/**
 * Shared severity ladder for calls and incidents: routine < minor < moderate < major.
 * Every call/incident gets one of these four. `"unknown"` (and any other
 * unrecognized value) is a legacy value still present on historical docs —
 * treat it as "no severity", not as a fifth level.
 */
import type { ReactElement } from "react";
import { SeverityMark } from "@/components/marks/SeverityMark";

export type Severity = "routine" | "minor" | "moderate" | "major";

export const SEVERITY_ORDER: Record<Severity, number> = { routine: 0, minor: 1, moderate: 2, major: 3 };
export const SEVERITY_LABEL: Record<Severity, string> = { routine: "Routine", minor: "Minor", moderate: "Moderate", major: "Major" };

/**
 * Validated against the dataviz all-pairs colour-blindness checker (see
 * UI_REDESIGN.md §2.3). Severity is the ONLY hue channel in the whole app —
 * moderate/major carry colour, routine/minor are neutral ink with no hue.
 * Colour is never the sole channel: SeverityMark also carries glyph shape
 * and spine thickness so the ladder survives grayscale.
 */
export const SEVERITY_COLORS: Record<Severity, string> = {
  routine: "var(--ink-muted)",
  minor: "var(--ink-2)",
  moderate: "var(--sev-moderate)",
  major: "var(--sev-major)",
};

export function isKnownSeverity(s: string | null | undefined): s is Severity {
  return s === "routine" || s === "minor" || s === "moderate" || s === "major";
}

/** Legacy/unset severities rank below `routine` so a recency-sorted list never confuses them with a real (low) severity. */
export function severityRank(s: string | null | undefined): number {
  return isKnownSeverity(s) ? SEVERITY_ORDER[s] : -1;
}

/** Renders the full severity mark (glyph + word chip). Use `<SeverityMark>` directly for more control (spine, size, label-off). */
export function severityBadge(severity: string | null | undefined): ReactElement | null {
  if (!isKnownSeverity(severity)) return null;
  return <SeverityMark severity={severity} showLabel />;
}