/**
 * # cli/render/frame — the human wrapper over the agent Frame ASCII (Kestrel CLI v1 §5)
 *
 * The Frame ASCII from `src/frame/render.ts` IS the canonical, token-efficient **agent** screen —
 * it is emitted verbatim in `text`/agent/piped mode. This module's only job is the `human` branch:
 * apply **non-destructive** ANSI color to the already-rendered string when `ctx.color` is set. It
 * MUST NOT re-layout, re-wrap, or invent values — the renderer already invents nothing (ADR-0008);
 * the human branch only colorizes. If not `ctx.color`, human === text output.
 */

import type { OutputCtx } from "../context.ts";

const RESET = "[0m";
const BOLD = "[1m";
const DIM = "[2m";
const GREEN = "[32m";
const RED = "[31m";

/**
 * Colorize the Frame ASCII line-by-line without changing any layout or value:
 * - the `KESTREL · …` header line → bold
 * - lines that are only box/separator glyphs (`─┈·|` and spaces) → dim
 * - a `—` unknown token stays as-is (already meaningful)
 * Signed dollar/number fields are left untouched in v1 (coloring them safely requires field
 * offsets the ASCII does not expose; over-eager regex coloring risks mangling the aligned tape).
 * The result is byte-identical to the input except for injected ANSI escapes on whole lines.
 */
export function colorizeFrame(ascii: string, ctx: OutputCtx): string {
  if (!(ctx.mode === "human" && ctx.color)) return ascii;
  return ascii
    .split("\n")
    .map((line) => {
      if (line.startsWith("KESTREL")) return `${BOLD}${line}${RESET}`;
      if (line.length > 0 && /^[\s─┈·|+]+$/.test(line)) return `${DIM}${line}${RESET}`;
      return line;
    })
    .join("\n");
}

/** Exposed for callers that want the raw color codes (kept internal to v1). */
export const FRAME_ANSI = { RESET, BOLD, DIM, GREEN, RED } as const;