import { visibleWidth } from "@earendil-works/pi-tui";

// Selective reset: clears bold/dim/italic/underline/fg but NOT background
const RESET = "\x1b[22;23;24;39m";
const BOLD = "\x1b[1m";
const DIM_CODE = "\x1b[2m";

function hexToAnsi(color: string): string {
  const h = color.replace("#", "");
  const r = parseInt(h.slice(0, 2), 16);
  const g = parseInt(h.slice(2, 4), 16);
  const b = parseInt(h.slice(4, 6), 16);
  return `\x1b[38;2;${r};${g};${b}m`;
}

// ThemeColor names — matched to pi's Theme.fg() API
export const COLORS = {
  accent:  "accent",
  success: "success",
  warning: "warning",
  header:  "text",
  muted:   "muted",
} as const;

// Hex fallbacks used when no pi theme is injected (tests, cold start)
const FALLBACK_HEX: Record<string, string> = {
  accent:  "#febc38",
  success: "#5faf5f",
  warning: "#ff9500",
  text:    "#00afaf",
  muted:   "#6c6c6c",
  // Thinking-level tokens — default values from pi's dark theme (used only
  // before a live pi theme is injected, e.g. tests / cold start).
  thinkingOff:     "#555555",
  thinkingMinimal: "#6e6e6e",
  thinkingLow:     "#5f87af",
  thinkingMedium:  "#81a2be",
  thinkingHigh:    "#b294bb",
  thinkingXhigh:   "#d183e8",
  thinkingMax:     "#ff5fff",
};

let _piTheme: any = null;

export function setPiTheme(t: any): void {
  _piTheme = t;
}

export function bold(text: string): string {
  if (_piTheme) return _piTheme.bold(text);
  return `${BOLD}${text}${RESET}`;
}

export function dim(text: string): string {
  if (_piTheme) return _piTheme.fg("dim", text);
  return `${DIM_CODE}${text}${RESET}`;
}

export function fg(colorName: string, text: string): string {
  if (_piTheme) return _piTheme.fg(colorName, text);
  const hex = FALLBACK_HEX[colorName] ?? "#ffffff";
  return `${hexToAnsi(hex)}${text}${RESET}`;
}

/**
 * Map a thinking level to pi's theme color token, mirroring pi's
 * `getThinkingBorderColor`. e.g. "high" -> "thinkingHigh", "xhigh" ->
 * "thinkingXhigh". Pass the result to `fg()` to reuse pi's own color.
 */
export function thinkingColorName(level: string): string {
  return "thinking" + level.charAt(0).toUpperCase() + level.slice(1);
}

export function formatDuration(ms: number): string {
  const s = Math.floor(ms / 1000);
  const m = Math.floor(s / 60);
  if (m > 0) return `${m}m${s % 60}s`;
  return `${s}s`;
}

export function formatRelativeTime(ms: number): string {
  return `${formatDuration(ms)} ago`;
}

export function formatTokens(n: number): string {
  if (n < 1000) return n.toString();
  if (n < 1_000_000) return `${Math.round(n / 1000)}k`;
  return `${(n / 1_000_000).toFixed(1)}M`;
}

export const SPINNER_FRAMES = ["⠋", "⠙", "⠹", "⠸", "⠼", "⠴", "⠦", "⠧", "⠇", "⠏"];

export function spinnerFrame(): string {
  return SPINNER_FRAMES[Math.floor(Date.now() / 80) % SPINNER_FRAMES.length];
}

/** Frame at an explicit index (wraps). Use with a tick counter for animation. */
export function spinnerFrameAt(i: number): string {
  return SPINNER_FRAMES[((i % SPINNER_FRAMES.length) + SPINNER_FRAMES.length) % SPINNER_FRAMES.length] ?? SPINNER_FRAMES[0]!;
}

export function formatDiffStat(added: number, removed: number): string {
  if (removed > 0) return `+${added} -${removed}`;
  return `+${added}`;
}

export function trunc(text: string, max: number): string {
  if (max <= 0) return "";
  if (visibleWidth(text) <= max) return text;
  let result = "";
  let w = 0;
  for (const ch of text) {
    const cw = visibleWidth(ch);
    if (w + cw > max - 1) break;
    result += ch;
    w += cw;
  }
  return result + "…";
}

export function panelHeader(title: string, width: number): string[] {
  const separatorLen = Math.max(0, width);
  return [
    bold(` ${title}`),
    dim("─".repeat(separatorLen)),
  ];
}