/**
 * KHAELOR
 * File: src/tui/components/permission-panel.ts
 * Description: The inline permission panel — CLAUDE.md §13 verbatim contract; render only, decisions surface as callbacks.
 *
 * Author: Simon-Pierre Boucher
 * Contact: contact@spboucher.ai
 */

import { padEndAnsi, truncateAnsi, visibleWidth } from "../renderer/ansi.js";
import type { Theme } from "../theme.js";

export interface PermissionPanelData {
  /** Action verb, e.g. `Run`, `Edit`. */
  verb: string;
  /** The subject: the command, or the target path. */
  subject: string;
  /** Working directory (for commands). */
  cwd?: string;
  /** ≤ 8-line diff preview (for edits) — already styled lines. */
  diffPreview?: string[];
  /**
   * Generalized "always allow" pattern from conservative shell-word analysis
   * (PERMISSION_MODEL §3.3). Absent → the [A] row is omitted entirely: no
   * persistable generalization is offered for what the analyzer could not read.
   */
  alwaysPattern?: string;
}

/**
 * Render the permission panel as live-region overlay lines. Three keys, no
 * typing, milliseconds (TUI_DESIGN §9.1). This component renders only —
 * Enter/A/Esc handling lives in the app's key dispatch.
 */
export function renderPermissionPanel(
  data: PermissionPanelData,
  width: number,
  theme: Theme,
): string[] {
  // Size the box to its widest content row (clamped to the terminal).
  const alwaysRow =
    data.alwaysPattern !== undefined
      ? `[ A ]     Always allow "${data.alwaysPattern}" in this project`
      : "";
  const contentWidth = Math.max(
    31, // title + option rows minimum
    visibleWidth(data.subject),
    visibleWidth(data.cwd ?? ""),
    visibleWidth(alwaysRow),
    ...(data.diffPreview ?? []).map((l) => visibleWidth(l)),
  );
  const inner = Math.max(34, Math.min(width - 4, contentWidth + 4));
  const dim = (s: string): string => theme.paint("accentDim", s);

  const row = (content: string): string =>
    " " + dim("│") + padEndAnsi(truncateAnsi("  " + content, inner - 1), inner) + dim("│");

  const out: string[] = [];
  const title = "─ KHAELOR requests permission ";
  out.push(" " + dim("╭" + title + "─".repeat(Math.max(0, inner - visibleWidth(title))) + "╮"));
  out.push(row(theme.paint("bold", data.verb)));
  out.push(row(theme.paint("accent", data.subject)));

  if (data.diffPreview !== undefined && data.diffPreview.length > 0) {
    out.push(row(""));
    for (const line of data.diffPreview.slice(0, 8)) out.push(row(line));
  }

  if (data.cwd !== undefined) {
    out.push(row(""));
    out.push(row(theme.paint("dim", "Working directory")));
    out.push(row(data.cwd));
  }

  out.push(row(""));
  out.push(row(`${theme.paint("accent", "[ Enter ]")} Allow once`));
  if (data.alwaysPattern !== undefined) {
    out.push(
      row(
        `${theme.paint("accent", "[ A ]")}     Always allow ${theme.paint("bold", `"${data.alwaysPattern}"`)} in this project`,
      ),
    );
  }
  out.push(row(`${theme.paint("accent", "[ Esc ]")}   Deny`));
  out.push(" " + dim("╰" + "─".repeat(inner) + "╯"));
  return out;
}