import chalk from 'chalk'
import { Options } from 'common'
import { sequence } from 'utils'
import ModuleContainer from './module'
import Renderer from './renderer'
import Debug from 'debug'
import enableDestroy from 'server-destroy'
import Module from 'module'
import { isPlainObject } from 'lodash'
import { join, resolve } from 'path'

const debug = Debug('nuxt:')
debug.color = 5

export default class Nuxt {
  constructor(options = {}) {
    this.options = Options.from(options)

    // Paths for resolving requires from `rootDir`
    this.nodeModulePaths = Module._nodeModulePaths(this.options.rootDir)

    if (this.options.nuxtDir.indexOf(this.options.rootDir) !== 0) {
      this.nodeModulePaths = [
        ...this.nodeModulePaths,
        ...Module._nodeModulePaths(this.options.nuxtDir)
      ]
    }

    this.initialized = false
    this.errorHandler = this.errorHandler.bind(this)
    // Hooks
    this._hooks = {}
    this.hook = this.hook.bind(this)

    // Create instance of core components
    this.moduleContainer = new ModuleContainer(this)
    this.renderer = new Renderer(this)

    // Backward compatibility
    this.render = this.renderer.app
    this.renderRoute = this.renderer.renderRoute.bind(this.renderer)
    this.renderAndGetWindow = this.renderer.renderAndGetWindow.bind(this.renderer)

    this._ready = this.ready().catch(this.errorHandler)
  }

  static get version() {
    return '__VERSION__'
  }

  async ready() {
    if (this._ready) {
      return this._ready
    }

    // Add hooks
    if (isPlainObject(this.options.hooks)) {
      this.addObjectHooks(this.options.hooks)
    } else if (typeof this.options.hooks === 'function') {
      this.options.hooks(this.hook)
    }
    // Add nuxt modules
    await this.moduleContainer.ready()
    await this.renderer.ready()

    this.initialized = true
    await this.callHook('ready', this)

    return this
  }

  plugin(name, fn) {
    // eslint-disable-next-line no-console
    console.error(`[warn] nuxt.plugin('${name}',..) is deprecated. Please use new hooks system.`)

    // A tiny backward compatibility util
    const hookMap = {
      'ready': 'ready',
      'close': 'close',
      'listen': 'listen',
      'built': 'build:done'
    }

    if (hookMap[name]) {
      this.hook(hookMap[name], fn)
    }

    // Always return nuxt class which has plugin() for two level hooks
    return this
  }

  hook(name, fn) {
    if (!name || typeof fn !== 'function') {
      return
    }
    this._hooks[name] = this._hooks[name] || []
    this._hooks[name].push(fn)
  }

  async callHook(name, ...args) {
    if (!this._hooks[name]) {
      return
    }
    debug(`Call ${name} hooks (${this._hooks[name].length})`)
    try {
      await sequence(this._hooks[name], (fn) => fn(...args))
    } catch (err) {
      console.error(`> Error on hook "${name}":`) // eslint-disable-line no-console
      console.error(err) // eslint-disable-line no-console
    }
  }

  addObjectHooks(hooksObj) {
    Object.keys(hooksObj).forEach((name) => {
      let hooks = hooksObj[name]
      hooks = (Array.isArray(hooks) ? hooks : [hooks])

      hooks.forEach((hook) => {
        this.hook(name, hook)
      })
    })
  }

  listen(port = 3000, host = 'localhost') {
    return new Promise((resolve, reject) => {
      const server = this.renderer.app.listen({ port, host, exclusive: false }, (err) => {
        /* istanbul ignore if */
        if (err) {
          return reject(err)
        }

        const _host = host === '0.0.0.0' ? 'localhost' : host
        // eslint-disable-next-line no-console
        console.log('\n' + chalk.bgGreen.black(' OPEN ') + chalk.green(` http://${_host}:${port}\n`))

        // Close server on nuxt close
        this.hook('close', () => new Promise((resolve, reject) => {
          // Destroy server by forcing every connection to be closed
          server.destroy(err => {
            debug('server closed')
            /* istanbul ignore if */
            if (err) {
              return reject(err)
            }
            resolve()
          })
        }))

        this.callHook('listen', server, { port, host }).then(resolve)
      })

      // Add server.destroy(cb) method
      enableDestroy(server)
    })
  }

  errorHandler/* istanbul ignore next */() {
    // Apply plugins
    // eslint-disable-next-line no-console
    this.callHook('error', ...arguments).catch(console.error)

    // Silent
    if (this.options.errorHandler === false) {
      return
    }

    // Custom errorHandler
    if (typeof this.options.errorHandler === 'function') {
      return this.options.errorHandler.apply(this, arguments)
    }

    // Default handler
    // eslint-disable-next-line no-console
    console.error(...arguments)
  }

  resolvePath(path) {
    // Try to resolve using NPM resolve path first
    try {
      let resolvedPath = Module._resolveFilename(path, { paths: this.nodeModulePaths })
      return resolvedPath
    } catch (e) {
      // Just continue
    }
    // Shorthand to resolve from project dirs
    if (path.indexOf('@@') === 0 || path.indexOf('~~') === 0) {
      return join(this.options.rootDir, path.substr(2))
    } else if (path.indexOf('@') === 0 || path.indexOf('~') === 0) {
      return join(this.options.srcDir, path.substr(1))
    }
    return resolve(this.options.srcDir, path)
  }

  async close(callback) {
    await this.callHook('close', this)

    /* istanbul ignore if */
    if (typeof callback === 'function') {
      await callback()
    }
  }
}