/**
 * Flags em-dashes in user-facing strings: JSX text, string literals and
 * template literal text under `src/`. Comments are not checked. See Microcopy
 * in the root DESIGN-GUIDELINES.md.
 *
 *     bun frontend/scripts/no-em-dash.ts [files…]   # no files: all of src/
 *
 * A literal that is only "—" is the empty-value placeholder and passes. The
 * other exception, a separator inside one line, goes in `no-em-dash.allow.json`
 * as the file (relative to `src/`) and the exact string. A template literal is
 * listed by its source text, backticks included.
 *
 * The same file lives in app/ and index/. Keep the two identical.
 */

import { readdirSync, readFileSync } from "node:fs"
import { join, relative, resolve } from "node:path"
import ts from "typescript"
import allow from "./no-em-dash.allow.json"

const src = resolve(import.meta.dir, "../src")
const skip = /(^|\/)client\/|\.gen\.ts$|\.(check|spec|test)\.ts$/
const dash = /—|—/

const allowed = allow as Record<string, string[]>
const squash = (s: string) => s.replace(/\s+/g, " ").trim()

const walk = (dir: string): string[] =>
  readdirSync(dir, { withFileTypes: true }).flatMap((e) =>
    e.isDirectory() ? walk(join(dir, e.name)) : [join(dir, e.name)],
  )

const args = process.argv.slice(2).map((f) => resolve(f))
const files = (args.length ? args : walk(src)).filter((f) => {
  const rel = relative(src, f)
  return /\.tsx?$/.test(f) && !rel.startsWith("..") && !skip.test(rel)
})

let found = 0
for (const file of files) {
  const rel = relative(src, file)
  const sf = ts.createSourceFile(
    file,
    readFileSync(file, "utf8"),
    ts.ScriptTarget.Latest,
    true,
    file.endsWith(".tsx") ? ts.ScriptKind.TSX : ts.ScriptKind.TS,
  )
  const report = (node: ts.Node, text: string) => {
    if (text === "—" || allowed[rel]?.includes(text)) return
    const { line } = sf.getLineAndCharacterOfPosition(node.getStart(sf))
    console.log(`${relative(process.cwd(), file)}:${line + 1}: ${text}`)
    found++
  }
  const visit = (node: ts.Node) => {
    if (ts.isTemplateExpression(node)) {
      const parts = [node.head, ...node.templateSpans.map((s) => s.literal)]
      if (parts.some((p) => dash.test(p.text))) report(node, node.getText(sf))
    } else if (
      (ts.isStringLiteral(node) ||
        ts.isNoSubstitutionTemplateLiteral(node) ||
        ts.isJsxText(node)) &&
      dash.test(node.text)
    ) {
      report(node, squash(node.text))
    }
    ts.forEachChild(node, visit)
  }
  visit(sf)
}

if (found) {
  console.log(
    `\n${found} em-dash(es) in user-facing strings. Rewrite them (Microcopy in DESIGN-GUIDELINES.md) or allowlist a separator in frontend/scripts/no-em-dash.allow.json.`,
  )
  process.exit(1)
}