import { isAbsolute, join, relative } from 'pathe'
import type { Component } from '@nuxt/schema'
import { genDynamicImport, genObjectFromRawEntries } from 'knitwork'

export type ComponentsTemplateOptions = {
  buildDir?: string
  components: Component[]
}

export type ImportMagicCommentsOptions = {
  chunkName:string
  prefetch?: boolean | number
  preload?: boolean | number
}

const createImportMagicComments = (options: ImportMagicCommentsOptions) => {
  const { chunkName, prefetch, preload } = options
  return [
    `webpackChunkName: "${chunkName}"`,
    prefetch === true || typeof prefetch === 'number' ? `webpackPrefetch: ${prefetch}` : false,
    preload === true || typeof preload === 'number' ? `webpackPreload: ${preload}` : false
  ].filter(Boolean).join(', ')
}

export const componentsTemplate = {
  filename: 'components.mjs',
  getContents ({ options }: { options: ComponentsTemplateOptions }) {
    return `import { defineAsyncComponent } from 'vue'

const components = ${genObjectFromRawEntries(options.components.filter(c => c.global === true).map((c) => {
  const exp = c.export === 'default' ? 'c.default || c' : `c['${c.export}']`
  const comment = createImportMagicComments(c)

  return [c.pascalName, `defineAsyncComponent(${genDynamicImport(c.filePath, { comment })}.then(c => ${exp}))`]
}))}

export default function (nuxtApp) {
  for (const name in components) {
    nuxtApp.vueApp.component(name, components[name])
    nuxtApp.vueApp.component('Lazy' + name, components[name])
  }
}
`
  }
}

export const componentsTypeTemplate = {
  filename: 'types/components.d.ts',
  getContents: ({ options }: { options: ComponentsTemplateOptions }) => `// Generated by components discovery
declare module 'vue' {
  export interface GlobalComponents {
${options.components.map(c => `    '${c.pascalName}': typeof ${genDynamicImport(isAbsolute(c.filePath) ? relative(join(options.buildDir, 'types'), c.filePath) : c.filePath, { wrapper: false })}['${c.export}']`).join(',\n')}
${options.components.map(c => `    'Lazy${c.pascalName}': typeof ${genDynamicImport(isAbsolute(c.filePath) ? relative(join(options.buildDir, 'types'), c.filePath) : c.filePath, { wrapper: false })}['${c.export}']`).join(',\n')}
  }
}
export {}
`
}