import { basename, classify } from '@vue-devtools/shared-utils'
import type { App, ComponentInstance } from '@vue/devtools-api'
import type { BackendContext } from '@vue-devtools/app-backend-api'

export function isBeingDestroyed(instance) {
  return instance._isBeingDestroyed || instance.isUnmounted
}

export function getAppRecord(instance) {
  if (instance.root) {
    return instance.appContext.app.__VUE_DEVTOOLS_APP_RECORD__
  }
}

export function isFragment(instance) {
  const appRecord = getAppRecord(instance)
  if (appRecord) {
    return appRecord.options.types.Fragment === instance.subTree?.type
  }
}

/**
 * Get the appropriate display name for an instance.
 *
 * @param {Vue} instance
 * @return {string}
 */
export function getInstanceName(instance) {
  const name = getComponentTypeName(instance.type || {})
  if (name) {
    return name
  }
  if (instance.root === instance) {
    return 'Root'
  }
  for (const key in instance.parent?.type?.components) {
    if (instance.parent.type.components[key] === instance.type) {
      return saveComponentName(instance, key)
    }
  }
  for (const key in instance.appContext?.components) {
    if (instance.appContext.components[key] === instance.type) {
      return saveComponentName(instance, key)
    }
  }
  const fileName = getComponentFileName(instance.type || {})
  if (fileName) {
    return fileName
  }
  return 'Anonymous Component'
}

function saveComponentName(instance, key) {
  instance.type.__vdevtools_guessedName = key
  return key
}

function getComponentTypeName(options) {
  return options.name || options._componentTag || options.__vdevtools_guessedName || options.__name
}

function getComponentFileName(options) {
  const file = options.__file // injected by vue-loader
  if (file) {
    return classify(basename(file, '.vue'))
  }
}

/**
 * Returns a devtools unique id for instance.
 * @param {Vue} instance
 */
export function getUniqueComponentId(instance, _ctx: BackendContext) {
  const appId = instance.appContext.app.__VUE_DEVTOOLS_APP_RECORD_ID__
  const instanceId = instance === instance.root ? 'root' : instance.uid
  return `${appId}:${instanceId}`
}

export function getRenderKey(value): string {
  if (value == null) {
    return
  }
  const type = typeof value
  if (type === 'number') {
    return value
  }
  else if (type === 'string') {
    return `'${value}'`
  }
  else if (Array.isArray(value)) {
    return 'Array'
  }
  else {
    return 'Object'
  }
}

export function getComponentInstances(app: App): ComponentInstance[] {
  const appRecord = app.__VUE_DEVTOOLS_APP_RECORD__
  const appId = appRecord.id.toString()
  return [...appRecord.instanceMap]
    .filter(([key]) => key.split(':')[0] === appId)
    .map(([,instance]) => instance)
}