import { normalize } from "@angular-devkit/core"
import { SchematicsException, Tree } from "@angular-devkit/schematics"
import { dirname } from "path"
import ts from "typescript"
import { findNode, getSourceNodes } from "./ast-utils"

export function findBootstrapModuleCall(
  host: Tree,
  mainPath: string
): ts.CallExpression | null {
  const mainText = host.readText(mainPath)
  const source = ts.createSourceFile(
    mainPath,
    mainText,
    ts.ScriptTarget.Latest,
    true
  )

  const allNodes = getSourceNodes(source)

  let bootstrapCall: ts.CallExpression | null = null

  for (const node of allNodes) {
    let bootstrapCallNode: ts.Node | null = null
    bootstrapCallNode = findNode(
      node,
      ts.SyntaxKind.Identifier,
      "bootstrapModule"
    )

    // Walk up the parent until CallExpression is found.
    while (
      bootstrapCallNode &&
      bootstrapCallNode.parent &&
      bootstrapCallNode.parent.kind !== ts.SyntaxKind.CallExpression
    ) {
      bootstrapCallNode = bootstrapCallNode.parent
    }

    if (
      bootstrapCallNode !== null &&
      bootstrapCallNode.parent !== undefined &&
      bootstrapCallNode.parent.kind === ts.SyntaxKind.CallExpression
    ) {
      bootstrapCall = bootstrapCallNode.parent as ts.CallExpression
      break
    }
  }

  return bootstrapCall
}

export function findBootstrapModulePath(host: Tree, mainPath: string): string {
  const bootstrapCall = findBootstrapModuleCall(host, mainPath)
  if (!bootstrapCall) {
    throw new SchematicsException("Bootstrap call not found")
  }

  const bootstrapModule = bootstrapCall.arguments[0]

  const mainText = host.readText(mainPath)
  const source = ts.createSourceFile(
    mainPath,
    mainText,
    ts.ScriptTarget.Latest,
    true
  )
  const allNodes = getSourceNodes(source)
  const bootstrapModuleRelativePath = allNodes
    .filter(ts.isImportDeclaration)
    .filter((imp) => {
      return findNode(imp, ts.SyntaxKind.Identifier, bootstrapModule.getText())
    })
    .map((imp) => {
      const modulePathStringLiteral = imp.moduleSpecifier as ts.StringLiteral

      return modulePathStringLiteral.text
    })[0]

  return bootstrapModuleRelativePath
}

export function getAppModulePath(host: Tree, mainPath: string): string {
  const moduleRelativePath = findBootstrapModulePath(host, mainPath)
  const mainDir = dirname(mainPath)
  const modulePath = normalize(`/${mainDir}/${moduleRelativePath}.ts`)

  return modulePath
}