/** Config: storage paths, server constants, and user-tunable theme settings. */

import { readFileSync } from "node:fs";
import { homedir } from "node:os";
import { join } from "node:path";

/** Directory for artifact files, relative to project root (mirrors plan-mode's .pi/plans). */
export const ARTIFACT_DIR = ".pi/artifacts";

/** Server bind host — localhost-only, never exposed externally. */
export const HOST = "127.0.0.1";

/** Mermaid CDN script URL (the only client-side JS; everything else renders at write time). */
export const MERMAID_CDN = "https://cdn.jsdelivr.net/npm/mermaid@11/dist/mermaid.min.js";

// ─── User config (optional): ~/.pi/agent/configs/artifacts.json ───────────────

export interface ArtifactsConfig {
  /** "auto" follows the OS via prefers-color-scheme; "light"/"dark" pin one scheme. */
  theme: "auto" | "light" | "dark";
  /** Accent color used on the dark scheme (links, badge, blockquote). */
  accent: string;
  /** Accent color used on the light scheme (darker for contrast on white). */
  accentLight: string;
  /** Content column width in px. */
  maxWidth: number;
}

const DEFAULTS: ArtifactsConfig = {
  theme: "auto",
  accent: "#d67858",
  accentLight: "#b95730",
  maxWidth: 860,
};

const CONFIG_PATH = join(homedir(), ".pi", "agent", "configs", "artifacts.json");

function loadConfig(): ArtifactsConfig {
  try {
    const raw = JSON.parse(readFileSync(CONFIG_PATH, "utf-8")) as Partial<ArtifactsConfig>;
    return {
      theme: raw.theme === "light" || raw.theme === "dark" ? raw.theme : DEFAULTS.theme,
      accent: typeof raw.accent === "string" ? raw.accent : DEFAULTS.accent,
      accentLight: typeof raw.accentLight === "string" ? raw.accentLight : DEFAULTS.accentLight,
      maxWidth: typeof raw.maxWidth === "number" && raw.maxWidth > 300 ? raw.maxWidth : DEFAULTS.maxWidth,
    };
  } catch {
    return DEFAULTS;
  }
}

export const CONFIG: ArtifactsConfig = loadConfig();