import { encodeEventTopics, parseAbiItem, type RpcLog } from 'viem'
import * as z from 'zod/mini'

import * as Transfers from '../apps/data/routes/transfers.js'
import * as Schema from './Schema.js'
import * as Value from './Value.js'

const event = parseAbiItem(Transfers.signature)
const topic = encodeEventTopics({ abi: [event] })[0]

/** Parsed transfer filter predicates. */
export type Filters = z.output<typeof Transfers.schema.Predicates>

/** One decoded TIP-20 Transfer row, as the read endpoint returns it. */
export type EventData = {
  address: string
  amount: string
  blockNumber: number
  logIndex: number
  recipient: string
  sender: string
  timestamp: string
  transactionHash: string
}

/** True when an address is in Tempo's deterministic TIP-20 contract range. */
function isTip20Address(address: string): boolean {
  const value = address.toLowerCase()
  return value >= Transfers.tip20AddressRange[0] && value < Transfers.tip20AddressRange[1]
}

/** Decodes one strict TIP-20 Transfer wire payload. */
export function decode(log: RpcLog, timestamp: string): EventData | undefined {
  if (!isTip20Address(log.address)) return undefined
  if (
    log.topics.length !== 3 ||
    log.topics[0]?.toLowerCase() !== topic.toLowerCase() ||
    !/^0x0{24}[0-9a-fA-F]{40}$/.test(log.topics[1] ?? '') ||
    !/^0x0{24}[0-9a-fA-F]{40}$/.test(log.topics[2] ?? '') ||
    !/^0x[0-9a-fA-F]{64}$/.test(log.data)
  )
    return undefined
  const address = Schema.TokenAddress.safeParse(log.address)
  const recipient = Schema.Address.safeParse(`0x${log.topics[2]!.slice(-40)}`)
  const sender = Schema.Address.safeParse(`0x${log.topics[1]!.slice(-40)}`)
  const transactionHash = Schema.Hash.safeParse(log.transactionHash)
  const amount = Value.fromHex(log.data)
  const blockNumber = Value.hexToNumber(log.blockNumber)
  const logIndex = Value.hexToNumber(log.logIndex)
  if (
    !address.success ||
    !recipient.success ||
    !sender.success ||
    !transactionHash.success ||
    amount === undefined ||
    blockNumber === undefined ||
    logIndex === undefined
  )
    return undefined
  return {
    address: address.data,
    amount,
    blockNumber,
    logIndex,
    recipient: recipient.data,
    sender: sender.data,
    timestamp,
    transactionHash: transactionHash.data,
  }
}

/** Re-checks every transfer filter after topic-level matching. */
export function matches(data: EventData, filters: Filters): boolean {
  if (filters.address && data.sender !== filters.address && data.recipient !== filters.address)
    return false
  if (filters.recipient && data.recipient !== filters.recipient) return false
  if (filters.sender && data.sender !== filters.sender) return false
  if (filters.token && data.address !== filters.token) return false
  return true
}