import { LITERAL_MARKER } from "../helpers/constants"

export const PostProcessorNames = {
  CONVERT_LITERALS: "convert-literals",
}

class Postprocessor {
  name: string
  private fn: any

  constructor(name: string, fn: any) {
    this.name = name
    this.fn = fn
  }

  process(statement: any) {
    return this.fn(statement)
  }
}

export const processors = [
  new Postprocessor(
    PostProcessorNames.CONVERT_LITERALS,
    (statement: string) => {
      if (
        typeof statement !== "string" ||
        !statement.includes(LITERAL_MARKER)
      ) {
        return statement
      }
      const splitMarkerIndex = statement.indexOf("-")
      const type = statement.substring(12, splitMarkerIndex)
      const value = statement.substring(
        splitMarkerIndex + 1,
        statement.length - 2
      )
      switch (type) {
        case "string":
          return value
        case "number":
          return parseFloat(value)
        case "boolean":
          return value === "true"
        case "object":
          return JSON.parse(value)
        case "js_result":
          // We use the literal helper to process the result of JS expressions
          // as we want to be able to return any types.
          // We wrap the value in an abject to be able to use undefined properly.
          return JSON.parse(value).data
      }
      return value
    }
  ),
]