import {compressActions, decompressActions} from "../serialization/actions"

export interface Chord {
  actions: number[]
  phrase: number[]
}

export function parsePhrase(phrase: string): number[] {
  return decompressActions(
    Uint8Array.from({length: phrase.length / 2}).map((_, i) =>
      Number.parseInt(phrase.slice(i * 2, i * 2 + 2), 16),
    ),
  )
}

export function stringifyPhrase(phrase: number[]): string {
  return [...compressActions(phrase)]
    .map(it => it.toString(16).padStart(2, "0"))
    .join("")
    .toUpperCase()
}

export function parseChordActions(actions: string): number[] {
  return deserializeActions(BigInt(`0x${actions}`))
}

export function stringifyChordActions(actions: number[]): string {
  return serializeActions(actions).toString(16).padStart(32, "0").toUpperCase()
}

/**
 * Binary serialization of actions
 *
 * Actions are represented as 10-bit codes, for a maximum of 12 actions
 */
export function serializeActions(actions: number[]): bigint {
  let native = 0n
  for (let i = 1; i <= actions.length; i++) {
    native |= BigInt(actions[actions.length - i] & 0x3ff) << BigInt((12 - i) * 10)
  }
  return native
}

/**
 * @see {serializeActions}
 */
export function deserializeActions(native: bigint): number[] {
  const actions = []
  for (let i = 0; i < 12; i++) {
    const action = Number(native & 0x3ffn)
    if (action !== 0) {
      actions.push(action)
    }
    native >>= 10n
  }

  return actions
}