import { schnorr } from "@noble/curves/secp256k1.js"
import { hexToBytes } from "@noble/hashes/utils.js"
import { EventExt } from "../event-ext"
import type { NostrEvent, ReqFilter } from "../nostr"
import { expandFilter } from "./request-expander"
import { flatMerge, mergeSimilar } from "./request-merger"
import { diffFilters } from "./request-splitter"

export interface FlatReqFilter {
  keys: number
  ids?: string
  authors?: string
  kinds?: number
  "#e"?: string
  "#p"?: string
  "#t"?: string
  "#d"?: string
  "#r"?: string
  search?: string
  since?: number
  until?: number
  limit?: number
  relay?: string
  resultSetId: string
}

export interface Optimizer {
  expandFilter(f: ReqFilter): Array<FlatReqFilter>
  getDiff(prev: Array<ReqFilter>, next: Array<ReqFilter>): Array<FlatReqFilter>
  flatMerge(all: Array<FlatReqFilter>): Array<ReqFilter>
  compress(all: Array<ReqFilter>): Array<ReqFilter>
  schnorrVerify(ev: NostrEvent): boolean
  batchVerify(evs: Array<NostrEvent>): Array<boolean>
}

export const DefaultOptimizer = {
  expandFilter: (f: ReqFilter) => {
    return expandFilter(f)
  },
  getDiff: (prev: Array<ReqFilter>, next: Array<ReqFilter>) => {
    const diff = diffFilters(
      prev.flatMap(a => expandFilter(a)),
      next.flatMap(a => expandFilter(a)),
    )
    return diff.added
  },
  flatMerge: (all: Array<FlatReqFilter>) => {
    return flatMerge(all)
  },
  compress: (all: Array<ReqFilter>) => {
    return mergeSimilar(all)
  },
  schnorrVerify: ev => {
    // Fast path: already verified (e.g. came through EventExt.verify earlier)
    if (EventExt.isVerified(ev)) return true
    const id = EventExt.createId(ev)
    const ok = schnorr.verify(hexToBytes(ev.sig), hexToBytes(id), hexToBytes(ev.pubkey))
    if (ok) EventExt.markVerified(ev)
    return ok
  },
  batchVerify: evs => {
    return evs.map(ev => {
      if (EventExt.isVerified(ev)) return true
      const id = EventExt.createId(ev)
      const ok = schnorr.verify(hexToBytes(ev.sig), hexToBytes(id), hexToBytes(ev.pubkey))
      if (ok) EventExt.markVerified(ev)
      return ok
    })
  },
} as Optimizer