ExplainerEngine.ts

import { ExplainerInput, ExplainerOutput } from './ExplainerTypes'
import { RiskPatterns } from './RiskPatterns'

export class ExplainerEngine {
  static explain(input: ExplainerInput): ExplainerOutput {
    const flags: string[] = []

    if (RiskPatterns.UNLIMITED_APPROVAL(input.method, input.params)) {
      flags.push('UNLIMITED_APPROVAL')
    }

    if (RiskPatterns.DELEGATECALL(input.method)) {
      flags.push('DELEGATECALL')
    }

    if (RiskPatterns.SELF_DESTRUCT(input.method)) {
      flags.push('SELF_DESTRUCT')
    }

    let riskLevel: ExplainerOutput['riskLevel'] = 'LOW'
    if (flags.length >= 2) riskLevel = 'HIGH'
    else if (flags.length === 1) riskLevel = 'MEDIUM'

    const summary = this.buildSummary(input, flags)

    return { summary, riskLevel, flags }
  }

  private static buildSummary(
    input: ExplainerInput,
    flags: string[]
  ): string {
    if (flags.includes('UNLIMITED_APPROVAL')) {
      return `⚠️ You are granting unlimited token access to ${input.params.spender}.`
    }

    return `You are calling "${input.method}" on contract ${input.contract}.`
  }
}