New Captcha Package added

2026-07-25 13:38:18 +05:30
parent d0aded0392
commit 8b728a3e5d
157 changed files with 12092 additions and 1913 deletions
@@ -0,0 +1,131 @@
+import type {
+  CaptchaConcreteImageStyle,
+  CaptchaImageStyle,
+} from "../types.ts";
+
+export const CAPTCHA_CONCRETE_IMAGE_STYLES = [
+  "classic",
+  "collision",
+  "snow",
+  "corrosion",
+  "spiderweb",
+  "cross-shadow",
+  "split",
+  "split2",
+  "cut",
+  "darts",
+  "distortion",
+  "stitch",
+  "striped",
+  "wave",
+  "grid-noise",
+  "scribble",
+  "pixel",
+  "broken-lines",
+] as const satisfies readonly CaptchaConcreteImageStyle[];
+
+export const CAPTCHA_IMAGE_STYLES = [
+  "random",
+  ...CAPTCHA_CONCRETE_IMAGE_STYLES,
+] as const satisfies readonly CaptchaImageStyle[];
+
+const CONCRETE_STYLE_SET = new Set<string>(CAPTCHA_CONCRETE_IMAGE_STYLES);
+const STYLE_SET = new Set<string>(CAPTCHA_IMAGE_STYLES);
+
+function styleValues(value: unknown): string[] {
+  if (Array.isArray(value)) return value.flatMap((item) => styleValues(item));
+  if (typeof value !== "string") return [];
+  return value
+    .split(",")
+    .map((item) => item.trim().toLowerCase())
+    .filter(Boolean);
+}
+
+export function isCaptchaImageStyle(value: unknown): value is CaptchaImageStyle {
+  return typeof value === "string" && STYLE_SET.has(value.trim().toLowerCase());
+}
+
+export function normalizeCaptchaImageStyle(
+  value: unknown,
+  fallback: CaptchaImageStyle = "random",
+): CaptchaImageStyle {
+  if (value === undefined || value === null || value === "") return fallback;
+  const normalized = String(value).trim().toLowerCase();
+  if (!STYLE_SET.has(normalized)) {
+    throw new RangeError(
+      `imageStyle must be one of: ${CAPTCHA_IMAGE_STYLES.join(", ")}`,
+    );
+  }
+  return normalized as CaptchaImageStyle;
+}
+
+export function normalizeCaptchaImageStyleList(
+  value: unknown,
+  name: "allowedStyles" | "excludedStyles",
+): CaptchaConcreteImageStyle[] {
+  const styles: CaptchaConcreteImageStyle[] = [];
+  for (const entry of styleValues(value)) {
+    if (entry === "random") continue;
+    if (!CONCRETE_STYLE_SET.has(entry)) {
+      throw new RangeError(
+        `${name} contains an unknown image style: ${entry}`,
+      );
+    }
+    const style = entry as CaptchaConcreteImageStyle;
+    if (!styles.includes(style)) styles.push(style);
+  }
+  return styles;
+}
+
+export interface ResolveCaptchaImageStyleOptions {
+  imageStyle?: unknown;
+  allowedStyles?: unknown;
+  excludedStyles?: unknown;
+  randomizeStyle?: boolean;
+  randomInt(min: number, max: number): number;
+}
+
+export interface ResolvedCaptchaImageStyle {
+  requested: CaptchaImageStyle;
+  resolved: CaptchaConcreteImageStyle;
+  pool: CaptchaConcreteImageStyle[];
+}
+
+export function resolveCaptchaImageStyle(
+  options: ResolveCaptchaImageStyleOptions,
+): ResolvedCaptchaImageStyle {
+  const requested = normalizeCaptchaImageStyle(options.imageStyle, "random");
+  const allowed = normalizeCaptchaImageStyleList(
+    options.allowedStyles,
+    "allowedStyles",
+  );
+  const excluded = new Set(
+    normalizeCaptchaImageStyleList(options.excludedStyles, "excludedStyles"),
+  );
+
+  const source = allowed.length
+    ? allowed
+    : [...CAPTCHA_CONCRETE_IMAGE_STYLES];
+  const pool = source.filter((style) => !excluded.has(style));
+
+  if (!pool.length) {
+    throw new RangeError(
+      "No CAPTCHA image styles remain after applying allowedStyles and excludedStyles",
+    );
+  }
+
+  if (!options.randomizeStyle && requested !== "random") {
+    if (!pool.includes(requested)) {
+      throw new RangeError(
+        `imageStyle ${requested} is not available in the configured style pool`,
+      );
+    }
+    return { requested, resolved: requested, pool };
+  }
+
+  return {
+    requested,
+    resolved: pool[options.randomInt(0, pool.length - 1)]!,
+    pool,
+  };
+}