assembler.ts

import { SourceMapGenerator } from 'source-map'
import { SFCCompiler, DescriptorCompileResult } from './compiler'
import { merge } from './source-map'
import * as path from 'path'

// const merge = require('merge-source-map')

export interface AssembleSource {
  filename: string
  script?: { source: string; map?: any }
  template?: { source: string; functional?: boolean }
  styles: Array<{
    source: string
    scoped?: boolean
    media?: string
    map?: any
    moduleName?: string
    module?: any
  }>
  scopeId: string
}

export interface AssembleResults {
  code: string
  map?: any
}

export interface AssembleOptions {
  isWebComponent?: boolean
  normalizer?: string
  styleInjector?: string
  styleInjectorSSR?: string
  styleInjectorShadow?: string
}

export function assemble(
  compiler: SFCCompiler,
  filename: string,
  result: DescriptorCompileResult,
  options: AssembleOptions = {}
): AssembleResults {
  return assembleFromSource(compiler, options, {
    filename,
    scopeId: result.scopeId,
    script: result.script && {
      source: result.script.code,
      map: result.script.map
    },
    template: result.template && {
      ...result.template,
      source: result.template.code,
      functional: result.template.functional
    } as any,
    styles: result.styles.map(style => {
      if (style.errors.length) {
        console.error(style.errors)
      }

      return {
        ...style,
        source: style.code,
        media: style.media,
        scoped: style.scoped,
        moduleName: style.moduleName,
        module: style.module
      }
    })
  })
}

export function assembleFromSource(
  compiler: SFCCompiler,
  options: AssembleOptions,
  { filename, script, template, styles, scopeId }: AssembleSource
): AssembleResults {
  script = script || { source: 'export default {}' }
  template = template || { source: '' }
  let map = undefined
  const mapGenerator = new SourceMapGenerator({ file: filename.replace(/\\/g, '/') })

  const hasScopedStyle = styles.some(style => style.scoped === true)
  const hasStyle = styles.some(style => style.source || style.module)
  const e = (any: any): string => JSON.stringify(any)
  const createImport = (name: string, value: string) =>
    value.startsWith('~')
      ? `import ${name} from '${value.substr(1)}'`
      : `const ${name} = ${value}`
  const o = e
  const IDENTIFIER = /^[a-z0-9]+$/i

  // language=JavaScript
  const inlineCreateInjector = `function __vue_create_injector__() {
    const styles = __vue_create_injector__.styles || (__vue_create_injector__.styles = {})
    const isOldIE =
      typeof navigator !== 'undefined' &&
      /msie [6-9]\\\\b/.test(navigator.userAgent.toLowerCase())

    return function addStyle(id, css) {
      if (document.querySelector('style[data-vue-ssr-id~="' + id + '"]')) return // SSR styles are present.

      const group = isOldIE ? css.media || 'default' : id
      const style = styles[group] || (styles[group] = { ids: [], parts: [], element: undefined })

      if (!style.ids.includes(id)) {
        let code = css.source
        let index = style.ids.length

        style.ids.push(id)

        if (${e(compiler.template.isProduction)} && css.map) {
          // https://developer.chrome.com/devtools/docs/javascript-debugging
          // this makes source maps inside style tags work properly in Chrome
          code += '\\n/*# sourceURL=' + css.map.sources[0] + ' */'
          // http://stackoverflow.com/a/26603875
          code +=
            '\\n/*# sourceMappingURL=data:application/json;base64,' +
            btoa(unescape(encodeURIComponent(JSON.stringify(css.map)))) +
            ' */'
        }

        if (isOldIE) {
          style.element = style.element || document.querySelector('style[data-group=' + group + ']')
        }

        if (!style.element) {
          const head = document.head || document.getElementsByTagName('head')[0]
          const el = style.element = document.createElement('style')
          el.type = 'text/css'

          if (css.media) el.setAttribute('media', css.media)
          if (isOldIE) {
            el.setAttribute('data-group', group)
            el.setAttribute('data-next-index', '0')
          }

          head.appendChild(el)
        }

        if (isOldIE) {
          index = parseInt(style.element.getAttribute('data-next-index'))
          style.element.setAttribute('data-next-index', index + 1)
        }

        if (style.element.styleSheet) {
          style.parts.push(code)
          style.element.styleSheet.cssText = style.parts
            .filter(Boolean)
            .join('\\n')
        } else {
          const textNode = document.createTextNode(code)
          const nodes = style.element.childNodes
          if (nodes[index]) style.element.removeChild(nodes[index])
          if (nodes.length) style.element.insertBefore(textNode, nodes[index])
          else style.element.appendChild(textNode)
        }
      }
    }
  }`
  const createInjector = options.styleInjector
    ? createImport('__vue_create_injector__', options.styleInjector)
    : inlineCreateInjector

  // language=JavaScript
  const inlineCreateInjectorSSR = `function __vue_create_injector_ssr__(context) {
    if (!context && typeof __VUE_SSR_CONTEXT__ !== 'undefined') {
      context = __VUE_SSR_CONTEXT__
    }

    if (!context) return function () {}

    if (!context.hasOwnProperty('styles')) {
      Object.defineProperty(context, 'styles', {
        enumerable: true,
        get: () => context._styles
      })
      context._renderStyles = renderStyles
    }

    function renderStyles(styles) {
      let css = ''
      for (const {ids, media, parts} of styles) {
        css +=
          '<style data-vue-ssr-id="' + ids.join(' ') + '"' + (media ? ' media="' + media + '"' : '') + '>'
          + parts.join('\\n') +
          '</style>'
      }

      return css
    }

    return function addStyle(id, css) {
      const group = ${e(
        compiler.template.isProduction
      )} ? css.media || 'default' : id
      const style = context._styles[group] || (context._styles[group] = { ids: [], parts: [] })

      if (!style.ids.includes(id)) {
        style.media = css.media
        style.ids.push(id)
        let code = css.source
        if (${e(!compiler.template.isProduction)} && css.map) {
          // https://developer.chrome.com/devtools/docs/javascript-debugging
          // this makes source maps inside style tags work properly in Chrome
          code += '\\n/*# sourceURL=' + css.map.sources[0] + ' */'
          // http://stackoverflow.com/a/26603875
          code +=
            '\\n/*# sourceMappingURL=data:application/json;base64,' +
            btoa(unescape(encodeURIComponent(JSON.stringify(css.map)))) +
            ' */'
        }
        style.parts.push(code)
      }
    }
  }`
  const createInjectorSSR = options.styleInjectorSSR
    ? createImport('__vue_create_injector_ssr__', options.styleInjectorSSR)
    : inlineCreateInjectorSSR

  const inlineCreateInjectorShadow = `function __vue_create_injector_shadow__(__, shadowRoot) {
    function createStyleElement(shadowRoot) {
      var styleElement = document.createElement('style')
      styleElement.type = 'text/css'
      shadowRoot.appendChild(styleElement)
    
      return styleElement
    }    

    return function addStyle(id, css) {
      const styleElement = createStyleElement(shadowRoot)
      if (css.media) styleElement.setAttribute('media', css.media)
      
      let code = css.source

      if (${e(compiler.template.isProduction)} && css.map) {
        // https://developer.chrome.com/devtools/docs/javascript-debugging
        // this makes source maps inside style tags work properly in Chrome
        code += '\\n/*# sourceURL=' + css.map.sources[0] + ' */'
        // http://stackoverflow.com/a/26603875
        code +=
          '\\n/*# sourceMappingURL=data:application/json;base64,' +
          btoa(unescape(encodeURIComponent(JSON.stringify(css.map)))) +
          ' */'
      }
      
      if ('styleSheet' in styleElement) {
        styleElement.styleSheet.cssText = code
      } else {
        while (styleElement.firstChild) {
          styleElement.removeChild(styleElement.firstChild)
        }
        styleElement.appendChild(document.createTextNode(code))
      }
    }
  }`

  const createInjectorShadow = options.styleInjectorShadow
    ? createImport('__vue_create_injector_shadow__', options.styleInjectorShadow)
    : inlineCreateInjectorShadow

  // language=JavaScript
  const inlineNormalizeComponent = `function __vue_normalize__(
    template, style, script,
    scope, functional, moduleIdentifier, shadowMode,
    createInjector, createInjectorSSR, createInjectorShadow
  ) {
    const component = (typeof script === 'function' ? script.options : script) || {}

    // For security concerns, we use only base name in production mode.
    component.__file = ${compiler.template.isProduction ? e(path.basename(filename)) : e(filename)}

    if (!component.render) {
      component.render = template.render
      component.staticRenderFns = template.staticRenderFns
      component._compiled = true

      if (functional) component.functional = true
    }

    component._scopeId = scope

    if (${e(hasStyle)}) {
      let hook
      if (${e(compiler.template.optimizeSSR)}) {
        // In SSR.
        hook = function(context) {
          // 2.3 injection
          context =
            context || // cached call
            (this.$vnode && this.$vnode.ssrContext) || // stateful
            (this.parent && this.parent.$vnode && this.parent.$vnode.ssrContext) // functional
          // 2.2 with runInNewContext: true
          if (!context && typeof __VUE_SSR_CONTEXT__ !== 'undefined') {
            context = __VUE_SSR_CONTEXT__
          }
          // inject component styles
          if (style) {
            style.call(this, createInjectorSSR(context))
          }
          // register component module identifier for async chunk inference
          if (context && context._registeredComponents) {
            context._registeredComponents.add(moduleIdentifier)
          }
        }
        // used by ssr in case component is cached and beforeCreate
        // never gets called
        component._ssrRegister = hook
      }
      else if (style) {
        hook = shadowMode 
          ? function(context) {
              style.call(this, createInjectorShadow(context, this.$root.$options.shadowRoot))
            }
          : function(context) {
              style.call(this, createInjector(context))
            }
      }

      if (hook !== undefined) {
        if (component.functional) {
          // register for functional component in vue file
          const originalRender = component.render
          component.render = function renderWithStyleInjection(h, context) {
            hook.call(context)
            return originalRender(h, context)
          }
        } else {
          // inject component registration as beforeCreate hook
          const existing = component.beforeCreate
          component.beforeCreate = existing ? [].concat(existing, hook) : [hook]
        }
      }
    }

    return component
  }`
  const normalizeComponent = options.normalizer
    ? createImport('__vue_normalize__', options.normalizer)
    : inlineNormalizeComponent

  const DEFAULT_EXPORT = 'const __vue_script__ ='
  // language=JavaScript
  let code =
    `/* script */\n${script.source.replace(
      /export\s+default/,
      DEFAULT_EXPORT
    )}` +
    `\n/* template */\n${template.source
      .replace('var render =', 'var __vue_render__ =')
      .replace('var staticRenderFns =', 'var __vue_staticRenderFns__ =')
      .replace('render._withStripped =', '__vue_render__._withStripped =')}
  /* style */
  const __vue_inject_styles__ = ${hasStyle ? `function (inject) {
    if (!inject) return
    ${styles.map((style, index) => {
      const source = IDENTIFIER.test(style.source)
        ? style.source
        : e(style.source)
      const map = !compiler.template.isProduction
        ? typeof style.map === 'string' && IDENTIFIER.test(style.map)
          ? style.map
          : o(style.map)
        : undefined
      const tokens =
        typeof style.module === 'string' && IDENTIFIER.test(style.module)
          ? style.module
          : o(style.module)

      return (
        (source
          ? `inject("${scopeId +
              '_' +
              index}", { source: ${source}, map: ${map}, media: ${e(
              style.media
            )} })\n`
          : '') +
        (style.moduleName
          ? `Object.defineProperty(this, "${
              style.moduleName
            }", { value: ${tokens} })` + '\n'
          : '')
      )
    })}
  }` : 'undefined'}
  /* scoped */
  const __vue_scope_id__ = ${hasScopedStyle ? e(scopeId) : 'undefined'}
  /* module identifier */
  const __vue_module_identifier__ = ${
    compiler.template.optimizeSSR ? e(scopeId) : 'undefined'
  }
  /* functional template */
  const __vue_is_functional_template__ = ${e(template.functional)}
  /* component normalizer */
  ${normalizeComponent}
  /* style inject */
  ${hasStyle && !compiler.template.optimizeSSR && !options.isWebComponent ? createInjector : ''}
  /* style inject SSR */
  ${hasStyle && compiler.template.optimizeSSR ? createInjectorSSR : ''}
  /* style inject shadow dom */
  ${hasStyle && options.isWebComponent ? createInjectorShadow : ''}

  `

  // generate source map.
  {
    const input = script.source.split('\n')

    input.forEach((sourceLine, index) => {
      if (!sourceLine) return
      const matches = /export\s+default/.exec(sourceLine)
      if (matches) {
        const pos = sourceLine.indexOf(matches[0])
        if (pos > 0) {
          mapGenerator.addMapping({
            source: filename,
            original: { line: index + 1, column: 0 },
            generated: { line: index + 2, column: 0 }
          })
        }

        mapGenerator.addMapping({
          source: filename,
          original: { line: index + 1, column: pos },
          generated: { line: index + 2, column: pos }
        })

        if (sourceLine.substr(pos + matches[0].length)) {
          mapGenerator.addMapping({
            source: filename,
            original: { line: index + 1, column: pos + matches[0].length },
            generated: { line: index + 2, column: pos + DEFAULT_EXPORT.length }
          })
        }
      } else {
        mapGenerator.addMapping({
          source: filename,
          original: { line: index + 1, column: 0 },
          generated: { line: index + 2, column: 0 }
        })
      }
    })
  }

  code += `
  const __vue_component__ = /*#__PURE__*/__vue_normalize__(
    ${
      code.indexOf('__vue_render__') > -1
        ? '{ render: __vue_render__, staticRenderFns: __vue_staticRenderFns__ }'
        : '{}'
    },
    __vue_inject_styles__,
    ${code.indexOf('__vue_script__') > -1 ? '__vue_script__' : '{}'},
    __vue_scope_id__,
    __vue_is_functional_template__,
    __vue_module_identifier__,
    ${options.isWebComponent ? 'true' : 'false'},
    ${
      code.indexOf('__vue_create_injector__') > -1
        ? '__vue_create_injector__'
        : 'undefined'
    },
    ${
      code.indexOf('__vue_create_injector_ssr__') > -1
        ? '__vue_create_injector_ssr__'
        : 'undefined'
    },
    ${
      code.indexOf('__vue_create_injector_shadow__') > -1
        ? '__vue_create_injector_shadow__'
        : 'undefined'
    }
  )\n
  export default __vue_component__`

  if (script.map) {
    map = merge(script.map, JSON.parse(mapGenerator.toString()))
  } else {
    map = JSON.parse(mapGenerator.toString())
  }

  return { code, map }
}