import { emptyDir, exists } from 'https://deno.land/std@0.119.0/fs/mod.ts'
import { copy } from 'https://deno.land/std@0.119.0/fs/copy.ts'
import { load } from 'https://deno.land/x/js_yaml_port@3.14.0/js-yaml.js'

const baseUrl = 'https://spec.utxo.cz'

const banner = `
██╗░░░██╗████████╗██╗░░██╗░█████╗░
██║░░░██║╚══██╔══╝╚██╗██╔╝██╔══██╗
██║░░░██║░░░██║░░░░╚███╔╝░██║░░██║
██║░░░██║░░░██║░░░░██╔██╗░██║░░██║
╚██████╔╝░░░██║░░░██╔╝╚██╗╚█████╔╝
░╚═════╝░░░░╚═╝░░░╚═╝░░╚═╝░╚════╝░
`

export class UTXOEngine {
  constructor (options = {}) {
    this.options = options
    this.srcDir = this.options.srcDir || './spec'
    if (!this.options.silent) {
      console.log(banner)
    }
    this.imageTypes = [
      ['web', 'png'],
      ['web', 'webp'],
      ['web', 'jpg'],
      ['sm', 'png'],
      ['sm', 'webp'],
      ['twitter', 'jpg']
    ]
  }

  async init () {
    this.entries = {}

    for await (const f of Deno.readDir(this.srcDir)) {
      if (!f.name.match(/^\d+$/)) {
        continue
      }
      const specDir = [this.srcDir, f.name].join('/')

      const entry = this.entries[f.name] = {}
      // load index
      entry.index = await this._yamlLoad([specDir, 'index.yaml'].join('/'))

      // load sub-specs
      entry.specs = {}
      for (const sp of entry.index.specDef) {
        entry.specs[sp.type] = await this._yamlLoad([specDir, `${sp.type}.yaml`].join('/'))

        // post processing of sub-specs
        switch (sp.type) {
          case 'speakers':
            for (const s of entry.specs[sp.type]) {
              if (!s.photos) {
                s.photos = []
              }
              for (const [it, format] of this.imageTypes) {
                if (await exists([this.srcDir, f.name, 'photos', 'speakers', `${s.id}-${it}.${format}`].join('/'))) {
                  s.photos.push(`${it}:${format}`)
                }
              }
            }
            break
        }
      }
    }
    if (!this.options.silent) {
      console.log(`UTXO entries: [ ${Object.keys(this.entries).join(', ')} ]\n`)
    }
  }

  entriesList () {
    return Object.keys(this.entries)
  }

  async build (outputDir) {
    await emptyDir(outputDir)
    const entriesIndex = []

    for (const entryId of Object.keys(this.entries)) {
      if (!this.options.silent) {
        console.log(`UTXO.${entryId}: building specs ..`)
      }
      const entry = this.entries[entryId]
      const entryDir = [outputDir, entryId].join('/')
      await emptyDir(entryDir)

      // write sub-specs
      const specEndpoints = {}
      for (const specName of Object.keys(entry.specs)) {
        await this._jsonWrite([entryDir, `${specName}.json`], entry.specs[specName])
        specEndpoints[specName] = `${baseUrl}/${entryId}/${specName}.json`
      }

      // write index
      const index = JSON.parse(JSON.stringify(entry.index))
      delete index.specDef
      index.spec = specEndpoints
      index.stats = {
        tracks: entry.specs.tracks.length,
        speakers: entry.specs.speakers.length,
        events: entry.specs.events.length,
        faqs: entry.specs.faqs.length
      }

      await this._jsonWrite([entryDir, 'index.json'], index)

      // write bundle
      const bundle = JSON.parse(JSON.stringify(index))
      bundle.spec = entry.specs
      await this._jsonWrite([entryDir, 'bundle.json'], bundle)

      // copy photos
      const outputPhotosDir = [entryDir, 'photos'].join('/')
      if (!this.options.silent) {
        console.log(`UTXO.${entryId}: copying photos ..`)
        console.log(`copying photos to ${outputPhotosDir}`)
      }
      await copy([this.srcDir, entryId, 'photos'].join('/'), outputPhotosDir, { overwrite: true })

      entriesIndex.push({
        id: `utxo${entryId}`,
        entryId,
        url: `${baseUrl}/${entryId}`
      })
    }

    // write global index
    await this._jsonWrite([outputDir, 'index.json'], entriesIndex)

    if (!this.options.silent) {
      console.log('\nBuild done')
    }
  }

  async schemas () {
    const schemaDir = './utils/schema'
    const arr = []
    for await (const f of Deno.readDir(schemaDir)) {
      const m = f.name.match(/^(.+)\.yaml$/)
      if (!m) {
        continue
      }
      arr.push({ name: m[1], schema: await this._yamlLoad([schemaDir, f.name].join('/')) })
    }
    return arr
  }

  async _yamlLoad (fn) {
    return load(await Deno.readTextFile(fn))
  }

  async _jsonWrite (fn, data) {
    if (Array.isArray(fn)) {
      fn = fn.join('/')
    }
    await Deno.writeTextFile(fn, JSON.stringify(data, null, 2))
    if (!this.options.silent) {
      console.log(`${fn} writed`)
    }
    return true
  }
}