import { mkdtempSync, rmSync, writeFileSync } from 'node:fs'
import { tmpdir } from 'node:os'
import { join } from 'node:path'
import { afterEach, describe, expect, it } from 'vitest'
import { loadEnvironmentFile } from '../src/server/environment.js'

const testVariable = 'PRODUCT_ISSUE_ENV_FILE_TEST'
const originalValue = process.env[testVariable]
const temporaryDirectories: string[] = []

afterEach(() => {
  if (originalValue === undefined) {
    delete process.env[testVariable]
  } else {
    process.env[testVariable] = originalValue
  }
  for (const directory of temporaryDirectories.splice(0)) {
    rmSync(directory, { recursive: true, force: true })
  }
})

function environmentFile(value: string): string {
  const directory = mkdtempSync(join(tmpdir(), 'product-issue-env-'))
  temporaryDirectories.push(directory)
  const filePath = join(directory, '.env')
  writeFileSync(filePath, `${testVariable}=${value}\n`, {
    encoding: 'utf8',
    mode: 0o600
  })
  return filePath
}

describe('loadEnvironmentFile', () => {
  it('loads values from an explicit environment file', () => {
    delete process.env[testVariable]

    const filePath = environmentFile('from-file')

    expect(loadEnvironmentFile(filePath)).toBe(filePath)
    expect(process.env[testVariable]).toBe('from-file')
  })

  it('does not override values already provided by the process', () => {
    process.env[testVariable] = 'from-process'

    loadEnvironmentFile(environmentFile('from-file'))

    expect(process.env[testVariable]).toBe('from-process')
  })

  it('fails when an explicitly configured file does not exist', () => {
    const directory = mkdtempSync(join(tmpdir(), 'product-issue-env-'))
    temporaryDirectories.push(directory)

    expect(() => loadEnvironmentFile(join(directory, '.env'))).toThrow(
      'Environment file does not exist'
    )
  })
})