/**
 * Theme-aware TUI primitives for Pisces terminal overlays.
 *
 * All functions are pure — they take a TuiTheme and return plain strings or
 * string arrays. No Pi SDK imports; safe to test with an identity theme.
 *
 * Design language (Editorial Noir terminal):
 *  - Box corners: ╭ ╮ ╰ ╯  Walls: │  Horizontal: ─
 *  - Color keys: "accent" (default), "warning", "muted", "dim", "error"
 *  - Bar chars: █ (filled) ░ (empty)
 *  - Badge style: [ LABEL ] with color surround
 */

// ── Theme contract ─────────────────────────────────────────────────────────────

export interface TuiTheme {
  fg(colorKey: string, text: string): string;
  getFgAnsi(colorKey: string): string;
}

// ── Panel framing ──────────────────────────────────────────────────────────────

const H = "─";
const FILLED = "█";
const EMPTY = "░";

/**
 * Top border of a panel.
 * innerW = content width (excluding the two wall chars + two spaces of padding).
 */
export function panelTop(innerW: number, colorKey: string, t: TuiTheme): string {
  return t.fg(colorKey, "╭" + H.repeat(innerW + 2) + "╮");
}

/**
 * Bottom border with a centered dismiss hint.
 * hint is rendered dim; remaining ─ fill is rendered in colorKey.
 */
export function panelBottom(
  innerW: number,
  hint: string,
  colorKey: string,
  t: TuiTheme,
): string {
  const fill = H.repeat(Math.max(0, innerW + 2 - hint.length));
  return t.fg(colorKey, "╰") + t.fg("dim", hint) + t.fg(colorKey, fill + "╯");
}

/** Blank row — an empty padded line inside the panel. */
export function panelBlank(innerW: number, colorKey: string, t: TuiTheme): string {
  return t.fg(colorKey, "│") + " ".repeat(innerW + 2) + t.fg(colorKey, "│");
}

/**
 * Content row — left-pads by 1, right-pads to innerW, then closes with wall.
 * content must already be visually innerW chars wide (strip ANSI before measuring).
 */
export function panelRow(
  content: string,
  contentVisualW: number,
  innerW: number,
  colorKey: string,
  t: TuiTheme,
): string {
  const pad = " ".repeat(Math.max(0, innerW - contentVisualW));
  return `${t.fg(colorKey, "│")} ${content}${pad} ${t.fg(colorKey, "│")}`;
}

// ── Content atoms ──────────────────────────────────────────────────────────────

/** [ LABEL ] badge — accent-colored surround, label in normal fg. */
export function badge(label: string, colorKey: string, t: TuiTheme): string {
  return `${t.fg(colorKey, "[")} ${label} ${t.fg(colorKey, "]")}`;
}

/**
 * Key-value stat row: label left-padded to labelW, value accent-colored.
 * Returns { text, visualW } so callers can pass visualW to panelRow.
 */
export function kv(
  label: string,
  value: string,
  labelW: number,
  colorKey: string,
  t: TuiTheme,
): { text: string; visualW: number } {
  const paddedLabel = t.fg("muted", label.padEnd(labelW));
  const coloredValue = t.fg(colorKey, value);
  const text = `${paddedLabel}  ${coloredValue}`;
  const visualW = labelW + 2 + value.length;
  return { text, visualW };
}

/**
 * Section divider: ─── <label> ─── filling innerW chars.
 * Returns { text, visualW } (visualW === innerW).
 */
export function sectionDivider(
  label: string,
  innerW: number,
  t: TuiTheme,
): { text: string; visualW: number } {
  const sides = Math.max(0, innerW - label.length - 2);
  const left = Math.floor(sides / 2);
  const right = sides - left;
  const text =
    t.fg("dim", H.repeat(left) + " ") +
    t.fg("muted", label) +
    t.fg("dim", " " + H.repeat(right));
  return { text, visualW: innerW };
}

/**
 * Mini horizontal bar: filled/empty blocks, barW total chars.
 * filledCount must be 0..barW.
 */
export function miniBar(
  filledCount: number,
  barW: number,
  colorKey: string,
  t: TuiTheme,
): string {
  const f = Math.min(Math.max(0, filledCount), barW);
  return t.fg(colorKey, FILLED.repeat(f)) + t.fg("dim", EMPTY.repeat(barW - f));
}

/**
 * Skill bar row: /name  ████░░░░  N session(s)
 * Returns { text, visualW }.
 */
export function skillBar(
  name: string,
  count: number,
  maxCount: number,
  nameW: number,
  barW: number,
  colorKey: string,
  t: TuiTheme,
): { text: string; visualW: number } {
  const nameStr = `/${name}`.padEnd(nameW);
  const filled = maxCount > 0 ? Math.round((count / maxCount) * barW) : 0;
  const bar = miniBar(filled, barW, colorKey, t);
  const countStr = `${count} session${count !== 1 ? "s" : ""}`;
  const text =
    t.fg("muted", nameStr) +
    "  " +
    bar +
    "  " +
    t.fg("dim", countStr);
  const visualW = nameW + 2 + barW + 2 + countStr.length;
  return { text, visualW };
}

/** Word-wrap plain text to lines of at most width chars. */
export function wordWrap(text: string, width: number): string[] {
  const words = text.split(" ");
  const lines: string[] = [];
  let cur = "";
  for (const word of words) {
    if (cur && cur.length + 1 + word.length > width) {
      lines.push(cur);
      cur = word;
    } else {
      cur = cur ? `${cur} ${word}` : word;
    }
  }
  if (cur) lines.push(cur);
  return lines;
}