import { readFile, readdir } from 'fs/promises'
import yaml from 'js-yaml'
import path from 'path'

import { allVersions } from '../../../lib/all-versions.js'

// Gets the full list of unpublished + active, deprecated + active,
// or active schemas from the github/github repo
// `openApiReleaseDir` is the path to the `app/api/description/config/releases`
// directory in `github/github`
// You can also specify getting specific versions of schemas.
export async function getSchemas(
  openApiReleaseDir,
  includeDeprecated = false,
  includeUnpublished = false,
  versions = []
) {
  const openAPIConfigs = await readdir(openApiReleaseDir)
  const unpublished = []
  const deprecated = []
  const currentReleases = []

  // The file content in the `github/github` repo is YAML before it is
  // bundled into JSON.
  for (const file of openAPIConfigs) {
    const fileBaseName = path.basename(file, '.yaml')
    const newFileName = `${fileBaseName}.deref.json`
    const content = await readFile(path.join(openApiReleaseDir, file), 'utf8')
    const yamlContent = yaml.load(content)

    const isDeprecatedInDocs = !Object.keys(allVersions).find(
      (version) => allVersions[version].openApiVersionName === fileBaseName
    )
    if (!yamlContent.published) {
      unpublished.push(newFileName)
    }
    // If it's deprecated, it must have been published at some point in the past
    // This checks if the schema is deprecated in github/github and
    // github/docs-internal. Sometimes deprecating in github/github lags
    // behind deprecating in github/docs-internal a few days
    if (
      (yamlContent.deprecated && yamlContent.published) ||
      (isDeprecatedInDocs && yamlContent.published)
    ) {
      deprecated.push(newFileName)
    }
    if (!yamlContent.deprecated && !isDeprecatedInDocs && yamlContent.published) {
      currentReleases.push(newFileName)
    }
  }

  const allSchemas = { currentReleases, unpublished, deprecated }
  if (versions.length) {
    await validateVersionsOptions(allSchemas, versions)
    return versions.map((elem) => `${elem}.deref.json`)
  }
  const schemas = allSchemas.currentReleases
  if (includeUnpublished) {
    schemas.push(...allSchemas.unpublished)
  }
  if (includeDeprecated) {
    schemas.push(...allSchemas.deprecated)
  }
  return schemas
}

async function validateVersionsOptions(schemas, versions) {
  // Validate individual versions provided
  versions.forEach((version) => {
    if (
      schemas.deprecated.includes(`${version}.deref.json`) ||
      schemas.unpublished.includes(`${version}.deref.json`)
    ) {
      const errorMsg = `🛑 This script doesn't support generating individual deprecated or unpublished schemas. Please reach out to #docs-engineering if this is a use case that you need.`
      throw new Error(errorMsg)
    } else if (!schemas.currentReleases.includes(`${version}.deref.json`)) {
      throw new Error(`🛑 The version (${version}) you specified is not valid.`)
    }
  })
}