import Inliner from '@tauri-apps/tauri-inliner'
import toml from '@tauri-apps/toml'
import chokidar, { FSWatcher } from 'chokidar'
import { existsSync, readFileSync, writeFileSync, mkdirSync } from 'fs-extra'
import { JSDOM } from 'jsdom'
import debounce from 'lodash.debounce'
import path from 'path'
import * as entry from './entry'
import { appDir, tauriDir } from './helpers/app-paths'
import logger from './helpers/logger'
import onShutdown from './helpers/on-shutdown'
import { spawn } from './helpers/spawn'
const getTauriConfig = require('./helpers/tauri-config')
import { TauriConfig } from './types/config'

const log = logger('app:tauri', 'green')
const warn = logger('app:tauri (template)', 'red')

class Runner {
  pid: number
  tauriWatcher?: FSWatcher
  devPath?: string
  killPromise?: Function

  constructor() {
    this.pid = 0
    this.tauriWatcher = undefined
    onShutdown(() => {
      this.stop().catch(e => {
        throw e
      })
    })
  }

  async run(cfg: TauriConfig): Promise<void> {
    const devPath = cfg.build.devPath

    if (this.pid) {
      if (this.devPath !== devPath) {
        await this.stop()
      } else {
        return
      }
    }

    this.__manipulateToml(toml => {
      this.__whitelistApi(cfg, toml)
    })

    const runningDevServer = devPath.startsWith('http')
    let inlinedAssets: string[] = []

    if (!runningDevServer) {
      inlinedAssets = await this.__parseHtml(cfg, devPath)
    }

    process.env.TAURI_INLINED_ASSSTS = inlinedAssets.join('|')

    entry.generate(tauriDir, cfg)

    this.devPath = devPath

    const features = runningDevServer ? ['dev-server'] : []

    const startDevTauri = async (): Promise<void> => {
      return this.__runCargoCommand({
        cargoArgs: ['run'].concat(
          features.length ? ['--features', ...features] : []
        ),
        dev: true
      })
    }

    // Start watching for tauri app changes
    // eslint-disable-next-line security/detect-non-literal-fs-filename
    this.tauriWatcher = chokidar
      .watch(
        [
          path.join(tauriDir, 'src'),
          path.join(tauriDir, 'Cargo.toml'),
          path.join(tauriDir, 'build.rs'),
          path.join(appDir, 'tauri.conf.js')
        ],
        {
          // TODO: incorrect options?
          // @ts-ignore
          watchers: {
            chokidar: {
              ignoreInitial: true
            }
          }
        }
      )
      .on(
        'change',
        debounce((path: string) => {
          this.__stopCargo()
            .then(() => {
              if (path.includes('tauri.conf.js')) {
                this.run(getTauriConfig({ ctx: cfg.ctx })).catch(e => {
                  throw e
                })
              } else {
                startDevTauri().catch(e => {
                  throw e
                })
              }
            })
            .catch(err => {
              warn(err)
              process.exit(1)
            })
        }, 1000)
      )

    return startDevTauri()
  }

  async build(cfg: TauriConfig): Promise<void> {
    this.__manipulateToml(toml => {
      this.__whitelistApi(cfg, toml)
    })

    const inlinedAssets = await this.__parseHtml(cfg, cfg.build.distDir)

    process.env.TAURI_INLINED_ASSSTS = inlinedAssets.join('|')
  
    entry.generate(tauriDir, cfg)

    const features = [
      cfg.tauri.embeddedServer.active ? 'embedded-server' : 'no-server'
    ]

    const buildFn = async (target?: string): Promise<void> =>
      this.__runCargoCommand({
        cargoArgs: [
          cfg.tauri.bundle.active ? 'tauri-cli' : 'build',
          '--features',
          ...features
        ]
          .concat(cfg.ctx.debug ? [] : ['--release'])
          .concat(target ? ['--target', target] : [])
      })

    if (cfg.ctx.debug || !cfg.ctx.targetName) {
      // on debug mode or if no target specified,
      // build only for the current platform
      await buildFn()
    } else {
      const targets = cfg.ctx.target.split(',')

      for (const target of targets) {
        await buildFn(target)
      }
    }
  }

  async __parseHtml(cfg: TauriConfig, indexDir: string): Promise<string[]> {
    const inlinedAssets: string[] = []
    const distDir = cfg.build.distDir

    return new Promise((resolve, reject) => {
      const distIndexPath = path.join(indexDir, 'index.html')
      if (!existsSync(distIndexPath)) {
        warn(
          `Error: cannot find index.html in "${indexDir}". Did you forget to build your web code or update the build.distDir in tauri.conf.js?`
        )
        reject(new Error('Could not find index.html in dist dir.'))
      }
      new Inliner(distIndexPath, (err: Error, html: string) => {
        if (err) {
          reject(err)
        } else {
          const dom = new JSDOM(html)
          const document = dom.window.document
          document.querySelectorAll('link').forEach(link => {
            link.removeAttribute('rel')
            link.removeAttribute('as')
          })

          const tauriScript = document.createElement('script')
          // @ts-ignore
          tauriScript.text = readFileSync(path.join(tauriDir, 'tauri.js'))
          document.body.insertBefore(tauriScript, document.body.firstChild)

          const csp = cfg.tauri.security.csp
          if (csp) {
            const cspTag = document.createElement('meta')
            cspTag.setAttribute('http-equiv', 'Content-Security-Policy')
            cspTag.setAttribute('content', csp)
            document.head.appendChild(cspTag)
          }

          if (!existsSync(distDir)) {
            mkdirSync(distDir, { recursive: true })
          }

          writeFileSync(
            path.join(distDir, 'index.tauri.html'),
            dom.serialize()
          )
          resolve(inlinedAssets)
        }
      }).on('progress', (event: string) => {
        const match = event.match(/([\S\d]+)\.([\S\d]+)/g)
        match && inlinedAssets.push(match[0])
      })
    })
  }

  async stop(): Promise<void> {
    return new Promise((resolve, reject) => {
      this.tauriWatcher && this.tauriWatcher.close()
      this.__stopCargo()
        .then(resolve)
        .catch(e => {
          console.error(e)
        })
    })
  }

  async __runCargoCommand({
    cargoArgs,
    extraArgs,
    dev = false
  }: {
    cargoArgs: string[]
    extraArgs?: string[]
    dev?: boolean
  }): Promise<void> {
    return new Promise(resolve => {
      this.pid = spawn(
        'cargo',

        extraArgs ? cargoArgs.concat(['--']).concat(extraArgs) : cargoArgs,

        tauriDir,

        code => {
          if (code) {
            warn()
            warn('⚠️  [FAIL] Cargo CLI has failed')
            warn()
            process.exit(1)
          }

          if (this.killPromise) {
            this.killPromise()
            this.killPromise = undefined
          } else if (dev) {
            warn()
            warn('Cargo process was killed. Exiting...')
            warn()
            process.exit(0)
          }
        }
      )

      resolve()
    })
  }

  async __stopCargo(): Promise<void> {
    const pid = this.pid

    if (!pid) {
      return Promise.resolve()
    }

    log('Shutting down tauri process...')
    this.pid = 0

    return new Promise((resolve, reject) => {
      this.killPromise = resolve
      process.kill(pid)
    })
  }

  __manipulateToml(callback: (tomlContents: object) => void): void {
    const tomlPath = path.join(tauriDir, 'Cargo.toml')
    // TODO: should this be read as buffer or string?
    const tomlFile = readFileSync(tomlPath)
    // @ts-ignore
    const tomlContents = toml.parse(tomlFile)

    callback(tomlContents)

    const output = toml.stringify(tomlContents)
    writeFileSync(tomlPath, output)
  }

  __whitelistApi(
    cfg: TauriConfig,
    tomlContents: { [index: string]: any }
  ): void {
    const tomlFeatures = []

    if (cfg.tauri.whitelist.all) {
      tomlFeatures.push('all-api')
    } else {
      const whitelist = Object.keys(cfg.tauri.whitelist).filter(
        w => cfg.tauri.whitelist[String(w)] === true
      )
      tomlFeatures.push(...whitelist)
    }

    if (cfg.tauri.edge.active) {
      tomlFeatures.push('edge')
    }

    tomlContents.dependencies.tauri.features = tomlFeatures
  }
}

export default Runner