import {PluginObj} from '@babel/core'
import {NodePath} from '@babel/traverse'
import * as BabelTypes from '@babel/types'

let idx = 0

export default function ({ types: t }: {types: typeof BabelTypes}): PluginObj {
  return {
    visitor: {
      Program: {
        enter(path, state) {
          path.traverse({
            ImportDeclaration (path: NodePath<BabelTypes.ImportDeclaration>, state) {
              const source = path.node.source.value
              if (source !== 'next/amp') return
              state.hasAmp = true
            },
          }, state)
        }
      },
      CallExpression (path: NodePath<BabelTypes.CallExpression>, state) {
        if (!state.hasAmp || state.insertedDrop) return
        // @ts-ignore
        if (path.node.callee.name !== 'withAmp') return

        if (path.node.arguments.length > 1) {
          if (!t.isObjectExpression(path.node.arguments[1])) return
          // @ts-ignore
          const options: BabelTypes.ObjectExpression = path.node.arguments[1]

          // make sure it isn't a hybrid page e.g. hybrid: true
          if (options.properties.some((prop: any): boolean => {
            if (!t.isObjectProperty(prop)) return false
            if (prop.key.name !== 'hybrid' || !t.isBooleanLiteral(prop.value)) {
              return false
            }
            // found hybrid: true
            return Boolean(prop.value.value)
          })) {
            return
          }
        }
        // use random number and an increment to make sure HMR still updates
        idx++
        state.insertedDrop = true
        path.replaceWith(t.expressionStatement(t.stringLiteral(`throw new Error('__NEXT_DROP_CLIENT_FILE__' + ${Math.random() + idx})`)));
      }
    }
  }
}