import crypto from "crypto"
import { Effect, Option } from "effect-app"
import { OptimisticConcurrencyException } from "../errors.js"
import type { PersistenceModelType, SupportedValues2 } from "./service.js"

export const makeETag = <E extends PersistenceModelType<{}>>(
  { _etag, ...e }: E
): E =>
  ({
    ...e,
    // we have to hash the JSON, as hashing the object might contain elements that won't be serialized anyway
    _etag: crypto.createHash("sha256").update(JSON.stringify(e)).digest("hex")
  }) as any

export const makeUpdateETag = (type: string) =>
  Effect.fnUntraced(function*<IdKey extends keyof E, E extends PersistenceModelType<{}>>(
    e: E,
    idKey: IdKey,
    current: Option.Option<E>
  ) {
    if (e._etag) {
      if (Option.isNone(current)) {
        return yield* new OptimisticConcurrencyException({
          type,
          id: e[idKey] as string,
          current: "",
          found: e._etag,
          code: 409
        })
      }
    }
    if (Option.isSome(current) && current.value._etag !== e._etag) {
      return yield* new OptimisticConcurrencyException({
        type,
        id: current.value[idKey] as string,
        current: current.value._etag,
        found: e._etag,
        code: 412
      })
    }
    return makeETag(e)
  })

export function lowercaseIfString<T>(val: T) {
  if (typeof val === "string") {
    return val.toLowerCase()
  }
  return val
}

export function compare(valA: unknown, valB: unknown) {
  return valA === valB
}

export function lowerThan(valA: SupportedValues2, valB: SupportedValues2) {
  return valA < valB
}

export function lowerThanExclusive(valA: SupportedValues2, valB: SupportedValues2) {
  return valA <= valB
}

export function greaterThan(valA: SupportedValues2, valB: SupportedValues2) {
  return valA > valB
}

export function greaterThanExclusive(valA: SupportedValues2, valB: SupportedValues2) {
  return valA >= valB
}