#!/usr/bin/env bun

/**

* Unwrap a TypeScript `export namespace` into flat exports + barrel.

*

* Usage:

* bun script/unwrap-namespace.ts src/bus/index.ts

* bun script/unwrap-namespace.ts src/bus/index.ts --dry-run

* bun script/unwrap-namespace.ts src/pty/index.ts --name service # avoid collision with pty.ts

*

* What it does:

* 1. Reads the file and finds the `export namespace Foo { ... }` block

* (uses ast-grep for accurate AST-based boundary detection)

* 2. Removes the namespace wrapper and dedents the body

* 3. Fixes self-references (e.g. Config.PermissionAction → PermissionAction)

* 4. If the file is index.ts, renames it to <lowercase-name>.ts

* 5. Creates/updates index.ts with `export * as Foo from "./<file>"`

* 6. Rewrites import paths across src/, test/, and script/

* 7. Fixes sibling imports within the same directory

*

* Requires: ast-grep (`brew install ast-grep` or `cargo install ast-grep`)

*/

import path from "path"

import fs from "fs"

const args = process.argv.slice(2)

const dryRun = args.includes("--dry-run")

const nameFlag = args.find((a, i) => args[i - 1] === "--name")

const filePath = args.find((a) => !a.startsWith("--") && args[args.indexOf(a) - 1] !== "--name")

if (!filePath) {

console.error("Usage: bun script/unwrap-namespace.ts <file> [--dry-run] [--name <impl-name>]")

process.exit(1)

}

const absPath = path.resolve(filePath)

if (!fs.existsSync(absPath)) {

console.error(`File not found: ${absPath}`)

process.exit(1)

}

const src = fs.readFileSync(absPath, "utf-8")

const lines = src.split("\n")

// Use ast-grep to find the namespace boundaries accurately.

// This avoids false matches from braces in strings, templates, comments, etc.

const astResult = Bun.spawnSync(

["ast-grep", "run", "--pattern", "export namespace $NAME { $$$BODY }", "--lang", "typescript", "--json", absPath],

{ stdout: "pipe", stderr: "pipe" },

)

if (astResult.exitCode !== 0) {

console.error("ast-grep failed:", astResult.stderr.toString())

process.exit(1)

}

const matches = JSON.parse(astResult.stdout.toString()) as Array<{

text: string

range: { start: { line: number; column: number }; end: { line: number; column: number } }

metaVariables: { single: Record<string, { text: string }>; multi: Record<string, Array<{ text: string }>> }

}>

if (matches.length === 0) {

console.error("No `export namespace Foo { ... }` found in file")

process.exit(1)

}

if (matches.length > 1) {

console.error(`Found ${matches.length} namespaces — this script handles one at a time`)

console.error("Namespaces found:")

for (const m of matches) console.error(` ${m.metaVariables.single.NAME.text} (line ${m.range.start.line + 1})`)

process.exit(1)

}

const match = matches[0]

const nsName = match.metaVariables.single.NAME.text

const nsLine = match.range.start.line // 0-indexed

const closeLine = match.range.end.line // 0-indexed, the line with closing `}`

console.log(`Found: export namespace ${nsName} { ... }`)

console.log(` Lines ${nsLine + 1}–${closeLine + 1} (${closeLine - nsLine + 1} lines)`)

// Build the new file content:

// 1. Everything before the namespace declaration (imports, etc.)

// 2. The namespace body, dedented by one level (2 spaces)

// 3. Everything after the closing brace (rare, but possible)

const before = lines.slice(0, nsLine)

const body = lines.slice(nsLine + 1, closeLine)

const after = lines.slice(closeLine + 1)

// Dedent: remove exactly 2 leading spaces from each line

const dedented = body.map((line) => {

if (line === "") return ""

if (line.startsWith(" ")) return line.slice(2)

return line

})

let newContent = [...before, ...dedented, ...after].join("\n")

// --- Fix self-references ---

// After unwrapping, references like `Config.PermissionAction` inside the same file

// need to become just `PermissionAction`. Only fix code positions, not strings.

const exportedNames = new Set<string>()

const exportRegex = /export\s+(?:const|function|class|interface|type|enum|abstract\s+class)\s+(\w+)/g

for (const line of dedented) {

for (const m of line.matchAll(exportRegex)) exportedNames.add(m[1])

}

const reExportRegex = /export\s*\{\s*([^}]+)\}/g

for (const line of dedented) {

for (const m of line.matchAll(reExportRegex)) {

for (const name of m[1].split(",")) {

const trimmed = name

.trim()

.split(/\s+as\s+/)

.pop()!

.trim()

if (trimmed) exportedNames.add(trimmed)

}

}

}

let selfRefCount = 0

if (exportedNames.size > 0) {

const fixedLines = newContent.split("\n").map((line) => {

// Split line into string-literal and code segments to avoid replacing inside strings

const segments: Array<{ text: string; isString: boolean }> = []

let i = 0

let current = ""

let inString: string | null = null

while (i < line.length) {

const ch = line[i]

if (inString) {

current += ch

if (ch === "\\" && i + 1 < line.length) {

current += line[i + 1]

i += 2

continue

}

if (ch === inString) {

segments.push({ text: current, isString: true })

current = ""

inString = null

}

i++

continue

}

if (ch === '"' || ch === "'" || ch === "`") {

if (current) segments.push({ text: current, isString: false })

current = ch

inString = ch

i++

continue

}

if (ch === "/" && i + 1 < line.length && line[i + 1] === "/") {

current += line.slice(i)

segments.push({ text: current, isString: true })

current = ""

i = line.length

continue

}

current += ch

i++

}

if (current) segments.push({ text: current, isString: !!inString })

return segments

.map((seg) => {

if (seg.isString) return seg.text

let result = seg.text

for (const name of exportedNames) {

const pattern = `${nsName}.${name}`

while (result.includes(pattern)) {

const idx = result.indexOf(pattern)

const charBefore = idx > 0 ? result[idx - 1] : " "

const charAfter = idx + pattern.length < result.length ? result[idx + pattern.length] : " "

if (/\w/.test(charBefore) || /\w/.test(charAfter)) break

result = result.slice(0, idx) + name + result.slice(idx + pattern.length)

selfRefCount++

}

}

return result

})

.join("")

})

newContent = fixedLines.join("\n")

}

// Figure out file naming

const dir = path.dirname(absPath)

const basename = path.basename(absPath, ".ts")

const isIndex = basename === "index"

const implName = nameFlag ?? (isIndex ? nsName.replace(/([a-z])([A-Z])/g, "$1-$2").toLowerCase() : basename)

const implFile = path.join(dir, `${implName}.ts`)

const indexFile = path.join(dir, "index.ts")

const barrelLine = `export * as ${nsName} from "./${implName}"\n`

console.log("")

if (isIndex) {

console.log(`Plan: rename ${basename}.ts → ${implName}.ts, create new index.ts barrel`)

} else {

console.log(`Plan: rewrite ${basename}.ts in place, create index.ts barrel`)

}

if (selfRefCount > 0) console.log(`Fixed ${selfRefCount} self-reference(s) (${nsName}.X → X)`)

console.log("")

if (dryRun) {

console.log("--- DRY RUN ---")

console.log("")

console.log(`=== ${implName}.ts (first 30 lines) ===`)

newContent

.split("\n")

.slice(0, 30)

.forEach((l, i) => console.log(` ${i + 1}: ${l}`))

console.log(" ...")

console.log("")

console.log(`=== index.ts ===`)

console.log(` ${barrelLine.trim()}`)

console.log("")

if (!isIndex) {

const relDir = path.relative(path.resolve("src"), dir)

console.log(`=== Import rewrites (would apply) ===`)

console.log(` ${relDir}/${basename}" → ${relDir}" across src/, test/, script/`)

} else {

console.log("No import rewrites needed (was index.ts)")

}

} else {

if (isIndex) {

fs.writeFileSync(implFile, newContent)

fs.writeFileSync(indexFile, barrelLine)

console.log(`Wrote ${implName}.ts (${newContent.split("\n").length} lines)`)

console.log(`Wrote index.ts (barrel)`)

} else {

fs.writeFileSync(absPath, newContent)

if (fs.existsSync(indexFile)) {

const existing = fs.readFileSync(indexFile, "utf-8")

if (!existing.includes(`export * as ${nsName}`)) {

fs.appendFileSync(indexFile, barrelLine)

console.log(`Appended to existing index.ts`)

} else {

console.log(`index.ts already has ${nsName} export`)

}

} else {

fs.writeFileSync(indexFile, barrelLine)

console.log(`Wrote index.ts (barrel)`)

}

console.log(`Rewrote ${basename}.ts (${newContent.split("\n").length} lines)`)

}

// --- Rewrite import paths across src/, test/, script/ ---

const relDir = path.relative(path.resolve("src"), dir)

if (!isIndex) {

const oldTail = `${relDir}/${basename}`

const searchDirs = ["src", "test", "script"].filter((d) => fs.existsSync(d))

const rgResult = Bun.spawnSync(["rg", "-l", `from.*${oldTail}"`, ...searchDirs], {

stdout: "pipe",

stderr: "pipe",

})

const filesToRewrite = rgResult.stdout

.toString()

.trim()

.split("\n")

.filter((f) => f.length > 0)

if (filesToRewrite.length > 0) {

console.log(`\nRewriting imports in ${filesToRewrite.length} file(s)...`)

for (const file of filesToRewrite) {

const content = fs.readFileSync(file, "utf-8")

fs.writeFileSync(file, content.replaceAll(`${oldTail}"`, `${relDir}"`))

}

console.log(` Done: ${oldTail}" → ${relDir}"`)

} else {

console.log("\nNo import rewrites needed")

}

} else {

console.log("\nNo import rewrites needed (was index.ts)")

}

// --- Fix sibling imports within the same directory ---

const siblingFiles = fs.readdirSync(dir).filter((f) => {

if (!f.endsWith(".ts")) return false

if (f === "index.ts" || f === `${implName}.ts`) return false

return true

})

let siblingFixCount = 0

for (const sibFile of siblingFiles) {

const sibPath = path.join(dir, sibFile)

const content = fs.readFileSync(sibPath, "utf-8")

const pattern = new RegExp(`from\\s+["']\\./${basename}["']`, "g")

if (pattern.test(content)) {

fs.writeFileSync(sibPath, content.replace(pattern, `from "."`))

siblingFixCount++

}

}

if (siblingFixCount > 0) {

console.log(`Fixed ${siblingFixCount} sibling import(s) in ${path.basename(dir)}/ (./${basename} → .)`)

}

}

console.log("")

console.log("=== Verify ===")

console.log("")

console.log("bunx --bun tsgo --noEmit # typecheck")

console.log("bun run test # run tests")