totalBytes,
    headerBytes,
    blockCount: parsed.blocks.length,
    warnings: parsed.warnings,
  }
}