import { execFileSync } from 'node:child_process'
import { mkdtempSync, readFileSync, rmSync, writeFileSync } from 'node:fs'
import { tmpdir } from 'node:os'
import { join } from 'node:path'
import { afterEach, describe, expect, it } from 'vitest'

const script = join(import.meta.dirname, 'patch-tfvars.mjs')

let dirs = []
afterEach(() => {
  for (const dir of dirs) rmSync(dir, { recursive: true, force: true })
  dirs = []
})

function tfvarsFile(initial) {
  const dir = mkdtempSync(join(tmpdir(), 'patch-tfvars-'))
  dirs.push(dir)
  const file = join(dir, 'terraform.tfvars.json')
  if (initial !== undefined) writeFileSync(file, initial)
  return file
}

function patch(file, key, value) {
  execFileSync(process.execPath, [script, file, key, value])
  return JSON.parse(readFileSync(file, 'utf8'))
}

describe('patch-tfvars.mjs', () => {
  it('creates the file when missing', () => {
    const file = tfvarsFile()
    expect(patch(file, 'release_sha', 'abc123def456')).toEqual({ release_sha: 'abc123def456' })
  })

  it('replaces an existing value', () => {
    const file = tfvarsFile('{"release_sha": "abc123def456"}\n')
    expect(patch(file, 'release_sha', 'def456abc123')).toEqual({ release_sha: 'def456abc123' })
  })

  it('preserves other variables', () => {
    const file = tfvarsFile('{"other_var": true, "release_sha": "abc123def456"}\n')
    expect(patch(file, 'release_sha', 'def456abc123')).toEqual({
      other_var: true,
      release_sha: 'def456abc123',
    })
  })

  it('fails rather than clobbering a file it cannot parse', () => {
    const file = tfvarsFile('not json')
    expect(() => patch(file, 'release_sha', 'abc123def456')).toThrow()
    expect(readFileSync(file, 'utf8')).toBe('not json')
  })
})