/**
 * 往返验证：读一份真实配置 → 改一处 → 写回，看未改动的部分保住了多少。
 *
 * 这是整个项目最先要回答的问题。如果写回之后文件面目全非，界面做得再好也没人敢用。
 *
 * 用法：
 *   bun run scripts/roundtrip.ts <源配置> <输出目录>
 *
 * 产出三个文件，各对应一种改动，再用 git diff --no-index 跟源文件比对。
 */
import { mkdirSync, readFileSync, writeFileSync } from 'node:fs'
import { join } from 'node:path'
import { replaceDocumentData, openDocument } from '../vendor/config-editor/index.ts'
import type { ConfigObject } from '../vendor/config-editor/index.ts'
import { restoreInlineCommentAlignment } from '../shared/yaml-cosmetics.ts'

const [sourcePath, outDir] = process.argv.slice(2)
if (!sourcePath || !outDir) {
  console.error('用法：bun run scripts/roundtrip.ts <源配置> <输出目录>')
  process.exit(1)
}

const source = readFileSync(sourcePath, 'utf8')
const doc = openDocument(source)
mkdirSync(outDir, { recursive: true })

const clone = (v: unknown) => JSON.parse(JSON.stringify(v)) as ConfigObject

/** 每个场景改一处，模拟界面上一次真实操作。 */
const scenarios: Array<{ file: string; what: string; mutate: (d: ConfigObject) => void }> = [
  {
    file: 'A-加一路入站.yaml',
    what: '新增命名入站 7778，出站固定走 AUTO（本项目的核心操作）',
    mutate: (d) => {
      d.listeners = [
        { name: '容器A', type: 'mixed', port: 7778, listen: '0.0.0.0', proxy: 'AUTO' },
      ]
    },
  },
  {
    file: 'B-改一条规则.yaml',
    what: '把最后一条兜底规则的出站从 PROXY 换成 AUTO',
    mutate: (d) => {
      const rules = d.rules as string[]
      rules[rules.length - 1] = 'MATCH,AUTO'
    },
  },
  {
    file: 'C-改一个策略组.yaml',
    what: '给 PROXY 组的成员列表加一个 REJECT',
    mutate: (d) => {
      const groups = d['proxy-groups'] as Array<Record<string, unknown>>
      const proxy = groups.find((g) => g.name === 'PROXY')!
      proxy.proxies = [...(proxy.proxies as string[]), 'REJECT']
    },
  },
]

const countComments = (yaml: string) =>
  yaml.split('\n').filter((line) => line.trim().startsWith('#') || / #\s/.test(line)).length

console.log(`源文件 ${sourcePath}`)
console.log(`  ${source.split('\n').length} 行，其中带注释 ${countComments(source)} 行\n`)

for (const scenario of scenarios) {
  const draft = clone(doc.data)
  scenario.mutate(draft)
  const result = replaceDocumentData(doc, draft)
  const written = restoreInlineCommentAlignment(source, result.yaml)
  const outPath = join(outDir, scenario.file)
  writeFileSync(outPath, written, 'utf8')

  const before = countComments(source)
  const after = countComments(written)
  console.log(`${scenario.file}`)
  console.log(`  改动：${scenario.what}`)
  console.log(`  注释行 ${before} → ${after}${after < before ? `（丢了 ${before - after} 行）` : '（没丢）'}`)
  console.log(`  写到 ${outPath}\n`)
}